Method for transmitting he-LTF sequence and apparatus

Abstract

Embodiments of the present invention provide several long training sequences that are in a wireless local area network and that comply with 802.11ax.

Description

METHOD FOR TRANSMITTING HE-LTF SEQUENCE AND APPARATUS TECHNICAL FIELD

[0001] The present invention relates to the field of wireless communications technologies, and more specifically, to a method for transmitting an HE-LTF sequence and an apparatus. BACKGROUND

[0002] With development of the mobile Internet and popularization of smart terminals, data traffic grows rapidly. With advantages of a high rate and low costs, a wireless local area network (WLAN, Wireless Local Area Network) becomes one of the mainstream mobile broadband access technologies.

[0003] To significantly improve a service transmission rate of a WLAN system, in the next-generation Institute of Electrical and Electronics Engineers (IEEE, Institute of Electrical and Electronics Engineers) 802.11ax standard, on the basis of an existing orthogonal frequency division multiplexing (OFDM, Orthogonal Frequency Division Multiplexing) technology, an orthogonal frequency division multiple access (OFDMA, Orthogonal Frequency Division Multiple Access) technology is further used. In the OFDMA technology, a time-frequency resource of an air interface radio channel is divided into multiple orthogonal time-frequency resource blocks (RB, Resource Block); the RBs may be shared in a time domain, and may be orthogonal in a frequency domain.

[0004] In an existing WiFi system (for example, 11n or 11ac), a terminal still performs channel access by using a contention manner of carrier sense with collision avoidance. When a quantity of users increases, because channel access collisions increase, a system average throughput drops rapidly. In current work of a new WiFi standard (11ax), it is already decided to introduce an OFDMA technology in a WiFi system, to achieve an objective of improving a system average throughput in a high-density scenario. As an important part used for channel estimation in the existing WiFi system, an LTF also continues to be used in an OFDMA mode in the new WiFi standard. Therefore, in the OFDMA mode, a manner of generating an LTF becomes a research focus.

[0005] In the prior art, an 80-MHz LTF or a 160-MHz LTF in the 802.11ac standard is used as a basic template, from which values in a carrier part corresponding to a resource block scheduled by a user in an OFDMA mode are extracted, and values in a carrier part that does not correspond to the resource block are padded with 0s, so as to generate an LTF used by the user in the OFDMA mode. However, when a method in the prior art is used, a peak to average power ratio (Peak to Average Power Ratio, PAPR for short below) is relatively high. SUMMARY

[0006] Embodiments of the present invention provide a method for sending wireless local area network information, so as to reduce a peak-to-average power ratio.

[0007] According to one aspect, a method for sending wireless local area network information is provided, including: obtaining a corresponding HE-LTF sequence according to a bandwidth, where the HE-LTF sequence is specifically a sequence in each embodiment; and sending a corresponding sequence segment in the HE-LTF sequence according to a size and a location of an RU allocated to a station.

[0008] According to another aspect, a method for receiving a wireless local area network PPDU is provided, including: receiving a PPDU, and obtaining a total transmission bandwidth indicated in the PPDU; obtaining a corresponding HE-LTF sequence according to the bandwidth, where the HE-LTF sequence is specifically a sequence in each embodiment; and selecting, according to a size and a location of an RU, a corresponding HE-LTF sequence segment, as a reference sequence of the RU for channel estimation, at a receive end, .

[0009] Correspondingly, an apparatus configured to execute the foregoing method is provided, and the apparatus is, for example, an AP, a STA, or a corresponding chip.

[0010] An HE-LTF sequence provided in an embodiment of the present invention is used, so that a next-generation wireless local area network has a relatively low PAPR. BRIEF DESCRIPTION OF DRAWINGS

[0011] To describe the technical solutions in the embodiments of the present invention or in the prior art more clearly, the following briefly describes the accompanying drawings required for describing the embodiments or the prior art. Apparently, the accompanying drawings in the following description show some embodiments of the present invention, and a person of ordinary skill in the art may still derive other drawings from these accompanying drawings without creative efforts.

[0012] FIG. 1a, FIG. 1b, and FIG. 1c are tone plans in different bandwidths in an OFDMA transmission manner according to an embodiment of the present invention;

[0013] FIG. 2a and FIG. 2b are schematic diagrams of PAPRs that are obtained if LTF simulation in 802.11ac continues to be used;

[0014] FIG. 3 is a simple schematic diagram of a wireless local area network according to an embodiment of the present invention;

[0015] FIG. 4 is a simple schematic diagram of a data structure of a PPDU in a multi-user transmission manner according to an embodiment of the present invention;

[0016] FIG. 5a, FIG. 5b, FIG. 5c, and FIG. 5d are tone plans including pilot locations in different bandwidths in an OFDMA transmission manner according to an embodiment of the present invention;

[0017] FIG. 6 is a schematic diagram of a PAPR that is obtained by means of simulation in a less preferred embodiment;

[0018] FIG. 7a and FIG. 7b are simple schematic diagrams in an uplink direction and a downlink direction in embodiments of the present invention;

[0019] FIG. 8a and FIG. 8b show PAPR values that are obtained by means of preferred -500:2:500 HE-LTF sequence simulation in a 20-MHz bandwidth;

[0020] FIG. 9 shows PAPR values that are obtained by means of preferred 2x HE-LTF sequence simulation in an 40 MHz transmission;

[0021] FIG. 10 and FIG. 11 show PAPR values that are obtained by means of preferred 2x HE-LTF sequence simulation in an 80 MHz transmission;

[0022] FIG. 12 shows PAPR values that are obtained by means of preferred 4x HE-LTF sequence simulation in a 20-MHz bandwidth transmission;

[0023] FIG. 13 shows PAPR values that are obtained by means of preferred 4x HE-LTF sequence simulation in a 40-MHz bandwidth transmission;

[0024] FIG. 14 shows PAPR values that are obtained by means of preferred 4x HE-LTF sequence simulation in an 80-MHz bandwidth transmission;

[0025] FIG. 15 is a block diagram of an access point according to an embodiment of the present invention; and

[0026] FIG. 16 is a block diagram of a station according to an embodiment of the present invention. DESCRIPTION OF EMBODIMENTS

[0027] The following clearly and completely describes the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Apparently, the described embodiments are a part rather than all of the embodiments of the present invention. All other embodiments obtained by a person of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0028] For ease of understanding, terms that may appear in the following embodiments are described as follows: AP Access point Access point HEW High efficiency WLAN High efficiency wireless local area network HE-LTF High efficiency Long training field High efficiency long training sequence OFDMA Orthogonal Frequency Division Multiple Access Orthogonal frequency division multiple access STA Station Station WLAN Wireless Local Area Networks Wireless local area network

[0029] An access point (AP, Access Point) may also be referred to as a wireless access point, a bridge, a hotspot, or the like, and may be an access server or a communications network.

[0030] A station (STA, Station) may be further referred to as a user, and may be a wireless sensor, a wireless communications terminal, or a mobile terminal, for example, a mobile telephone (or referred to as a "cellular" phone) that supports a WiFi communication function and a computer that has a wireless communication function. For example, the station may be a portable, pocket-sized, handheld, computer built-in, wearable, or in-vehicle wireless communications apparatus that supports the WiFi communication function, and exchanges communication data such as voice and data with a wireless access network.

[0031] The next-generation wireless local area network standard 802.11ax intends to further improve WLAN spectrum efficiency, a throughput of an area, actual user experience, and performance in various indoor and outdoor dense network deployment environments. In addition, the solution is further required to suppress interference between devices and meet large-scale and high-load networking requirements. In conventional WiFi, an indoor channel is mainly used, an OFDM transmission manner is used, a symbol length is 3.2 <com:Math><semantics>μ<annotation encoding="application / x-tex">\mu< / annotation>< / semantics>< / com:Math> s, and a subcarrier spacing is 1 / 3.2 <com:Math><semantics>μ<annotation encoding="application / x-tex">\mu< / annotation>< / semantics>< / com:Math> s = 312.5 kHz. In 20 MHz, a 64-FFT is used to generate an OFDM symbol, and among all 56 subcarriers, there are 52 data subcarriers and 4 subcarriers. In 40 MHz, a 128-FFT is used to generate an OFDM symbol, and among all 128 subcarriers, there are 108 data subcarriers and 6 subcarriers. When a 256-FFT is used to generate an OFDM symbol, among all 256 subcarriers, there are 234 data subcarriers and 8 subcarriers.

[0032] For an 802.11ax system, to support indoor and outdoor scenarios, a symbol length (4 x <com:Math><semantics>3.2μs=12.8μs<annotation encoding="application / x-tex">3.2 \mu s = 12.8 \mu s< / annotation>< / semantics>< / com:Math>) that is 4 times a symbol length in 802.11ac may be used, and a subcarrier spacing is <com:Math><semantics>312.5 / 4=78.125<annotation encoding="application / x-tex">312.5 / 4 = 78.125< / annotation>< / semantics>< / com:Math> kHz. To support OFDMA transmission, a tone plan (distribution of subcarriers that carry data) below is used, and location relationships between different resource blocks (RU: resource unit) are shown in FIG. 1a to FIG. 1c, where an arrow indicates a location of a leftover subcarrier (leftover tone) between RUs. A quantity of subcarriers of a large RU is the same as a total sum of a quantity of subcarriers of multiple small RUs that may be correspondingly accommodated by the large RU and a quantity of leftover subcarriers between small RUs.

[0033] Referring to FIG. 1a, FIG. 1a is a simple schematic diagram of resource blocks (English: "tone plan", or referred to as resource block distribution) that may be allocated in OFDMA in 20 MHz; FIG. 1b is a simple schematic diagram of locations of OFDMA resource blocks in 40 MHz; and FIG. 1c is a simple schematic diagram of locations of OFDMA resource blocks in 80 MHz. An OFDMA multi-user data packet in 802.11ax is formed by resource blocks (RU: resource unit) of various sizes. An AP allocates one RU to each user. An optional RU that may be allocated to a user is: 1) an RU formed by 26 consecutive subcarriers, comprising: 24 data subcarriers and 2 pilot pilot subcarriers; 2) an RU formed by 52 consecutive subcarriers, comprising: 48 data subcarriers and 4 pilot pilot subcarriers; 3) an RU formed by 106 consecutive subcarriers, comprising: 24 data subcarriers and 2 pilot pilot subcarriers; 4) an RU formed by 242 consecutive subcarriers, comprising: 234 data subcarriers and 8 pilot pilot subcarriers; 5) an RU formed by 484 consecutive subcarriers, comprising: 468 data subcarriers and 16 pilot pilot subcarriers; and 6) an RU formed by 996 consecutive subcarriers, comprising: 980 data subcarriers and 16 pilot pilot subcarriers.

[0034] A 484-RU is used in multi-user transmission of 40 MHz, and an 996-RU is used in multi-user transmission of 80 / 160 MHz. It may be learned that 160 MHz is formed by two 80-MHz tone plans. Locations of pilot subcarriers indicated by arrows in FIG. 1a, FIG. 1b, and FIG. 1c are locations of the foregoing pilot subcarriers.

[0035] In addition, in an 802.11ax system, for an HE-LTF used for channel estimation, a 2x mode and a 4x mode are used. The 4x mode means that subcarrier indexes, mapped by an 4x HE-LTF sequence, is the same as subcarrier indexes mapped by a resource block distribution (tone plan) of a data part. The 2x mode means that, indexes of a 2x HE-LTF sequence corresponds to indexes of a 4x HE-LTF sequence divided by 2. That is, subcarrier indexes, mapped by an 2x HE-LTF sequence, is as half of subcarrier indexes, mapped by a resource block distribution (tone plan) of a data part.

[0036] In the 802.11ax system, a tone plan (subcarrier distribution) of OFDMA transmission is different from a tone plan of OFDM in an existing 802.11ac system. Therefore, a VHT-LTF sequence of 20 / 40 defined in 802.11ac is inapplicable. In a specific case, a total subcarrier quantity 242 of 80 MHz in 802.11ac is the same as a total subcarrier quantity of 20 MHz in 802.11ax. However, it is found that when a VHT-LTF sequence is directly used in an 802.11ax 20-MHz bandwidth, a peak-to-average power ratio (PAPR: Peak-to-average power ratio) is relatively high.

[0037] Referring to FIG. 2a and FIG. 2b, it may be learned that if a VHT-LTF of 802.11ac 80 MHz is used in 802.11ax 20 MHz, a PAPR of the VHT-LTF is significantly increased as compared with a PAPR of a conventional LTF sequence, which affects power control efficiency, and further reduces precision of channel estimation.

[0038] In addition, for a tone plan of 802.11ax in 40 / 80 MHz, a quantity of subcarriers already exceeds a conventional sequence, and a VHT-LTF sequence of 802.11ac cannot be reused.

[0039] FIG. 3 is a simple schematic diagram of a WLAN system applied in an embodiment of the present invention. The system in FIG. 3 includes one or more access points APs 101 and one or more stations STAs 102. The access points 101 and the stations 102 perform wireless communication by using an OFDMA technology.

[0040] Referring to FIG. 4, FIG. 4 shows a possible frame structure of a data packet PPDU sent by an AP in the foregoing downlink WLAN system. In a specific example, the frame structure complies with related regulations in 802.11ax.

[0041] According to a data structure of a PPDU shown in FIG. 4, for a downlink multi-user PPDU sent by the AP, an HE-SIG-A includes information used to indicate a transmission bandwidth of a downlink user STA, and an HE-SIG-B includes information used to indicate a size and a location of an RU allocated to a downlink scheduled user, or further includes a STA ID corresponding to each scheduled user and other scheduling information such as a spatial flow number or modulation and coding mode. In an example, the HE-SIG-A or the HE-SIG-B may further comprise: an HE-LTF length, that is, a quantity N of symbols of an HE-LTF, used to instruct to perform alignment of multiple users.

[0042] In an additional embodiment, for each RU in a subcarrier distribution (tone plan) of OFDMA of an HE-LTF, a quantity of pilot subcarriers, locations of the pilot subcarriers, and a sending manner are given. For corresponding content, refer to Motion #3, October 29, 2014, Removed with Motion 10, March 6, 2015 below.

[0043] For example, referring to FIG. 5a, FIG. 5b, FIG. 5c, and FIG. 5d, on the basis of the tone plans shown in FIG. 1a, FIG. 1b, and FIG. 1c, locations of pilot subcarriers are given, that is, locations indicated by long arrows in FIG. 5a, FIG. 5b, FIG. 5c, and FIG. 5d. For example, the sending manner is: in single-user transmission, uplink and downlink OFDMA transmission, and downlink MU-MIMO transmission, pilots in an HE-LTF in 802.11ax are sent according to a single flow (similar to 802.11ac).

[0044] In a specific example, during uplink MU-MIMO transmission, an HE-LTF sequence of each STA is multiplied by an identification code allocated by the AP, in frequency, and the AP may estimate a CFO of each STA depending on a frequency identification code of each STA. Therefore, there is no special pilot subcarrier in an HE-LTF sequence of uplink MU-MIMO, and the HE-LTF sequence of uplink MU-MIMO is different from an HE-LTF sequence of downlink MU-MIMO.

[0045] In some less preferred embodiments, some HE-LTFs or some methods for generating an HE-LTF are provided; however, the impact of a pilot is not considered, and in the corresponding methods, a PAPR is relatively high.

[0046] For example, in a less preferred embodiment, a Barker sequence, that is, x, whose length is 13, is provided. A sequence whose length is 121 is generated according to the Barker sequence, and is represented by using <com:Math><semantics>M1<annotation encoding="application / x-tex">M_1< / annotation>< / semantics>< / com:Math>. In addition, Barker sequences whose lengths are respectively 13 and 7 are found, and are respectively represented by using M<com:Sub>2< / com:Sub> and M<com:Sub>3< / com:Sub>. Specific sequences are represented as follows: [Image disponible dans le document PDF, Image available in the PDF document] [Image disponible dans le document PDF, Image available in the PDF document] [Image disponible dans le document PDF, Image available in the PDF document] % 121 tones [Image disponible dans le document PDF, Image available in the PDF document] [Image disponible dans le document PDF, Image available in the PDF document] % Barker 7 tones.

[0047] Next, sequences x, M<com:Sub>1< / com:Sub>, M<com:Sub>2< / com:Sub>, and M<com:Sub>3< / com:Sub> are used to generate an HE-LTF sequence in the 2x / 4x mode. The generated HE-LTF sequence is as follows:

[0048] HE-LTF sequences in the 2x mode: 20 MHz 122 tones 2X sequence: [Image disponible dans le document PDF, Image available in the PDF document] 40 MHz 242 tones 2X sequence: <com:Math><semantics>LTF484<annotation encoding="application / x-tex">LTF_{484}< / annotation>< / semantics>< / com:Math> (-244:2:244) = [M<com:Sub>1< / com:Sub>, 0, 0, 0, M<com:Sub>1< / com:Sub>]; 80 MHz 498 tones 2X sequence: [Image disponible dans le document PDF, Image available in the PDF document]

[0049] HE-LTF sequences in the 4x mode: 20 MHz 242 tones 4X sequence: <com:Math><semantics>LTF242(−122:122)=[M1,0,0,0,M11;<annotation encoding="application / x-tex">LTF_{242}(-122:122) = [M_1, 0, 0, 0, M_{11};< / annotation>< / semantics>< / com:Math> 40 MHz 484 tones 4X sequence: <com:Math><semantics>LTF484=[M1,M1,0,0,0,0,0,M1,−M1];<annotation encoding="application / x-tex">LTF_{484} = [M_1, M_1, 0, 0, 0, 0, 0, M_1, -M_1];< / annotation>< / semantics>< / com:Math> 80 MHz 996 tones 4X sequence: <com:Math><semantics>LTF996=[M1,−M1,−M1,−M1,M2,1,0,0,0,0,0,1,M2,M1,−M1,M1,M1].<annotation encoding="application / x-tex">LTF_{996} = [M_1, -M_1, -M_1, -M_1, M_2, 1, 0, 0, 0, 0, 0, 1, M_2, M_1, -M_1, M_1, M_1].< / annotation>< / semantics>< / com:Math>

[0050] However, all scenarios in which pilot subcarriers and other subcarriers in the HE-LTF in FIG. 5a, FIG. 5b, FIG. 5c, or FIG. 5d are multiplied by different phases are analyzed. It may be learned that in different cases, a PAPR changes significantly. In some cases, a PAPR is relatively high. In the foregoing case, phase change of pilot subcarrier(s) corresponds to a first row in a P-maxtrix, and phase change of other subcarriers corresponds to a corresponding row in the P-matrix in accordance with a spatial flow. These cases may be summarized into the following four cases: if a phase of a pilot subcarrier does not change and the pilot subcarrier is always multiplied by '+1', a phase of another subcarrier changes, and the another subcarrier is separately multiplied by '+1', '-1', 'w', or 'w<com:Sup>2< / com:Sup>', where <com:Math><semantics>w=exp⁡(−1i*2*pi / 6)<annotation encoding="application / x-tex">w = \exp(-1i*2*pi / 6)< / annotation>< / semantics>< / com:Math>.

[0051] For example, in a solution in the prior art, results of a PAPR are as follows, where a phase of a pilot subcarrier does not change, and the pilot subcarrier is always multiplied by '+1', and a phase of another subcarrier changes, and the another subcarrier is separately multiplied by '+1', '-1', 'w', or 'w<com:Sup>2< / com:Sup>'. A PAPR corresponding to each row is shown in FIG. 6. It may be learned that PAPRs change significantly, and some PAPRs already exceed 7 dB.

[0052] Some embodiments are provided below. In a corresponding HE-LTF sequence, because different values are set at a location of a pilot, PAPRs are all relatively low.

[0053] In some preferred embodiments, requirements such as a low storage load and easy implementation in hardware implementation may also be met.

[0054] According to an aspect, a method for sending an HE-LTF sequence is provided, including: obtaining a corresponding HE-LTF sequence according to a bandwidth, where the HE-LTF sequence is specifically a sequence in the following embodiments; and sending, according to a size of an RU and a location of an RU that are in resource allocation information, a sequence segment at a location corresponding to the HE-LTF sequence.

[0055] Referring to FIG. 7a and FIG. 7b, FIG. 7a and FIG. 7b are simple schematic diagrams of the foregoing method in an uplink direction and a downlink direction.

[0056] To make the foregoing method clearer, an uplink transmission procedure and a downlink transmission procedure are described below in detail.

[0057] Downlink transmission process:

[0058] An AP sends a data packet PPDU. For the PPDU, refer to the structure shown in FIG. 4. The downlink transmission process includes:

[0059] 101: The AP obtains, according to a total transmission bandwidth, an HE-LTF sequence corresponding to the bandwidth.

[0060] The HE-LTF sequence may be stored on the AP, or may be obtained by generating according to a particular principle. For a specific example of the HE-LTF, refer to subsequent examples.

[0061] 102: Obtain a corresponding HE-LTF sequence segment from the HE-LTF sequence according to a size and a location of a resource block RU allocated to a scheduled user, map the HE-LTF sequence segment to subcarriers of the allocated RU, and send the HE-LTF sequence segment.

[0062] In a preferred example, the PPDU includes multi-flow / multi-user transmission, and an HE-LTF needs to be sent on N symbols, where N should be greater than or equal to a maximum value M of a corresponding allocated total flow quantity of a user on each RU, which is denoted as <com:Math><semantics>N≥M<annotation encoding="application / x-tex">N \ge M< / annotation>< / semantics>< / com:Math>, where <com:Math><semantics>N=1,2,4,6<annotation encoding="application / x-tex">N = 1, 2, 4, 6< / annotation>< / semantics>< / com:Math>, or 8, and <com:Math><semantics>M=1<annotation encoding="application / x-tex">M = 1< / annotation>< / semantics>< / com:Math> to 8. The AP sequentially allocates, to each flow on an RU, a row in a P-matrix matrix whose size is NxN, where the row is used as a feature code used to distinguish a flow. Specifically, when an HE-LTF sequence of each flow on an RU is sent, a length value of a tone plan, excluding a location of a pilot subcarrier, on an n<com:Sup>th< / com:Sup> symbol of an HE-LTF needs to be multiplied by an n<com:Sup>th< / com:Sup> code word correspondingly used to distinguish a feature code of the flow. A person skilled in the art knows that for processing of a location of a pilot subcarrier, processing is performed according to an existing technical solution, and details are not described herein.

[0063] A method used by a downlink scheduled STA to receive data packet PPDU of 802.11ax includes:

[0064] 201: A scheduled STA receives a PPDU, to obtain a total transmission bandwidth that is in an HE-SIG-A and that is indicated by an AP.

[0065] 202: Obtain, according to the total transmission bandwidth, an HE-LTF sequence corresponding to the bandwidth.

[0066] The HE-LTF sequence may be stored on an AP or a STA, or may be obtained by generating according to a particular principle. For a specific example of the HE-LTF sequence, refer to subsequent embodiments.

[0067] 203: The scheduled STA identifies, according to an HE-SIG-B in the PPDU and by using a STA ID of the scheduled STA, information indicating that the scheduled STA is scheduled, and obtains, from the indication information, a size and a location of an RU allocated by the AP, to a user. According to the indicated size and location of the RU, from an HE-LTF sequence corresponding to a size of the total transmission bandwidth, a corresponding HE-LTF sequence segment is selected as a reference sequence that is at a receive end, that corresponds to the RU, and that is used for channel estimation, so as to perform a subsequent channel estimation operation. A principle is not described herein again.

[0068] Uplink transmission process:

[0069] For sending an 802.11ax data packet PPDU by an uplink STA, refer to FIG. 4 above. An AP indicates uplink scheduling information by using a triggering frame, where the uplink scheduling information includes a transmission bandwidth of an uplink user STA, an ID of an uplink scheduled STA, and a size and a location of an RU allocated to the STA, or an HE-LTF length for alignment of multiple uplink users. The HE-LTF length is a quantity N of symbols, and a maximum value of a corresponding allocated total flow quantity of a user on each RU is M, where <com:Math><semantics>N≥M<annotation encoding="application / x-tex">N \ge M< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>N=1,2,4,6<annotation encoding="application / x-tex">N = 1, 2, 4, 6< / annotation>< / semantics>< / com:Math>, or 8, and <com:Math><semantics>M=1<annotation encoding="application / x-tex">M = 1< / annotation>< / semantics>< / com:Math> to 8.

[0070] When the uplink STA sends a data packet PPDU of 802.11ax:

[0071] 301: The STA obtains, according to a size of an indicated total transmission bandwidth, an HE-LTF sequence corresponding to the bandwidth.

[0072] The HE-LTF sequence may be stored on the AP or the STA, or may be obtained by generating according to a particular principle. For a specific example of the HE-LTF sequence, refer to subsequent embodiments.

[0073] 302: The STA selects an HE-LTF sequence segment that is at a corresponding location from the HE-LTF sequence according to a size and a location of an allocated resource block RU, so as to map the HE-LTF sequence segment at subcarriers in the allocated RU to send the HE-LTF sequence segment.

[0074] 303: Send N symbols according to an indicated HE-LTF length, where each symbol carries an HE-LTF.

[0075] Correspondingly, when an uplink AP receives a data packet PPDU of 802.11ax, including:

[0076] 401: An AP obtains, according to a total transmission bandwidth, an HE-LTF sequence corresponding to the bandwidth.

[0077] The HE-LTF sequence may be stored on the AP, or may be obtained by generating according to a particular principle. For a specific example of the HE-LTF sequence, refer to subsequent embodiments.

[0078] 402: The AP selects a corresponding HE-LTF sequence segment from the HE-LTF sequence as a reference sequence of the RU according to a size and a location of a resource block RU allocated by each uplink scheduled user (station), so as to perform channel estimation.

[0079] A person skilled in the art knows that a data packet that complies with 802.11ax may have a transmission mode or data structure of SU, MU, OFDMA, or the like. An HE-LTF sequence provided in embodiments of the present invention is not limited to being applied in transmission of a specific data structure, but instead may be applied in transmission of various data packets that comply with the 802.11ax standard. For example, in the SU transmission mode, the size and location of the resource block RU allocated to the station mentioned in the foregoing embodiments is an entire bandwidth that is used in current transmission, and details are not described herein again.

[0080] In an embodiment of the present invention, a method for generating an HE-LTF sequence is provided, and may be applied in the foregoing embodiments, especially, for sizes and locations of different resource blocks RUs in an 802.11ax OFDMA tone plan:

[0081] 501: Select, in an OFDMA subcarrier layout, one or a group of basic HE-LTF sequences with a small RU length. The small RU herein may refer to the foregoing RU whose quantity of subcarriers is 26. For a 4x mode, the basic HE-LTF sequence is a sub-sequence whose length is 26. For a 2x mode, because an HE-LTF sequence number corresponds to a 4x HE-LTF sequence number divided by 2, and a basic HE-LTF sequence in the 2x mode is a sub-sequence whose length is 13.

[0082] 502: According to sizes and locations of different RUs in an OFDMA tone plan, repeat the basic HE-LTF sequence, or repeat one basic HE-LTF sequence in the group of basic HE-LTF sequences, and perform phase rotation of <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math> or <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math> by using the basic HE-LTF sequence as a unit.

[0083] 503: Concatenate several basic HE-LTF sequences that are obtained after the phase rotation, so as to generate an HE-LTF sequence of a large RU, and further pad +1 or -1 at a corresponding location according to a quantity and locations of leftover subcarriers between several small RUs corresponding to the large RU.

[0084] 504: Perform concatenation from a small RU to a large RU within a transmission bandwidth, and select a PAPR sequence with an optimal PAPR of various RUs as an HE-LTF sequence corresponding to the bandwidth.

[0085] It should be noted that for different bandwidths, an HE-LTF sequence generated according to the foregoing method may be respectively stored at an AP end and a STA end in a wireless local area network, so that the HE-LTF sequence is directly used in the uplink and downlink transmission processes mentioned above.

[0086] Some more specific embodiments are described below. In the foregoing embodiments, it is mentioned that in different OFDMA subcarrier mapping manners, a transmitter (an AP or a STA) sends different HE-LTF sequences according to different bandwidths, different RU locations, and different RU sizes. The manner includes the following steps:

[0087] 601: Select one HE-LTF sequence according to a bandwidth, where the one HE-LTF sequence has two forms that respectively correspond to a 2x mode and a 4x mode in 802.11ax.

[8800] Preferably, the HE-LTF in the 2x mode includes: a sub-sequence Ga, a sub-sequence Gb, and +1 or -1 that is located at a leftover (leftover) subcarrier location. Ga and Gb are sequences that are formed by +1 or -1 and that have a length of 13. In a specific example, Ga and Gb are respectively: [Image disponible dans le document PDF, Image available in the PDF document] [Image disponible dans le document PDF, Image available in the PDF document]

[0089] The HE-LTF in the 2x mode may further include a sequence that is generated according to Ga and Gb. Herein, the sequence generated according to Ga and Gb is referred to as a derived sequence, which specifically includes, but is not limited to: a sequence that is obtained after a phase of a value at a pilot location of the Ga sequence is reversed, where the sequence may be represented by <com:Math><semantics>Gap<annotation encoding="application / x-tex">G_a^p< / annotation>< / semantics>< / com:Math>; a sequence that is obtained after a phase of a value at a pilot location of the Gb sequence is reversed, where the sequence may be represented by <com:Math><semantics>Gbp<annotation encoding="application / x-tex">G_b^p< / annotation>< / semantics>< / com:Math>; a sequence that is obtained after a phase of a value on an even-numbered subcarrier of the Ga sequence is reversed, where the sequence may be represented by <com:Math><semantics>Gc<annotation encoding="application / x-tex">G_c< / annotation>< / semantics>< / com:Math>; and a sequence that is obtained after a phase of a value on an even-numbered subcarrier of the Gb sequence is reversed, where the sequence may be represented by <com:Math><semantics>Gd<annotation encoding="application / x-tex">G_d< / annotation>< / semantics>< / com:Math>.

[0090] In addition, the derived sequence further includes: a sequence that is obtained after a phase of a value at a pilot location of a <com:Math><semantics>Gc<annotation encoding="application / x-tex">G_c< / annotation>< / semantics>< / com:Math> sequence is reversed, where the sequence may be represented by <com:Math><semantics>Gcp<annotation encoding="application / x-tex">G_c^p< / annotation>< / semantics>< / com:Math>; and a sequence that is obtained after a phase of a value at a pilot location of a <com:Math><semantics>Gd<annotation encoding="application / x-tex">G_d< / annotation>< / semantics>< / com:Math> sequence is reversed, where the sequence may be represented by <com:Math><semantics>Gdp<annotation encoding="application / x-tex">G_d^p< / annotation>< / semantics>< / com:Math>.

[0091] The foregoing derived sequences may be generated by using the following formula: [Image disponible dans le document PDF, Image available in the PDF document] [Image disponible dans le document PDF, Image available in the PDF document] [Image disponible dans le document PDF, Image available in the PDF document] [Image disponible dans le document PDF, Image available in the PDF document] [Image disponible dans le document PDF, Image available in the PDF document] where <com:Math><semantics>Gap={+1,+1,−1,+1,+1,+1,+1,+1,+1,+1,+1,+1,+<annotation encoding="application / x-tex">G_{ap} = \{+1, +1, -1, +1, +1, +1, +1, +1, +1, +1, +1, +1, +< / annotation>< / semantics>< / com:Math> indicates that negation is performed at a pilot location (that is, locations of subcarriers whose sequence numbers are 3 and 10); [Image disponible dans le document PDF, Image available in the PDF document] indicates that negation is performed at a pilot location (that is, locations of subcarriers whose sequence numbers are 4 and 11); and <com:Math><semantics>Gxn={+1,−1,+1,−1,+1,−1,+1,−1,+1,−1,+1,−1,+1}<annotation encoding="application / x-tex">G_{xn} = \{+1, -1, +1, -1, +1, -1, +1, -1, +1, -1, +1, -1, +1\}< / annotation>< / semantics>< / com:Math> indicates that negation is performed at an even-numbered location. It should be noted that the foregoing <com:Math><semantics>Ga<annotation encoding="application / x-tex">G_a< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>Gc<annotation encoding="application / x-tex">G_c< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>Gap<annotation encoding="application / x-tex">G_a^p< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>Gcp<annotation encoding="application / x-tex">G_c^p< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>Gbp<annotation encoding="application / x-tex">G_b^p< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>Gd<annotation encoding="application / x-tex">G_d< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>Gbp<annotation encoding="application / x-tex">G_b^p< / annotation>< / semantics>< / com:Math>, and <com:Math><semantics>Gdp<annotation encoding="application / x-tex">G_d^p< / annotation>< / semantics>< / com:Math>

[0092] have the following relationships.

[0093] 1. A PAPR value of the <com:Math><semantics>Ga<annotation encoding="application / x-tex">G_a< / annotation>< / semantics>< / com:Math> sequence after IFFT is equal to a PAPR value of the <com:Math><semantics>Gc<annotation encoding="application / x-tex">G_c< / annotation>< / semantics>< / com:Math> sequence after IFFT.

[0094] 2. Maximum PAPR values obtained after different phase changes are performed on values at pilot locations of the sequences <com:Math><semantics>Ga<annotation encoding="application / x-tex">G_a< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>Gc<annotation encoding="application / x-tex">G_c< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>Gap<annotation encoding="application / x-tex">G_a^p< / annotation>< / semantics>< / com:Math>, and <com:Math><semantics>Gcp<annotation encoding="application / x-tex">G_c^p< / annotation>< / semantics>< / com:Math> and IFFT are the same.

[0095] 3. Similar to <com:Math><semantics>Ga<annotation encoding="application / x-tex">G_a< / annotation>< / semantics>< / com:Math> and a derived sequence of <com:Math><semantics>Ga<annotation encoding="application / x-tex">G_a< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>Gb<annotation encoding="application / x-tex">G_b< / annotation>< / semantics>< / com:Math> and a derived sequence of <com:Math><semantics>Gb<annotation encoding="application / x-tex">G_b< / annotation>< / semantics>< / com:Math> have properties the same as those described in the foregoing 1 and 2.

[0096] A person skilled in the art may know that the foregoing derived sequences may have different Equation manners. For example, the foregoing <com:Math><semantics>Gc<annotation encoding="application / x-tex">G_c< / annotation>< / semantics>< / com:Math> is replaced with <com:Math><semantics>Ga<annotation encoding="application / x-tex">G_a< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>Gd<annotation encoding="application / x-tex">G_d< / annotation>< / semantics>< / com:Math> is replaced with <com:Math><semantics>G̃bp<annotation encoding="application / x-tex">\tilde{G}_b^p< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>Gcp<annotation encoding="application / x-tex">G_c^p< / annotation>< / semantics>< / com:Math> is replaced with <com:Math><semantics>G̃ap<annotation encoding="application / x-tex">\tilde{G}_a^p< / annotation>< / semantics>< / com:Math>, and <com:Math><semantics>Gdp<annotation encoding="application / x-tex">G_d^p< / annotation>< / semantics>< / com:Math> is replaced with <com:Math><semantics>G̃bp<annotation encoding="application / x-tex">\tilde{G}_b^p< / annotation>< / semantics>< / com:Math>. The essence thereof stays the same. Alternatively, all basic sub-sequences and corresponding derived sequences have different Equation manners.

[0097] The HE-LTF in the 4x mode includes: a sequence Ga, a sub-sequence Gb, and +1 or -1 that is located at a leftover leftover subcarrier location. The Ga or Gb is a sequence that is formed by <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math> or <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math> and that has a length of 26. Specifically: [Image disponible dans le document PDF, Image available in the PDF document] <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>]; and [Image disponible dans le document PDF, Image available in the PDF document] +1].

[0098] The HE-LTF in the 4x mode may further include a sequence that is generated according to Ga or Gb. Herein, the sequence that is generated according to Ga or Gb is referred to as a derived sequence, which includes, but is not limited to: a sequence that is obtained after a phase of a value at a pilot location of the Ga sequence is reversed, where the sequence may be denoted as <com:Math><semantics>Gap<annotation encoding="application / x-tex">G_a^p< / annotation>< / semantics>< / com:Math>; a sequence that is obtained after a phase of a value at a pilot location of the Gb sequence is reversed, where the sequence may be denoted as <com:Math><semantics>Gbp<annotation encoding="application / x-tex">G_b^p< / annotation>< / semantics>< / com:Math>; a sequence that is obtained after a phase of a value on an even-numbered subcarrier of the Ga sequence is reversed, where the sequence may be denoted as <com:Math><semantics>Gc<annotation encoding="application / x-tex">G_c< / annotation>< / semantics>< / com:Math>; a sequence that is obtained after a phase of a value on an even-numbered subcarrier of the Gb sequence is reversed, where the sequence may be denoted as <com:Math><semantics>Gd<annotation encoding="application / x-tex">G_d< / annotation>< / semantics>< / com:Math>: a sequence that is obtained after a phase of a value at a pilot location of a <com:Math><semantics>Gc<annotation encoding="application / x-tex">G_c< / annotation>< / semantics>< / com:Math> sequence is reversed, where the sequence may be denoted as <com:Math><semantics>Gcp<annotation encoding="application / x-tex">G_c^p< / annotation>< / semantics>< / com:Math>; and a sequence that is obtained after a phase of a value at a pilot location of a <com:Math><semantics>Gd<annotation encoding="application / x-tex">G_d< / annotation>< / semantics>< / com:Math> sequence is reversed, where the sequence may be denoted as <com:Math><semantics>Gdp<annotation encoding="application / x-tex">G_d^p< / annotation>< / semantics>< / com:Math>.

[0100] The foregoing derived sequence may be generated by using the following formula: [Image disponible dans le document PDF, Image available in the PDF document] [Image disponible dans le document PDF, Image available in the PDF document] [Image disponible dans le document PDF, Image available in the PDF document] [Image disponible dans le document PDF, Image available in the PDF document] [Image disponible dans le document PDF, Image available in the PDF document] [Image disponible dans le document PDF, Image available in the PDF document] [Image disponible dans le document PDF, Image available in the PDF document] where <com:Math><semantics>Gap={1,1,1,1,1,1,1,1,1,1,1,1,1,1<annotation encoding="application / x-tex">G_{ap} = \{1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1< / annotation>< / semantics>< / com:Math> negation is performed at a pilot location (that is, subcarrier whose sequence numbers are 6 and 20). <com:Math><semantics>Gbp={1,1,1,1,1,1,1,1,1,1,1,1,1,1<annotation encoding="application / x-tex">G_{bp} = \{1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1< / annotation>< / semantics>< / com:Math> negation is performed at a pilot location (that is, subcarriers whose sequence numbers are 7 and 21). <com:Math><semantics>Gxp={+1,−1,+1,−1,+1,−1,+1,−1,+1,−1,+1,−1,+1,−1,+1,−1,+1,−1,+1,−1,+1,−1,+1,−1,+1,−1,+1,−1,+1,−1,+1,−1,+1,−1,+1,−1,+1,−1,+1,−1,+1,−1,+1,−1,+1,−1,+1,−1,+1,−1,+1,−1,+1<annotation encoding="application / x-tex">G_{xp} = \{+1, -1, +1, -1, +1, -1, +1, -1, +1, -1, +1, -1, +1, -1, +1, -1, +1, -1, +1, -1, +1, -1, +1, -1, +1, -1, +1, -1, +1, -1, +1, -1, +1, -1, +1, -1, +1, -1, +1, -1, +1, -1, +1, -1, +1, -1, +1, -1, +1, -1, +1, -1, +1< / annotation>< / semantics>< / com:Math> <com:Math><semantics>−1,+1,−1,+1,−1<annotation encoding="application / x-tex">-1, +1, -1, +1, -1< / annotation>< / semantics>< / com:Math>} indicates that negation is performed at an even-numbered location.

[0101] It should be noted that the foregoing <com:Math><semantics>Ga<annotation encoding="application / x-tex">G_a< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>Gc<annotation encoding="application / x-tex">G_c< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>Gap<annotation encoding="application / x-tex">G_a^p< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>Gcp<annotation encoding="application / x-tex">G_c^p< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>Gb<annotation encoding="application / x-tex">G_b< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>Gd<annotation encoding="application / x-tex">G_d< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>Gbp<annotation encoding="application / x-tex">G_b^p< / annotation>< / semantics>< / com:Math>, and <com:Math><semantics>Gdp<annotation encoding="application / x-tex">G_d^p< / annotation>< / semantics>< / com:Math> have the following relationships.

[0102] 1: A PAPR value of the <com:Math><semantics>Ga<annotation encoding="application / x-tex">G_a< / annotation>< / semantics>< / com:Math> sequence after IFFT is equal to a PAPR value of the <com:Math><semantics>Gc<annotation encoding="application / x-tex">G_c< / annotation>< / semantics>< / com:Math> sequence after IFFT.

[0103] 2: Maximum PAPR values obtained after different phase changes are performed on values at pilot locations of the sequences <com:Math><semantics>Ga<annotation encoding="application / x-tex">G_a< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>Gc<annotation encoding="application / x-tex">G_c< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>Gap<annotation encoding="application / x-tex">G_a^p< / annotation>< / semantics>< / com:Math>, and <com:Math><semantics>Gcp<annotation encoding="application / x-tex">G_c^p< / annotation>< / semantics>< / com:Math> and IFFT are the same.

[0104] 3. Similar to <com:Math><semantics>Ga<annotation encoding="application / x-tex">G_a< / annotation>< / semantics>< / com:Math> and a derived sequence of <com:Math><semantics>Ga<annotation encoding="application / x-tex">G_a< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>Gb<annotation encoding="application / x-tex">G_b< / annotation>< / semantics>< / com:Math> and a derived sequence of <com:Math><semantics>Gb<annotation encoding="application / x-tex">G_b< / annotation>< / semantics>< / com:Math> have properties the same as those described in the foregoing 1 and 2.

[0105] A person skilled in the art may know that the foregoing sub-sequences and derived sequences may have different Equation manners. For example, the foregoing <com:Math><semantics>Gc<annotation encoding="application / x-tex">G_c< / annotation>< / semantics>< / com:Math> is replaced with <com:Math><semantics>G̃a<annotation encoding="application / x-tex">\tilde{G}_a< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>Gd<annotation encoding="application / x-tex">G_d< / annotation>< / semantics>< / com:Math> is replaced with <com:Math><semantics>G̃b<annotation encoding="application / x-tex">\tilde{G}_b< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>Gcp<annotation encoding="application / x-tex">G_c^p< / annotation>< / semantics>< / com:Math> is replaced with <com:Math><semantics>G̃ap<annotation encoding="application / x-tex">\tilde{G}_a^p< / annotation>< / semantics>< / com:Math>, and <com:Math><semantics>Gdp<annotation encoding="application / x-tex">G_d^p< / annotation>< / semantics>< / com:Math> is replaced with <com:Math><semantics>G̃bp<annotation encoding="application / x-tex">\tilde{G}_b^p< / annotation>< / semantics>< / com:Math>. The essence thereof stays the same. Alternatively, all basic sub-sequences and corresponding derived sequences have different Equation manners, and the essence thereof stays the same.

[0106] In a preferred embodiment, for different <com:Math><semantics>2x / 4x<annotation encoding="application / x-tex">2x / 4x< / annotation>< / semantics>< / com:Math> modes, the HE-LTF sequence further includes different combinations of derived sequences.

[0107] For the Ga sequence, the Gb sequence, and different derived sequences that are generated according to the Ga sequence and the Gb sequence, a concatenated combination in the 2x mode includes, but is not limited to, one or any combination of the following sequences: [Image disponible dans le document PDF, Image available in the PDF document] <com:Math><semantics>{+Gcp,+Gcp},{+Gcp,−Gcp},{+Gb,+Gbp},{+Gb,−Gbp},{+Gbp,+Gb},{+Gbp},{+Gbp},{+Gbp},{+Gbp},{+Gbp},{+Gbp},{+Gbp},{+Gbp},{+Gbp},{+Gbp},{+Gbp},{+Gbp},{+Gbp},{+Gbp},{+Gbp},{+Gbp},{+<annotation encoding="application / x-tex">\{+G_c^p,+G_c^p\},\{+G_c^p,-G_c^p\},\{+G_b,+G_b^p\},\{+G_b,-G_b^p\},\{+G_b^p,+G_b\},\{+G_b^p\},\{+G_b^p\},\{+G_b^p\},\{+G_b^p\},\{+G_b^p\},\{+G_b^p\},\{+G_b^p\},\{+G_b^p\},\{+G_b^p\},\{+G_b^p\},\{+G_b^p\},\{+G_b^p\},\{+G_b^p\},\{+G_b^p\},\{+G_b^p\},\{+G_b^p\},\{+< / annotation>< / semantics>< / com:Math> <com:Math><semantics>+Gdp<annotation encoding="application / x-tex">+G_d^p< / annotation>< / semantics>< / com:Math> \ <com:Math><semantics>{+Gdp,−Gdp},{+Gdp,+Gdp}, and {+Gdp,−Gdp}.<annotation encoding="application / x-tex">\{+G_d^p, -G_d^p\}, \{+G_d^p, +G_d^p\}, \text{ and } \{+G_d^p, -G_d^p\}.< / annotation>< / semantics>< / com:Math>

[0108] For the Ga sequence, the Gb sequence, and different derived sequences that are generated according to the Ga sequence and the Gb sequence, a concatenated combination in the 4x mode includes, but is not limited to, one or any combination of the following sequences: [Image disponible dans le document PDF, Image available in the PDF document] <com:Math><semantics>{−Gap,−Ga},{−Gap,+Ga},{+Gcp,+Gcp},{+Gcp,−Gcp},{+Gcp,+Gcp},{+Gcp,−Gcp},{−Gcp,−Gcp},{−Gcp,−Gcp},{−Gcp,−Gcp},{−Gcp,−Gcp},{−Gcp,−Gcp},{−Gcp,−Gcp},{−Gcp,−<annotation encoding="application / x-tex">\{-G_a^p, -Ga\}, \{-G_a^p, +Ga\}, \{+G_c^p, +G_c^p\}, \{+G_c^p, -G_c^p\}, \{+G_c^p, +G_c^p\}, \{+G_c^p, -G_c^p\}, \{-G_c^p, -G_c^p\}, \{-G_c^p, -G_c^p\}, \{-G_c^p, -G_c^p\}, \{-G_c^p, -G_c^p\}, \{-G_c^p, -G_c^p\}, \{-G_c^p, -G_c^p\}, \{-G_c^p, -< / annotation>< / semantics>< / com:Math> <com:Math><semantics>−Gcp<annotation encoding="application / x-tex">-G_{c}^{p}< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>{−Gcp,+Gcp}<annotation encoding="application / x-tex">\{-G_{c}^{p}, +G_{c}^{p}\}< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>{−Gcp,−Gcp}<annotation encoding="application / x-tex">\{-G_{c}^{p}, -G_{c}^{p}\}< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>{−Gcp,+Gcp}<annotation encoding="application / x-tex">\{-G_{c}^{p}, +G_{c}^{p}\}< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>{+Gb,+Gbp}<annotation encoding="application / x-tex">\{+Gb, +G_{b}^{p}\}< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>{+Gb,−Gbp}<annotation encoding="application / x-tex">\{+Gb, -G_{b}^{p}\}< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>{+Gb,−Gbp}<annotation encoding="application / x-tex">\{+Gb, -G_{b}^{p}\}< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>{+Gb,−Gbp}<annotation encoding="application / x-tex">\{+Gb, -G_{b}^{p}\}< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>{+Gb,−Gbp}<annotation encoding="application / x-tex">\{+Gb, -G_{b}^{p}\}< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>{+Gb,−Gbp}<annotation encoding="application / x-tex">\{+Gb, -G_{b}^{p}\}< / annotation>< / semantics>< / com:Math> <Formule mathématique disponible dans le document PDF, Math available in the PDF document>$\{+G_b^p, -G_b\}, \{-G_b, -G_b^p\}, \{-G_b, +G_b^p\}, \{-G_b^p, -G_b\}, \{-G_b^p, +G_b\}, \{+G_d, +G_d^p\}, \{+G_d, +G_d^p\}, \{+G_d, +G_d^p\}, \{+G_d, +G_d^p\}, \{+G_d, +G_d^p\}, \{+G_d, +G_d^p\}, \{+G_d, +G_d^p\}, \{+G_d, +G_d^p\}, \{+G_d, +G_d^$ <com:Math><semantics>−Gdp<annotation encoding="application / x-tex">-G_d^p< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>{+Gdp,+Gdp,−Gdp}<annotation encoding="application / x-tex">\{+G_d^p, +G_d^p, -G_d^p\}< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>{+Gdp,−Gdp}<annotation encoding="application / x-tex">\{+G_d^p, -G_d^p\}< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>{−Gdp,−Gdp}<annotation encoding="application / x-tex">\{-G_d^p, -G_d^p\}< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>{−Gdp,+Gdp}<annotation encoding="application / x-tex">\{-G_d^p, +G_d^p\}< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>{−Gdp,−Gdp}<annotation encoding="application / x-tex">\{-G_d^p, -G_d^p\}< / annotation>< / semantics>< / com:Math>, and <com:Math><semantics>{−Gdp,−Gdp}<annotation encoding="application / x-tex">\{-G_d^p, -G_d^p\}< / annotation>< / semantics>< / com:Math> <com:Math><semantics>+Gd<annotation encoding="application / x-tex">+G_{d}< / annotation>< / semantics>< / com:Math>.

[0109] Certainly, according to different Equation manners of a sequence, the foregoing concatenated combination may also have a corresponding different Equation manner, and content of the different Equation manner is substantially the same.

[0110] Herein, it should be noted that in an AP or a STA in a wireless local area network, only the sub-sequence Ga and the sub-sequence Gb may be stored. When a PPDU needs to be sent, an HE-LTF sequence is generated and is then sent, or the foregoing HE-LTF sequence may also be directly stored in the AP or STA, and the HE-LTF sequence is sent on a corresponding subcarrier when necessary.

[0111] 602: Send the HE-LTF sequence according to a size of an RU and a location of an RU that are in resource allocation information.

[0112] Specifically, with reference to tone plans in FIG. 1a, FIG. 1b, and FIG. 1c, a sub-sequence segment at a corresponding location of an HE-LTF sequence is placed on a subcarrier at the corresponding location and is then sent.

[0113] Some more specific HE-LTF sequences are provided below, and these sequences all have the foregoing feature that a PAPR is relatively low. Embodiment 1

[0114] There are 128 subcarriers on a 2x symbol of a 20-MHz bandwidth in the 2x mode. According to different resource block sizes, as shown in FIG. 1a, an RU size may be 13, 26, 54, or 121 subcarriers.

[0115] There are many types of 2x HE-LTF sequences in an 20-MHz transmission. Only several types of preferred HE-LTF sequences are listed below. [Image disponible dans le document PDF, Image available in the PDF document]

[0116] A person skilled in the art knows that <com:Math><semantics>−122:2:122<annotation encoding="application / x-tex">-122:2:122< / annotation>< / semantics>< / com:Math> means subcarriers with even indexes in indexes -122 to 122, i.e., subcarriers with indexes {-122, -120, ..., -2, 0, +2, ..., +120, +122}. Values (mapped) on the above subcarriers are elements at corresponding locations in the foregoing sequence. Values (mapped) on subcarriers with other locations(indexes) are 0. Subsequently, such an Equation manner will not be described repeatedly.

[0117] The HE-LTF sequence includes the Ga sequence, the Gb sequence, sequences <com:Math><semantics>Gap<annotation encoding="application / x-tex">G_a^p< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>Gbp<annotation encoding="application / x-tex">G_b^p< / annotation>< / semantics>< / com:Math>, G<com:Sub>c< / com:Sub>, and G<com:Sub>c< / com:Sub><com:Sup>p< / com:Sup> that are generated according to the Ga sequence and the Gb sequence (for specific content, refer to the foregoing descriptions), and <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math> or <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math> that is located at a leftover leftover subcarrier location, and may further include consecutive <com:Math><semantics>+Ga,−Gap<annotation encoding="application / x-tex">{}^{+G_a, -G_a^p}< / annotation>< / semantics>< / com:Math>, consecutive <com:Math><semantics>+Gb,+Gbp<annotation encoding="application / x-tex">{}^{+G_b, +G_b^p}< / annotation>< / semantics>< / com:Math>, consecutive <com:Math><semantics>+Gc,−Gcp<annotation encoding="application / x-tex">+G_c, -G_c^p< / annotation>< / semantics>< / com:Math>, consecutive <com:Math><semantics>−Gbp,−Gb<annotation encoding="application / x-tex">-G_b^p, -G_b< / annotation>< / semantics>< / com:Math>, or the like, where <com:Math><semantics>Ga={+1,+1,+1,−1,+1,+1,+1,−1,+1,−1,+1,−1}andGb={+1,+1,+1,−1,−1,−1,−1,+1,−1,−1,+1,−1,−1,+1,−1,−1,−1,−1,−1,−1,−1,−1,−1,−<annotation encoding="application / x-tex">G_{a} = \{+1, +1, +1, -1, +1, +1, +1, -1, +1, -1, +1, -1\} \quad \text{and} \quad G_{b} = \{+1, +1, +1, -1, -1, -1, -1, +1, -1, -1, +1, -1, -1, +1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -< / annotation>< / semantics>< / com:Math>

[0118] For details and generating processes of the foregoing sequences, refer to the foregoing descriptions of the 2x HE-LTF sequence.

[0119] More specifically, the foregoing 2X HE-LTF sequence may be directly stored as: <com:Math><semantics>HELTF2x(−122:2:122)=<annotation encoding="application / x-tex">HELTF_{2x}(-122:2:122) =< / annotation>< / semantics>< / com:Math> <com:Math><semantics>[+1,+1,+1,+1,−1,+1,+1,+1,−1,+1,−1,−1,+1,−1,−1,+1,−1,−1,+1,−1,−1,+1,−1,+1,+1,+1,+1,+1,+1,+1,+1,+1,+<annotation encoding="application / x-tex">[+1, +1, +1, +1, -1, +1, +1, +1, -1, +1, -1, -1, +1, -1, -1, +1, -1, -1, +1, -1, -1, +1, -1, +1, +1, +1, +1, +1, +1, +1, +1, +1, +< / annotation>< / semantics>< / com:Math> <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1,−1,−1,−1,+1,−1,−1,−1,+1,−1,+1,+1,+1,+1,−1,<annotation encoding="application / x-tex">-1, -1, -1, -1, +1, -1, -1, -1, +1, -1, +1, +1, +1, +1, -1,< / annotation>< / semantics>< / com:Math> <com:Math><semantics>−1,−1,+1,−1,−1,+1,+1,−1,−1,−1,+1,−1,−1,+1,−1,<annotation encoding="application / x-tex">-1, -1, +1, -1, -1, +1, +1, -1, -1, -1, +1, -1, -1, +1, -1,< / annotation>< / semantics>< / com:Math> <com:Math><semantics>+1,0,−1,−1,−1,+1,+1,−1,−1,−1,+1,+1,+1,+1,<annotation encoding="application / x-tex">+1, 0, -1, -1, -1, +1, +1, -1, -1, -1, +1, +1, +1, +1,< / annotation>< / semantics>< / com:Math> <com:Math><semantics>−1,+1,+1,+1,+1,−1,−1,−1,−1,+1,+1,−1,−1,+1,−1,<annotation encoding="application / x-tex">-1, +1, +1, +1, +1, -1, -1, -1, -1, +1, +1, -1, -1, +1, -1,< / annotation>< / semantics>< / com:Math> <com:Math><semantics>−1,−1,+1,+1,+1,+1,−1,−1,−1,−1,+1,+1,+1,+1,+1,+1,<annotation encoding="application / x-tex">-1, -1, +1, +1, +1, +1, -1, -1, -1, -1, +1, +1, +1, +1, +1, +1,< / annotation>< / semantics>< / com:Math> <com:Math><semantics>+1,−1,−1,+1,−1,−1,−1,+1,+1,+1,+1,−1,+1,+1,+1<annotation encoding="application / x-tex">+1, -1, -1, +1, -1, -1, -1, +1, +1, +1, +1, -1, +1, +1, +1< / annotation>< / semantics>< / com:Math> <com:Math><semantics>−1,+1,−1<annotation encoding="application / x-tex">-1, +1, -1< / annotation>< / semantics>< / com:Math>

[0120] FIG. 8a shows PAPR values when the foregoing HE-LTF sequence is used in an 20-MHz bandwidth transmission. It may be learned, according to the group of PAPR values, that when different rotational phases are introduced in pilot subcarriers and other subcarriers, PAPR values are still very small.

[0121] The first group of PAPR values is sequentially PAPR values corresponding to 26-subcarrier resource blocks from left to right. Values in the first row, 2.76, 3.68, 2.76, 3.68, ..., are PAPR values corresponding to an HE-LTF sequence when values at data locations are all multiplied by +1 and values at pilot locations are all multiplied by +1, and sequentially from left to right in the first row, 2.76 is a PAPR value corresponding to a first 26-subcarrier resource block, 3.68 is a PAPR value corresponding to a second 26-subcarrier resource block from left to right, and so on. Values in the second row, 3.67, 2.76, 3.68, 2.76, ..., are PAPR values corresponding to an HE-LTF sequence when values at data locations are all multiplied by <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math> and values at pilot locations are all multiplied by +1, and sequentially from left to right in the second row, 3.68 is a PAPR value corresponding to a first 26-subcarrier resource block, 2.76 is a PAPR value corresponding to a second 26-subcarrier resource block from left to right, and so on. Values in the third row, 3.30, 4.46, 3.30, 4.46, ..., are PAPR values corresponding to an HE-LTF sequence when values at data locations are all multiplied by w and values at pilot locations are all multiplied by <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, and sequentially from left to right in the third row, 3.30 is a PAPR value corresponding to a first 26-subcarrier resource block, 4.46 is a PAPR value corresponding to a second 26-subcarrier resource block from left to right, and so on. Values in the fourth row, 4.46, 3.30, 4.46, 3.30, ..., are PAPR values corresponding to an HE-LTF sequence when values at data locations are all multiplied by w<com:Sup>2< / com:Sup> and values at pilot locations are all multiplied by +1, and sequentially from left to right in the fourth row, 4.46 is a PAPR value corresponding to a first 26-subcarrier resource block, 3.30 is a PAPR value corresponding to a second 26-subcarrier resource block from left to right, and so on.

[0122] The second group of PAPR values is sequentially PAPR values corresponding to 52-subcarrier resource blocks in a second row from left to right. Values in the first row, 4.68, 4.68, 4.33, 4.68, ..., are PAPR values corresponding to an HE-LTF sequence when values at data locations are all multiplied by +1 and values at pilot locations are all multiplied by +1, and sequentially from left to right in the second row, the first 4.68 is a PAPR value corresponding to a first 52-subcarrier resource block, the second 4.68 is a PAPR value corresponding to a second 52-subcarrier resource block from left to right, and so on.

[0123] Values in the second row, 4.68, 4.68, 4.48, and 4.68, are PAPR values corresponding to an HE-LTF sequence when values at data locations are all multiplied by -1 and values at pilot locations are all multiplied by +1, and sequentially from left to right in the second row, the first 4.68 is a PAPR value corresponding to a first 52-subcarrier resource block, the second 4.68 is a PAPR value corresponding to a second 52-subcarrier resource block from left to right, and so on. Values in the third row, 4.69, 4.69, 4.35, and 4.69, are PAPR values corresponding to an HE-LTF sequence when values at data locations are all multiplied by w and values at pilot locations are all multiplied by +1, and sequentially from left to right in the third row, the first 4.69 is a PAPR value corresponding to a first 52-subcarrier resource block, the second 4.69 is a PAPR value corresponding to a second 52-subcarrier resource block from left to right, and so on. Values in the fourth row, 4.69, 4.69, 4.77, and 4.69, are PAPR values corresponding to an HE-LTF sequence when values at data locations are all multiplied by w<com:Sup>2< / com:Sup> and values at pilot locations are all multiplied by +1, and sequentially from left to right in the fourth row, the first 4.69 is a PAPR value corresponding to a first 52-subcarrier resource block, the second 4.69 is a PAPR value corresponding to a second 52-subcarrier resource block from left to right, and so on.

[0124] The third group of PAPR values is sequentially PAPR values corresponding to 106-subcarrier resource blocks in the third row from left to right. Values in the first row, 4.89 and 3.93, are PAPR values corresponding to an HE-LTF sequence when values at data locations are all multiplied by +1 and values at pilot locations are all multiplied by +1, and sequentially from left to right in the third row, 4.89 is a PAPR value corresponding to a first 106-subcarrier resource block, and 3.93 is a PAPR value corresponding to a second 106-subcarrier resource block from left to right. Values in the second row, 4.23 and 4.76, are PAPR values corresponding to an HE-LTF sequence when values at data locations are all multiplied by <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math> and values at pilot locations are all multiplied by +1, and sequentially from left to right in the second row, 4.23 is a PAPR value corresponding to a first 106-subcarrier resource block, and 4.76 is a PAPR value corresponding to a second 106-subcarrier resource block from left to right. Values in the third row, 4.79 and 4.73, are PAPR values corresponding to an HE-LTF sequence when values at data locations are all multiplied by w and values at pilot locations are all multiplied by <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, and sequentially from left to right in the third row, 4.79 is a PAPR value corresponding to a first 106-subcarrier resource block, and 4.73 is a PAPR value corresponding to a second 106-subcarrier resource block from left to right. Values in the fourth row, 4.38 and 4.87, are PAPR values corresponding to an HE-LTF sequence when values at data locations are all multiplied by <com:Math><semantics>w2<annotation encoding="application / x-tex">w^2< / annotation>< / semantics>< / com:Math> and values at pilot locations are all multiplied by <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, and sequentially from left to right in the fourth row, 4.38 is a PAPR value corresponding to a first 106-subcarrier resource block, and 4.87 is a PAPR value corresponding to a second 106-subcarrier resource block from left to right.

[0125] The fourth group of values, 5.31, 5.32, 5.48, and 5.46, are PAPR values corresponding to 242-subcarrier resource blocks in a fourth row, where the first 5.31 is a PAPR value corresponding to an HE-LTF sequence when values at data locations are all multiplied by +1 and values at pilot locations are all multiplied by +1; the second 5.32 is a PAPR value corresponding to an HE-LTF sequence when values at data locations are all multiplied by <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math> and values at pilot locations are all multiplied by +1; the third 5.48 is a PAPR value corresponding to an HE-LTF sequence when values at data locations are all multiplied by w and values at pilot locations are all multiplied by +1; the first 5.46 is a PAPR value corresponding to an HE-LTF sequence when values at data locations are all multiplied by <com:Math><semantics>w2<annotation encoding="application / x-tex">w^2< / annotation>< / semantics>< / com:Math> and values at pilot locations are all multiplied by <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>.

[0126] A second HE-LTF sequence in the 2x mode: [Image disponible dans le document PDF, Image available in the PDF document]

[0127] The HE-LTF sequence in the 2x mode includes the Ga sequence and sequences <com:Math><semantics>Gap<annotation encoding="application / x-tex">G_a^p< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>Gcp<annotation encoding="application / x-tex">G_c^p< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>Gdp<annotation encoding="application / x-tex">G_d^p< / annotation>< / semantics>< / com:Math>, and <com:Math><semantics>Gdp<annotation encoding="application / x-tex">G_d^p< / annotation>< / semantics>< / com:Math> that are generated according to the Ga sequence and the Gb sequence, and +1 or -1 that is located at leftover leftover subcarrier locations. For the content of the foregoing sequences, refer to the foregoing embodiments, and details are not described again.

[0128] Further, the HE-LTF sequence further includes consecutive <com:Math><semantics>−Gc,−Gcp<annotation encoding="application / x-tex">{}^{-G_c, -G_c^p}< / annotation>< / semantics>< / com:Math> or consecutive <com:Math><semantics>+Ga<annotation encoding="application / x-tex">+G_a< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+Gap<annotation encoding="application / x-tex">+G_a^p< / annotation>< / semantics>< / com:Math>, (or for example, the consecutive <com:Math><semantics>−Gd<annotation encoding="application / x-tex">-G_d< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+Gdp<annotation encoding="application / x-tex">+G_d^p< / annotation>< / semantics>< / com:Math> listed in the foregoing sequence, consecutive <com:Math><semantics>+Ga,+Gap<annotation encoding="application / x-tex">{}^{+G_a,+G_a^p}< / annotation>< / semantics>< / com:Math>, or consecutive <com:Math><semantics>−Gdp,+Gd<annotation encoding="application / x-tex">{}^{-G_d^p,+G_d}< / annotation>< / semantics>< / com:Math>).

[0129] Certainly, the foregoing HE-LTF sequence in the 2x mode may be directly stored as: [Image disponible dans le document PDF, Image available in the PDF document]

[0130] PAPR values obtained by using the foregoing HE-LTF sequence are the same as those shown in FIG. 8a.

[0131] A third HE-LTF sequence in the 2x mode: [Image disponible dans le document PDF, Image available in the PDF document]

[0132] The HE-LTF sequence includes the Ga sequence and the Gb sequence, sequences <com:Math><semantics>Gap<annotation encoding="application / x-tex">G^{p}_{a}< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>Gdp<annotation encoding="application / x-tex">G_{d}^{p}< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>Gd<annotation encoding="application / x-tex">G_{d}< / annotation>< / semantics>< / com:Math>, and <com:Math><semantics>Gbp<annotation encoding="application / x-tex">G_{b}^{p}< / annotation>< / semantics>< / com:Math> that are generated according to the Ga sequence and the Gb sequence, and +1 or -1 that are located at leftover leftover subcarrier locations. Further, the HE-LTF sequence may further include consecutive <com:Math><semantics>+Ga,−Gap<annotation encoding="application / x-tex">{}^{+G_a, -G_a^p}< / annotation>< / semantics>< / com:Math>, consecutive <com:Math><semantics>+Gdp,+Gd<annotation encoding="application / x-tex">{}^{+G_d^p, +G_d}< / annotation>< / semantics>< / com:Math>, consecutive <com:Math><semantics>+Gap,−Ga<annotation encoding="application / x-tex">{}^{+G_a^p, -G_a}< / annotation>< / semantics>< / com:Math>, and consecutive <com:Math><semantics>−Gbp,−Gb<annotation encoding="application / x-tex">-G_b^p, -G_b< / annotation>< / semantics>< / com:Math>. For the specific content of each sequence, refer to the foregoing embodiments, and details are not described again.

[0133] The HE-LTF sequence in the foregoing 2x mode may be directly stored as: [Image disponible dans le document PDF, Image available in the PDF document]

[0134] FIG. 8b shows PAPR values of an HE-LTF sequence in the 20-MHz bandwidth. It may be learned, according to the group of PAPR values, that when different rotational phases are introduced in pilot subcarriers and other subcarriers, PAPR values are still very small.

[0135] The first group of values is sequentially PAPR values corresponding to 26-subcarrier resource blocks from left to right. Values in the first row, 2.76, 3.68, 2.76, 3.68, ..., are PAPR values corresponding to an HE-LTF sequence when values at data locations are all multiplied by +1 and values at pilot locations are all multiplied by +1, and sequentially from left to right in the first row, 2.76 is a PAPR value corresponding to a first 26-subcarrier resource block, 3.68 is a PAPR value corresponding to a second 26-subcarrier resource block from left to right, and so on. Values in the second row, 3.68, 2.76, 3.68, 2.76, ..., are PAPR values corresponding to an HE-LTF sequence when values at data locations are all multiplied by <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math> and values at pilot locations are all multiplied by <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, and sequentially from left to right in the second row, 3.68 is a PAPR value corresponding to a first 26-subcarrier resource block, 2.76 is a PAPR value corresponding to a second 26-subcarrier resource block from left to right, and so on. Values in the third row, 3.30, 4.46, 4.46, 3.30, ..., are PAPR values corresponding to an HE-LTF sequence when values at data locations are all multiplied by w and values at pilot locations are all multiplied by +1, and sequentially from left to right in the third row, 3.30 is a PAPR value corresponding to a first 26-subcarrier resource block, 4.46 is a PAPR value corresponding to a second 26-subcarrier resource block from left to right, and so on. Values in the fourth row, 4.46, 3.30, 3.30, 4.46, ..., are PAPR values corresponding to an HE-LTF sequence when values at data locations are all multiplied by w<com:Sup>2< / com:Sup> and values at pilot locations are all multiplied by +1, and sequentially from left to right in the fourth row, 4.46 is a PAPR value corresponding to a first 26-subcarrier resource block, 3.30 is a PAPR value corresponding to a second 26-subcarrier resource block from left to right, and so on.

[0136] The second group of values is sequentially PAPR values corresponding to 52-subcarrier resource blocks in a second row from left to right. Values in the first row, 4.68, 4.33, 4.68, and 4.68, are PAPR values corresponding to an HE-LTF sequence when values at data locations are all multiplied by +1 and values at pilot locations are all multiplied by +1, and sequentially from left to right in the second row, the first 4.68 is a PAPR value corresponding to the first 52-subcarrier resource block, the second 4.33 is a PAPR value corresponding to a second 52-subcarrier resource block from left to right, and so on.

[0137] Values in the second row, 4.68, 4.48, 4.68, and 4.68, are PAPR values corresponding to an HE-LTF sequence when values at data locations are all multiplied by -1 and values at pilot locations are all multiplied by +1, and sequentially from left to right in the second row, the first 4.48 is a PAPR value corresponding to a first 52-subcarrier resource block, the second 4.68 is a PAPR value corresponding to a second 52-subcarrier resource block from left to right, and so on. Values in the third row, 4.69, 4.35, 4.69, and 4.69, are PAPR values corresponding to an HE-LTF sequence when values at data locations are all multiplied by w and values at pilot locations are all multiplied by +1, and sequentially from left to right in the third row, the first 4.69 is a PAPR value corresponding to a first 52-subcarrier resource block, the second 4.35 is a PAPR value corresponding to a second 52-subcarrier resource block from left to right, and so on. Values in the fourth row, 4.69, 4.77, 4.69, 4.69, are PAPR values corresponding to an HE-LTF sequence when values at data locations are all multiplied by <com:Math><semantics>w2<annotation encoding="application / x-tex">w^2< / annotation>< / semantics>< / com:Math> and values at pilot locations are all multiplied by <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, and sequentially from left to right in the fourth row, the first 4.69 is a PAPR value corresponding to a first 52-subcarrier resource block, the second 4.77 is a PAPR value corresponding to a second 52-subcarrier resource block from left to right, and so on.

[0138] The third group of values is sequentially from left to right PAPR values corresponding to 106-subcarrier resource blocks in a third row. Values in the first row, 3.93 and 4.89, are PAPR values corresponding to an HE-LTF sequence when values at data locations are all multiplied by +1 and values at pilot locations are all multiplied by <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, and sequentially from left to right in the third row, 3.93 is a PAPR value corresponding to a first 106-subcarrier resource block, and 4.89 is a PAPR value corresponding to a second 106-subcarrier resource block from left to right. Values in the second row, 4.76 and 4.23, are PAPR values corresponding to an HE-LTF sequence when values at data locations are all multiplied by <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math> and values at pilot locations are all multiplied by <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, and sequentially from left to right in the second row, 4.76 is a PAPR value corresponding to a first 106-subcarrier resource block, and 4.23 is a PAPR value corresponding to a second 106-subcarrier resource block from left to right. Values in the third row, 4.73 and 4.79, are PAPR values corresponding to an HE-LTF sequence when values at data locations are all multiplied by w and values at pilot locations are all multiplied by +1, and sequentially from left to right in the third row, 4.73 is a PAPR value corresponding to a first 106-subcarrier resource block, and 4.79 is a PAPR value corresponding to a second 106-subcarrier resource block from left to right. Values in the fourth row, 4.87 and 4.38, are PAPR values corresponding to an HE-LTF sequence when values at data locations are all multiplied by w<com:Sup>2< / com:Sup> and values at pilot locations are all multiplied by +1, and sequentially from left to right in the fourth row, 4.87 is a PAPR value corresponding to a first 106-subcarrier resource block, and 4.38 is a PAPR value corresponding to a second 106-subcarrier resource block from left to right.

[0139] The fourth group of values, 5.31, 5.32, 5.48, and 5.46, are PAPR values corresponding to 242-subcarrier resource blocks in a fourth row. The first 5.31 is a PAPR value corresponding to an HE-LTF sequence when values at data locations are all multiplied by +1 and values at pilot locations are all multiplied by +1. The second 5.32 is a PAPR value corresponding to an HE-LTF sequence when values at data locations are all multiplied by <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math> and values at pilot locations are all multiplied by +1. The third 5.48 is a PAPR value corresponding to an HE-LTF sequence when values at data locations are all multiplied by w and values at pilot locations are all multiplied by +1. The first 5.46 is a PAPR value corresponding to an HE-LTF sequence when values at data locations are all multiplied by <com:Math><semantics>w2<annotation encoding="application / x-tex">w^2< / annotation>< / semantics>< / com:Math> and values at pilot locations are all multiplied by <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>.

[0140] A fourth HE-LTF sequence in the 2x mode: [Image disponible dans le document PDF, Image available in the PDF document]

[0141] The HE-LTF sequence includes the Gb sequence, sequences <com:Math><semantics>Gc<annotation encoding="application / x-tex">G_c< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>Gcp<annotation encoding="application / x-tex">G_c^p< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>Gbp<annotation encoding="application / x-tex">G_b^p< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>Gdp<annotation encoding="application / x-tex">G_d^p< / annotation>< / semantics>< / com:Math>, and <com:Math><semantics>Gd<annotation encoding="application / x-tex">G_d< / annotation>< / semantics>< / com:Math> that are generated according to the Ga sequence and the Gb sequence, and +1 or -1 that is located at a leftover leftover subcarrier location. Further, the HE-LTF sequence may further include consecutive <com:Math><semantics>−Gc<annotation encoding="application / x-tex">-G_c< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−Gcp<annotation encoding="application / x-tex">-G_c^p< / annotation>< / semantics>< / com:Math>, consecutive <com:Math><semantics>−Gbp<annotation encoding="application / x-tex">-G_b^p< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+Gb<annotation encoding="application / x-tex">+G_b< / annotation>< / semantics>< / com:Math>, consecutive <com:Math><semantics>+Gcp<annotation encoding="application / x-tex">+G_c^p< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+Gc<annotation encoding="application / x-tex">+G_c< / annotation>< / semantics>< / com:Math>, or consecutive <com:Math><semantics>−Gdp<annotation encoding="application / x-tex">-G_d^p< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+Gd<annotation encoding="application / x-tex">+G_d< / annotation>< / semantics>< / com:Math>.

[0142] In addition to using another sequence Equation manner, the HE-LTF sequence may also be directly stored as: [Image disponible dans le document PDF, Image available in the PDF document] •

[0143] PAPR values obtained by using the foregoing HE-LTF sequence are the same as those shown in FIG. 8b, and details are not described herein again. Embodiment 2

[0144] There are 512 subcarriers on a 2x symbol of a 40-MHz bandwidth. According to different resource block sizes, as shown in FIG. 1b, an RU size may be 26, 52, 106, 242, or 484 subcarriers.

[0145] There are many types of HE-LTF sequences in the 40-MHz 484-subcarrier 2X mode. Only several types of the HE-LTF sequences are listed below.

[0146] A first HE-LTF sequence in the 40-MHz 2X mode: [Image disponible dans le document PDF, Image available in the PDF document] [Image disponible dans le document PDF, Image available in the PDF document] [Image disponible dans le document PDF, Image available in the PDF document]

[0147] The HE-LTF sequence includes the Ga sequence and the Gb sequence, sequences <com:Math><semantics>Gc<annotation encoding="application / x-tex">^{G}{}_{c}< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>Gcp<annotation encoding="application / x-tex">G_c^p< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>Gap<annotation encoding="application / x-tex">G_a^p< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>Gbp<annotation encoding="application / x-tex">G_b^p< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>Gdp<annotation encoding="application / x-tex">G_d^p< / annotation>< / semantics>< / com:Math>, and <com:Math><semantics>Gd<annotation encoding="application / x-tex">G_d< / annotation>< / semantics>< / com:Math> that are generated according to the Ga sequence and the Gb sequence, and +1 or -1 that is located at a leftover leftover subcarrier location. Further, the HE-LTF sequence may further include: consecutive <com:Math><semantics>−Gc<annotation encoding="application / x-tex">{}^{-G_c}< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−Gc<annotation encoding="application / x-tex">{}^{-G_c}< / annotation>< / semantics>< / com:Math>, consecutive <com:Math><semantics>−Ga<annotation encoding="application / x-tex">{}^{-G_a}< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+Gap<annotation encoding="application / x-tex">{}^{+G_a^p}< / annotation>< / semantics>< / com:Math>, consecutive <com:Math><semantics>+Ga<annotation encoding="application / x-tex">+G_a< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+Gap<annotation encoding="application / x-tex">+G_a^p< / annotation>< / semantics>< / com:Math>, consecutive <com:Math><semantics>+Gcp<annotation encoding="application / x-tex">+G_c^p< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−Gc<annotation encoding="application / x-tex">-G_c< / annotation>< / semantics>< / com:Math>, consecutive <com:Math><semantics>+Gd<annotation encoding="application / x-tex">+G_d< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+Gdp<annotation encoding="application / x-tex">+G_d^p< / annotation>< / semantics>< / com:Math>, consecutive <com:Math><semantics>+Gbp<annotation encoding="application / x-tex">+G_b^p< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−Gd<annotation encoding="application / x-tex">-G_d< / annotation>< / semantics>< / com:Math>, consecutive <com:Math><semantics>+Gbp,−Gb<annotation encoding="application / x-tex">+G_b^p, -G_b< / annotation>< / semantics>< / com:Math>, consecutive <com:Math><semantics>+Gcp,+Gbp,+Gb<annotation encoding="application / x-tex">+G_c^p, +G_b^p, +G_b< / annotation>< / semantics>< / com:Math>, or consecutive <com:Math><semantics>+Gdp,−Gd<annotation encoding="application / x-tex">+G_d^p, -G_d< / annotation>< / semantics>< / com:Math>. For the content of the foregoing sequences, refer to sequences on a 2x symbol of the foregoing 40-MHz bandwidth.

[0148] In addition to using another Equation manner, the foregoing sequence may be further directly stored as: [Image disponible dans le document PDF, Image available in the PDF document]

[0149] A person skilled in the art knows that the foregoing sequence that is simply expressed by using the foregoing Equation should be: [Image disponible dans le document PDF, Image available in the PDF document] [Image disponible dans le document PDF, Image available in the PDF document] [Image disponible dans le document PDF, Image available in the PDF document] [Image disponible dans le document PDF, Image available in the PDF document]

[0150] FIG. 9 shows PAPR values of an HE-LTF sequence in the 40-MHz bandwidth. It may be learned, according to the group of PAPR values, that when different rotational phases are introduced in pilot subcarriers and other subcarriers, PAPR values are still very small.

[0151] The first group of values is sequentially PAPR values corresponding to 26-subcarrier resource blocks from left to right. Values in the first row, 2.76, 3.68, 2.76, 3.68, ..., are PAPR values corresponding to an HE-LTF sequence when values at data locations are all multiplied by +1 and values at pilot locations are all multiplied by +1, and sequentially from left to right in the first row, 2.76 is a PAPR value corresponding to a first 26-subcarrier resource block, 3.68 is a PAPR value corresponding to a second 26-subcarrier resource block from left to right, and so on. Values in the second row, 3.68, 2.76, 3.68, 2.76, ..., are PAPR values corresponding to an HE-LTF sequence when values at data locations are all multiplied by <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math> and values at pilot locations are all multiplied by <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, and sequentially from left to right in the second row, 3.68 is a PAPR value corresponding to a first 26-subcarrier resource block, 2.76 is a PAPR value corresponding to a second 26-subcarrier resource block from left to right, and so on. Values in the third row, 3.30, 4.46, 3.30, 4.46 ..., are PAPR values corresponding to an HE-LTF sequence when values at data locations are all multiplied by w and values at pilot locations are all multiplied by +1, and sequentially from left to right in the third row, 3.30 is a PAPR value corresponding to a first 26-subcarrier resource block, 4.46 is a PAPR value corresponding to a second 26-subcarrier resource block from left to right, and so on. Values in the fourth row, 4.46, 3.30, 4.46, 3.30, ..., are PAPR values corresponding to an HE-LTF sequence when values at data locations are all multiplied by w<com:Sup>2< / com:Sup> and values at pilot locations are all multiplied by +1, and sequentially from left to right in the fourth row, 4.46 is a PAPR value corresponding to a first 26-subcarrier resource block, 3.30 is a PAPR value corresponding to a second 26-subcarrier resource block from left to right, and so on.

[0152] The second group of values is sequentially PAPR values corresponding to 52-subcarrier resource blocks in a second row from left to right. Values in the first row, 4.68, 4.68, 4.34, 4.48, ..., are PAPR values corresponding to an HE-LTF sequence when values at data locations are all multiplied by +1 and values at pilot locations are all multiplied by +1, and sequentially from left to right in the first row, the first 4.68 is a PAPR value corresponding to the first 52-subcarrier resource block, the second 4.68 is a PAPR value corresponding to a second 52-subcarrier resource block from left to right, and so on. Values in the second row, 4.68, 4.68, 4.48, 4.34, ..., are PAPR values corresponding to an HE-LTF sequence when values at data locations are all multiplied by -1 and values at pilot locations are all multiplied by <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, and sequentially from left to right in the second row, the first 4.68 is a PAPR value corresponding to a first 52-subcarrier resource block, the second 4.68 is a PAPR value corresponding to a second 52-subcarrier resource block from left to right, and so on. Values in the third row, 4.69, 4.69, 4.35, 4.77, ..., are PAPR values corresponding to an HE-LTF sequence when values at data locations are all multiplied by w and values at pilot locations are all multiplied by +1, and sequentially from left to right in the third row, the first 4.69 is a PAPR value corresponding to a first 52-subcarrier resource block, the second 4.69 is a PAPR value corresponding to a second 52-subcarrier resource block from left to right, and so on. Values in the fourth row, 4.69, 4.69, 4.77, and 4.35, are PAPR values corresponding to an HE-LTF sequence when values at data locations are all multiplied by w<com:Sup>2< / com:Sup> and values at pilot locations are all multiplied by +1, and sequentially from left to right in the fourth row, the first 4.69 is a PAPR value corresponding to a first 52-subcarrier resource block, the second 4.69 is a PAPR value corresponding to a second 52-subcarrier resource block from left to right, and so on.

[0153] The third group of values is sequentially PAPR values corresponding to 106-subcarrier resource blocks in a third row from left to right. Values in the first row, 5.42, 4.34, 4.34, and 5.42, are PAPR values corresponding to an HE-LTF sequence when values at data locations are all multiplied by +1 and values at pilot locations are all multiplied by +1, and sequentially from left to right in the first row, 5.42 is a PAPR value corresponding to a first 106-subcarrier resource block, 4.34 is a PAPR value corresponding to a second 106-subcarrier resource block from left to right, and so on. Values in the second row, 4.85, 5.50, 5.50, and 4.85, are PAPR values corresponding to an HE-LTF sequence when values at data locations are all multiplied by -1 and values at pilot locations are all multiplied by +1, and sequentially from left to right in the second row, 4.85 is a PAPR value corresponding to a first 106-subcarrier resource block, 5.50 is a PAPR value corresponding to a second 106-subcarrier resource block from left to right, and so on. Values in the third row, 4.94, 4.63, 4.63, and 4.94, are PAPR values corresponding to an HE-LTF sequence when values at data locations are all multiplied by w and values at pilot locations are all multiplied by <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, and sequentially from left to right in the third row, 4.94 is a PAPR value corresponding to a first 106-subcarrier resource block, 4.63 is a PAPR value corresponding to a second 106-subcarrier resource block from left to right, and so on. Values in the fourth row, 4.68, 5.16, 5.16, and 4.68, are PAPR values corresponding to an HE-LTF sequence when values at data locations are all multiplied by <com:Math><semantics>w2<annotation encoding="application / x-tex">w^2< / annotation>< / semantics>< / com:Math> and values at pilot locations are all multiplied by <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, and sequentially from left to right in the fourth row, 4.68 is a PAPR value corresponding to a first 106-subcarrier resource block, and 5.16 is a PAPR value corresponding to a second 106-subcarrier resource block from left to right.

[0154] The fourth group of values is sequentially PAPR values corresponding to 242-subcarrier resource blocks from left to right in a third row. Values in the first row, 5.32 and 5.32, are PAPR values corresponding to an HE-LTF sequence when values at data locations are all multiplied by +1 and values at pilot locations are all multiplied by +1, and sequentially from left to right in the first row, the first 5.32 is a PAPR value corresponding to a first 242-subcarrier resource block, and the second 5.32 is a PAPR value corresponding to a second 242-subcarrier resource block from left to right. Values in the second row, 5.37 and 5.37, are PAPR values corresponding to an HE-LTF sequence when values at data locations are all multiplied by -1 and values at pilot locations are all multiplied by +1, and sequentially from left to right in the second row, the first 5.37 is a PAPR value corresponding to a first 242-subcarrier resource block, and the second 5.37 is a PAPR value corresponding to a second 242-subcarrier resource block from left to right. Values in the third row, 5.50 and 5.50, are PAPR values corresponding to an HE-LTF sequence when values at data locations are all multiplied by w and values at pilot locations are all multiplied by +1, and sequentially from left to right in the third row, the first 5.50 is a PAPR value corresponding to a first 242-subcarrier resource block, and the second 5.50 is a PAPR value corresponding to a second 242-subcarrier resource block from left to right. Values in the fourth row, 5.39 and 5.39, are PAPR values corresponding to an HE-LTF sequence when values at data locations are all multiplied by w<com:Sup>2< / com:Sup> and values at pilot locations are all multiplied by <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, and sequentially from left to right in the fourth row, the first 5.39 is a PAPR value corresponding to a first 242-subcarrier resource block, and the second 5.39 is a PAPR value corresponding to a second 242-subcarrier resource block from left to right.

[0155] The fifth group of values, 6.00, 4.98, 6.15, and 5.26, are PAPR values corresponding to 242-subcarrier resource blocks in a fourth row. The first 6.00 is a PAPR value corresponding to an HE-LTF sequence when values at data locations are all multiplied by +1 and values at pilot locations are all multiplied by +1. The second 4.98 is a PAPR value corresponding to an HE-LTF sequence when values at data locations are all multiplied by -1 and values at pilot locations are all multiplied by +1. The third 6.15 is a PAPR value corresponding to an HE-LTF sequence when values at data locations are all multiplied by w and values at pilot locations are all multiplied by +1. The first 5.26 is a PAPR value corresponding to an HE-LTF sequence when values at data locations are all multiplied by <com:Math><semantics>w2<annotation encoding="application / x-tex">w^2< / annotation>< / semantics>< / com:Math> and values at pilot locations are all multiplied by <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>.

[0156] A second HE-LTF sequence in the 40-MHz 2x mode: [Image disponible dans le document PDF, Image available in the PDF document] [Image disponible dans le document PDF, Image available in the PDF document] [Image disponible dans le document PDF, Image available in the PDF document]

[0157] The HE-LTF sequence includes the Ga sequence and the Gb sequence, sequences Gc, <com:Math><semantics>Gcp<annotation encoding="application / x-tex">G_{c}^{p}< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>Gdp<annotation encoding="application / x-tex">G_{d}^{p}< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>Gdp<annotation encoding="application / x-tex">G_{d}^{p}< / annotation>< / semantics>< / com:Math>, and <com:Math><semantics>Gdd<annotation encoding="application / x-tex">G_{d}^{d}< / annotation>< / semantics>< / com:Math> that are generated according to the Ga sequence and the Gb sequence, and +1 or -1 that is located at a leftover leftover subcarrier location.

[0158] Further, the HE-LTF sequence may include consecutive <com:Math><semantics>+Ga,−Gap<annotation encoding="application / x-tex">{}^{+G_a, -G_a^p}< / annotation>< / semantics>< / com:Math>, consecutive <com:Math><semantics>−Gc,−Gcp,−Gbp<annotation encoding="application / x-tex">-G_c, -G_c^p, -G_b^p< / annotation>< / semantics>< / com:Math>, consecutive <com:Math><semantics>+Gc,−Gcp<annotation encoding="application / x-tex">+G_c, -G_c^p< / annotation>< / semantics>< / com:Math>, consecutive <com:Math><semantics>−Gap,−Ga<annotation encoding="application / x-tex">-G_a^p, -G_a< / annotation>< / semantics>< / com:Math>, consecutive <com:Math><semantics>+Gb,−Gbp<annotation encoding="application / x-tex">+G_b, -G_b^p< / annotation>< / semantics>< / com:Math>, consecutive <com:Math><semantics>−Gdp<annotation encoding="application / x-tex">-G_d^p< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−Gd<annotation encoding="application / x-tex">-G_d< / annotation>< / semantics>< / com:Math>, consecutive <com:Math><semantics>+Gap<annotation encoding="application / x-tex">+G_a^p< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−Gdp<annotation encoding="application / x-tex">-G_d^p< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+Gd<annotation encoding="application / x-tex">+G_d< / annotation>< / semantics>< / com:Math>, or consecutive <com:Math><semantics>+Gbp<annotation encoding="application / x-tex">+G_b^p< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+Gb<annotation encoding="application / x-tex">+G_b< / annotation>< / semantics>< / com:Math>.

[0159] Similarly, the HE-LTF sequence may be directly stored as: <com:Math><semantics>HELTF2x(−244:2:244)=<annotation encoding="application / x-tex">HELTF_{2x}(-244:2:244) =< / annotation>< / semantics>< / com:Math> <com:Math><semantics>[+1,+1,+1,+1,−1,+1,+1,+1,−1,+1,−1,−1,+1,−1,−1,+1,−1,−1,+1,+1,+1,+1,+1,+1,+1,+1,+1,+<annotation encoding="application / x-tex">[+1, +1, +1, +1, -1, +1, +1, +1, -1, +1, -1, -1, +1, -1, -1, +1, -1, -1, +1, +1, +1, +1, +1, +1, +1, +1, +1, +< / annotation>< / semantics>< / com:Math> <com:Math><semantics>−1,+1,+1,−1,−1,−1,+1,−1,+1,−1,+1,+1,−1,+1,<annotation encoding="application / x-tex">-1, +1, +1, -1, -1, -1, +1, -1, +1, -1, +1, +1, -1, +1,< / annotation>< / semantics>< / com:Math> <com:Math><semantics>−1,−1,−1,+1,−1,−1,−1,−1,+1,+1,+1,−1,+1,+1,−1,<annotation encoding="application / x-tex">-1, -1, -1, +1, -1, -1, -1, -1, +1, +1, +1, -1, +1, +1, -1,< / annotation>< / semantics>< / com:Math> <com:Math><semantics>−1,+1,−1,−1,−1,+1,+1,+1,+1,−1,−1,−1,−1,+1,+1,<annotation encoding="application / x-tex">-1, +1, -1, -1, -1, +1, +1, +1, +1, -1, -1, -1, -1, +1, +1,< / annotation>< / semantics>< / com:Math> <com:Math><semantics>+1,−1,+1,+1,−1,−1,+1,−1,+1,+1,+1,+1,+1,+1,+1,+1,+1,+<annotation encoding="application / x-tex">+1, -1, +1, +1, -1, -1, +1, -1, +1, +1, +1, +1, +1, +1, +1, +1, +1, +< / annotation>< / semantics>< / com:Math> <com:Math><semantics>+1,+1,+1,−1,−1,−1,−1,+1,+1,−1,−1,+1,−1,−1,−1,<annotation encoding="application / x-tex">+1, +1, +1, -1, -1, -1, -1, +1, +1, -1, -1, +1, -1, -1, -1,< / annotation>< / semantics>< / com:Math> <com:Math><semantics>+1,+1,+1,+1,+1,−1,−1,+1,+1,−1,−1,−1,+1,−1,−1,<annotation encoding="application / x-tex">+1, +1, +1, +1, +1, -1, -1, +1, +1, -1, -1, -1, +1, -1, -1,< / annotation>< / semantics>< / com:Math> <com:Math><semantics>+1,−1,+1,−1,−1,−1,+1,−1,−1,+1,−1,+1,−1,<annotation encoding="application / x-tex">+1, -1, +1, -1, -1, -1, +1, -1, -1, +1, -1, +1, -1,< / annotation>< / semantics>< / com:Math> <com:Math><semantics>+1,0,0,0,+1,+1,+1,−1,−1,−1,+1,−1,−1,−1,<annotation encoding="application / x-tex">+1,0,0,0,+1,+1,+1,-1,-1,-1,+1,-1,-1,-1,< / annotation>< / semantics>< / com:Math> <com:Math><semantics>+1,−1,−1,−1,−1,−1,+1,+1,+1,−1,+1,+1,−1,−1,+1,<annotation encoding="application / x-tex">+1, -1, -1, -1, -1, -1, +1, +1, +1, -1, +1, +1, -1, -1, +1,< / annotation>< / semantics>< / com:Math> <com:Math><semantics>+1,−1,+1,−1,+1,+1,−1,+1,+1,−1,−1,+1,+1,−1,<annotation encoding="application / x-tex">+1, -1, +1, -1, +1, +1, -1, +1, +1, -1, -1, +1, +1, -1,< / annotation>< / semantics>< / com:Math> <com:Math><semantics>+1,−1,−1,+1,−1,+1,+1,+1,+1,+1,+1,+1,+1,+1,+<annotation encoding="application / x-tex">+1, -1, -1, +1, -1, +1, +1, +1, +1, +1, +1, +1, +1, +1, +< / annotation>< / semantics>< / com:Math> <com:Math><semantics>−1,−1,+1,+1,+1,−1,+1,+1,−1,+1,−1,+1,−1,+1,<annotation encoding="application / x-tex">-1, -1, +1, +1, +1, -1, +1, +1, -1, +1, -1, +1, -1, +1,< / annotation>< / semantics>< / com:Math> <com:Math><semantics>+1,−1,+1,+1,+1,−1,−1,+1,+1,+1,−1,+1,+1,−1,+1,<annotation encoding="application / x-tex">+1, -1, +1, +1, +1, -1, -1, +1, +1, +1, -1, +1, +1, -1, +1,< / annotation>< / semantics>< / com:Math> <com:Math><semantics>−1,−1,−1,+1,−1,−1,−1,−1,+1,+1,+1,+1,−1,−1,−1,<annotation encoding="application / x-tex">-1, -1, -1, +1, -1, -1, -1, -1, +1, +1, +1, +1, -1, -1, -1,< / annotation>< / semantics>< / com:Math> <com:Math><semantics>+1,−1,−1,+1,+1,−1,+1,+1,−1,−1,−1,−1,+1,−1,<annotation encoding="application / x-tex">+1,-1,-1,+1,+1,-1,+1,+1,-1,-1,-1,-1,+1,-1,< / annotation>< / semantics>< / com:Math> <com:Math><semantics>−1,−1,+1,−1,+1<annotation encoding="application / x-tex">-1, -1, +1, -1, +1< / annotation>< / semantics>< / com:Math>

[0160] A person skilled in the art knows that the foregoing sequence that is simply expressed by using the foregoing Equation should be: [Image disponible dans le document PDF, Image available in the PDF document] [Image disponible dans le document PDF, Image available in the PDF document] [Image disponible dans le document PDF, Image available in the PDF document]

[0161] PAPR values obtained by using the foregoing HE-LTF sequence are the same as those shown in FIG. 9, and details are not described again. Embodiment 3

[0162] There are 256 subcarriers on a 2x symbol of an 80-MHz bandwidth. According to different resource block sizes, as shown in FIG. 1c, an RU size may be 26, 52, 106, 242, 484, or 996 subcarriers.

[0163] There may be many types of HE-LTF sequences for 2x symbol of the 996 subcarriers in an 80 MHz transmission. Several types of the HE-LTF sequences are listed as follows:

[0164] A first 2x HE-LTF sequence in an 80 MHz transmission is: [Image disponible dans le document PDF, Image available in the PDF document]

[0165] The HE-LTF sequence includes the <com:Math><semantics>Ga<annotation encoding="application / x-tex">G_a< / annotation>< / semantics>< / com:Math> sequence and the <com:Math><semantics>Gb<annotation encoding="application / x-tex">G_b< / annotation>< / semantics>< / com:Math> sequence, sequences <com:Math><semantics>Gap<annotation encoding="application / x-tex">G_a^p< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>Gcp<annotation encoding="application / x-tex">G_c^p< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>Gbp<annotation encoding="application / x-tex">G_b^p< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>Gdp<annotation encoding="application / x-tex">G_d^p< / annotation>< / semantics>< / com:Math>, and <com:Math><semantics>Gdp<annotation encoding="application / x-tex">G_d^p< / annotation>< / semantics>< / com:Math> that are generated according to the <com:Math><semantics>Gap<annotation encoding="application / x-tex">G_a^p< / annotation>< / semantics>< / com:Math> sequence and the G<com:Sub>b< / com:Sub> sequence, and +1 or -1 that is located at a leftover leftover subcarrier location. Further, the HE-LTF sequence may further include consecutive <com:Math><semantics>−Ga,+Gap<annotation encoding="application / x-tex">{}^{-G_a,+G_a^p}< / annotation>< / semantics>< / com:Math>, consecutive <com:Math><semantics>+Gc,+Gcp,+Gb<annotation encoding="application / x-tex">{}^{+G_c,+G_c^p,+G_b}< / annotation>< / semantics>< / com:Math>, consecutive <com:Math><semantics>+Gap,−Ga<annotation encoding="application / x-tex">+G_a^p, -G_a< / annotation>< / semantics>< / com:Math>, consecutive <com:Math><semantics>−Gcp,−Gc<annotation encoding="application / x-tex">-G_c^p, -G_c< / annotation>< / semantics>< / com:Math>, consecutive <com:Math><semantics>−Gc,−Gcp<annotation encoding="application / x-tex">-G_c, -G_c^p< / annotation>< / semantics>< / com:Math>, consecutive <com:Math><semantics>−Ga,+Gap,−Gd<annotation encoding="application / x-tex">-G_a, +G_a^p, -G_d< / annotation>< / semantics>< / com:Math>, consecutive <com:Math><semantics>−Gcp,−Gc<annotation encoding="application / x-tex">-G_c^p, -G_c< / annotation>< / semantics>< / com:Math>, consecutive <com:Math><semantics>−Gap,+Ga<annotation encoding="application / x-tex">-G_a^p, +G_a< / annotation>< / semantics>< / com:Math>, consecutive <com:Math><semantics>+Gd,−Gdp<annotation encoding="application / x-tex">+G_d, -G_d^p< / annotation>< / semantics>< / com:Math>, consecutive <com:Math><semantics>−Gb,−Gbp<annotation encoding="application / x-tex">-G_b, -G_b^p< / annotation>< / semantics>< / com:Math>, consecutive <com:Math><semantics>−Ga,−Gdp,−Gd<annotation encoding="application / x-tex">-G_a, -G_d^p, -G_d< / annotation>< / semantics>< / com:Math>, consecutive <com:Math><semantics>−Ga,+Gdp,−Gd<annotation encoding="application / x-tex">-G_a, +G_d^p, -G_d< / annotation>< / semantics>< / com:Math>, consecutive <com:Math><semantics>−Gbp,−Gb<annotation encoding="application / x-tex">-G_b^p, -G_b< / annotation>< / semantics>< / com:Math>, consecutive <com:Math><semantics>Gb,+Gbp<annotation encoding="application / x-tex">G_b, +G_b^p< / annotation>< / semantics>< / com:Math>, consecutive <com:Math><semantics>+Gd,−Gdp<annotation encoding="application / x-tex">+G_d, -G_d^p< / annotation>< / semantics>< / com:Math>, consecutive <com:Math><semantics>−Gc,−Gbp,−Gb<annotation encoding="application / x-tex">-G_c, -G_b^p, -G_b< / annotation>< / semantics>< / com:Math>, or consecutive <com:Math><semantics>−Gdp<annotation encoding="application / x-tex">-G_d^p< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+Gd<annotation encoding="application / x-tex">+G_d< / annotation>< / semantics>< / com:Math>

[0166] Certainly, the HE-LTF sequence may also be stored as: <com:Math><semantics>HELTF2x(−500:2:500)=<annotation encoding="application / x-tex">HELTF_{2x}(-500:2:500) =< / annotation>< / semantics>< / com:Math> <com:Math><semantics>[+1,−1,−1,−1,+1,−1,−1,+1,+1,+1,+1,+1,+1,+1,+1,+1,+1,+1,+1,+1<annotation encoding="application / x-tex">[+1,-1,-1,-1,+1,-1,-1,+1,+1,+1,+1,+1,+1,+1,+1,+1,+1,+1,+1,+1< / annotation>< / semantics>< / com:Math> <com:Math><semantics>+1,−1,−1,+1,+1,+1,−1,+1,−1,+1,−1,+1,−1,+1,−1,<annotation encoding="application / x-tex">+1,-1,-1,+1,+1,+1,-1,+1,-1,+1,-1,+1,-1,+1,-1,< / annotation>< / semantics>< / com:Math> <com:Math><semantics>+1,+1,+1,−1,+1,+1,+1,+1,−1,−1,−1,+1,−1,−1,+1,<annotation encoding="application / x-tex">+1, +1, +1, -1, +1, +1, +1, +1, -1, -1, -1, +1, -1, -1, +1,< / annotation>< / semantics>< / com:Math> <com:Math><semantics>+1,−1,+1,+1,+1,−1,−1,−1,+1,+1,+1,+1,−1,−1,−1,<annotation encoding="application / x-tex">+1,-1,+1,+1,+1,-1,-1,-1,+1,+1,+1,+1,-1,-1,-1,< / annotation>< / semantics>< / com:Math> <com:Math><semantics>−1,+1,−1,−1,−1,+1,−1,+1,+1,+1,−1,−1,+1,+1,+1,<annotation encoding="application / x-tex">-1, +1, -1, -1, -1, +1, -1, +1, +1, +1, -1, -1, +1, +1, +1,< / annotation>< / semantics>< / com:Math> <com:Math><semantics>−1,+1,+1,−1,+1,−1,−1,−1,−1,+1,−1,−1,+1,−1,<annotation encoding="application / x-tex">-1, +1, +1, -1, +1, -1, -1, -1, -1, +1, -1, -1, +1, -1,< / annotation>< / semantics>< / com:Math> <com:Math><semantics>+1,+1,−1,+1,+1,−1,+1,+1,−1,−1,+1,−1,−1,+1,<annotation encoding="application / x-tex">+1, +1, -1, +1, +1, -1, +1, +1, -1, -1, +1, -1, -1, +1,< / annotation>< / semantics>< / com:Math> <com:Math><semantics>+1,+1,+1,−1,+1,−1,−1,−1,+1,−1,−1,−1,−1,+1,+1,<annotation encoding="application / x-tex">+1, +1, +1, -1, +1, -1, -1, -1, +1, -1, -1, -1, -1, +1, +1,< / annotation>< / semantics>< / com:Math> <com:Math><semantics>+1,−1,−1,+1,−1,−1,+1,−1,−1,−1,+1,+1,+1,+1<annotation encoding="application / x-tex">+1,-1,-1,+1,-1,-1,+1,-1,-1,-1,+1,+1,+1,+1< / annotation>< / semantics>< / com:Math> <com:Math><semantics>−1,+1,+1,−1,−1,+1,−1,−1,−1,+1,+1,+1,+1,−1,−1,<annotation encoding="application / x-tex">-1, +1, +1, -1, -1, +1, -1, -1, -1, +1, +1, +1, +1, -1, -1,< / annotation>< / semantics>< / com:Math> <com:Math><semantics>−1,−1,+1,−1,−1,−1,+1,−1,+1,+1,−1,+1,+1,+1,−1,<annotation encoding="application / x-tex">-1, -1, +1, -1, -1, -1, +1, -1, +1, +1, -1, +1, +1, +1, -1,< / annotation>< / semantics>< / com:Math> <com:Math><semantics>−1,+1,+1,+1,−1,+1,+1,−1,+1,−1,−1,+1,−1,−1,+1,<annotation encoding="application / x-tex">-1, +1, +1, +1, -1, +1, +1, -1, +1, -1, -1, +1, -1, -1, +1,< / annotation>< / semantics>< / com:Math> <com:Math><semantics>−1,+1,+1,+1,−1,+1,+1,+1,+1,−1,+1,+1,−1,−1,+1,<annotation encoding="application / x-tex">-1, +1, +1, +1, -1, +1, +1, +1, +1, -1, +1, +1, -1, -1, +1,< / annotation>< / semantics>< / com:Math> <com:Math><semantics>−1,−1,−1,+1,+1,+1,+1,−1,+1,−1,−1,−1,+1,−1,−1,<annotation encoding="application / x-tex">-1, -1, -1, +1, +1, +1, +1, -1, +1, -1, -1, -1, +1, -1, -1,< / annotation>< / semantics>< / com:Math> <com:Math><semantics>−1,−1,+1,+1,+1,−1,−1,−1,+1,+1,−1,−1,−1,+1,−1,<annotation encoding="application / x-tex">-1, -1, +1, +1, +1, -1, -1, -1, +1, +1, -1, -1, -1, +1, -1,< / annotation>< / semantics>< / com:Math> <com:Math><semantics>−1,+1,−1,+1,+1,+1,+1,−1,+1,+1,+1,−1,+1,−1,−1,−1,<annotation encoding="application / x-tex">-1, +1, -1, +1, +1, +1, +1, -1, +1, +1, +1, -1, +1, -1, -1, -1,< / annotation>< / semantics>< / com:Math> <com:Math><semantics>+1,−1,+1,+1,−1,+1,+1,−1,+1,0,0,0,+1,+1,−1,<annotation encoding="application / x-tex">+1, -1, +1, +1, -1, +1, +1, -1, +1, 0, 0, 0, +1, +1, -1,< / annotation>< / semantics>< / com:Math> <com:Math><semantics>−1,+1,+1,+1,+1,−1,+1,+1,−1,+1,−1,−1,−1,+1,−1,<annotation encoding="application / x-tex">-1, +1, +1, +1, +1, -1, +1, +1, -1, +1, -1, -1, -1, +1, -1,< / annotation>< / semantics>< / com:Math> <com:Math><semantics>−1,−1,−1,+1,−1,+1,+1,−1,+1,+1,−1,−1,+1,+1,<annotation encoding="application / x-tex">-1, -1, -1, +1, -1, +1, +1, -1, +1, +1, -1, -1, +1, +1,< / annotation>< / semantics>< / com:Math> <com:Math><semantics>+1,−1,−1,−1,+1,+1,+1,+1,−1,+1,+1,+1,−1,+1,−1,<annotation encoding="application / x-tex">+1, -1, -1, -1, +1, +1, +1, +1, -1, +1, +1, +1, -1, +1, -1,< / annotation>< / semantics>< / com:Math> <com:Math><semantics>−1,−1,−1,+1,+1,+1,−1,+1,+1,−1,−1,+1,−1,−1,−1,<annotation encoding="application / x-tex">-1, -1, -1, +1, +1, +1, -1, +1, +1, -1, -1, +1, -1, -1, -1,< / annotation>< / semantics>< / com:Math> <com:Math><semantics>−1,+1,−1,−1,−1,+1,−1,+1,+1,−1,+1,−1,+1,−1,<annotation encoding="application / x-tex">-1, +1, -1, -1, -1, +1, -1, +1, +1, -1, +1, -1, +1, -1,< / annotation>< / semantics>< / com:Math> <com:Math><semantics>−1,+1,−1,−1,−1,+1,+1,−1,−1,−1,+1,−1,−1,+1,−1,<annotation encoding="application / x-tex">-1, +1, -1, -1, -1, +1, +1, -1, -1, -1, +1, -1, -1, +1, -1,< / annotation>< / semantics>< / com:Math> <com:Math><semantics>+1,+1,+1,−1,+1,+1,+1,+1,−1,−1,−1,−1,+1,+1,+1,<annotation encoding="application / x-tex">+1, +1, +1, -1, +1, +1, +1, +1, -1, -1, -1, -1, +1, +1, +1,< / annotation>< / semantics>< / com:Math> <com:Math><semantics>−1,+1,+1,−1,−1,+1,−1,−1,−1,+1,+1,+1,+1,+1,+1,+1,<annotation encoding="application / x-tex">-1, +1, +1, -1, -1, +1, -1, -1, -1, +1, +1, +1, +1, +1, +1, +1,< / annotation>< / semantics>< / com:Math> <com:Math><semantics>+1,+1,−1,+1,+1,+1,+1,+1,−1,−1,−1,−1,+1,−1,−1,<annotation encoding="application / x-tex">+1, +1, -1, +1, +1, +1, +1, +1, -1, -1, -1, -1, +1, -1, -1,< / annotation>< / semantics>< / com:Math> <com:Math><semantics>−1,+1,−1,+1,+1,+1,+1,−1,−1,−1,+1,−1,−1,+1,+1,<annotation encoding="application / x-tex">-1, +1, -1, +1, +1, +1, +1, -1, -1, -1, +1, -1, -1, +1, +1,< / annotation>< / semantics>< / com:Math> <com:Math><semantics>−1,+1,+1,−1,+1,+1,−1,+1,−1,−1,−1,+1,−1,−1,−1,<annotation encoding="application / x-tex">-1, +1, +1, -1, +1, +1, -1, +1, -1, -1, -1, +1, -1, -1, -1,< / annotation>< / semantics>< / com:Math> <com:Math><semantics>−1,+1,−1,+1,+1,−1,+1,+1,+1,−1,−1,+1,+1,+1,−1,<annotation encoding="application / x-tex">-1, +1, -1, +1, +1, -1, +1, +1, +1, -1, -1, +1, +1, +1, -1,< / annotation>< / semantics>< / com:Math> <com:Math><semantics>+1,−1,−1,−1,+1,−1,−1,−1,+1,+1,+1,+1,−1,−1,−1,<annotation encoding="application / x-tex">+1,-1,-1,-1,+1,-1,-1,-1,+1,+1,+1,+1,-1,-1,-1,< / annotation>< / semantics>< / com:Math> <com:Math><semantics>−1,+1,+1,+1,−1,+1,+1,−1,−1,+1,−1,−1,−1,+1,+1,<annotation encoding="application / x-tex">-1, +1, +1, +1, -1, +1, +1, -1, -1, +1, -1, -1, -1, +1, +1,< / annotation>< / semantics>< / com:Math> <com:Math><semantics>+1,+1,−1,+1,+1,+1,−1,+1,−1,+1,−1,+1,−1,+1,−1,<annotation encoding="application / x-tex">+1, +1, -1, +1, +1, +1, -1, +1, -1, +1, -1, +1, -1, +1, -1,< / annotation>< / semantics>< / com:Math> <com:Math><semantics>+1,+1,+1,−1,−1,+1,+1,+1,−1,+1,+1,−1,+1,−1,−1,<annotation encoding="application / x-tex">+1, +1, +1, -1, -1, +1, +1, +1, -1, +1, +1, -1, +1, -1, -1,< / annotation>< / semantics>< / com:Math> <com:Math><semantics>−1,+1,−1,−1,−1,+1<annotation encoding="application / x-tex">-1, +1, -1, -1, -1, +1< / annotation>< / semantics>< / com:Math>

[0167] A person skilled in the art knows that the foregoing sequence that is simply expressed by using the foregoing Equation should be: [Image disponible dans le document PDF, Image available in the PDF document]

[0168] FIG. 10 shows PAPR values of an HE-LTF sequence in the 80-MHz bandwidth. It may be learned, according to the group of PAPR values, that when different rotational phases are introduced in pilot subcarriers and other subcarriers, PAPR values are still very small.

[0169] The first group of values is sequentially PAPR values corresponding to 26-subcarrier resource blocks from left to right. Values in the first row, 2.76, 3.68, 2.76, 3.68, ..., are PAPR values corresponding to an HE-LTF sequence when values at data locations are all multiplied by +1 and values at pilot locations are all multiplied by +1, and sequentially from left to right in the first row, 2.76 is a PAPR value corresponding to a first 26-subcarrier resource block, 3.68 is a PAPR value corresponding to a second 26-subcarrier resource block from left to right, and so on. Values in the second row, 3.68, 2.76, 3.68, 2.76, ..., are PAPR values corresponding to an HE-LTF sequence when values at data locations are all multiplied by <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math> and values at pilot locations are all multiplied by <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, and sequentially from left to right in the second row, 3.68 is a PAPR value corresponding to a first 26-subcarrier resource block, 2.76 is a PAPR value corresponding to a second 26-subcarrier resource block from left to right, and so on. Values in the third row, 3.30, 4.46, 3.30, 4.46, ..., are PAPR values corresponding to an HE-LTF sequence when values at data locations are all multiplied by w and values at pilot locations are all multiplied by +1, and sequentially from left to right in the third row, 3.30 is a PAPR value corresponding to a first 26-subcarrier resource block, 4.46 is a PAPR value corresponding to a second 26-subcarrier resource block from left to right, and so on. Values in the fourth row, 4.46, 3.30, 4.46, 3.30, ..., are PAPR values corresponding to an HE-LTF sequence when values at data locations are all multiplied by w<com:Sup>2< / com:Sup> and values at pilot locations are all multiplied by +1, and sequentially from left to right in the fourth row, 4.46 is a PAPR value corresponding to a first 26-subcarrier resource block, 3.30 is a PAPR value corresponding to a second 26-subcarrier resource block from left to right, and so on.

[0170] The second group of values is sequentially PAPR values corresponding to 52-subcarrier resource blocks in a second row from left to right. Values in the first row, 4.68, 4.68, 4.69, 4.69, ..., are PAPR values corresponding to an HE-LTF sequence when values at data locations are all multiplied by +1 and values at pilot locations are all multiplied by +1, and sequentially from left to right in the first row, the first 4.68 is a PAPR value corresponding to a first 52-subcarrier resource block, the second 4.68 is a PAPR value corresponding to a second 52-subcarrier resource block from left to right, and so on. Values in the second row, 4.68, 4.69, 4.69, ..., are PAPR values corresponding to an HE-LTF sequence when values at data locations are all multiplied by -1 and values at pilot locations are all multiplied by <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, and sequentially from left to right in the second row, the first 4.68 is a PAPR value corresponding to a first 52-subcarrier resource block, the second 4.68 is a PAPR value corresponding to a second 52-subcarrier resource block from left to right, and so on. Values in the third row, 4.68, 4.68, 4.69, 4.69, ..., are PAPR values corresponding to an HE-LTF sequence when values at data locations are all multiplied by w and values at pilot locations are all multiplied by +1, and sequentially from left to right in the third row, the first 4.68 is a PAPR value corresponding to a first 52-subcarrier resource block, the second 4.68 is a PAPR value corresponding to a second 52-subcarrier resource block from left to right, and so on. Values in the fourth row, 4.68, 4.69, and 4.69, are PAPR values corresponding to an HE-LTF sequence when values at data locations are all multiplied by w<com:Sup>2< / com:Sup> and values at pilot locations are all multiplied by +1, and sequentially from left to right in the fourth row, the first 4.68 is a PAPR value corresponding to a first 52-subcarrier resource block, the second 4.68 is a PAPR value corresponding to a second 52-subcarrier resource block from left to right, and so on.

[0171] The third group of values is sequentially PAPR values corresponding to 106-subcarrier resource blocks in a third row from left to right. Values in the first row, 5.42, 5.33, 5.42, 5.33 ..., are PAPR values corresponding to an HE-LTF sequence when values at data locations are all multiplied by +1 and values at pilot locations are all multiplied by +1, and sequentially from left to right in the first row, 5.42 is a PAPR value corresponding to a first 106-subcarrier resource block, 5.33 is a PAPR value corresponding to a second 106-subcarrier resource block from left to right, and so on. Values in the second row, 4.85, 5.41, 4.85, 5.41, ..., are that PAPR values corresponding to an HE-LTF sequence when values at data locations are all multiplied by -1 and values at pilot locations are all multiplied by +1, and sequentially from left to right in the second row, 4.85 is a PAPR value corresponding to a first 106-subcarrier resource block, 5.50 is a PAPR value corresponding to a second 106-subcarrier resource block from left to right, and so on. Values in the third row, 4.95, 5.18, 4.95, 5.18, ..., are PAPR values corresponding to an HE-LTF sequence when values at data locations are all multiplied by w and values at pilot locations are all multiplied by +1, and sequentially from left to right in the third row, 4.95 is a PAPR value corresponding to a first 106-subcarrier resource block, 5.18 is a PAPR value corresponding to a second 106-subcarrier resource block from left to right, and so on. Values in the fourth row, 4.68, 4.97, 4.68, 4.97, ..., are PAPR values corresponding to an HE-LTF sequence when values at data locations are all multiplied by <com:Math><semantics>w2<annotation encoding="application / x-tex">w^2< / annotation>< / semantics>< / com:Math> and values at pilot locations are all multiplied by <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, and sequentially from left to right in the fourth row, 4.68 is a PAPR value corresponding to a first 106-subcarrier resource block, and 4.97 is a PAPR value corresponding to a second 106-subcarrier resource block from left to right.

[0172] The fourth group of values is sequentially PAPR values corresponding to 242-subcarrier resource blocks from left to right in a fourth row. Values in the first row, 5.29 and 5.29, are that PAPR values corresponding to an HE-LTF sequence when values at data locations are all multiplied by +1 and values at pilot locations are all multiplied by +1, and sequentially from left to right in the first row, the first 5.29 is a PAPR value corresponding to a first 242-subcarrier resource block, and the second 5.29 is a PAPR value corresponding to a second 242-subcarrier resource block from left to right. Values in the second row, 5.58 and 5.58, are PAPR values corresponding to an HE-LTF sequence when values at data locations are all multiplied by <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math> and values at pilot locations are all multiplied by +1, and sequentially from left to right in the second row, the first 5.58 is a PAPR value corresponding to a first 242-subcarrier resource block, the second 5.58 is a PAPR value corresponding to a second 242-subcarrier resource block from left to right. Values in the third row, 5.40 and 5.40, are PAPR values corresponding to an HE-LTF sequence when values at data locations are all multiplied by w and values at pilot locations are all multiplied by +1, and sequentially from left to right in the third row, the first 5.40 is a PAPR value corresponding to a first 242-subcarrier resource block, and the second 5.40 is a PAPR value corresponding to a second 242-subcarrier resource block from left to right. Values in the fourth row, 5.46 and 5.46, are PAPR values corresponding to an HE-LTF sequence when values at data locations are all multiplied by w<com:Sup>2< / com:Sup> and values at pilot locations are all multiplied by <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, and sequentially from left to right in the fourth row, the first 5.46 is a PAPR value corresponding to a first 242-subcarrier resource block, and the second 5.46 is a PAPR value corresponding to a second 242-subcarrier resource block from left to right.

[0173] The fifth group of values is sequentially PAPR values corresponding to 484-subcarrier resource blocks in a fifth row from left to right. Values in the first row, 6.27 and 6.13, are PAPR values corresponding to an HE-LTF sequence when values at data locations are all multiplied by +1 and values at pilot locations are all multiplied by +1, and sequentially from left to right in the first row, 6.27 is a PAPR value corresponding to a first 484-subcarrier resource block, and 6.13 is a PAPR value corresponding to a second 484-subcarrier resource block from left to right. Values in the second row, 6.11 and 6.40, are PAPR values corresponding to an HE-LTF sequence when values at data locations are all multiplied by <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math> and values at pilot locations are all multiplied by <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, and sequentially from left to right in the second row, 6.11 is a PAPR value corresponding to a first 242-subcarrier resource block, and 6.40 is a PAPR value corresponding to a second 484-subcarrier resource block from left to right. Values in the third row, 6.24 and 6.34, are PAPR values corresponding to an HE-LTF sequence when values at data locations are all multiplied by w and values at pilot locations are all multiplied by +1, and sequentially from left to right in the third row, 6.24 is a PAPR value corresponding to a first 484-subcarrier resource block, and 6.34 is a PAPR value corresponding to a second 484-subcarrier resource block from left to right. Values in the fourth row, 6.29 and 6.25, are PAPR values corresponding to an HE-LTF sequence when values at data locations are all multiplied by w<com:Sup>2< / com:Sup> and values at pilot locations are all multiplied by +1, and sequentially from left to right in the fourth row, 6.29 is a PAPR value corresponding to a first 484-subcarrier resource block, and 6.25 is a PAPR value corresponding to a second 484-subcarrier resource block from left to right.

[0174] The sixth group of values, 6.01, 5.68, 6.08, and 5.92, are PAPR values corresponding to 996-subcarrier resource blocks in a sixth row. The first 6.08 is a PAPR value corresponding to an HE-LTF sequence when values at data locations are all multiplied by +1 and values at pilot locations are all multiplied by +1. The second 5.68 is a PAPR value corresponding to an HE-LTF sequence when values at data locations are all multiplied by <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math> and values at pilot locations are all multiplied by +1. The third 6.08 is a PAPR value corresponding to an HE-LTF sequence when values at data locations are all multiplied by w and values at pilot locations are all multiplied by +1. The fourth 5.92 is a PAPR value corresponding to an HE-LTF sequence when values at data locations are all multiplied by <com:Math><semantics>w2<annotation encoding="application / x-tex">w^2< / annotation>< / semantics>< / com:Math> and values at pilot locations are all multiplied by <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>.

[0175] A second HE-LTF sequence in 80 MHz 2X: [Image disponible dans le document PDF, Image available in the PDF document]

[0176] The HE-LTF sequence includes the <com:Math><semantics>Ga<annotation encoding="application / x-tex">G_a< / annotation>< / semantics>< / com:Math> sequence and the <com:Math><semantics>Gb<annotation encoding="application / x-tex">G_b< / annotation>< / semantics>< / com:Math> sequence, sequences <com:Math><semantics>Gap<annotation encoding="application / x-tex">G_a^p< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>Gcp<annotation encoding="application / x-tex">G_c^p< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>Gbp<annotation encoding="application / x-tex">G_b^p< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>Gdp<annotation encoding="application / x-tex">G_d^p< / annotation>< / semantics>< / com:Math>, and <com:Math><semantics>Gdp<annotation encoding="application / x-tex">G_d^p< / annotation>< / semantics>< / com:Math> that are generated according to the <com:Math><semantics>Gap<annotation encoding="application / x-tex">G_a^p< / annotation>< / semantics>< / com:Math> sequence and the G<com:Sub>b< / com:Sub> sequence, and +1 or -1 that is located at a leftover leftover subcarrier location. Further, the HE-LTF sequence may further include consecutive <com:Math><semantics>+Gc,+Gcp<annotation encoding="application / x-tex">{}^{+G_c, +G_c^p}< / annotation>< / semantics>< / com:Math>, consecutive <com:Math><semantics>+Ga,−Gap,+Gd<annotation encoding="application / x-tex">{}^{+G_a, -G_a^p, +G_d}< / annotation>< / semantics>< / com:Math>, consecutive <com:Math><semantics>+Gcp,+Gc<annotation encoding="application / x-tex">+G_c^p,+G_c< / annotation>< / semantics>< / com:Math>, consecutive <com:Math><semantics>+Gap,−Ga<annotation encoding="application / x-tex">+G_a^p,-G_a< / annotation>< / semantics>< / com:Math>, consecutive <com:Math><semantics>−Ga,+Gap<annotation encoding="application / x-tex">-G_a,+G_a^p< / annotation>< / semantics>< / com:Math>, consecutive <com:Math><semantics>+Gc,+Gcp,+Gb<annotation encoding="application / x-tex">+G_c, +G_c^p, +G_b< / annotation>< / semantics>< / com:Math>, consecutive <com:Math><semantics>+Gap,−Ga<annotation encoding="application / x-tex">+G_a^p, -G_a< / annotation>< / semantics>< / com:Math>, consecutive <com:Math><semantics>−Gcp,−Gc<annotation encoding="application / x-tex">-G_c^p, -G_c< / annotation>< / semantics>< / com:Math>, consecutive <com:Math><semantics>−Gb,−Gbp<annotation encoding="application / x-tex">-G_b, -G_b^p< / annotation>< / semantics>< / com:Math>, consecutive <com:Math><semantics>−Gd<annotation encoding="application / x-tex">-G_d< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+Gdp<annotation encoding="application / x-tex">+G_d^p< / annotation>< / semantics>< / com:Math>, consecutive <com:Math><semantics>+Gc<annotation encoding="application / x-tex">+G_c< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+Gbp<annotation encoding="application / x-tex">+G_b^p< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+Gb<annotation encoding="application / x-tex">+G_b< / annotation>< / semantics>< / com:Math>, consecutive <com:Math><semantics>+Gdp<annotation encoding="application / x-tex">+G_d^p< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−Gd<annotation encoding="application / x-tex">-G_d< / annotation>< / semantics>< / com:Math>, consecutive <com:Math><semantics>+Gd<annotation encoding="application / x-tex">+G_{d}< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−Gdp<annotation encoding="application / x-tex">-G_{d}^{p}< / annotation>< / semantics>< / com:Math>, consecutive <com:Math><semantics>−Gb<annotation encoding="application / x-tex">-G_{b}< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−Gbp<annotation encoding="application / x-tex">-G_{b}^{p}< / annotation>< / semantics>< / com:Math>, consecutive <com:Math><semantics>−Ga<annotation encoding="application / x-tex">-G_{a}< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+Gdp<annotation encoding="application / x-tex">+G_{d}^{p}< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−Gd<annotation encoding="application / x-tex">-G_{d}< / annotation>< / semantics>< / com:Math>, or consecutive <com:Math><semantics>−Gbp<annotation encoding="application / x-tex">-G_{b}^{p}< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−Gb<annotation encoding="application / x-tex">-G_{b}< / annotation>< / semantics>< / com:Math>

[0177] The HE-LTF sequence may also be directly stored as: HE-LTF <com:Math><semantics>2x<annotation encoding="application / x-tex">_{2x}< / annotation>< / semantics>< / com:Math> (-500:2:500) = [+1, +1, -1, +1, +1, +1, +1, +1, +1, +1, +1, +1, + <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, +1, -1, +1, +1, +1, -1, +1, -1, -1, +1, -1, -1, +1, +1, <com:Math><semantics>−1,−1,−1,+1,−1,−1,+1,−1,+1,−1,+1,+1,−1,+1<annotation encoding="application / x-tex">-1, -1, -1, +1, -1, -1, +1, -1, +1, -1, +1, +1, -1, +1< / annotation>< / semantics>< / com:Math> <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, +1, +1, -1, -1, -1, +1, -1, +1, +1, +1, +1, +1, +1, +1, +1, -1, -1, -1, +1, +1, -1, -1, +1, +1, +1, -1, +1, +1, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, +1. +1. -1. -1. -1. +1. -1. -1. +1. -1. +1. +1. -1. +1. +1, +1, -1, -1, +1, +1, +1, -1, +1, -1, +1, -1, -1, +1, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, +1, +1, -1, +1, +1, -1, -1, -1, -1, +1, +1, +1, -1, -1, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, +1, -1, +1, +1, -1, +1, -1, -1, -1, +1, -1, -1, +1, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, +1, +1, +1, +1, -1, -1, -1, -1, -1, -1, -1, -1, -1, +1, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>0<annotation encoding="application / x-tex">0< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>0<annotation encoding="application / x-tex">0< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>0<annotation encoding="application / x-tex">0< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, +1, +1, -1, +1, -1, -1, +1, +1, +1, +1, +1, +1, +1, +1, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, +1, +1, +1, -1, +1, +1, +1, -1, -1, -1, +1, +1, +1, +1, <com:Math><semantics>−1,−1,−1,+1,−1,−1,+1,+1,−1,+1,+1,−1,−1,−1,<annotation encoding="application / x-tex">-1, -1, -1, +1, -1, -1, +1, +1, -1, +1, +1, -1, -1, -1,< / annotation>< / semantics>< / com:Math> <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, +1, +1, -1, -1, -1, +1, +1, +1, +1, -1, +1, +1, +1, -1, +1, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, [Image disponible dans le document PDF, Image available in the PDF document]

[0178] After the second HE-LTF sequence is used, PAPR values corresponding to the second HE-LTF sequence are the same as PAPR values (shown in FIG. 10) of the first HE-LTF sequence.

[0179] A third HE-LTF sequence in 80 MHz 2X: [Image disponible dans le document PDF, Image available in the PDF document]

[0180] The HE-LTF sequence includes the <com:Math><semantics>Ga<annotation encoding="application / x-tex">G_a< / annotation>< / semantics>< / com:Math> sequence and the <com:Math><semantics>Gb<annotation encoding="application / x-tex">G_b< / annotation>< / semantics>< / com:Math> sequence, sequences <com:Math><semantics>Gap<annotation encoding="application / x-tex">G_a^p< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>Gc<annotation encoding="application / x-tex">G_c< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>Gbp<annotation encoding="application / x-tex">G_b^p< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>Gd<annotation encoding="application / x-tex">G_d< / annotation>< / semantics>< / com:Math>, and <com:Math><semantics>Gdp<annotation encoding="application / x-tex">G_d^p< / annotation>< / semantics>< / com:Math> that are generated according to the <com:Math><semantics>Ga<annotation encoding="application / x-tex">G_a< / annotation>< / semantics>< / com:Math> sequence and the G<com:Sub>b< / com:Sub> sequence, and +1 or -1 that is located at a leftover leftover subcarrier location. Further, the HE-LTF sequence may further include consecutive <com:Math><semantics>−Ga,+Gap<annotation encoding="application / x-tex">{}^{-G_a,+G_a^p}< / annotation>< / semantics>< / com:Math>, consecutive <com:Math><semantics>+Gc,+Gcp,+Gb<annotation encoding="application / x-tex">{}^{+G_c,+G_c^p,+G_b}< / annotation>< / semantics>< / com:Math>, consecutive <com:Math><semantics>+Gap,−Ga<annotation encoding="application / x-tex">+G_a^p, -G_a< / annotation>< / semantics>< / com:Math>, consecutive <com:Math><semantics>−Gcp,−Gc<annotation encoding="application / x-tex">-G_c^p, -G_c< / annotation>< / semantics>< / com:Math>, consecutive <com:Math><semantics>+Gc,+Gcp<annotation encoding="application / x-tex">+G_c, +G_c^p< / annotation>< / semantics>< / com:Math>, consecutive <com:Math><semantics>+Ga,−Gap,+Gd<annotation encoding="application / x-tex">+G_a, -G_a^p, +G_d< / annotation>< / semantics>< / com:Math>, consecutive <com:Math><semantics>+Gcp,+Gc<annotation encoding="application / x-tex">+G_c^p, +G_c< / annotation>< / semantics>< / com:Math>, consecutive <com:Math><semantics>+Gap,−Ga<annotation encoding="application / x-tex">+G_a^p, -G_a< / annotation>< / semantics>< / com:Math>, consecutive <com:Math><semantics>−Gd,+Gdp<annotation encoding="application / x-tex">-G_d, +G_d^p< / annotation>< / semantics>< / com:Math>, consecutive <com:Math><semantics>+Gb,+Gbp<annotation encoding="application / x-tex">+G_b, +G_b^p< / annotation>< / semantics>< / com:Math>, consecutive <com:Math><semantics>+Ga,−Gdp,+Gb<annotation encoding="application / x-tex">+G_a, -G_d^p, +G_b< / annotation>< / semantics>< / com:Math>, consecutive <com:Math><semantics>+Ga,−Gdp,+Gd<annotation encoding="application / x-tex">+G_a, -G_d^p, +G_d< / annotation>< / semantics>< / com:Math>, consecutive <com:Math><semantics>+Gbp,+Gb<annotation encoding="application / x-tex">+G_b^p,+G_b< / annotation>< / semantics>< / com:Math>, consecutive <com:Math><semantics>+Gb,+Gbp<annotation encoding="application / x-tex">+G_b,+G_b^p< / annotation>< / semantics>< / com:Math>, consecutive <com:Math><semantics>+Gd,−Gdp<annotation encoding="application / x-tex">+G_d,-G_d^p< / annotation>< / semantics>< / com:Math> consecutive <com:Math><semantics>−Gc,−Gbp,−Gb<annotation encoding="application / x-tex">-G_c,-G_b^p,-G_b< / annotation>< / semantics>< / com:Math>, or consecutive <com:Math><semantics>−Gdp<annotation encoding="application / x-tex">-G_d^p< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+Gd<annotation encoding="application / x-tex">+G_d< / annotation>< / semantics>< / com:Math>.

[0181] The HE-LTF sequence may also be directly stored as the following sequence: HE-LTF <com:Math><semantics>2x<annotation encoding="application / x-tex">_{2x}< / annotation>< / semantics>< / com:Math> (-500:2:500) = [+1, -1, -1, -1, +1, -1, -1, +1, -1, +1, +1, +1, +1, +1, +1, +1, +1, +1, + +1, -1, -1, +1, +1, +1, -1, +1, -1, +1, -1, -1, +1, -1, +1, +1, +1, -1, +1, +1, +1, -1, -1, -1, +1, -1, -1, +1, +1, -1, +1, +1, +1, -1, -1, -1, +1, +1, +1, -1, -1, -1, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, +1, +1, -1, +1, +1, -1, +1, -1, -1, +1, -1, -1, -1, +1, +1, +1, +1, -1, +1, -1, -1, +1, -1, -1, -1, +1, +1, +1, +1, +1, -1, +1, +1, +1, +1, +1, +1, +1, -1, -1, -1, +1, -1, -1, +1, +1, -1, +1, +1, -1, -1, -1, -1, +1, +1, +1, +1, -1, +1, +1, +1, -1, +1, -1, -1, +1, -1, -1, +1, +1, -1, -1, -1, +1, -1, +1, -1, +1, +1, -1, +1, -1, +1, -1, -1, -1, +1, -1, -1, -1, +1, -1, -1, +1, +1, -1, +1, +1, +1, -1, -1, -1, +1, -1, +1, +1, +1, +1, +1, +1, +1, +1, -1, -1, -1, +1, +1, -1, -1, +1, +1, +1, +1, +1, -1, +1, +1, -1, +1, -1, -1, -1, +1, -1, -1, +1, -1, +1, +1, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>0<annotation encoding="application / x-tex">0< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>0<annotation encoding="application / x-tex">0< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>0<annotation encoding="application / x-tex">0< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, +1, -1, +1, +1, -1, +1, -1, +1, -1, +1, +1, +1, +1, +1, +1, +1, +1, -1, +1, -1, -1, -1, -1, -1, +1, +1, -1, -1, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, +1, +1, +1, -1, -1, -1, +1, -1, +1, +1, +1, +1, +1, +1, +1, -1, +1, +1, +1, -1, +1, -1, -1, +1, -1, +1, -1, +1, +1, -1, +1, +1, +1, -1, -1, +1, +1, +1, -1, +1, +1, -1, +1, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, +1, -1, -1, +1, +1, -1, +1, +1, -1, -1, -1, -1, +1, -1, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, +1, -1, -1, -1, +1, -1, -1, -1, +1, +1, +1, -1, -1, -1, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, +1, +1, -1, +1, +1, -1, +1, -1, -1, +1, -1, +1, -1, +1, +1, +1, -1, -1, +1, +1, -1, +1, -1, +1, -1, -1, -1, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>].

[0182] FIG. 11 shows PAPR values of an HE-LTF sequence in the 80-MHz bandwidth. It may be learned, according to the group of PAPR values, that when different rotational phases are introduced in pilot subcarriers and other subcarriers, PAPR values are still very small.

[0183] The first group of values are sequentially PAPR values corresponding to 26-subcarrier resource blocks from left to right. Values in the first row, 2.76, 3.68, 2.76, 3.68, ..., are PAPR values corresponding to an HE-LTF sequence when values at data locations are all multiplied by +1 and values at pilot locations are all multiplied by +1, and sequentially from left to right in the first row, 2.76 is a PAPR value corresponding to a first 26-subcarrier resource block, 3.68 is a PAPR value corresponding to a second 26-subcarrier resource block from left to right, and so on. Values in the second row, 3.68, 2.76, 3.68, 2.76, ..., are PAPR values corresponding to an HE-LTF sequence when values at data locations are all multiplied by <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math> and values at pilot locations are all multiplied by <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, and sequentially from left to right in the second row, 3.68 is a PAPR value corresponding to a first 26-subcarrier resource block, 2.76 is a PAPR value corresponding to a second 26-subcarrier resource block from left to right, and so on. Values in the third row, 3.30, 4.46, 3.30, 4.46, ..., are PAPR values corresponding to an HE-LTF sequence when values at data locations are all multiplied by w and values at pilot locations are all multiplied by <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, and sequentially from left to right in the third row, 3.30 is a PAPR value corresponding to a first 26-subcarrier resource block, 4.46 is a PAPR value corresponding to a second 26-subcarrier resource block from left to right, and so on. Values in the fourth row, 4.46, 3.30, 4.46, 3.30, ..., are PAPR values corresponding to an HE-LTF sequence when values at data locations are all multiplied by w<com:Sup>2< / com:Sup> and values at pilot locations are all multiplied by +1, and sequentially from left to right in the fourth row, 4.46 is a PAPR value corresponding to a first 26-subcarrier resource block, 3.30 is a PAPR value corresponding to a second 26-subcarrier resource block from left to right, and so on.

[0184] The second group of values are sequentially PAPR values corresponding to 52-subcarrier resource blocks in a second row from left to right. Values in the first row, 4.68, 4.68, 4.69, 4.69, ..., are PAPR values corresponding to an HE-LTF sequence when values at data locations are all multiplied by +1 and values at pilot locations are all multiplied by +1, and sequentially from left to right in the first row, the first 4.68 is a PAPR value corresponding to a first 52-subcarrier resource block, and the second 4.68 is a PAPR value corresponding to a second 52-subcarrier resource block from left to right, and so on. Values in the second row, 4.68, 4.69, 4.69, ..., are PAPR values corresponding to an HE-LTF sequence when values at data locations are all multiplied by -1 and values at pilot locations are all multiplied by <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, and sequentially from left to right in the second row, the first 4.68 is a PAPR value corresponding to a first 52-subcarrier resource block, the second 4.68 is a PAPR value corresponding to a second 52-subcarrier resource block from left to right, and so on. Values in the third row, 4.68, 4.68, 4.69, 4.69, ..., are PAPR values corresponding to an HE-LTF sequence when values at data locations are all multiplied by w and values at pilot locations are all multiplied by +1, and sequentially from left to right in the third row, the first 4.68 is a PAPR value corresponding to a first 52-subcarrier resource block, the second 4.68 is a PAPR value corresponding to a second 52-subcarrier resource block from left to right, and so on. Values in the fourth row, 4.68, 4.69, and 4.69, are PAPR values corresponding to an HE-LTF sequence when values at data locations are all multiplied by w<com:Sup>2< / com:Sup> and values at pilot locations are all multiplied by +1, and sequentially from left to right in the fourth row, the first 4.68 is a PAPR value corresponding to a first 52-subcarrier resource block, the second 4.68 is a PAPR value corresponding to a second 52-subcarrier resource block from left to right, and so on.

[0185] The third group of values are sequentially PAPR values corresponding to 106-subcarrier resource blocks in a third row from left to right. Values in the first row, 5.42, 5.33, 5.42, 5.33, ..., are PAPR values corresponding to an HE-LTF sequence when values at data locations are all multiplied by +1 and values at pilot locations are all multiplied by +1, and sequentially from left to right in the first row, 5.42 is a PAPR value corresponding to a first 106-subcarrier resource block, 5.33 is a PAPR value corresponding to a second 106-subcarrier resource block from left to right, and so on. Values in the second row, 4.85, 5.41, 4.85, 5.41, ..., are PAPR values corresponding to an HE-LTF sequence when values at data locations are all multiplied by <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math> and values at pilot locations are all multiplied by +1, and sequentially from left to right in the second row, 4.85 is a PAPR value corresponding to a first 106-subcarrier resource block, 5.50 is a PAPR value corresponding to a second 106-subcarrier resource block from left to right, and so on. Values in the third row, 4.95, 5.18, 4.95, 5.18, ..., are PAPR values corresponding to an HE-LTF sequence when values at data locations are all multiplied by w and values at pilot locations are all multiplied by +1, and sequentially from left to right in the third row, 4.95 is a PAPR value corresponding to a first 106-subcarrier resource block, 5.18 is a PAPR value corresponding to a second 106-subcarrier resource block from left to right, and so on. Values in the fourth row, 4.68, 4.97, 4.68, 4.97, ..., are PAPR values corresponding to an HE-LTF sequence when values at data locations are all multiplied by <com:Math><semantics>w2<annotation encoding="application / x-tex">w^2< / annotation>< / semantics>< / com:Math> and values at pilot locations are all multiplied by <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, and sequentially from left to right in the fourth row, 4.68 is a PAPR value corresponding to a first 106-subcarrier resource block, and 4.97 is a PAPR value corresponding to a second 106-subcarrier resource block from left to right.

[0186] The fourth group of values is sequentially PAPR values corresponding to 242-subcarrier resource blocks from left to right in a fourth row. Values in the first row, 5.29 and 5.29, are PAPR values corresponding to an HE-LTF sequence when values at data locations are all multiplied by +1 and values at pilot locations are all multiplied by +1, and sequentially from left to right in the first row, the first 5.29 is a PAPR value corresponding to a first 242-subcarrier resource block, and the second 5.29 is a PAPR value corresponding to a second 242-subcarrier resource block from left to right. Values in the second row, 5.58 and 5.58, are PAPR values corresponding to an HE-LTF sequence when values at data locations are all multiplied by <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math> and values at pilot locations are all multiplied by +1, and sequentially from left to right in the second row, the first 5.58 is a PAPR value corresponding to a first 242-subcarrier resource block, and the second 5.58 is a PAPR value corresponding to a second 242-subcarrier resource block from left to right. Values in the third row, 5.40 and 5.40, are PAPR values corresponding to an HE-LTF sequence when values at data locations are all multiplied by w and values at pilot locations are all multiplied by +1, and sequentially from left to right in the third row, the first 5.40 is a PAPR value corresponding to a first 242-subcarrier resource block, and the second 5.40 is a PAPR value corresponding to a second 242-subcarrier resource block from left to right. Values in the fourth row, 5.46 and 5.46, are PAPR values corresponding to an HE-LTF sequence when values at data locations are all multiplied by w<com:Sup>2< / com:Sup> and values at pilot locations are all multiplied by <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, and sequentially from left to right in the fourth row, the first 5.46 is a PAPR value corresponding to a first 242-subcarrier resource block, and the second 5.46 is a PAPR value corresponding to a second 242-subcarrier resource block from left to right.

[0187] The fifth group of values is sequentially PAPR values corresponding to 484-subcarrier resource blocks in a fifth row from left to right. Values in the first row, 6.13 and 6.27, are PAPR values corresponding to an HE-LTF sequence when values at data locations are all multiplied by +1 and values at pilot locations are all multiplied by +1, and sequentially from left to right in the first row, 6.13 is a PAPR value corresponding to a first 484-subcarrier resource block, and 6.27 is a PAPR value corresponding to a second 484-subcarrier resource block from left to right. Values in the second row, 6.40 and 6.11, are PAPR values corresponding to an HE-LTF sequence when values at data locations are all multiplied by <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math> and values at pilot locations are all multiplied by <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, and sequentially from left to right in the second row, 6.40 is a PAPR value corresponding to a first 242-subcarrier resource block, and 6.11 is a PAPR value corresponding to a second 484-subcarrier resource block from left to right. Values in the third row, 6.34 and 6.24, are PAPR values corresponding to an HE-LTF sequence when values at data locations are all multiplied by w and values at pilot locations are all multiplied by +1, and sequentially from left to right in the third row, 6.34 is a PAPR value corresponding to a first 484-subcarrier resource block, and 6.24 is a PAPR value corresponding to a second 484-subcarrier resource block from left to right. Values in the fourth row, 6.25 and 6.29, are PAPR values corresponding to an HE-LTF sequence when values at data locations are all multiplied by w<com:Sup>2< / com:Sup> and values at pilot locations are all multiplied by +1, and sequentially from left to right in the fourth row, 6.25 is a PAPR value corresponding to a first 484-subcarrier resource block, and 6.29 is a PAPR value corresponding to a second 484-subcarrier resource block from left to right.

[0188] The sixth group of values, 6.01, 5.68, 6.08, and 5.92, are PAPR values corresponding to 996-subcarrier resource blocks in a sixth row. The first 6.08 is a PAPR value corresponding to an HE-LTF sequence when values at data locations are all multiplied by +1 and values at pilot locations are all multiplied by +1. The second 5.68 is a PAPR value corresponding to an HE-LTF sequence when values at data locations are all multiplied by -1 and values at pilot locations are all multiplied by +1. The third 6.08 is a PAPR value corresponding to an HE-LTF sequence when values at data locations are all multiplied by w and values at pilot locations are all multiplied by +1. The fourth 5.92 is a PAPR value corresponding to an HE-LTF sequence when values at data locations are all multiplied by <com:Math><semantics>w2<annotation encoding="application / x-tex">w^2< / annotation>< / semantics>< / com:Math> and values at pilot locations are all multiplied by <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>.

[0189] A fourth HE-LTF sequence in the 80 MHz 2x mode: [Image disponible dans le document PDF, Image available in the PDF document]

[0190] The HE-LTF sequence includes the <com:Math><semantics>Ga<annotation encoding="application / x-tex">G_a< / annotation>< / semantics>< / com:Math> sequence and <com:Math><semantics>Gb<annotation encoding="application / x-tex">G_b< / annotation>< / semantics>< / com:Math> sequence, sequences <com:Math><semantics>Gap<annotation encoding="application / x-tex">G_a^p< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>Gc<annotation encoding="application / x-tex">G_c< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>Gcp<annotation encoding="application / x-tex">G_c^p< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>Gbp<annotation encoding="application / x-tex">G_b^p< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>Gd<annotation encoding="application / x-tex">G_d< / annotation>< / semantics>< / com:Math>, and <com:Math><semantics>Gdp<annotation encoding="application / x-tex">G_d^p< / annotation>< / semantics>< / com:Math> that are generated according to the <com:Math><semantics>Ga<annotation encoding="application / x-tex">G_a< / annotation>< / semantics>< / com:Math> sequence and the <com:Math><semantics>Gb<annotation encoding="application / x-tex">G_b< / annotation>< / semantics>< / com:Math> sequence, and +1 or -1 that is located at a leftover leftover subcarrier location. Further, the HE-LTF sequence may further include consecutive <com:Math><semantics>+Gc<annotation encoding="application / x-tex">{}^{+G_c}< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+Gc<annotation encoding="application / x-tex">{}^{+G_c}< / annotation>< / semantics>< / com:Math>, consecutive <com:Math><semantics>+Ga<annotation encoding="application / x-tex">{}^{+G_a}< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−Gap<annotation encoding="application / x-tex">{}^{-G_a^p}< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+Gd<annotation encoding="application / x-tex">{}^{+G_d}< / annotation>< / semantics>< / com:Math>, consecutive <com:Math><semantics>+Gcp,+Gc<annotation encoding="application / x-tex">+G_c^p,+G_c< / annotation>< / semantics>< / com:Math>, consecutive <com:Math><semantics>+Gap,−Ga<annotation encoding="application / x-tex">+G_a^p,-G_a< / annotation>< / semantics>< / com:Math> consecutive <com:Math><semantics>+Ga−Gap<annotation encoding="application / x-tex">+G_a-G_a^p< / annotation>< / semantics>< / com:Math>, consecutive <com:Math><semantics>−Gc,−Gcp,−Gb<annotation encoding="application / x-tex">-G_c,-G_c^p,-G_b< / annotation>< / semantics>< / com:Math>, consecutive <com:Math><semantics>−Gap,+Ga<annotation encoding="application / x-tex">-G_a^p, +G_a< / annotation>< / semantics>< / com:Math>, consecutive <com:Math><semantics>+Gcp,+Gc<annotation encoding="application / x-tex">+G_c^p, +G_c< / annotation>< / semantics>< / com:Math>, consecutive <com:Math><semantics>+Gb,+Gbp<annotation encoding="application / x-tex">+G_b, +G_b^p< / annotation>< / semantics>< / com:Math>, consecutive <com:Math><semantics>+Gd,−Gdp<annotation encoding="application / x-tex">+G_d, -G_d^p< / annotation>< / semantics>< / com:Math> consecutive <com:Math><semantics>−Gc,−Gbp,−Gb<annotation encoding="application / x-tex">-G_c, -G_b^p, -G_b< / annotation>< / semantics>< / com:Math>, consecutive <com:Math><semantics>−Gdp,+Gd<annotation encoding="application / x-tex">-G_d^p, +G_d< / annotation>< / semantics>< / com:Math>, consecutive <com:Math><semantics>+Gd,−Gdp<annotation encoding="application / x-tex">+G_d, -G_d^p< / annotation>< / semantics>< / com:Math>, consecutive <com:Math><semantics>−Gb,−Gbp<annotation encoding="application / x-tex">-G_b, -G_b^p< / annotation>< / semantics>< / com:Math>, consecutive <com:Math><semantics>−Ga,+Gdp,−Gd<annotation encoding="application / x-tex">-G_a, +G_d^p, -G_d< / annotation>< / semantics>< / com:Math>, or consecutive <com:Math><semantics>−Gbp,−Gb<annotation encoding="application / x-tex">-G_b^p, -G_b< / annotation>< / semantics>< / com:Math>. HE-LTF <com:Math><semantics>2x<annotation encoding="application / x-tex">_{2x}< / annotation>< / semantics>< / com:Math> (-500:2:500) = [+1, +1, -1, +1, +1, +1, +1, +1, +1, +1, +1, +1, + <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, +1, -1, +1, +1, +1, -1, +1, -1, -1, +1, -1, -1, +1, +1, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, +1, +1, -1, -1, -1, -1, +1, -1, +1, +1, +1, +1, +1, +1, +1, +1. -1. -1. +1. +1. +1. -1. -1. +1. +1. +1. +1. +1. +1. <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, +1, -1, +1, +1, +1, -1, +1, +1, -1, +1, -1, -1, +1, -1, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, +1, -1, -1, -1, -1, -1, -1, -1, +1, +1, +1, -1, +1, +1, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, +1, +1, -1, +1, +1, -1, -1, -1, -1, -1, +1, +1, -1, -1, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, +1, -1, -1, +1, -1, -1, +1, -1, +1, +1, +1, +1, +1, +1, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1,−1,+1,−1,+1,+1,−1,−1,+1,0,0,0,+1,+1,+1,<annotation encoding="application / x-tex">-1, -1, +1, -1, +1, +1, -1, -1, +1, 0, 0, 0, +1, +1, +1,< / annotation>< / semantics>< / com:Math> <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, +1, -1, +1, +1, +1, -1, -1, -1, +1, -1, -1, +1, +1, -1, +1, +1, -1, +1, +1, -1, +1, -1, -1, +1, -1, -1, -1, -1, +1, -1, +1, +1, -1, +1, +1, -1, -1, +1, +1, +1, -1, +1, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, +1, +1, +1, -1, +1, -1, -1, -1, -1, -1, +1, +1, +1, +1, -1, +1, +1, +1, -1, +1, -1, +1, -1, +1, +1, -1, +1, +1, +1, -1, -1, +1, +1, +1, -1, +1, -1, +1, -1, -1, -1, +1, -1, -1, -1, +1, +1, -1, +1, -1, +1, -1, -1, -1, +1, -1, -1, -1, -1, +1, -1, +1, +1, -1, +1, +1, +1, -1, -1, +1, +1, +1, -1, -1, -1, +1, +1, +1, +1, -1, +1, +1, +1, -1, +1, <com:Math><semantics>−1,−1,−1,−1,+1,+1,+1,−1,+1,+1,−1,−1,+1,−1,−1,<annotation encoding="application / x-tex">-1, -1, -1, -1, +1, +1, +1, -1, +1, +1, -1, -1, +1, -1, -1,< / annotation>< / semantics>< / com:Math> <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1,−1,+1,−1,−1,−1,+1,+1,−1,−1,−1,+1,−1,−1,+1,<annotation encoding="application / x-tex">-1, -1, +1, -1, -1, -1, +1, +1, -1, -1, -1, +1, -1, -1, +1,< / annotation>< / semantics>< / com:Math> <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, +1, -1, +1, +1, -1, -1, +1, -1, -1, +1, +1, +1, +1, -1, +1, +1, +1, -1, +1, +1|.

[0191] After the fourth HE-LTF sequence is used, PAPR values corresponding to the fourth HE-LTF sequence are the same as the PAPR values of the third HE-LTF sequence. For details, refer to FIG. 11. It may be learned, according to the group of PAPR values, that when different rotational phases are introduced in pilot subcarriers and other subcarriers, PAPR values are still very small. Embodiment 4

[0192] There are 256 subcarriers on a 4x symbol of the 20-MHz bandwidth in the 4x mode. According to different resource block sizes, an RU size shown in FIG. 1a may be 26, 52, 106, or 242 subcarriers.

[0193] There are many types of HE-LTF sequences in the 20-MHz 242-subcarrier 4X mode. Only several types of the HE-LTF sequences are listed below.

[0194] A first HE-LTF sequence in the 20-MHz 242-subcarrier 4X mode: [Image disponible dans le document PDF, Image available in the PDF document] where <com:Math><semantics>Ge={1,−1,1,−1,1,1,1,1,−1,−1,−1,1,1,1,1,1,1,1,1,−1,−<annotation encoding="application / x-tex">G_e = \{1, -1, 1, -1, 1, 1, 1, 1, -1, -1, -1, 1, 1, 1, 1, 1, 1, 1, 1, -1, -< / annotation>< / semantics>< / com:Math> The HE-LTF sequence includes the <com:Math><semantics>Ge<annotation encoding="application / x-tex">G_e< / annotation>< / semantics>< / com:Math> sequence, derived sequences <com:Math><semantics>Ge<annotation encoding="application / x-tex">G_e< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>Gep<annotation encoding="application / x-tex">G_e^p< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>Gd<annotation encoding="application / x-tex">G_d< / annotation>< / semantics>< / com:Math>.

[0195] and <com:Math><semantics>Gdp<annotation encoding="application / x-tex">G_d^p< / annotation>< / semantics>< / com:Math> that are generated according to the Ga sequence and the Gb sequence, and +1 or -1 that is located at a leftover leftover subcarrier location. Further, the HE-LTF sequence may further include consecutive <com:Math><semantics>+Gc,−Gcp<annotation encoding="application / x-tex">{}^{+G_c, -G_c^p}< / annotation>< / semantics>< / com:Math>, consecutive <com:Math><semantics>+Gd,−Gdp<annotation encoding="application / x-tex">{}^{+G_d, -G_d^p}< / annotation>< / semantics>< / com:Math>, consecutive <com:Math><semantics>−Gc,+Gcp<annotation encoding="application / x-tex">{}^{-G_c, +G_c^p}< / annotation>< / semantics>< / com:Math>, or consecutive <com:Math><semantics>+Gd,+Gdp<annotation encoding="application / x-tex">{}^{+G_d, +G_d^p}< / annotation>< / semantics>< / com:Math>.

[0196] The HE-LTF sequence may also be directly stored as: HE-LTF <com:Math><semantics>4x<annotation encoding="application / x-tex">_{4x}< / annotation>< / semantics>< / com:Math> (-122:122) = [+1, -1, +1, -1, +1, -1, +1, +1, +1, +1, +1, +1, -1, -1, -1, -1, -1, -1, -1, -1, -1, - <com:Math><semantics>+1,−1,−1,−1,−1,−1,+1,+1,−1,−1,−1,−1,−1,+1,−1,<annotation encoding="application / x-tex">+1, -1, -1, -1, -1, -1, +1, +1, -1, -1, -1, -1, -1, +1, -1,< / annotation>< / semantics>< / com:Math> +1, -1, -1, +1, +1, -1, +1, +1, -1, -1, -1, -1, -1, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, +1, -1, +1, -1, +1, +1, -1, -1, +1, -1, -1, +1, -1, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, +1, +1, -1, +1, -1, +1, +1, +1, -1, -1, -1, +1, +1, +1, <com:Math><semantics>−1,0,0,0,+1,−1,+1,+1,+1,+1,+1,+1,−1,+1,−1<annotation encoding="application / x-tex">-1, 0, 0, 0, +1, -1, +1, +1, +1, +1, +1, +1, -1, +1, -1< / annotation>< / semantics>< / com:Math> <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1,−1,−1,+1,−1,−1,−1,−1,+1,+1,−1,−1,−1,−1,<annotation encoding="application / x-tex">+1, -1, -1, +1, -1, -1, -1, -1, +1, +1, -1, -1, -1, -1,< / annotation>< / semantics>< / com:Math> +1, -1, +1, -1, +1, -1, -1, -1, -1, -1, +1, +1, -1, +1, +1, +1, +1, -1, -1, -1, +1, +1, +1, +1, +1, +1, +1, -1, +1, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1,−1,−1,−1,+1<annotation encoding="application / x-tex">-1, -1, -1, -1, +1< / annotation>< / semantics>< / com:Math>].

[0197] FIG. 12 shows PAPR values of an HE-LTF sequence in the 20-MHz bandwidth. It may be learned, according to the group of PAPR values, that when different rotational phases are introduced in pilot subcarriers and other subcarriers, PAPR values are still very small.

[0198] The first group of values is sequentially PAPR values corresponding to 26-subcarrier resource blocks from left to right. Values in the first row, 3.51, 3.78, 3.51, 3.78, ..., are PAPR values corresponding to an HE-LTF sequence when values at data locations are all multiplied by +1 and values at pilot locations are all multiplied by +1, and sequentially from left to right in the first row, 3.51 is a PAPR value corresponding to a first 26-subcarrier resource block, 3.78 is a PAPR value corresponding to a second 26-subcarrier resource block from left to right, and so on. Values in the second row, 3.78, 3.51, 3.78, 3.51, ..., are PAPR values corresponding to an HE-LTF sequence when values at data locations are all multiplied by <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math> and values at pilot locations are all multiplied by <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, and sequentially from left to right in the second row, 3.78 is a PAPR value corresponding to a first 26-subcarrier resource block, 3.51 is a PAPR value corresponding to a second 26-subcarrier resource block from left to right, and so on. Values in the third row, 3.28, 3.48, 3.28, 3.48, ..., are PAPR values corresponding to an HE-LTF sequence when values at data locations are all multiplied by w and values at pilot locations are all multiplied by <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, and sequentially from left to right in the third row, 3.28 is a PAPR value corresponding to a first 26-subcarrier resource block, 3.48 is a PAPR value corresponding to a second 26-subcarrier resource block from left to right, and so on. Values in the fourth row, 3.48, 3.28, 3.48, 3.28, ..., are PAPR values corresponding to an HE-LTF sequence when values at data locations are all multiplied by w<com:Sup>2< / com:Sup> and values at pilot locations are all multiplied by +1, and sequentially from left to right in the fourth row, 3.48 is a PAPR value corresponding to a first 26-subcarrier resource block, 3.28 is a PAPR value corresponding to a second 26-subcarrier resource block from left to right, and so on.

[0199] The second group of values is sequentially PAPR values corresponding to 52-subcarrier resource blocks in a second row from left to right. Values in the first row, 4.42, 4.59, 4.63, and 4.42, are PAPR values corresponding to an HE-LTF sequence when values at data locations are all multiplied by +1 and values at pilot locations are all multiplied by +1, and sequentially from left to right in the first row, the first 4.42 is a PAPR value corresponding to a first 52-subcarrier resource block, and the second 4.59 is a PAPR value corresponding to a second 52-subcarrier resource block from left to right, and so on. Values in the second row, 4.42, 4.63, 4.59, and 4.42, are PAPR values corresponding to an HE-LTF sequence when values at data locations are all multiplied by -1 and values at pilot locations are all multiplied by +1, and sequentially from left to right in the second row, the first 4.42 is a PAPR value corresponding to a first 52-subcarrier resource block, the second 4.63 is a PAPR value corresponding to a second 52-subcarrier resource block from left to right, and so on. Values in the third row, 4.44, 4.86, 4.97, and 4.42, are PAPR values corresponding to an HE-LTF sequence when values at data locations are all multiplied by w and values at pilot locations are all multiplied by +1, and sequentially from left to right in the third row, the first 4.44 is a PAPR value corresponding to a first 52-subcarrier resource block, a second 4.86 is a PAPR value corresponding to a second 52-subcarrier resource block from left to right, and so on. Values in the fourth row, 4.42, 4.97, 4.86, and 4.44, are PAPR values corresponding to an HE-LTF sequence when values at data locations are all multiplied by w<com:Sup>2< / com:Sup> and values at pilot locations are all multiplied by +1, and sequentially from left to right in the fourth row, the first 4.42 is a PAPR value corresponding to a first 52-subcarrier resource block, the second 4.97 is a PAPR value corresponding to a second 52-subcarrier resource block from left to right, and so on.

[0200] The third group of values is sequentially PAPR values corresponding to 106-subcarrier resource blocks in a third row from left to right. Values in the first row, 4.65 and 4.90, are PAPR values corresponding to an HE-LTF sequence when values at data locations are all multiplied by +1 and values at pilot locations are all multiplied by +1, and sequentially from left to right in the first row, 4.65 is a PAPR value corresponding to a first 106-subcarrier resource block, and 4.90 is a PAPR value corresponding to a second 106-subcarrier resource block from left to right. Values in the second row, 4.69 and 5.01, are PAPR values corresponding to an HE-LTF sequence when values at data locations are all multiplied by <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math> and values at pilot locations are all multiplied by <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, and sequentially from left to right in the second row, 4.69 is a PAPR value corresponding to a first 106-subcarrier resource block, and 5.01 is a PAPR value corresponding to a second 106-subcarrier resource block from left to right. Values in the third row, 4.90 and 4.95, are PAPR values corresponding to an HE-LTF sequence when values at data locations are all multiplied by w and values at pilot locations are all multiplied by +1, and sequentially from left to right in the third row, 4.90 is a PAPR value corresponding to a first 106-subcarrier resource block, and 4.95 is a PAPR value corresponding to a second 106-subcarrier resource block from left to right. Values in the fourth row, 4.92 and 4.87, are PAPR values corresponding to an HE-LTF sequence when values at data locations are all multiplied by w<com:Sup>2< / com:Sup> and values at pilot locations are all multiplied by +1, and sequentially from left to right in the fourth row, 4.92 is a PAPR value corresponding to a first 106-subcarrier resource block, and 4.87 is a PAPR value corresponding to a second 106-subcarrier resource block from left to right.

[0201] The fourth group of values, 5.26, 5.30, 5.29, and 5.56, are PAPR values corresponding to 242-subcarrier resource blocks in a fourth row. The first 5.26 is a PAPR value corresponding to an HE-LTF sequence when values at data locations are all multiplied by +1 and values at pilot locations are all multiplied by +1. The second 5.30 is a PAPR value corresponding to an HE-LTF sequence when values at data locations are all multiplied by <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math> and values at pilot locations are all multiplied by +1. The third 5.29 is a PAPR value corresponding to an HE-LTF sequence when values at data locations are all multiplied by w and values at pilot locations are all multiplied by +1. The first 5.56 is a PAPR value corresponding to an HE-LTF sequence when values at data locations are all multiplied by <com:Math><semantics>w2<annotation encoding="application / x-tex">w^2< / annotation>< / semantics>< / com:Math> and values at pilot locations are all multiplied by <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>.

[0202] A second HE-LTF sequence in the 20-MHz 242-subcarrier 4X mode: [Image disponible dans le document PDF, Image available in the PDF document] where [Image disponible dans le document PDF, Image available in the PDF document]

[0203] The HE-LTF sequence includes the <com:Math><semantics>Gϵ<annotation encoding="application / x-tex">G_{\epsilon}< / annotation>< / semantics>< / com:Math> sequence, the Ga sequence and the Gb sequence, derived sequences <com:Math><semantics>Gap<annotation encoding="application / x-tex">G_a^p< / annotation>< / semantics>< / com:Math> and <com:Math><semantics>Gbp<annotation encoding="application / x-tex">G_b^p< / annotation>< / semantics>< / com:Math> that are generated according to the Ga sequence and Gb sequence, and +1 or -1 that is located at a leftover leftover subcarrier location. Further, the HE-LTF sequence may further include: consecutive <com:Math><semantics>+Ga,+Gap<annotation encoding="application / x-tex">{}^{+G_a,+G_a^p}< / annotation>< / semantics>< / com:Math>, consecutive <com:Math><semantics>+Gb,−Gbp<annotation encoding="application / x-tex">{}^{+G_b,-G_b^p}< / annotation>< / semantics>< / com:Math>, consecutive <com:Math><semantics>+Ga,−Gap<annotation encoding="application / x-tex">+G_a, -G_a^p< / annotation>< / semantics>< / com:Math>, consecutive <com:Math><semantics>+Gb,+Gbp<annotation encoding="application / x-tex">+G_b, +G_b^p< / annotation>< / semantics>< / com:Math> or <com:Math><semantics>+Ge(1:13),+Ge(14:26)<annotation encoding="application / x-tex">+G_e(1:13), +G_e(14:26)< / annotation>< / semantics>< / com:Math>

[0204] The HE-LTF sequence may also be directly stored as: HE-LTF <com:Math><semantics>4x(−122:122)=[+1,+1,+1,+1,+1,+1,+1,+1,+1,+1,<annotation encoding="application / x-tex">_{4x}(-122:122) = [+1, +1, +1, +1, +1, +1, +1, +1, +1, +1,< / annotation>< / semantics>< / com:Math> <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, +1, +1, -1, -1, +1, +1, -1, +1, +1, -1, -1, -1, +1, -1, +1, +1, -1, +1, +1, -1, +1, -1, +1, +1, +1, +1, -1, -1, +1, +1, +1, +1, +1, -1, +1, -1, -1, -1, -1, -1, -1, -1, +1, -1, +1, -1, +1, -1, -1, -1, +1, +1, +1, -1, -1, -1, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>+1<annotation encoding="application / x-tex">+1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotation>< / semantics>< / com:Math>, <com:Math><semantics>−1<annotation encoding="application / x-tex">-1< / annotatio...

Claims

1. A method for sending a long training sequence in a wireless local area network which supports Orthogonal Frequency Division Multiple Access, OFDMA, technology, wherein the method comprises: selecting a long training sequence according to a bandwidth, wherein the long training sequence is a 2x mode long training sequence; and sending a sub-sequence segment of the long training sequence according to a location and a size of an allocated resource unit, RU, wherein the sub-sequence segment at a corresponding location of the long training sequence is carried on subcarriers at the corresponding location, wherein, when the bandwidth is 80 MHz, the 2x mode long training sequence includes values on subcarriers with indexes − 500 : 2 : 500 -500:2:500 , and the values on subcarriers with indexes − 500 : 2 : 500 -500:2:500 are + 1 , + 1 , − 1 , + 1 , + 1 , + 1 , − 1 , + 1 , + 1 , + 1 , − 1 , − 1 , − 1 , + 1 , +1, +1, -1, +1, +1, +1, -1, +1, +1, +1, -1, -1, -1, +1, − 1 , − 1 , + 1 , + 1 , − 1 , + 1 , + 1 , + 1 , − 1 , − 1 , − 1 , + 1 , + 1 , + 1 , -1, -1, +1, +1, -1, +1, +1, +1, -1, -1, -1, +1, +1, +1, +1, -1, +1, +1, +1, -1, +1, -1, -1, +1, -1, -1, +1, +1, − 1 -1 , − 1 -1 , + 1 +1 , − 1 -1 , + 1 +1 , − 1 -1 , + 1 +1 , + 1 +1 , − 1 -1 , + 1 +1 , + 1 +1 , − 1 -1 , + 1 +1 , − 1 , − 1 , − 1 , + 1 , − 1 , − 1 , − 1 , − 1 , + 1 , − 1 , − 1 , + 1 , + 1 , − 1 , + 1 , -1, -1, -1, +1, -1, -1, -1, -1, +1, -1, -1, +1, +1, -1, +1, +1, +1, -1, -1, -1, -1, +1, -1, +1, +1, +1, +1, +1, +1, + 1 , − 1 , − 1 , − 1 , + 1 , + 1 , + 1 , − 1 , − 1 , + 1 , + 1 , + 1 , + 1 , + 1 , + 1 , + 1 +1, -1, -1, -1, +1, +1, +1, -1, -1, +1, +1, +1, +1, +1, +1, +1 − 1 , + 1 , − 1 , − 1 , − 1 , − 1 , + 1 , − 1 , − 1 , + 1 , − 1 , + 1 , − 1 , -1, +1, -1, -1, -1, -1, +1, -1, -1, +1, -1, +1, -1, + 1 , + 1 , − 1 , − 1 , − 1 , + 1 , − 1 , − 1 , + 1 , − 1 , + 1 , + 1 , − 1 , + 1 , +1, +1, -1, -1, -1, +1, -1, -1, +1, -1, +1, +1, -1, +1, + 1 , + 1 , − 1 , − 1 , + 1 , + 1 , + 1 , − 1 , + 1 , − 1 , + 1 , − 1 , + 1 , − 1 , + 1 , +1, +1, -1, -1, +1, +1, +1, -1, +1, -1, +1, -1, +1, -1, +1, − 1 , + 1 , + 1 , + 1 , − 1 , + 1 , + 1 , + 1 , + 1 , − 1 , − 1 , − 1 , + 1 , − 1 , − 1 , -1, +1, +1, +1, -1, +1, +1, +1, +1, -1, -1, -1, +1, -1, -1, + 1 , + 1 , − 1 , + 1 , + 1 , + 1 , − 1 , − 1 , − 1 , + 1 , + 1 , + 1 , + 1 , − 1 , − 1 , +1, +1, -1, +1, +1, +1, -1, -1, -1, +1, +1, +1, +1, -1, -1, − 1 -1 , − 1 -1 , + 1 +1 , − 1 -1 , − 1 -1 , − 1 -1 , + 1 +1 , + 1 +1 , + 1 +1 , + 1 +1 , − 1 -1 , − 1 -1 , + 1 +1 , + 1 +1 , + 1 , − 1 , + 1 , + 1 , − 1 , + 1 , − 1 , − 1 , − 1 , + 1 , − 1 , − 1 , + 1 , +1, -1, +1, +1, -1, +1, -1, -1, -1, +1, -1, -1, +1, − 1 -1 , + 1 +1 , + 1 +1 , − 1 -1 , + 1 +1 , + 1 +1 , − 1 -1 , + 1 +1 , − 1 -1 , − 1 -1 , − 1 -1 , − 1 -1 , − 1 -1 , − 1 -1 , − 1 -1 , − 1 -1 , − 1 -1 , − 1 -1 , − 1 -1 , − 1 -1 , − 1 -1 , − 1 -1 , − 1 -1 , − 1 -1 , − 1 -1 , − 1 -1 , − 1 -1 , − 1 -1 , − 1 -1 , − 1 -1 , − 1 -1 , − 1 -1 , − 1 -1 , − 1 -1 , − 1 -1 , − 1 -1 , − 1 -1 , + 1 , + 1 , + 1 , + 1 , − 1 , + 1 , − 1 , − 1 , − 1 , + 1 , − 1 , − 1 , − 1 , + 1 , +1, +1, +1, +1, -1, +1, -1, -1, -1, +1, -1, -1, -1, +1, + 1 , + 1 , + 1 , − 1 , − 1 , − 1 , + 1 , + 1 , + 1 , 0 , 0 , 0 , + 1 , − 1 , − 1 , +1, +1, +1, -1, -1, -1, +1, +1, +1, 0, 0, 0, +1, -1, -1, +1, +1, -1, +1, -1, -1, -1, +1, +1, +1, +1, +1, +1, +1, +1. − 1 , + 1 , − 1 , − 1 , − 1 , − 1 , + 1 , + 1 , + 1 , − 1 , + 1 , + 1 , − 1 , − 1 , + 1 , -1, +1, -1, -1, -1, -1, +1, +1, +1, -1, +1, +1, -1, -1, +1, − 1 , − 1 , + 1 , − 1 , − 1 , + 1 , − 1 , + 1 , + 1 , + 1 , + 1 , + 1 , + 1 , + 1 , + 1 -1, -1, +1, -1, -1, +1, -1, +1, +1, +1, +1, +1, +1, +1, +1 − 1 , + 1 , − 1 , − 1 , + 1 , − 1 , − 1 , + 1 , + 1 , − 1 , − 1 , − 1 , + 1 , − 1 , -1, +1, -1, -1, +1, -1, -1, +1, +1, -1, -1, -1, +1, -1, +1, +1, +1, -1, +1, +1, +1, -1, -1, -1, +1, +1, +1, +1, − 1 , − 1 , − 1 , + 1 , − 1 , − 1 , + 1 , + 1 , − 1 , + 1 , + 1 , + 1 , − 1 , − 1 , − 1 , -1, -1, -1, +1, -1, -1, +1, +1, -1, +1, +1, +1, -1, -1, -1, − 1 , + 1 , − 1 , − 1 , − 1 , + 1 , − 1 , + 1 , − 1 , + 1 , − 1 , − 1 , + 1 , − 1 , -1, +1, -1, -1, -1, +1, -1, +1, -1, +1, -1, -1, +1, -1, − 1 , − 1 , + 1 , + 1 , − 1 , − 1 , − 1 , + 1 , − 1 , + 1 , + 1 , + 1 , + 1 , + 1 -1, -1, +1, +1, -1, -1, -1, +1, -1, +1, +1, +1, +1, +1 − 1 , + 1 , + 1 , + 1 , − 1 , + 1 , − 1 , + 1 , − 1 , + 1 , − 1 , − 1 , − 1 , + 1 , -1, +1, +1, +1, -1, +1, -1, +1, -1, +1, -1, -1, -1, +1, − 1 , − 1 , − 1 , − 1 , + 1 , − 1 , + 1 , + 1 , − 1 , + 1 , + 1 , + 1 , − 1 , − 1 , + 1 , -1, -1, -1, -1, +1, -1, +1, +1, -1, +1, +1, +1, -1, -1, +1, + 1 , + 1 , − 1 , − 1 , − 1 , + 1 , + 1 , + 1 , + 1 , − 1 , + 1 , + 1 , + 1 , − 1 , + 1 , +1, +1, -1, -1, -1, +1, +1, +1, +1, -1, +1, +1, +1, -1, +1, − 1 , − 1 , − 1 , − 1 , + 1 , + 1 , + 1 , − 1 , + 1 , + 1 , − 1 , − 1 , + 1 , − 1 , − 1 , -1, -1, -1, -1, +1, +1, +1, -1, +1, +1, -1, -1, +1, -1, -1, − 1 , − 1 , + 1 , − 1 , − 1 , − 1 , + 1 , − 1 , + 1 , + 1 , − 1 , + 1 , + 1 , − 1 , + 1 -1, -1, +1, -1, -1, -1, +1, -1, +1, +1, -1, +1, +1, -1, +1 − 1 , − 1 , + 1 , − 1 , − 1 , − 1 , + 1 , + 1 , − 1 , − 1 , − 1 , + 1 , − 1 , − 1 , + 1 -1, -1, +1, -1, -1, -1, +1, +1, -1, -1, -1, +1, -1, -1, +1 − 1 , + 1 , + 1 , + 1 , − 1 , + 1 , + 1 , + 1 , + 1 , − 1 , − 1 , − 1 , − 1 , + 1 , + 1 , -1, +1, +1, +1, -1, +1, +1, +1, +1, -1, -1, -1, -1, +1, +1, + 1 , − 1 , + 1 , + 1 , − 1 , − 1 , + 1 , − 1 , − 1 , + 1 , + 1 , + 1 , + 1 , + 1 , − 1 , +1, -1, +1, +1, -1, -1, +1, -1, -1, +1, +1, +1, +1, +1, -1, + 1 , + 1 , + 1 , − 1 , + 1 , + 1 +1, +1, +1, -1, +1, +12. A method in a wireless local area network which supports Orthogonal Frequency Division Multiple Access, OFDMA, technology, wherein the method comprises: receiving a physical layer protocol data unit, PPDU; and determining, according to a size and a location of an allocated resource unit, RU, a corresponding long training sequence segment as a reference sequence that corresponds to the allocated RU for channel estimation, wherein the long training sequence corresponds with a bandwidth of the wireless local area network, wherein the long training sequence is a 2x mode long training sequence, wherein, when the bandwidth is 80 MHz, the 2x mode long training sequence includes values on subcarriers with indexes − 500 : 2 : 500 -500:2:500 , and the values on subcarriers with indexes − 500 : 2 : 500 -500:2:500 are +1, +1, -1, +1, +1, +1, -1, +1, +1, +1, -1, -1, -1, +1, − 1 , − 1 , + 1 , + 1 , − 1 , + 1 , + 1 , + 1 , − 1 , − 1 , − 1 , + 1 , + 1 , + 1 , -1, -1, +1, +1, -1, +1, +1, +1, -1, -1, -1, +1, +1, +1, +1, -1, +1, +1, +1, -1, +1, -1, -1, +1, -1, -1, +1, +1, − 1 , − 1 , − 1 , + 1 , − 1 , − 1 , + 1 , − 1 , + 1 , − 1 , + 1 , + 1 , − 1 , + 1 , -1, -1, -1, +1, -1, -1, +1, -1, +1, -1, +1, +1, -1, +1, − 1 , − 1 , − 1 , + 1 , − 1 , − 1 , − 1 , − 1 , + 1 , − 1 , − 1 , + 1 , + 1 , − 1 , + 1 -1, -1, -1, +1, -1, -1, -1, -1, +1, -1, -1, +1, +1, -1, +1 +1, +1, -1, -1, -1, -1, +1, -1, +1, +1, +1, +1, +1, +1, + 1 , − 1 , − 1 , − 1 , + 1 , + 1 , + 1 , − 1 , − 1 , + 1 , + 1 , + 1 , − 1 , + 1 , + 1 +1, -1, -1, -1, +1, +1, +1, -1, -1, +1, +1, +1, -1, +1, +1 − 1 , + 1 , − 1 , − 1 , − 1 , − 1 , + 1 , − 1 , − 1 , + 1 , − 1 , + 1 , − 1 , -1, +1, -1, -1, -1, -1, +1, -1, -1, +1, -1, +1, -1, + 1 , + 1 , − 1 , − 1 , − 1 , + 1 , − 1 , − 1 , + 1 , − 1 , + 1 , + 1 , − 1 , + 1 , +1, +1, -1, -1, -1, +1, -1, -1, +1, -1, +1, +1, -1, +1, + 1 , + 1 , − 1 , − 1 , + 1 , + 1 , + 1 , − 1 , + 1 , − 1 , + 1 , − 1 , + 1 , − 1 , + 1 , +1, +1, -1, -1, +1, +1, +1, -1, +1, -1, +1, -1, +1, -1, +1, − 1 , + 1 , + 1 , + 1 , − 1 , + 1 , + 1 , + 1 , + 1 , − 1 , − 1 , − 1 , + 1 , − 1 , − 1 , -1, +1, +1, +1, -1, +1, +1, +1, +1, -1, -1, -1, +1, -1, -1, + 1 , + 1 , − 1 , + 1 , + 1 , + 1 , − 1 , − 1 , − 1 , + 1 , + 1 , + 1 , + 1 , − 1 , − 1 , +1, +1, -1, +1, +1, +1, -1, -1, -1, +1, +1, +1, +1, -1, -1, − 1 , − 1 , + 1 , − 1 , − 1 , − 1 , + 1 , − 1 , + 1 , + 1 , + 1 , − 1 , − 1 , + 1 , + 1 , -1, -1, +1, -1, -1, -1, +1, -1, +1, +1, +1, -1, -1, +1, +1, + 1 , − 1 , + 1 , + 1 , − 1 , + 1 , − 1 , − 1 , − 1 , + 1 , − 1 , − 1 , + 1 , +1, -1, +1, +1, -1, +1, -1, -1, -1, +1, -1, -1, +1, − 1 , + 1 , + 1 , − 1 , + 1 , + 1 , − 1 , + 1 , + 1 , − 1 , − 1 , + 1 , − 1 , − 1 , − 1 , -1, +1, +1, -1, +1, +1, -1, +1, +1, -1, -1, +1, -1, -1, -1, + 1 , + 1 , + 1 , + 1 , − 1 , + 1 , − 1 , − 1 , − 1 , + 1 , − 1 , − 1 , − 1 , + 1 , +1, +1, +1, +1, -1, +1, -1, -1, -1, +1, -1, -1, -1, +1, + 1 , + 1 , + 1 , − 1 , − 1 , − 1 , + 1 , + 1 , + 1 , 0 , 0 , 0 , + 1 , − 1 , − 1 , +1, +1, +1, -1, -1, -1, +1, +1, +1, 0, 0, 0, +1, -1, -1, + 1 , + 1 , − 1 , + 1 , − 1 , − 1 , − 1 , + 1 , + 1 , + 1 , + 1 , + 1 , + 1 , + 1 , + 1 +1, +1, -1, +1, -1, -1, -1, +1, +1, +1, +1, +1, +1, +1, +1 − 1 , + 1 , − 1 , − 1 , − 1 , − 1 , + 1 , + 1 , + 1 , − 1 , + 1 , + 1 , − 1 , + 1 -1, +1, -1, -1, -1, -1, +1, +1, +1, -1, +1, +1, -1, +1 − 1 , − 1 , + 1 , − 1 , − 1 , + 1 , − 1 , + 1 , + 1 , + 1 , + 1 , + 1 , + 1 , + 1 , + 1 -1, -1, +1, -1, -1, +1, -1, +1, +1, +1, +1, +1, +1, +1, +1 − 1 , + 1 , − 1 , − 1 , + 1 , − 1 , − 1 , + 1 , + 1 , − 1 , − 1 , − 1 , + 1 , − 1 , -1, +1, -1, -1, +1, -1, -1, +1, +1, -1, -1, -1, +1, -1, +1, +1, +1, -1, +1, +1, +1, -1, -1, -1, +1, +1, +1, +1, − 1 , − 1 , − 1 , + 1 , − 1 , − 1 , + 1 , + 1 , − 1 , + 1 , + 1 , + 1 , − 1 , − 1 , − 1 , -1, -1, -1, +1, -1, -1, +1, +1, -1, +1, +1, +1, -1, -1, -1, − 1 , + 1 , − 1 , − 1 , − 1 , + 1 , − 1 , + 1 , − 1 , + 1 , − 1 , − 1 , + 1 , − 1 , -1, +1, -1, -1, -1, +1, -1, +1, -1, +1, -1, -1, +1, -1, − 1 , − 1 , + 1 , + 1 , − 1 , − 1 , − 1 , + 1 , − 1 , + 1 , + 1 , + 1 , + 1 , + 1 -1, -1, +1, +1, -1, -1, -1, +1, -1, +1, +1, +1, +1, +1 − 1 , + 1 , + 1 , + 1 , − 1 , + 1 , − 1 , + 1 , − 1 , + 1 , − 1 , − 1 , − 1 , + 1 , -1, +1, +1, +1, -1, +1, -1, +1, -1, +1, -1, -1, -1, +1, − 1 , − 1 , − 1 , − 1 , + 1 , − 1 , + 1 , + 1 , − 1 , + 1 , + 1 , + 1 , − 1 , − 1 , + 1 , -1, -1, -1, -1, +1, -1, +1, +1, -1, +1, +1, +1, -1, -1, +1, + 1 , + 1 , − 1 , − 1 , − 1 , + 1 , + 1 , + 1 , + 1 , − 1 , + 1 , + 1 , + 1 , − 1 , + 1 , +1, +1, -1, -1, -1, +1, +1, +1, +1, -1, +1, +1, +1, -1, +1, − 1 , − 1 , − 1 , − 1 , + 1 , + 1 , + 1 , − 1 , + 1 , + 1 , − 1 , − 1 , + 1 , − 1 , − 1 , -1, -1, -1, -1, +1, +1, +1, -1, +1, +1, -1, -1, +1, -1, -1, − 1 , − 1 , + 1 , − 1 , − 1 , − 1 , + 1 , − 1 , + 1 , + 1 , − 1 , + 1 , + 1 , − 1 , + 1 , -1, -1, +1, -1, -1, -1, +1, -1, +1, +1, -1, +1, +1, -1, +1, − 1 , − 1 , + 1 , − 1 , − 1 , − 1 , + 1 , + 1 , − 1 , − 1 , − 1 , + 1 , − 1 , − 1 , + 1 , -1, -1, +1, -1, -1, -1, +1, +1, -1, -1, -1, +1, -1, -1, +1, − 1 , + 1 , + 1 , + 1 , − 1 , + 1 , + 1 , + 1 , + 1 , − 1 , − 1 , − 1 , − 1 , + 1 , + 1 , -1, +1, +1, +1, -1, +1, +1, +1, +1, -1, -1, -1, -1, +1, +1, + 1 , − 1 , + 1 , + 1 , − 1 , − 1 , + 1 , − 1 , − 1 , − 1 , + 1 , + 1 , + 1 , + 1 , − 1 , +1, -1, +1, +1, -1, -1, +1, -1, -1, -1, +1, +1, +1, +1, -1, + 1 , + 1 , + 1 , − 1 , + 1 , + 1 . +1, +1, +1, -1, +1, +1.

3. The method according to claim 1 or 2, wherein the method comprises: storing the long training sequence; or storing a sub-sequence configured for constructing the long training sequence.

4. The method according to claim 1 or 2, wherein the 2x mode long training sequence corresponds to [Image disponible dans le document PDF, Image available in the PDF document] [Image disponible dans le document PDF, Image available in the PDF document] [Image disponible dans le document PDF, Image available in the PDF document] [Image disponible dans le document PDF, Image available in the PDF document] [Image disponible dans le document PDF, Image available in the PDF document] [Image disponible dans le document PDF, Image available in the PDF document] wherein G a = { + 1 , + 1 , + 1 , − 1 , + 1 , + 1 , + 1 , − 1 , + 1 , − 1 , + 1 , − 1 , + 1 , − 1 } G_a = \{+1, +1, +1, -1, +1, +1, +1, -1, +1, -1, +1, -1, +1, -1\} , [Image disponible dans le document PDF, Image available in the PDF document] G a p G_a^p is a sequence that is obtained after a phase of a value at a pilot location of the G a G_a sequence is reversed, G b p G_b^p is a sequence that is obtained after a phase of a value at a pilot location of the G b G_b sequence is reversed, G c G_c is a sequence that is obtained after a phase of a value on an even-numbered subcarrier of the Ga sequence is reversed, G d G_d is a sequence that is obtained after a phase of a value on an even-numbered subcarrier of the G b sequence is reversed, G c p G_{c}^{p} is a sequence that is obtained after a phase of a value at a pilot location of a G c p G_{c}^{p} sequence is reversed, and G d p G_{d}^{p} is a sequence that is obtained after a phase of a value at a pilot location of a G d G_d sequence is reversed.

5. The method according to claim 1 or 2, wherein the allocated RU corresponds to an RU formed by 26 consecutive subcarriers, an RU formed by 52 consecutive subcarriers, an RU formed by 106 consecutive subcarriers, an RU formed by 242 consecutive subcarriers, an RU formed by 484 consecutive subcarriers, or an RU formed by 996 consecutive subcarriers.

6. An apparatus for sending a long training sequence in a wireless local area network which supports Orthogonal Frequency Division Multiple Access, OFDMA, technology, wherein the apparatus comprises: a module configured to select a long training sequence according to a bandwidth, wherein the long training sequence is a 2x mode long training sequence; and a module configured to send a sub-sequence segment of the long training sequence according to a location and a size of an allocated resource unit, RU, wherein the sub-sequence segment at a corresponding location of the long training sequence is carried on subcarriers at the corresponding location, wherein, when the bandwidth is 80 MHz, the 2x mode long training sequence includes values on subcarriers with indexes -500:2:500, and the values on subcarriers with indexes -500:2:500 are + 1 , + 1 , − 1 , + 1 , + 1 , + 1 , − 1 , + 1 , + 1 , + 1 , + 1 , − 1 , − 1 , − 1 , + 1 , +1, +1, -1, +1, +1, +1, -1, +1, +1, +1, +1, -1, -1, -1, +1, − 1 , − 1 , + 1 , + 1 , − 1 , + 1 , + 1 , + 1 , − 1 , − 1 , − 1 , − 1 , + 1 , + 1 , + 1 , -1, -1, +1, +1, -1, +1, +1, +1, -1, -1, -1, -1, +1, +1, +1, + 1 , − 1 , + 1 , + 1 , + 1 , − 1 , + 1 , − 1 , − 1 , + 1 , − 1 , − 1 , + 1 , + 1 , +1, -1, +1, +1, +1, -1, +1, -1, -1, +1, -1, -1, +1, +1, − 1 , − 1 , − 1 , + 1 , − 1 , − 1 , + 1 , − 1 , + 1 , − 1 , + 1 , + 1 , − 1 , + 1 , -1, -1, -1, +1, -1, -1, +1, -1, +1, -1, +1, +1, -1, +1, − 1 , − 1 , − 1 , + 1 , − 1 , − 1 , − 1 , − 1 , + 1 , − 1 , − 1 , + 1 , + 1 , − 1 , + 1 , -1, -1, -1, +1, -1, -1, -1, -1, +1, -1, -1, +1, +1, -1, +1, + 1 , + 1 , − 1 , − 1 , − 1 , − 1 , + 1 , − 1 , + 1 , + 1 , + 1 , + 1 , + 1 , + 1 , + 1 +1, +1, -1, -1, -1, -1, +1, -1, +1, +1, +1, +1, +1, +1, +1 + 1 , − 1 , − 1 , − 1 , + 1 , + 1 , + 1 , − 1 , − 1 , + 1 , + 1 , + 1 , + 1 , + 1 , + 1 , + 1 +1, -1, -1, -1, +1, +1, +1, -1, -1, +1, +1, +1, +1, +1, +1, +1 − 1 , + 1 , − 1 , − 1 , − 1 , − 1 , + 1 , − 1 , − 1 , + 1 , − 1 , + 1 , − 1 , -1, +1, -1, -1, -1, -1, +1, -1, -1, +1, -1, +1, -1, + 1 , + 1 , − 1 , − 1 , − 1 , + 1 , − 1 , − 1 , + 1 , − 1 , + 1 , + 1 , − 1 , + 1 , +1, +1, -1, -1, -1, +1, -1, -1, +1, -1, +1, +1, -1, +1, + 1 , + 1 , − 1 , − 1 , + 1 , + 1 , + 1 , − 1 , + 1 , − 1 , + 1 , − 1 , + 1 , − 1 , + 1 , +1, +1, -1, -1, +1, +1, +1, -1, +1, -1, +1, -1, +1, -1, +1, − 1 , + 1 , + 1 , + 1 , − 1 , + 1 , + 1 , + 1 , + 1 , − 1 , − 1 , − 1 , + 1 , − 1 , − 1 , -1, +1, +1, +1, -1, +1, +1, +1, +1, -1, -1, -1, +1, -1, -1, + 1 , + 1 , − 1 , + 1 , + 1 , + 1 , − 1 , − 1 , − 1 , + 1 , + 1 , + 1 , + 1 , − 1 , − 1 , +1, +1, -1, +1, +1, +1, -1, -1, -1, +1, +1, +1, +1, -1, -1, − 1 , − 1 , + 1 , − 1 , − 1 , − 1 , + 1 , − 1 , + 1 , + 1 , + 1 , − 1 , − 1 , + 1 , + 1 , -1, -1, +1, -1, -1, -1, +1, -1, +1, +1, +1, -1, -1, +1, +1, + 1 , − 1 , + 1 , + 1 , − 1 , + 1 , − 1 , − 1 , − 1 , − 1 , + 1 , − 1 , − 1 , − 1 , + 1 , +1, -1, +1, +1, -1, +1, -1, -1, -1, -1, +1, -1, -1, -1, +1, − 1 , + 1 , + 1 , − 1 , + 1 , + 1 , − 1 , + 1 , + 1 , − 1 , − 1 , + 1 , − 1 , − 1 , − 1 , -1, +1, +1, -1, +1, +1, -1, +1, +1, -1, -1, +1, -1, -1, -1, + 1 , + 1 , + 1 , + 1 , − 1 , + 1 , − 1 , − 1 , − 1 , + 1 , − 1 , − 1 , − 1 , + 1 , +1, +1, +1, +1, -1, +1, -1, -1, -1, +1, -1, -1, -1, +1, + 1 , + 1 , + 1 , − 1 , − 1 , − 1 , + 1 , + 1 , + 1 , 0 , 0 , 0 , + 1 , − 1 , − 1 , +1, +1, +1, -1, -1, -1, +1, +1, +1, 0, 0, 0, +1, -1, -1, +1, +1, -1, +1, -1, -1, -1, +1, +1, +1, +1, +1, +1, +1, +1, − 1 , + 1 , − 1 , − 1 , − 1 , − 1 , + 1 , + 1 , + 1 , − 1 , + 1 , + 1 , − 1 , − 1 , + 1 , -1, +1, -1, -1, -1, -1, +1, +1, +1, -1, +1, +1, -1, -1, +1, − 1 , − 1 , + 1 , − 1 , − 1 , + 1 , − 1 , + 1 , + 1 , + 1 , + 1 , + 1 , + 1 , + 1 , + 1 -1, -1, +1, -1, -1, +1, -1, +1, +1, +1, +1, +1, +1, +1, +1 − 1 , + 1 , − 1 , − 1 , + 1 , − 1 , − 1 , + 1 , + 1 , − 1 , − 1 , − 1 , + 1 , − 1 , -1, +1, -1, -1, +1, -1, -1, +1, +1, -1, -1, -1, +1, -1, +1, +1, +1, -1, +1, +1, +1, -1, -1, -1, +1, +1, +1, +1, − 1 , − 1 , − 1 , + 1 , − 1 , − 1 , + 1 , + 1 , − 1 , + 1 , + 1 , + 1 , − 1 , − 1 , − 1 , -1, -1, -1, +1, -1, -1, +1, +1, -1, +1, +1, +1, -1, -1, -1, − 1 , + 1 , − 1 , − 1 , − 1 , + 1 , − 1 , + 1 , − 1 , + 1 , − 1 , − 1 , + 1 , − 1 , -1, +1, -1, -1, -1, +1, -1, +1, -1, +1, -1, -1, +1, -1, − 1 , − 1 , + 1 , + 1 , − 1 , − 1 , − 1 , + 1 , − 1 , + 1 , + 1 , + 1 , + 1 , + 1 -1, -1, +1, +1, -1, -1, -1, +1, -1, +1, +1, +1, +1, +1 − 1 -1 , + 1 +1 , + 1 +1 , + 1 +1 , − 1 -1 , + 1 +1 , − 1 -1 , + 1 +1 , − 1 -1 , + 1 +1 , − 1 -1 , − 1 -1 , − 1 -1 , + 1 +1 , − 1 , − 1 , − 1 , − 1 , + 1 , − 1 , + 1 , + 1 , − 1 , + 1 , + 1 , + 1 , − 1 , − 1 , + 1 , -1, -1, -1, -1, +1, -1, +1, +1, -1, +1, +1, +1, -1, -1, +1, + 1 , + 1 , − 1 , − 1 , − 1 , + 1 , + 1 , + 1 , + 1 , − 1 , + 1 , + 1 , + 1 , + 1 , + 1 , + 1 +1, +1, -1, -1, -1, +1, +1, +1, +1, -1, +1, +1, +1, +1, +1, +1 − 1 , − 1 , − 1 , − 1 , + 1 , + 1 , + 1 , − 1 , + 1 , + 1 , − 1 , − 1 , + 1 , − 1 , − 1 , -1, -1, -1, -1, +1, +1, +1, -1, +1, +1, -1, -1, +1, -1, -1, − 1 , − 1 , + 1 , − 1 , − 1 , − 1 , + 1 , − 1 , + 1 , + 1 , − 1 , + 1 , + 1 , − 1 , + 1 -1, -1, +1, -1, -1, -1, +1, -1, +1, +1, -1, +1, +1, -1, +1 − 1 , − 1 , + 1 , − 1 , − 1 , − 1 , + 1 , + 1 , − 1 , − 1 , − 1 , + 1 , − 1 , − 1 , + 1 , -1, -1, +1, -1, -1, -1, +1, +1, -1, -1, -1, +1, -1, -1, +1, − 1 , + 1 , + 1 , + 1 , − 1 , + 1 , + 1 , + 1 , + 1 , − 1 , − 1 , − 1 , − 1 , + 1 , + 1 , -1, +1, +1, +1, -1, +1, +1, +1, +1, -1, -1, -1, -1, +1, +1, + 1 , − 1 , + 1 , + 1 , − 1 , − 1 , + 1 , − 1 , − 1 , + 1 , + 1 , + 1 , + 1 , + 1 , − 1 , +1, -1, +1, +1, -1, -1, +1, -1, -1, +1, +1, +1, +1, +1, -1, + 1 , + 1 , + 1 , − 1 , + 1 , + 1 +1, +1, +1, -1, +1, +17. An apparatus in a wireless local area network which supports Orthogonal Frequency Division Multiple Access, OFDMA, technology, wherein the apparatus comprises: a module configured to receive a physical layer protocol data unit, PPDU; and a module configured to determine, according to a size and a location of an allocated resource unit, RU, a corresponding long training sequence segment as a reference sequence that corresponds to the allocated RU for channel estimation, wherein the long training sequence corresponds with a bandwidth of the wireless local area network, wherein the long training sequence is a 2x mode long training sequence, wherein, when the bandwidth is 80 MHz, the 2x mode long training sequence includes values on subcarriers with indexes -500:2:500, and the values on subcarriers with indexes -500:2:500 are + 1 , + 1 , − 1 , + 1 , + 1 , + 1 , − 1 , + 1 , + 1 , + 1 , + 1 , − 1 , − 1 , − 1 , + 1 , +1, +1, -1, +1, +1, +1, -1, +1, +1, +1, +1, -1, -1, -1, +1, − 1 , − 1 , + 1 , + 1 , − 1 , + 1 , + 1 , + 1 , − 1 , − 1 , − 1 , − 1 , + 1 , + 1 , + 1 , -1, -1, +1, +1, -1, +1, +1, +1, -1, -1, -1, -1, +1, +1, +1, + 1 , − 1 , + 1 , + 1 , + 1 , − 1 , + 1 , − 1 , − 1 , + 1 , − 1 , − 1 , + 1 , + 1 , +1, -1, +1, +1, +1, -1, +1, -1, -1, +1, -1, -1, +1, +1, − 1 , − 1 , − 1 , + 1 , − 1 , − 1 , + 1 , − 1 , + 1 , + 1 , − 1 , + 1 , + 1 , − 1 , + 1 -1, -1, -1, +1, -1, -1, +1, -1, +1, +1, -1, +1, +1, -1, +1 − 1 , − 1 , − 1 , + 1 , − 1 , − 1 , − 1 , − 1 , + 1 , − 1 , − 1 , + 1 , + 1 , − 1 , + 1 , -1, -1, -1, +1, -1, -1, -1, -1, +1, -1, -1, +1, +1, -1, +1, + 1 , + 1 , − 1 , − 1 , − 1 , − 1 , + 1 , − 1 , + 1 , + 1 , + 1 , + 1 , + 1 , + 1 , + 1 +1, +1, -1, -1, -1, -1, +1, -1, +1, +1, +1, +1, +1, +1, +1 + 1 , − 1 , − 1 , − 1 , + 1 , + 1 , + 1 , − 1 , − 1 , + 1 , + 1 , + 1 , + 1 , + 1 , + 1 +1, -1, -1, -1, +1, +1, +1, -1, -1, +1, +1, +1, +1, +1, +1 − 1 , + 1 , − 1 , − 1 , − 1 , − 1 , + 1 , − 1 , − 1 , + 1 , − 1 , + 1 , − 1 , -1, +1, -1, -1, -1, -1, +1, -1, -1, +1, -1, +1, -1, + 1 , + 1 , − 1 , − 1 , − 1 , + 1 , − 1 , − 1 , + 1 , − 1 , + 1 , + 1 , − 1 , + 1 , +1, +1, -1, -1, -1, +1, -1, -1, +1, -1, +1, +1, -1, +1, + 1 , + 1 , − 1 , − 1 , + 1 , + 1 , + 1 , − 1 , + 1 , + 1 , − 1 , + 1 , − 1 , + 1 , +1, +1, -1, -1, +1, +1, +1, -1, +1, +1, -1, +1, -1, +1, − 1 , + 1 , + 1 , + 1 , − 1 , + 1 , + 1 , + 1 , + 1 , − 1 , − 1 , − 1 , + 1 , − 1 , − 1 , -1, +1, +1, +1, -1, +1, +1, +1, +1, -1, -1, -1, +1, -1, -1, + 1 , + 1 , − 1 , + 1 , + 1 , + 1 , − 1 , − 1 , − 1 , + 1 , + 1 , + 1 , + 1 , − 1 , − 1 , +1, +1, -1, +1, +1, +1, -1, -1, -1, +1, +1, +1, +1, -1, -1, − 1 , − 1 , + 1 , − 1 , − 1 , − 1 , + 1 , − 1 , + 1 , + 1 , + 1 , − 1 , − 1 , + 1 , + 1 , -1, -1, +1, -1, -1, -1, +1, -1, +1, +1, +1, -1, -1, +1, +1, + 1 , − 1 , + 1 , + 1 , − 1 , + 1 , − 1 , − 1 , − 1 , + 1 , − 1 , − 1 , + 1 , +1, -1, +1, +1, -1, +1, -1, -1, -1, +1, -1, -1, +1, − 1 , + 1 , + 1 , − 1 , + 1 , + 1 , − 1 , + 1 , + 1 , − 1 , − 1 , + 1 , − 1 , − 1 , − 1 , -1, +1, +1, -1, +1, +1, -1, +1, +1, -1, -1, +1, -1, -1, -1, + 1 , + 1 , + 1 , + 1 , − 1 , + 1 , − 1 , − 1 , − 1 , + 1 , − 1 , − 1 , − 1 , + 1 , +1, +1, +1, +1, -1, +1, -1, -1, -1, +1, -1, -1, -1, +1, + 1 , + 1 , + 1 , − 1 , − 1 , − 1 , + 1 , + 1 , + 1 , 0 , 0 , 0 , + 1 , − 1 , − 1 , +1, +1, +1, -1, -1, -1, +1, +1, +1, 0, 0, 0, +1, -1, -1, + 1 , + 1 , − 1 , + 1 , − 1 , − 1 , − 1 , + 1 , + 1 , + 1 , + 1 , + 1 , + 1 , + 1 , + 1 +1, +1, -1, +1, -1, -1, -1, +1, +1, +1, +1, +1, +1, +1, +1 − 1 , + 1 , − 1 , − 1 , − 1 , − 1 , + 1 , + 1 , + 1 , − 1 , + 1 , + 1 , − 1 , − 1 , + 1 , -1, +1, -1, -1, -1, -1, +1, +1, +1, -1, +1, +1, -1, -1, +1, − 1 , − 1 , + 1 , − 1 , − 1 , + 1 , − 1 , + 1 , + 1 , + 1 , + 1 , + 1 , + 1 , + 1 , + 1 -1, -1, +1, -1, -1, +1, -1, +1, +1, +1, +1, +1, +1, +1, +1 − 1 , + 1 , − 1 , − 1 , + 1 , − 1 , − 1 , + 1 , + 1 , − 1 , − 1 , − 1 , + 1 , − 1 , -1, +1, -1, -1, +1, -1, -1, +1, +1, -1, -1, -1, +1, -1, +1, +1, +1, -1, +1, +1, +1, -1, -1, -1, +1, +1, +1, +1 − 1 , − 1 , − 1 , + 1 , − 1 , − 1 , + 1 , + 1 , − 1 , + 1 , + 1 , + 1 , − 1 , − 1 , − 1 , -1, -1, -1, +1, -1, -1, +1, +1, -1, +1, +1, +1, -1, -1, -1, − 1 , + 1 , − 1 , − 1 , + 1 , − 1 , + 1 , + 1 , − 1 , + 1 , − 1 , + 1 , − 1 , + 1 , − 1 , -1, +1, -1, -1, +1, -1, +1, +1, -1, +1, -1, +1, -1, +1, -1, − 1 , − 1 , + 1 , + 1 , − 1 , − 1 , − 1 , + 1 , − 1 , + 1 , + 1 , + 1 , + 1 , + 1 -1, -1, +1, +1, -1, -1, -1, +1, -1, +1, +1, +1, +1, +1 − 1 , + 1 , + 1 , + 1 , − 1 , + 1 , − 1 , + 1 , − 1 , + 1 , − 1 , − 1 , − 1 , + 1 , -1, +1, +1, +1, -1, +1, -1, +1, -1, +1, -1, -1, -1, +1, − 1 , − 1 , − 1 , − 1 , + 1 , − 1 , + 1 , + 1 , − 1 , + 1 , + 1 , + 1 , − 1 , − 1 , + 1 , -1, -1, -1, -1, +1, -1, +1, +1, -1, +1, +1, +1, -1, -1, +1, + 1 , + 1 , − 1 , − 1 , − 1 , + 1 , + 1 , + 1 , + 1 , − 1 , + 1 , + 1 , + 1 , + 1 , + 1 , + 1 +1, +1, -1, -1, -1, +1, +1, +1, +1, -1, +1, +1, +1, +1, +1, +1 − 1 , − 1 , − 1 , − 1 , + 1 , + 1 , + 1 , − 1 , + 1 , + 1 , − 1 , − 1 , + 1 , − 1 , − 1 , -1, -1, -1, -1, +1, +1, +1, -1, +1, +1, -1, -1, +1, -1, -1, − 1 , − 1 , + 1 , − 1 , − 1 , − 1 , + 1 , − 1 , + 1 , + 1 , − 1 , + 1 , + 1 , − 1 , + 1 , -1, -1, +1, -1, -1, -1, +1, -1, +1, +1, -1, +1, +1, -1, +1, − 1 , − 1 , + 1 , − 1 , − 1 , − 1 , + 1 , + 1 , − 1 , − 1 , − 1 , + 1 , − 1 , − 1 , + 1 , -1, -1, +1, -1, -1, -1, +1, +1, -1, -1, -1, +1, -1, -1, +1, − 1 , + 1 , + 1 , + 1 , − 1 , + 1 , + 1 , + 1 , + 1 , − 1 , − 1 , − 1 , − 1 , + 1 , + 1 , -1, +1, +1, +1, -1, +1, +1, +1, +1, -1, -1, -1, -1, +1, +1, + 1 , − 1 , + 1 , + 1 , − 1 , − 1 , + 1 , − 1 , − 1 , + 1 , + 1 , + 1 , + 1 , + 1 , − 1 +1, -1, +1, +1, -1, -1, +1, -1, -1, +1, +1, +1, +1, +1, -1 + 1 , + 1 , + 1 , − 1 , + 1 , + 1 +1, +1, +1, -1, +1, +18. The apparatus according to claim 6 or 7, wherein the apparatus further comprises a module, configured to store the long training sequence, or store a sub-sequence configured for constructing the long training sequence.

9. The apparatus according to claim 6 or 7, wherein the 2x mode long traing sequence corresponds to [Image disponible dans le document PDF, Image available in the PDF document] [Image disponible dans le document PDF, Image available in the PDF document] [Image disponible dans le document PDF, Image available in the PDF document] [Image disponible dans le document PDF, Image available in the PDF document] [Image disponible dans le document PDF, Image available in the PDF document] , wherein G a = { + 1 , + 1 , + 1 , − 1 , + 1 , + 1 , + 1 , − 1 , + 1 , − 1 , + 1 , − 1 , + 1 , − 1 } G_a = \{+1, +1, +1, -1, +1, +1, +1, -1, +1, -1, +1, -1, +1, -1\} [Image disponible dans le document PDF, Image available in the PDF document] G a p G_a^p is a sequence that is obtained after a phase of a value at a pilot location of the G a G_a sequence is reversed, G b p G_b^p is a sequence that is obtained after a phase of a value at a pilot location of the G b G_b sequence is reversed, G c G_c is a sequence that is obtained after a phase of a value on an even-numbered subcarrier of the Ga sequence is reversed, G d G_d is a sequence that is obtained after a phase of a value on an even-numbered subcarrier of the G b sequence is reversed, G c p G_c^p is a sequence that is obtained after a phase of a value at a pilot location of a G c p G_c^p sequence is reversed, and G d p G^{p}_{d} is a sequence that is obtained after a phase of a value at a pilot location of a G d p G^{p}_{d} sequence is reversed.

10. The apparatus according to claim 6 or 7, wherein the allocated RU corresponds to an RU formed by 26 consecutive subcarriers, an RU formed by 52 consecutive subcarriers, an RU formed by 106 consecutive subcarriers, an RU formed by 242 consecutive subcarriers, an RU formed by 484 consecutive subcarriers, or an RU formed by 996 consecutive subcarriers.