Communication method and device

Abstract

The invention relates to the technical field of communication, in particular to a communication method and device. The method can be applied to the IEEE 802.11 ax standard, the 802.11 be standard, the 802.11 bn standard and the like and other standards of the IEEE 802.11 series, such as the 802.15 standard, the 802.11 bf standard, the IMMW standard or the star flash standard and the like. According to the invention, a new LTF sequence is designed, and the PAPR of an LTF field can be reduced by the LTF sequence. The LTF sequence comprises a non-zero LTF sequence value, and the non-zero LTF sequence value corresponds to a subcarrier. The LTF sequence can meet the following conditions: the LTF sequence value corresponding to the first subcarrier group is opposite to the LTF sequence value corresponding to the second subcarrier group, and the LTF sequence value corresponding to the third subcarrier group is the same as the LTF sequence value corresponding to the fourth subcarrier group.

Description

Technical Field

[0001] This application relates to the field of communication technology, and in particular to a communication method and apparatus. Background Technology

[0002] Wireless local area networks (WLANs) have evolved from 802.11a / b / g to 802.11n, 802.11ac, 802.11ax, 802.11be, and 802.11bn. The 802.11a / b / g standards are collectively referred to as non-high throughput (non-HT), the 802.11n standard as high throughput (HT), the 802.11ac standard as very high throughput (VHT), the 802.11ax standard as high efficient (HE), the 802.11be standard as extremely high throughput (EHT), and the 802.11bn standard as ultra-high reliability (UHR).

[0003] With the increasing number of WLAN-based Internet of Things (IoT) devices and the difficulty of deploying multiple access points (APs) in home environments, the demand for WLAN to support long-distance transmission is growing. The 802.11b standard employs direct-sequence spread spectrum (DSSS) modulation to convert digital signals into wider-bandwidth analog signals, enhancing data transmission reliability. However, long-distance transmission schemes based on the 802.11b standard have low spectral efficiency, and the standard is relatively old, making network management difficult. Therefore, in 802.11bn or later standards, long-distance transmission, such as enhanced long-range (ELR) transmission based on orthogonal frequency division multiplexing (OFDM) modulation, has become a research hotspot.

[0004] LTF sequences are an important part of channel estimation in WLAN networks and are currently a research hotspot. Summary of the Invention

[0005] This application provides a communication method and apparatus that can effectively reduce the PAPR of long training field (LTF) fields, or the PAPR of LTF sequences.

[0006] In a first aspect, embodiments of this application provide a communication method applied to a first site, which may be a Wi-Fi device, or a chip or functional module placed within the Wi-Fi device, including but not limited to an IoT device. The method includes:

[0007] An LTF field is generated based on an LTF sequence, which satisfies at least one of the following: the LTF sequence value corresponding to the first subcarrier group is opposite to the LTF sequence value corresponding to the second subcarrier group, and the LTF sequence value corresponding to the third subcarrier group is the same as the LTF sequence value corresponding to the fourth subcarrier group; an enhanced long range physical protocol data unit (ELR-PPDU) including the LTF field is transmitted.

[0008] In other words, the LTF sequence value corresponding to the i-th subcarrier in the first subcarrier group is the opposite of the LTF sequence value corresponding to the i-th subcarrier in the second subcarrier group, and the LTF sequence value corresponding to the i-th subcarrier in the third subcarrier group is the same as the LTF sequence value corresponding to the i-th subcarrier in the fourth subcarrier group.

[0009] The number of subcarriers is the same in the first to fourth subcarrier groups. The LTF field includes one or more OFDM symbols.

[0010] In this embodiment of the application, the LTF sequence value corresponding to the subcarrier in each of the above subcarrier groups is 1 or -1. By satisfying the above characteristics, the LTF sequence can effectively reduce the PAPR of the LTF field and improve system performance.

[0011] Secondly, embodiments of this application provide a communication method applied to a second station, which may be a Wi-Fi device, or a chip or functional module placed within the Wi-Fi device, including but not limited to an IoT device. The method includes:

[0012] Receive an ELR-PPDU, which includes an LTF field; perform channel estimation based on the LTF sequence and the LTF field, wherein the LTF sequence satisfies at least one of the following: the LTF sequence value corresponding to the first subcarrier group is opposite to the LTF sequence value corresponding to the second subcarrier group, and the LTF sequence value corresponding to the third subcarrier group is the same as the LTF sequence value corresponding to the fourth subcarrier group.

[0013] The LTF sequence value corresponding to the subcarriers in each of the above subcarrier groups is 1 or -1. For an explanation of the beneficial effects of the second aspect, please refer to the first aspect; details will not be elaborated here.

[0014] In conjunction with either the first or second aspect, in one possible implementation, the LTF sequence is a 2xLTF sequence pattern. That is, this LTF sequence can also be called a 2x LTF sequence. In this LTF sequence, there is at least one zero separating two adjacent non-zero elements.

[0015] In conjunction with the first or second aspect, in one possible implementation, the LTF sequence value corresponding to the first subcarrier group is [1 1 -1 -1 1 1 1 1 1 1 1 1 -1 -1], or the LTF sequence value corresponding to the first subcarrier group is the LTF sequence value after processing [1 1-1 -1 1 1 1 1 1 1 1 1 -1 -1]. The processing method includes at least one of the following: reversing the order, inverting all elements, or inverting some elements.

[0016] In conjunction with the first or second aspect, in one possible implementation, the LTF sequence value corresponding to the first subcarrier group is [1 1 -1 -1 1 1 1 1 1 1 1 -1 -1], or the LTF sequence value corresponding to the first subcarrier group is [-1 -1 1 1 -1 -1 -1 -1 -1 -1 -1 -1 1 1], or the LTF sequence value corresponding to the first subcarrier group is [-1 1 1 -1 -1 1 -1 1 -1 1 -1 -1 1 -1 1], or the LTF sequence value corresponding to the first subcarrier group is [1 -1 -1 1 1 -1 1 -1 1 -1 1 -1 1 1 -1].

[0017] In conjunction with the first or second aspect, in one possible implementation, the LTF sequence value corresponding to the third subcarrier group is [-1 -1 -1 1 1 1 -1 -1 1 1 1 1 1], or the LTF sequence value corresponding to the third subcarrier group is the LTF sequence value after processing [-1 -1 -1 1 1 1 -1 -1 1 1 1 1 1]. The processing method includes at least one of the following: reversing the order, inverting all elements, or inverting some elements.

[0018] In conjunction with the first or second aspect, in one possible implementation, the LTF sequence value corresponding to the third subcarrier group is [-1 -1 -1 1 1 1 -1 -1 1 1 1 1 1 1], or the LTF sequence value corresponding to the third subcarrier group is [1 11 -1 -1 -1 1 1 -1 -1 -1 -1 -1 -1], or the LTF sequence value corresponding to the third subcarrier group is [1 -1 1 1 -11 1 -1 -1 1 -1 1 -1 1 -1], or the LTF sequence value corresponding to the third subcarrier group is [-1 1 -1 -1 1 -1 -1 11 -1 1 -1 1 1 -1 1].

[0019] In conjunction with the first or second aspect, in one possible implementation, the index of the subcarrier in the first to fourth subcarrier groups is less than 0, or the index of the subcarrier in the first to fourth subcarrier groups is greater than 0.

[0020] In conjunction with the first or second aspect, in one possible implementation, when the index of a subcarrier in the first to fourth subcarrier groups is less than 0, the non-zero LTF sequence value corresponding to the subcarrier with an index greater than 0 is determined based on the odd-numbered and even-numbered LTF sequence values ​​among the LTF sequence values ​​corresponding to the subcarriers in the first to fourth subcarrier groups; or, when the index of a subcarrier in the first to fourth subcarrier groups is greater than 0, the non-zero LTF sequence value corresponding to the subcarrier with an index less than 0 is determined based on the odd-numbered and even-numbered LTF sequence values ​​among the LTF sequence values ​​corresponding to the subcarriers in the first to fourth subcarrier groups.

[0021] In conjunction with the first or second aspect, in one possible implementation, the subcarrier index in the first subcarrier group is [-120:2:-96], the subcarrier index in the second subcarrier group is [-68:2:-44], or the subcarrier index in the second subcarrier group is [-42:2:-18]; the subcarrier index in the third subcarrier group is [-94:2:-70], the subcarrier index in the fourth subcarrier group is [-42:2:-18], or the subcarrier index in the fourth subcarrier group is [-68:2:-44];

[0022] Alternatively, the subcarrier index in the first subcarrier group is [120:-2:96], the subcarrier index in the second subcarrier group is [68:-2:44], or the subcarrier index in the second subcarrier group is [42:-2:18]; the subcarrier index in the third subcarrier group is [94:-2:70], the subcarrier index in the fourth subcarrier group is [42:-2:18], or the subcarrier index in the fourth subcarrier group is [68:-2:44].

[0023] In conjunction with the first or second aspect, in one possible implementation, when the index of a subcarrier in the first to fourth subcarrier groups is less than 0, the LTF sequence value corresponding to the other subcarriers in the subcarriers with indices less than 0, excluding the subcarriers in the first to fourth subcarrier groups, is 0.

[0024] In conjunction with the first or second aspect, in one possible implementation, when the index of a subcarrier in the first to fourth subcarrier groups is greater than 0, the LTF sequence value corresponding to the other subcarriers in the subcarriers with indexes greater than 0, excluding the subcarriers in the first to fourth subcarrier groups, is 0.

[0025] In conjunction with the first or second aspect, in one possible implementation, the bandwidth used for transmitting ELR-PPDU is 20MHz. Taking a subcarrier spacing of 78.125KHz as an example, there are 256 subcarriers within 20MHz, with an index range of [-128:127].

[0026] In conjunction with the first or second aspect, in one possible implementation, the ELR-PPDU also includes an ELR-data field, the RU corresponding to which is four 52-tone RUs. That is, the data information of this ELR-data field is transmitted on four 52-tone RUs.

[0027] In conjunction with the first or second aspect, in one possible implementation, the ELR-PPDU also includes ELR signaling (SIG) (ELR-SIG), where the RU corresponding to the ELR-SIG field is four 52-tone RUs. That is, the signaling information of the ELR-SIG field is transmitted on four 52-tone RUs.

[0028] In one possible implementation, combining the first or second aspect, the RU corresponding to the LTF field is four 52-tone RUs. That is, the signaling information of the LTF field is transmitted on four 52-tone RUs.

[0029] Thirdly, embodiments of this application provide a communication method applied to a first site, which may be a Wi-Fi device, or a chip or functional module placed in the Wi-Fi device, including but not limited to an IoT device. The method includes:

[0030] Obtain the LTF sequence, which will be used in subsequent embodiments; send the LTF sequence.

[0031] Fourthly, embodiments of this application provide a communication method applied to a second station, which may be a Wi-Fi device, or a chip or functional module placed within a Wi-Fi device, including but not limited to an IoT device. The method includes:

[0032] Receive a PPDU, which is an ELR-PPDU and includes an LTF field;

[0033] The LTF sequence is obtained as a reference sequence for channel estimation, and this LTF sequence is the sequence used in subsequent embodiments;

[0034] Channel estimation is performed based on the LTF field and LTF sequence.

[0035] Fifthly, embodiments of this application provide a first site for performing the methods in the first aspect, the third aspect, or any possible implementation. The first site includes modules for performing the methods in the first aspect, the third aspect, or any possible implementation.

[0036] Sixthly, embodiments of this application provide a second site for performing the methods in the second aspect, the fourth aspect, or any possible implementation. The second site includes modules for performing the methods in the second aspect, the fourth aspect, or any possible implementation.

[0037] In a seventh aspect, embodiments of this application provide a first site, the first site including a processor, configured to cause the first site to perform the methods shown in the first aspect, the third aspect, or any possible implementation thereof. Alternatively, the processor is configured to execute a computer program stored in a memory, wherein when the computer program is executed, the methods shown in the first aspect, the third aspect, or any possible implementation thereof are performed.

[0038] In one possible implementation, the memory is located outside the first site mentioned above.

[0039] In one possible implementation, the memory is located within the aforementioned first site.

[0040] In this embodiment, the processor and memory can also be integrated into a single device, meaning they can be combined. For example, the first station can be a chip.

[0041] In one possible implementation, the first station further includes a transceiver for receiving or transmitting signals. Exemplarily, the transceiver can also be used to transmit ELR-PPDUs, such as when the first station is a WLAN device.

[0042] Eighthly, embodiments of this application provide a second site, the second site including a processor, configured to cause the second site to perform the methods shown in the second aspect, the fourth aspect, or any possible implementation thereof. Alternatively, the processor is configured to execute a computer program stored in memory, wherein when the computer program is executed, the methods shown in the second aspect, the fourth aspect, or any possible implementation thereof are performed.

[0043] In one possible implementation, the memory is located outside the aforementioned second site.

[0044] In one possible implementation, the memory is located within the aforementioned second site.

[0045] In this embodiment, the processor and memory can also be integrated into a single device, meaning they can be combined. For example, the second station can be a chip.

[0046] In one possible implementation, the second station further includes a transceiver for receiving or transmitting signals. For example, this transceiver may be used to receive ELR-PPDUs, such as when the second station is a WLAN device.

[0047] Ninthly, embodiments of this application provide a first site, the first site including logic circuitry and an interface, the logic circuitry and the interface being coupled; the interface is used for inputting and / or outputting information, and the logic circuitry is used to cause the first site to perform the methods described in the first aspect, the fourth aspect, or any possible implementation thereof.

[0048] For example, the interface for outputting information may include: an interface for inputting an ELR-PPDU. For example, logic circuitry for generating an LTF field based on an LTF sequence, etc.

[0049] In a tenth aspect, embodiments of this application provide a second site, the second site including logic circuitry and an interface, the logic circuitry and the interface being coupled; the interface is used for inputting and / or outputting information, and the logic circuitry is used to cause the second site to perform the methods described in the second aspect, the fourth aspect, or any possible implementation thereof.

[0050] For example, the interface for outputting information includes: an interface for outputting ELR-PPDU. For example, logic circuitry for performing channel estimation, etc., based on the LTF sequence and LTF field.

[0051] Eleventhly, embodiments of this application provide a computer-readable storage medium for storing a computer program that, when run on a computer (such as the site shown above), causes the methods shown in any of the first to fourth aspects or any possible implementation thereof to be executed.

[0052] In a twelfth aspect, embodiments of this application provide a computer program product comprising a computer program that, when run on a computer (such as the site shown above), causes the methods shown in any of the first to fourth aspects or any possible implementation thereof to be executed.

[0053] In a thirteenth aspect, embodiments of this application provide a computer program that, when run on a computer, executes the methods shown in any of the first to fourth aspects or any possible implementations described above.

[0054] In a fourteenth aspect, embodiments of this application provide a communication system comprising a first station and a second station, wherein the first station is configured to perform the methods described in the first aspect, the third aspect, or any possible implementation thereof, and the second station is configured to perform the methods described in the second aspect, the fourth aspect, or any possible implementation thereof. Attached Figure Description

[0055] Figure 1 This is a schematic diagram of the architecture of the communication system provided in the embodiments of this application;

[0056] Figure 2a This is a schematic diagram of the ELR-PPDU format provided in the embodiments of this application;

[0057] Figure 2b This is a schematic diagram of the ELR-PPDU format provided in the embodiments of this application;

[0058] Figure 3 This is a schematic diagram of the RU for transmitting the ELR-SIG field and the ELR data field provided in the embodiments of this application;

[0059] Figure 4a and Figure 4b This is a schematic diagram of a HE LTF sequence with a bandwidth of 20MHz provided in an embodiment of this application;

[0060] Figure 5 This is a flowchart illustrating the communication method provided in an embodiment of this application;

[0061] Figure 6 This is a flowchart illustrating the communication method provided in an embodiment of this application;

[0062] Figure 7 This is a schematic diagram of a communication device provided in an embodiment of this application;

[0063] Figure 8 This is another schematic diagram of the communication device provided in the embodiments of this application;

[0064] Figure 9This is a schematic diagram of a chip structure provided in an embodiment of this application. Detailed Implementation

[0065] To facilitate understanding of the technical solution of this application, the application will be further described below with reference to the accompanying drawings.

[0066] The terms "first" and "second," etc., used in the specification, claims, and drawings of this application are used only to distinguish different objects and not to describe a specific order. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or apparatus that includes a series of steps or units is not limited to the listed steps or units, but may optionally include steps or units not listed, or may optionally include other steps or units inherent to these processes, methods, products, or apparatuses.

[0067] The term "embodiment" as used herein means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0068] In this application, "at least one (item)" refers to one or more, "more than one" refers to two or more, "at least two (items)" refers to two or three or more, and "and / or" is used to describe the relationship between related objects, indicating that there can be three relationships. For example, "A and / or B" can mean: only A exists, only B exists, and both A and B exist simultaneously, where A and B can be singular or plural. "Or" indicates that there can be two relationships, such as only A exists and only B exists; when A and B are not mutually exclusive, it can also mean that there are three relationships, such as only A exists, only B exists, and both A and B exist simultaneously. The character " / " generally indicates that the preceding and following related objects are in an "or" relationship. "At least one (item) of the following" or similar expressions refer to any combination of these items. For example, at least one (item) of a, b, or c can mean: a, b, c, "a and b", "a and c", "b and c", or "a and b and c".

[0069] Understandably, for ease of reference later, this application numbers some implementation methods or examples.

[0070] The following describes the communication system involved in the embodiments of this application.

[0071] The technical solutions provided in this application can be applied to wireless local area network (WLAN) systems, such as Wi-Fi. For example, the methods provided in this application can be applied to the Institute of Electrical and Electronics Engineers (IEEE) 802.11 series standards, such as the 802.11be standard, the 802.11bn standard (also known as Wi-Fi 8, or ultra-high reliability (UHR) or ultra-high reliability and throughput (UHRT)), or next-generation standards of the 802.11bn standard, or standards supporting ambient power (AMP). The technical solutions provided in this application can also be applied to wireless personal area networks (WPANs) based on integrated millimeter wave (IMMW) and ultra-wideband (UWB) technologies. The methods provided in the embodiments of this application can be applied to the IEEE 802.15 series standards, such as the 802.15.4a, 802.15.4z, or 802.15.4ab standards, or future UWB WPAN standards. The technical solutions provided in the embodiments of this application can also be applied to the Spark Link or NearLink standards. The technical solutions provided in the embodiments of this application can also be applied to the following communication systems, for example, Internet of Things (IoT) systems, vehicle-to-everything (V2X, where X can represent anything), device-to-device (D2D), narrowband Internet of Things (NB-IoT) systems, long-term evolution (LTE) systems, 5th-generation (5G) communication systems, and new communication systems emerging in future communication developments.For example, V2X can include vehicle-to-vehicle (V2V), vehicle-to-infrastructure (V2I), vehicle-to-pedestrian (V2P), or vehicle-to-network (V2N) communication.

[0072] WLAN systems can provide high-speed, low-latency transmission. As WLAN application scenarios continue to evolve, WLAN systems will be applied to more scenarios or industries, such as the Internet of Things industry, the Internet of Vehicles industry, the banking industry, enterprise offices, stadiums and exhibition halls, concert halls, hotel rooms, dormitories, hospital wards, classrooms, shopping malls, squares, streets, production workshops and warehouses, etc. Of course, devices that support WLAN communication or sensing (such as access points or sites) can be sensor nodes in smart cities (such as smart water meters, smart electricity meters, and smart air monitoring nodes), smart devices in smart homes (such as smart cameras, projectors, displays, televisions, speakers, refrigerators, and washing machines), nodes in the Internet of Things (IoT), entertainment terminals (such as wearable devices for augmented reality (AR) and virtual reality (VR), smart devices in smart offices (such as printers, projectors, loudspeakers, and speakers), vehicle-to-everything (V2X) devices, infrastructure in daily life scenarios (such as vending machines, self-service navigation kiosks in supermarkets, self-service checkout machines, and self-service ordering machines), and equipment in large sports and music venues.

[0073] Although the embodiments of this application primarily use WLAN as an example, especially networks applied to the IEEE 802.11 series of standards, the various aspects involved in the embodiments of this application can be extended to other networks employing various standards. For example, Bluetooth, high-performance radio LAN (HIPERLAN) (a wireless standard similar to the IEEE 802.11 standard), and wide area network (WAN) or other networks now known or developed in the future.

[0074] In one possible implementation, the method provided in this application embodiment can be implemented by a communication device in a communication system. For example, the communication device can be an access point (AP) or a station (STA).

[0075] An Access Point (AP) is a device with wireless communication capabilities that supports communication, sensing, or power transmission using WLAN standards. It has the function of communicating or sensing with other devices in the WLAN network (such as non-access point stations (non-APSTAs) or other access points). Alternatively, an access point acts as a bridge connecting wired and wireless networks, primarily connecting various wireless network clients together and then connecting the wireless network to the Ethernet. In a WLAN system, an access point can be called an Access Point Station (AP STA). An AP is a device that provides services to non-AP STAs and can support 802.11 series standards or later standards. For example, an access point can be an access point for terminals (such as mobile phones) to enter a wired (or wireless) network, mainly deployed in homes, buildings, and campuses, with a typical coverage radius of tens to hundreds of meters; it can also be deployed outdoors. Furthermore, an AP can be a communication server, router, switch, bridge, or other communication entity; APs can include various forms of macro base stations, micro base stations, and repeaters. An AP can be a complete device (such as a WLAN device, Wi-Fi device, or IoT device), or it can be a chip, processing system, or functional module installed in a complete device. Devices with these chips, processing systems, or functional modules installed can implement the methods and functions of the embodiments of this application under the control of the chips, processing systems, or functional modules.

[0076] A Station-Style (STA) is a device with wireless communication capabilities that supports communication, sensing, or power transmission using WLAN standards. It has the ability to communicate, sense, or transmit power with other non-access point (AP) STAs or access points within a WLAN network. In a WLAN system, a station can be called a non-access point station (non-AP STA). For example, an STA is any user communication device that allows a user to communicate with an access point (AP) or sense or transmit power, thereby communicating with the WLAN. For instance, an STA can be a wireless communication chip, a wireless sensor, or a wireless communication terminal, and can also be referred to as a user. Furthermore, an STA can be a mobile phone with Wi-Fi capabilities, a tablet computer with Wi-Fi capabilities, a set-top box with Wi-Fi capabilities, a smart TV with Wi-Fi capabilities, a smart wearable device with Wi-Fi capabilities, an in-vehicle communication device with Wi-Fi capabilities, and a computer with Wi-Fi capabilities. STA can be a complete device (such as a WLAN device, Wi-Fi device, or IoT device), or it can be a chip, processing system, or functional module installed in a complete device. Devices that install these chips, processing systems, or functional modules can implement the methods and functions of the embodiments of this application under the control of the chips, processing systems, or functional modules.

[0077] The communication system may include access points and sites. For example, the embodiments of this application can be applied to scenarios of communication or sensing between AP and STA, between APs, or between STAs in a WLAN, and the embodiments of this application are not limited thereto. Optionally, the AP can communicate or sense with a single STA, or the AP can communicate or sense with multiple STAs simultaneously. Specifically, communication or sensing between the AP and multiple STAs can be further divided into downlink transmission where the AP sends signals to multiple STAs simultaneously, and uplink transmission where multiple STAs send signals to the AP. Among these, the communication between AP and STA, between APs, and between STAs can support WLAN communication standards, which may include the IEEE 802.11 series of standards, such as the 802.11bn standard, and of course, standards after 802.11bn are also applicable.

[0078] Figure 1 This is a schematic diagram of the architecture of a communication system provided in an embodiment of this application. The communication system may include one or more APs and one or more STAs. Figure 1 The diagram illustrates two access points, such as AP1 and AP2, and three stations, such as STA1, STA2, and STA3. As an example, the method provided in this application embodiment can be applied to data communication or sensing between an AP and one or more STAs, such as... Figure 1 The communication between AP1 and STA1 is shown. As another example, the method provided in this application embodiment can be applied to communication between APs, such as... Figure 1 The example illustrates communication or sensing between AP1 and AP2. As another example, the method provided in this application embodiment can be applied to communication or sensing between STAs, such as... Figure 1 The communication or sensing between STA2 and STA3 is shown.

[0079] Figure 1 The use of STA (station) as a mobile phone and AP (access point) as a router is merely an example and does not imply limitation on the types of AP and STA in the embodiments of this application. Furthermore, Figure 1 The number of APs and STAs shown are merely examples. In a specific implementation, the number of APs or STAs may be more or less, and this application does not limit this.

[0080] From the perspectives of transmitting and receiving signals, the first station shown below can be understood as a communication device that transmits PPDUs, and the second station can be understood as a communication device that receives PPDUs.

[0081] From the perspective of different devices, as an example, the first site can be an access point (AP), and the second site can be a non-AP STA. As another example, both the first and second sites can be non-AP STAs or both can be APs. As yet another example, the first site can be a non-AP STA, and the second site can be an AP. The specific forms of the first and second sites will not be listed here.

[0082] This application embodiment describes the method provided by the first station and the second station as both sides. However, during the transmission of signals, the first station and the second station can also forward the signals through other devices, such as forwarding the signals between the first station and the second station through a forwarding device. This application embodiment does not limit other devices besides the first station and the second station.

[0083] The following describes the methods involved in the embodiments of this application.

[0084] In the time domain, the amplitude of a wireless signal is constantly changing, therefore its transmit power is not constant. PAPR (Peak Power Ratio) refers to the ratio of the signal's peak power to its average power over a period of time. Since an OFDM symbol is composed of multiple independently modulated subcarrier signals superimposed, when the phases of the subcarriers are the same or close, the superimposed signal will be modulated by the same initial phase signal, resulting in a large instantaneous power peak, which in turn leads to a high PAPR. Because the dynamic range of a typical power amplifier is limited, OFDM symbols with a high PAPR are prone to entering the nonlinear region of the power amplifier, causing nonlinear distortion, significant spectral spread interference, and in-band signal distortion, resulting in a severe degradation of the overall system performance.

[0085] The following examples illustrate the format of the ELR-PPDU involved in the embodiments of this application:

[0086] Figure 2a This is a schematic diagram of the ELR-PPDU format provided in an embodiment of this application. For example... Figure 2a As shown, the ELR-PPDU includes the following fields: legacy preamble (or legacy code), ELR preamble (or ELR code), and ELR data. The legacy preamble field can be used to instruct legacy devices to avoid transmitting this ELR-PPDU. That is, through this legacy preamble field, legacy devices can avoid transmitting the PPDU during its transmission time. The ELR preamble field is used for ELR-PPDU detection, channel estimation, and to indicate modulation and coding information in the ELR data field. The ELR data field can carry data.

[0087] Figure 2b This is a schematic diagram of the ELR-PPDU format provided in an embodiment of this application. For example... Figure 2b As shown, the ELR-PPDU includes at least one of the following fields: legacy-short training field (L-STF), legacy-long training field (L-LTF) (or legacy-channel estimation field (L-CEF), legacy signal (L-SIG), repetition legacy signal (RL-SIG), universal signal (U-SIG)1, U-SIG2, ELR mark (ELR-mark)1, ELR mark 2, ELR-STF, ELR-LTF, ELR-SIG, or ELR data. Figure 2b The power gains of L-STF, L-STF, ELR-STF, and ELR-LTF are also illustrated by way of example. Figure 2b The value is +3dB.

[0088] L-STF can be used for ELR-PPDU discovery, coarse synchronization, or automatic gain control (AGC). L-LTF can be used for fine synchronization and channel estimation. L-SIG and RL-SIG can be used to carry information related to the length of the ELR-PPDU. U-SIG can carry physical layer version indication. ELR-STF can be used for automatic gain control in subsequent fields. For explanations of other fields, please refer to the above; they will not be repeated here.

[0089] Understandable Figure 2b The order or position of the fields shown is merely illustrative and not intended to limit the embodiments of this application. As standards evolve, ELR-PPDU may also have other formats. Figure 2b The format of the ELR-PPDU shown is not limited in this application embodiment. The transmission distance of the ELR-PPDU can be greater than a certain threshold. As standards advance, PPDUs including the LTF field may have other functions or other names, but as long as the relationship between the LTF field and the LTF sequence in the PPDU conforms to the relationship shown in the embodiments of this application, the PPDU falls within the protection scope of this application embodiment.

[0090] Optionally, to increase the transmission distance of ELR-PPDU, the site can send the ELR-SIG field and / or ELR data field based on the four 52-tone RUs. For example, data from one 52-tone RU can be copied to the other three 52-tone RUs, while simultaneously processing data on some RUs according to... Figure 3 Phase rotation is performed as shown, thereby reducing the PAPR of the ELR-SIG field and the ELR data field.

[0091] Figure 3 This is a schematic diagram of the RU for transmitting the ELR-SIG field and the ELR data field provided in the embodiments of this application. Figure 3 The subcarrier ranges of the four 52-tone RUs shown can be found in Table 1. The data on the third and fourth 52-tone RUs can be phase-rotated. Figure 3 In the diagram, [1 1 1 1 -1 1 1 -1] represents the phase rotation case, where 1 indicates no phase rotation and -1 indicates phase rotation.

[0092] Table 1 provides an example of four 52-tone RUs and their corresponding subcarrier ranges. The subcarrier indices for each RU are shown in Table 1.

[0093] Table 1

[0094]

[0095] In existing technologies, there are already such Figure 4a and Figure 4b The LTF sequence corresponding to 20MHz. In a previous implementation, the ELR-LTF field could be based on... Figure 4a or Figure 4b The LTF sequence generation is shown below. The LTF sequence value corresponding to the subcarrier in the RU used for information transmission (such as the four 52-tone RUs mentioned above) is... Figure 4a or Figure 4b The value at the corresponding position in the LTF sequence is 0 for subcarriers other than the RU mentioned above.

[0096] Figure 4a and Figure 4b This is a schematic diagram of the HE LTF sequence with a bandwidth of 20MHz provided in the embodiments of this application. Taking a subcarrier spacing of 78.125KHz as an example, a bandwidth of 20MHz can correspond to 256 subcarriers, whose indices are denoted as [-128:127]. Figure 4a The sequence shown is a 2x LTF sequence. Figure 4b The sequence shown is a 4x LTF sequence. Figure 4a and Figure 4bThe LTF sequence value corresponding to the index [-122:122] is shown as an example, while the value of the other subcarriers with index not shown is 0.

[0097] Table 2 illustrates examples of the use of Figure 4a or Figure 4b The PAPR of the LTF sequence is shown. 2x ELR-LTF represents the PAPR when generating the ELR-LTF field based on the 2x LTF sequence. 4x ELR-LTF represents the PAPR when generating the ELR-LTF field based on the 4x LTF sequence.

[0098] Table 2

[0099] ELR-STF 2x ELR-LTF 4x ELR-LTF PAPR (dB) 2.22 4.36 4.82

[0100] As shown in Table 2, the PAPR of the ELR-LTF field is larger than that of the ELR-STF field. Furthermore, since the ELR-PPDU requires a 3dB power amplification of the ELR-LTF field, this problem of a large PAPR is exacerbated. A larger PAPR in the ELR-LTF field can lead to more nonlinear distortion and reduce the efficiency of the power amplifier, thus affecting system performance.

[0101] To address the issue that directly reusing HE-LTF sequences in ELR-LTF fields leads to a large PAPR in the ELR-LTF fields, this application designs a new LTF sequence that can improve the overall performance of the ELR system.

[0102] Figure 5 This is a flowchart illustrating the communication method provided in an embodiment of this application. For a description of the first and second stations involved in this method, please refer to... Figure 1 This will not be elaborated upon here. For example... Figure 5 As shown, the method includes:

[0103] 501. The first station generates an LTF field based on the LTF sequence.

[0104] The LTF sequence values ​​in the LTF sequence are mapped to the corresponding subcarriers. The values ​​carried by these subcarriers undergo inverse Fourier transform (and other processing operations) to form the LTF field of the OFDM symbol in the time domain. This LTF field includes one or more OFDM symbols. The LTF sequence is used for channel estimation, or in other words, the LTF field is used for channel estimation. This LTF field can also be called the ELR-LTF field, or simply ELR-LTF.

[0105] The kth subcarrier in the bandwidth corresponds to the kth LTF sequence value in the LTF sequence. kFor example, with a bandwidth of 20MHz and a subcarrier spacing of 78.125KHz, there are 256 subcarriers within this 20MHz. The index of these 256 subcarriers is [-128:127].

[0106] In this embodiment, [a:b:c] can refer to all integers from a to c (a and c are also integers), with a step size of b. That is: a, (a+b), (a+2b), (a+3b), ..., c. Whether the last value c can be obtained depends on whether ca is exactly an integer multiple of b. If not, element c is not included. When b equals 1, [a:c] can usually be used to represent [a:1:c]. For example, [-128:127] represents -128, -127, -126, -125, ..., 125, 126, 127.

[0107] As one possible implementation, the LTF sequence has a length of 256, meaning it consists of 256 LTF sequence values, each corresponding to one of the 256 subcarriers. The LTF sequence is represented as LTF. -128:127 , or ELRLTF -128:127 The LTF sequence value for the guard subcarrier and DC subcarrier among the 256 subcarriers is 0. The LTF sequence value for the null subcarrier among these 256 subcarriers is also 0.

[0108] As another possible implementation, the LTF sequence has a length of 241, meaning it consists of 241 LTF sequence values, each corresponding to one of the 241 subcarriers. The indices of these 241 subcarriers are [-120:120]. The LTF sequence is represented as LTF. -120:120 Or ELR LTF -120:120 The LTF sequence value for all subcarriers in [-128:127] except [-120:120] is 0.

[0109] As another possible implementation, the LTF sequence has a length of 243, meaning it consists of 243 LTF sequence values, each corresponding to one of the 243 subcarriers. The indices of these 243 subcarriers are [-121:121]. The LTF sequence is represented as LTF. -121:121 Or ELR LTF -121:121 The LTF sequence value for all subcarriers in [-128:127] except [-121:121] is 0.

[0110] Implementation methods 1 to 3 exemplify different expressions for LTF sequences. In specific implementations, the length of the LTF sequence can also be greater than 240 and less than 256. The expressions for LTF sequences will not be listed one by one.

[0111] As a possible implementation 4, the LTF sequence value corresponding to the k-th subcarrier is the k-th LTF sequence value in the LTF sequence. The value of k is referenced from implementations 1 to 3 above. For example, the LTF sequence is designed based on resource allocations (RUs) used for transmitting information. The values ​​corresponding to the other subcarriers in the LTF sequence, except for the aforementioned RUs, are all 0. This information includes, but is not limited to, at least one of the ELR-data field or the ELR-SIG field. For example, the RUs used for transmitting information are the four 52-tone RUs shown in Table 1 above. The LTF sequence specifies the LTF sequence values ​​corresponding to each subcarrier in the aforementioned RU1 to RU4 (as shown in Table 1), and the LTF sequence values ​​corresponding to the subcarriers not shown are all 0.

[0112] As another possible implementation 5, the LTF sequence value corresponding to the k-th subcarrier is determined based on the k-th LTF sequence value in the LTF sequence and whether the k-th subcarrier belongs to a subcarrier in the RU used to transmit the LTF field. The value of k is referenced from implementations 1 to 3 above. For example, if the k-th subcarrier belongs to a subcarrier in the RU used to transmit the LTF field, then the LTF sequence value corresponding to the k-th subcarrier is the k-th LTF sequence value in the LTF sequence. Alternatively, if the k-th subcarrier does not belong to a subcarrier in the RU used to transmit the LTF field, then the LTF sequence value corresponding to the k-th subcarrier is 0. In addition to specifying the LTF sequence values ​​corresponding to each subcarrier in RU1 to RU4, the LTF sequence also specifies the LTF sequence values ​​corresponding to subcarriers not shown above, which may be 0, 1, or -1.

[0113] In one possible implementation, the first site determines the LTF sequence.

[0114] The first station determines the LTF sequence based on a sequence pattern, which can be a 1x LTF sequence pattern (or simply a 1x LTF sequence), a 2x LTF sequence pattern (or simply a 2x LTF sequence), or a 4x LTF sequence pattern (or simply a 4x LTF sequence). In a 1x LTF sequence, there must be at least three zeros between two adjacent non-zero elements; in a 2x LTF sequence, there must be at least one zero between two adjacent non-zero elements; and in a 4x LTF sequence, there can be consecutive non-zero elements. The 4x LTF sequence has the densest concentration of non-zero elements, thus providing the most accurate channel estimation.

[0115] Optionally, for ELR-PPDU, the LTF sequence can only have a 2x LTF sequence pattern, so that the first site can directly generate the LTF field based on the 2xLTF sequence.

[0116] For example, the first site determines the LTF sequence based on the bandwidth. The LTF sequence can be designed for different bandwidths, meaning different bandwidths can correspond to different LTF sequences. For instance, the LTF sequence for 20MHz is different from the LTF sequence for 40MHz.

[0117] Optionally, for the ELR-PPDU, the bandwidth of the ELR-PPDU can be only 20MHz, so that the first station can directly generate the LTF field based on the LTF sequence. Optionally, the first station can transmit the ELR-PPDU in 20MHz units.

[0118] For example, the first station determines the LTF sequence based on the sequence pattern and bandwidth. For an explanation of sequence pattern and bandwidth, please refer to the above text; it will not be elaborated upon here.

[0119] For example, the first site determines the LTF sequence based on the type of the PPDU. The PPDU type includes ELR-PPDUs or non-ELR-PPDUs. For ELR-PPDUs, the LTF sequence can be the sequence used in subsequent embodiments. For non-ELR-PPDUs, the LTF sequence can be... Figure 4a or Figure 4b The sequence shown is not limited to ELR-PPDU. Other sequences may also correspond to non-ELR-PPDU sequences, but this application does not limit this.

[0120] Alternatively, the first site determines the LTF sequence based on whether the PPDU is an ELR-PPDU.

[0121] Further information regarding LTF sequences can be found below, but will not be elaborated upon here.

[0122] 502. The first station sends an ELR-PPDU including the LTF field. Correspondingly, the second station receives the ELR-PPDU.

[0123] The ELR-PPDU can also include an ELR data field. The RU corresponding to the LTF field is the same as the RU corresponding to the data field. For example, the RU can be one of the four 52-tone RUs shown in Table 1.

[0124] The ELR-PPDU may also include an ELR general (signal, SIG) field (or ELR-SIG). For example, the RU corresponding to the ELR-SIG field and the ELR data field is the same as the RU corresponding to the LTF field. This RU can be one of the four 52-tone RUs shown in Table 1.

[0125] Optionally, to improve channel estimation performance, the LTF field can also have a 3dB power gain. For example, when the first station transmits the LTF field, it can have a 3dB power gain relative to the data field.

[0126] Optionally, the ELR-PPDU may further include a flag field, which is used to identify whether the PPDU including the flag field is a PPDU of this cell. Optionally, the flag field is used to identify whether the PPDU including the flag field is an ELR-PPDU. Optionally, the flag field is used to identify whether the PPDU including the flag field is an ELR-PPDU of this cell.

[0127] For details regarding ELR-PPDU, please refer to [link / reference]. Figure 2a and Figure 2b This will not be elaborated upon here.

[0128] 503. The second station performs channel estimation based on the LTF sequence and LTF field.

[0129] The second station can decode the ELR-SIG field and the ELR data field based on the channel estimation results.

[0130] For an explanation of the LTF sequence, please refer to step 201 or the following text; it will not be elaborated upon here.

[0131] The LTF sequence provided in this application embodiment can effectively reduce the PAPR of the LTF field and improve system performance.

[0132] Figure 6 This is a schematic flowchart of the communication method provided in an embodiment of this application. For a description of the first and second stations involved in this method, please refer to... Figure 1 This will not be elaborated upon here. For example... Figure 6 As shown, the method includes:

[0133] 601. Obtain the LTF sequence at the first site.

[0134] The first station obtains the LTF sequence based on a sequence pattern, which includes a 1x LTF sequence pattern (or simply 1x LTF sequence), a 2x LTF sequence pattern (or simply 2x LTF sequence), or a 4x LTF sequence pattern (or simply 4x LTF sequence). In a 1x LTF sequence, there must be at least three zeros between two adjacent non-zero elements; in a 2x LTF sequence, there must be at least one zero between two adjacent non-zero elements; and in a 4x LTF sequence, there can be consecutive non-zero elements. The 4x LTF sequence has the densest concentration of non-zero elements, thus providing the most accurate channel estimation.

[0135] Optionally, for ELR-PPDU, the LTF sequence can only have a 2x LTF sequence mode, so that the first station can directly obtain the 2xLTF sequence.

[0136] For example, the first station obtains the LTF sequence based on the bandwidth. The LTF sequence can be designed for different bandwidths, meaning different bandwidths can correspond to different LTF sequences. For instance, the LTF sequence for 20MHz is different from the LTF sequence for 40MHz.

[0137] Optionally, for the ELR-PPDU, the bandwidth of the ELR-PPDU can be only 20MHz, so that the first station can directly obtain the LTF sequence at 20MHz. Optionally, the first station can transmit the ELR-PPDU in 20MHz units.

[0138] For example, the first station determines the LTF sequence based on the sequence pattern and bandwidth. For an explanation of sequence pattern and bandwidth, please refer to the above text; it will not be elaborated upon here.

[0139] For example, the first site determines the LTF sequence based on the type of PPDU. For an explanation of step 601, please refer to step 501 above; it will not be detailed here.

[0140] Further information regarding LTF sequences can be found below, but will not be elaborated upon here.

[0141] 602. The first station sends the LTF sequence.

[0142] Correspondingly, the second station receives the PPDU, which includes the LTF field.

[0143] For steps 601 and 602, the first station acquires the LTF and sends an LTF sequence including at least one of (a) to (g):

[0144] (a) Sequence generation: Generate LTF sequences in the frequency domain over the bandwidth.

[0145] (b) Matrix mapping: Apply the P matrix to the data subcarriers of the LTF sequence and the R matrix to the pilot subcarriers of the EHT-LTF sequence.

[0146] (c) Cyclic shift delay (CSD): Apply CSD to each spatial flow.

[0147] (d) Spatial mapping: applying the Q matrix.

[0148] (e) Inverse Discrete Fourier Transform (IDFT): Calculate the inverse discrete Fourier transform.

[0149] (f) Insert GI and apply windowing: Preset GI and apply windowing.

[0150] (g) Analog and Radio Frequency (RF): Based on the center frequency of the desired channel, the complex baseband waveforms associated with each transmit chain are converted into RF signals and transmitted.

[0151] Optionally, the number of spatial streams for transmitting the LTF sequence is one. In this case, the process of transmitting the LTF sequence may not include steps (b) and (d) above.

[0152] Optionally, the bandwidth for transmitting the LTF sequence is only 20 MHz. Alternatively, the LTF sequence can be transmitted in 20 MHz units.

[0153] For specific details regarding (a) to (g), please refer to the description in the 802.11 standard, which will not be elaborated here.

[0154] 603. The second station obtains the LTF sequence as a reference sequence for channel estimation, and performs channel estimation based on the LTF field and the LTF sequence.

[0155] Figure 6 For explanations of other related content, please refer to the following. Figure 5 The details are similar to those in the following text, and will not be elaborated here.

[0156] The LTF sequence provided in this application embodiment can effectively reduce the PAPR of the LTF field and improve system performance.

[0157] The following describes the characteristics satisfied by the LTF sequences involved in the embodiments of this application.

[0158] As one possible implementation, the LTF sequence satisfies at least one of the following: the LTF sequence value corresponding to the first subcarrier group is opposite to the LTF sequence value corresponding to the second subcarrier group, or the LTF sequence value corresponding to the third subcarrier group is the same as the LTF sequence value corresponding to the fourth subcarrier group.

[0159] The number of subcarriers in the first to fourth subcarrier groups is the same. The LTF sequence value corresponding to the i-th subcarrier in the first subcarrier group is the opposite of the LTF sequence value corresponding to the i-th subcarrier in the second subcarrier group, and the LTF sequence value corresponding to the i-th subcarrier in the third subcarrier group is the same as the LTF sequence value corresponding to the i-th subcarrier in the fourth subcarrier group.

[0160] Optionally, the subcarriers in the first and third subcarrier groups are determined based on the RUs used for transmitting information. For example, the subcarriers in the first and third subcarrier groups can be subcarriers in RU1. Or, for example, the subcarriers in the first and third subcarrier groups can be subcarriers in RU4.

[0161] Optionally, the subcarriers in the second and fourth subcarrier groups are determined based on the RU used for transmitting information. For example, the subcarriers in the second and fourth subcarrier groups can be subcarriers in RU2. Alternatively, the subcarriers in the second and fourth subcarrier groups can be subcarriers in RU3.

[0162] For explanations of RU1 to RU4, please refer to the above text; they will not be elaborated upon here.

[0163] It is understood that a subcarrier group can also be called a subcarrier segment or a subcarrier interval. For example, the first subcarrier group is called the first subcarrier segment or the first subcarrier interval. To illustrate the characteristics satisfied by the LTF sequence, this application embodiment distinguishes between the first subcarrier group to the fourth subcarrier group, dividing the subcarriers into groups. However, in specific implementations, the subcarriers may not be divided into groups.

[0164] As an example a, the indices of the subcarriers in the first to fourth subcarrier groups are all less than 0.

[0165] For example, the subcarrier index in the first subcarrier group is [-120:2:-96], the subcarrier index in the second subcarrier group is [-68:2:-44], the subcarrier index in the third subcarrier group is [-94:2:-70], and the subcarrier index in the fourth subcarrier group is [-42:2:-18].

[0166] For example, the subcarrier index in the first subcarrier group is [-120:2:-96], the subcarrier index in the second subcarrier group is [-42:2:-18], the subcarrier index in the third subcarrier group is [-94:2:-70], and the subcarrier index in the fourth subcarrier group is [-68:2:-44].

[0167] Optionally, the LTF sequence value corresponding to the subcarriers other than those in the first to fourth subcarrier groups among the subcarriers with an index less than 0 is 0.

[0168] For example, the LTF sequence values ​​corresponding to the first subcarrier group correspond to the 13 elements in sequence a1, and the LTF sequence values ​​corresponding to the third subcarrier group correspond to the 13 elements in sequence a2. The non-zero LTF sequence values ​​(excluding 0, i.e., LTF sequence value 0) corresponding to the subcarriers with indices less than 0 are [a1, a2, -a1, a2] or [a1, a2, a1, -a2].

[0169] In this embodiment, the LTF sequence value corresponding to the subcarrier with an index less than 0 can be the sequence [a1, a2]. By copying this sequence and performing phase rotation, [c1a1, c2a2, c3a1, c4a2] can be obtained. When the rotation coefficients [c1, c3] and [c2, c4] corresponding to a1 and a2 respectively form a Gray complement pair sequence, the PAPR of the copied subsequence can also be lower. At the same time, the storage space requirement of the LTF sequence can be reduced through the above design. For example, the station can store short sequences such as [a1, a2] and corresponding rotation coefficients to obtain the LTF sequence value corresponding to the subcarrier with an index less than 0, and also to obtain the LTF sequence.

[0170] For example a, the non-zero LTF sequence value corresponding to the subcarrier with an index greater than 0 is determined based on the odd-numbered and even-numbered LTF sequence values ​​among the LTF sequence values ​​corresponding to the subcarriers in the first to fourth subcarrier groups. For example, the non-zero LTF sequence values ​​corresponding to the subcarriers with an index greater than 0 are the LTF sequence values ​​corresponding to [-120:4:-18] and [-118:4:-18], respectively. Or, for another example, the non-zero LTF sequence values ​​corresponding to the subcarriers with an index greater than 0 are the LTF sequence values ​​corresponding to [-118:4:-18] and [-120:4:-18], respectively.

[0171] For example, the LTF sequence values ​​corresponding to the subcarriers in the first to fourth subcarrier groups are the following 52 elements: [a1, a2, a1, -a2]. If the non-zero LTF sequence values ​​corresponding to the subcarriers with indices greater than 0 are: the 1st element of a1, the 3rd element of a1, the 5th element of a1, and so on, up to the 13th element of a1; the 2nd element of a2, the 4th element of a2, and so on, up to the 12th element of a2; the 1st element of a1, the 3rd element of a1, the 5th element of a1, and so on, up to the 13th element of a1; the 2nd element of -a2, the 4th element of -a2, and so on, up to the 13th element of a1; and so on, up to the 2nd element of -a2, the 4th element of -a2, and so on, up to the 13th element of a1; and so on, up to the 13th element of -a2. And so on, the 12th element in -a2; and the 2nd element, the 4th element, the 6th element in a1, and so on, the 12th element in a1; the 1st element, the 3rd element in a2, and so on, the 13th element in a2; the 2nd element, the 4th element, the 6th element in a1, and so on, the 12th element in a1; the 1st element, the 3rd element in -a2, and so on, the 13th element in -a2. For example, the non-zero LTF sequence values ​​corresponding to subcarriers with an index greater than 0 are, in order: the 2nd element of a1, the 4th element of a1, the 6th element of a1, and so on, up to the 12th element of a1; the 1st element of a2, the 3rd element of a2, and so on, up to the 13th element of a2; the 2nd element of a1, the 4th element of a1, the 6th element of a1, and so on, up to the 12th element of a1; the 1st element of -a2, the 3rd element of -a2, and so on, up to the 13th element of a2; the 2nd element of a1, the 4th element of a1, the 6th element of a1, and so on, up to the 12th element of a1; the 1st element of -a2, the 3rd element of -a2, and so on, up to the 13th element of -a2. And so on, the 13th element in -a2; and the 1st element, the 3rd element, the 5th element in a1, and so on, the 13th element in a1; the 2nd element, the 4th element in a2, and so on, the 12th element in a2; the 1st element, the 3rd element, the 5th element in a1, and so on, the 13th element in a1; the 2nd element, the 4th element in -a2, and so on, the 12th element in -a2.

[0172] Alternatively, the non-zero LTF sequence value corresponding to the subcarrier with an index greater than 0 is obtained by sampling the LTF sequence value corresponding to the subcarrier with index [-120:2:-20] with a sampling step size of 2, and then sampling the LTF sequence value corresponding to the subcarrier with index [-118:2:-18] with a sampling step size of 2. Or, the non-zero LTF sequence value corresponding to the subcarrier with an index greater than 0 is obtained by sampling the LTF sequence value corresponding to the subcarrier with index [-118:2:-18] with a sampling step size of 2, and then sampling the LTF sequence value corresponding to the subcarrier with index [-120:2:-20] with a sampling step size of 2.

[0173] Optionally, the sampling step size can also be 3 or 4, etc., which will not be listed here.

[0174] In this embodiment, in the first to fourth subcarrier groups, the LTF sequence value corresponding to the odd-numbered subcarrier is odd-symmetric, and the LTF sequence value corresponding to the even-numbered subcarrier is even-symmetric; alternatively, the LTF sequence value corresponding to the even-numbered subcarrier is odd-symmetric, and the LTF sequence value corresponding to the odd-numbered subcarrier is even-symmetric. The time-domain signal corresponding to the odd-symmetric LTF sequence value has only an imaginary part, and the time-domain signal corresponding to the even-symmetric LTF sequence value has only a real part. When the two are superimposed, the power of the corresponding time-domain signal is equal to the sum of the powers of the two. When designing the LTF sequence value corresponding to the negative half-axis subcarrier, its time-domain signal contains both real and imaginary parts, and when the LTF sequence value is random, the real and imaginary parts are approximately independently distributed. According to the law of large numbers and Pisserwald's theorem, both the real and imaginary parts are approximately Gaussian distributed and have the same variance as the even-symmetric and odd-symmetric time-domain signals. Therefore, by using the relationship between the LTF sequence values ​​corresponding to subcarriers with indices less than 0 and those corresponding to subcarriers with indices greater than 0 as shown in the embodiments of this application, the PAPR of the LTF sequence values ​​corresponding to subcarriers with indices greater than 0 and the PAPR of the LTF sequence values ​​corresponding to subcarriers with indices less than 0 can have an approximate PAPR distribution, thus avoiding the problem that the PAPR of the LTF sequence increases due to the increase in the number of subcarriers.

[0175] As another example b, the indices of the subcarriers in the first to fourth subcarrier groups are all greater than 0.

[0176] For example, the subcarrier index in the first subcarrier group is [120:-2:96], the subcarrier index in the second subcarrier group is [68:-2:44], the subcarrier index in the third subcarrier group is [94:-2:70], and the subcarrier index in the fourth subcarrier group is [42:-2:18].

[0177] For example, the subcarrier index in the first subcarrier group is [120:-2:96], the subcarrier index in the second subcarrier group is [42:-2:18], the subcarrier index in the third subcarrier group is [94:-2:70], or the subcarrier index in the fourth subcarrier group is [68:-2:44].

[0178] Optionally, the LTF sequence value corresponding to the subcarriers other than those in the first to fourth subcarrier groups among the subcarriers with an index greater than 0 is 0.

[0179] For a description of the first to fourth subcarrier groups, please refer to Example a. The details are similar and will not be elaborated here.

[0180] For example b, the non-zero LTF sequence value corresponding to the subcarrier with an index less than 0 is determined based on the odd-numbered and even-numbered LTF sequence values ​​among the LTF sequence values ​​corresponding to the subcarriers in the first to fourth subcarrier groups. For example, the non-zero LTF sequence values ​​corresponding to the subcarriers with an index less than 0 are the LTF sequence values ​​corresponding to [120:-4:18] and [118:-4:18], respectively. Or, for another example, the non-zero LTF sequence values ​​corresponding to the subcarriers with an index less than 0 are the LTF sequence values ​​corresponding to [118:-4:18] and [120:-4:18], respectively.

[0181] Alternatively, the non-zero LTF sequence value corresponding to the subcarrier with an index less than 0 is obtained by sampling the LTF sequence value corresponding to the subcarrier with index [120:-2:20] with a sampling step size of 2, and then sampling the LTF sequence value corresponding to the subcarrier with index [118:-2:18] with a sampling step size of 2. Or, the non-zero LTF sequence value corresponding to the subcarrier with an index greater than 0 is obtained by sampling the LTF sequence value corresponding to the subcarrier with index [118:-2:18] with a sampling step size of 2, and then sampling the LTF sequence value corresponding to the subcarrier with index [120:-2:20] with a sampling step size of 2.

[0182] For an explanation of the non-zero LTF sequence values ​​corresponding to subcarriers with indices less than 0, please refer to Example a. The details are similar and will not be elaborated here.

[0183] For a 2xELR-LTF sequence, the LTF sequence value corresponding to [120:2:-18, 18:2:120] is non-zero. For example, the LTF sequence value corresponding to [-120:2:-70] forms a sequence, and the sequence a has a length of 26 (i.e., 26 LTF sequence values). Sequence a is split into two subsequences of equal length, i.e., a = [a1, a2]. The LTF sequence value corresponding to [-68:2:-44] is sequence -a1 (or a1), and the LTF sequence value corresponding to the subcarrier [-42:2:-18] is sequence a2 (or -a2). Sequence b = [a1, a2, -a1, a2], and the elements in sequence b are divided into two subsequences of equal length, b1 and b2, according to the odd-numbered and even-numbered elements. The LTF sequence value corresponding to [120:-4:20] is sequence -b1, and the LTF sequence value corresponding to [118:-4:18] is sequence b2. Therefore, we traverse sequence a, calculate the PAPR of the corresponding sequence, and select the sequence with the lowest PAPR as the 2xELR-LTF sequence.

[0184] The LTF sequences obtained based on the features satisfied by the LTF sequences shown in the embodiments of this application, and the search methods described below, are all within the protection scope of the embodiments of this application.

[0185] By designing a mapping extension of short sequences to construct longer sequences, and then iterating through the short sequences to select the long sequence with the lowest PAPR as the ELR-LTF sequence, the constructed ELR-LTF sequence has a lower PAPR.

[0186] Based on examples a and b above, the LTF sequence values ​​corresponding to the first to fourth subcarrier groups are described below.

[0187] As an example c, the LTF sequence values ​​corresponding to the first subcarrier group are [1 1 -1 -1 1 1 1 1 1 1 11 -1 -1], and the LTF sequence values ​​corresponding to the second subcarrier group are [-1 -1 1 1 -1 -1 -1 -1 -1 -1 -1 -1 11]. The subcarrier indices corresponding to each LTF sequence value shown here are the same as those in example a or example b above, and will not be detailed here.

[0188] As another example d, the LTF sequence value corresponding to the first subcarrier group is the LTF sequence value after processing [1 1 -1 -1 1 1 1 1 1 1 11 -1 -1]. The processing method includes at least one of the following: reversing the order, inverting all elements, or inverting some elements.

[0189] For example, the LTF sequence value corresponding to the first subcarrier group is [-1 -1 1 1 -1 -1 -1 -1 -1 -1 -1 11], and the LTF sequence value corresponding to the second subcarrier group is [1 1 -1 -1 1 1 1 1 1 1 1 -1 -1].

[0190] For example, the LTF sequence value corresponding to the first subcarrier group is [-1 1 1 -1 -1 1 -1 1 -1 1 -1 1 -1 -1], and the LTF sequence value corresponding to the second subcarrier group is [1 -1 -1 1 1 -1 1 -1 1 -1 1 -1 1 -1].

[0191] For example, the LTF sequence value corresponding to the first subcarrier group is [1 -1 -1 1 1 -1 1 -1 1 -1 1 1 -1], and the LTF sequence value corresponding to the second subcarrier group is [-1 1 1 -1 -1 1 -1 1 -1 1 -1 1 -1 1 -1 1].

[0192] As an example e, the LTF sequence value corresponding to the third subcarrier group is [-1 -1 -1 1 1 1 -1 -1 1 1 1 1 1], and the LTF sequence value corresponding to the fourth subcarrier group is [-1 -1 -1 1 1 1 -1 -1 1 1 1 1 1]. The subcarrier indices corresponding to each LTF sequence value shown here are the same as those in example a or example b above, and will not be detailed here.

[0193] As another example f, the LTF sequence value corresponding to the third subcarrier group is the LTF sequence value after processing [-1 -1 -1 1 1 1 -1 -11 1 1 1 1]. The processing method includes at least one of the following: reversing the order, inverting all elements, or inverting some elements.

[0194] For example, the LTF sequence value corresponding to the third subcarrier group is [1 1 1 -1 -1 -1 1 1 -1 -1 -1 -1 -1], and the LTF sequence value corresponding to the fourth subcarrier group is [1 1 1 -1 -1 -1 1 1 -1 -1 -1 -1 -1].

[0195] For example, the LTF sequence value corresponding to the third subcarrier group is [1 -1 1 1 -1 1 1 -1 -1 1 -1 1 -1 1 -1], and the LTF sequence value corresponding to the fourth subcarrier group is [1 -1 1 1 -1 1 1 -1 -1 1 -1 1 -1 1 -1].

[0196] For example, the LTF sequence value corresponding to the third subcarrier group is [-1 1 -1 -1 1 -1 -1 1 1 -1 1 -1 1 -11], and the LTF sequence value corresponding to the fourth subcarrier group is [-1 1 -1 -1 1 -1 -1 1 1 -1 1 -1 1 1].

[0197] By combining examples c to d above, and the relationship between the LTF sequence values ​​corresponding to subcarriers with indices less than 0 and those corresponding to subcarriers with indices greater than 0 shown in examples a and b, an LTF sequence can be obtained. This LTF sequence can be referenced below. The LTF sequences shown below are merely examples; other LTF sequences can be obtained by combining the methods described above, which will not be listed hereafter.

[0198] The LTF sequences involved in the embodiments of this application are described below. All LTF sequences shown below satisfy the characteristics of the LTF sequences described above.

[0199] As an example, the LTF sequence is:

[0200] LTF -120:120 =

[0201] [1 0 1 0 -1 0 -1 0 1 0 1 0 1 0 1 0 1 0 1 0 -1 0 -1 0 -1 0 -1 0 -10 1 0 1 0 1 0 -1 0 -1 0 1 0 1 0 1 0 1 0 1 0 1 0 -1 0 -1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 - ... 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0-1 0 1 0 -1 0 1 0 1 0 -1 0 -1 0 1 0 -1 0 -1 0 1 0 -1 0 -1 0 1 0 1 0 -1 0 1 0 -1 0 1 0-1 0 1 0 -1 0 1 0 -1 0 -1 0 1 0 -1 0 1 0 -1 0 1 0 -1 0 1 0 1 0 -1 0 1 0 1 0 -1 0 1 0 -1 0 1 0 1 0 -1 0 1 0 -1 0 1 0 -1 0 1 0 -1 0 1 0 -1 0 -1 0 ...

[0202] Or, LTF -121:121 =

[0203] [0 1 0 1 0 -1 0 -1 0 1 0 1 0 1 0 1 0 1 0 1 0 -1 0 -1 0 -1 0 -1 0 -1 0 -1 0 1 0 1 0 1 0 -1 0 -1 0 1 0 1 0 1 0 1 0 1 0 -1 0 -1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 - ... 0 0 0 0 0 0 0 0 0 0 0 0 0 0 01 0 -1 0 1 0 -1 0 1 0 1 0 -1 0 -1 0 1 0 -1 0 -1 0 1 0 -1 0 -1 0 1 0 1 0 -1 01 0 -1 0 1 0 -1 0 1 0 1 0 -1 0 -1 0 1 0 -1 0 1 0 -1 0 1 0 -1 0 1 0 1 0 -1 0 1 0 1 0 -1 0 1 0 -1 0 1 0 1 0 -1 0 1 0 1 0 -1 0 1 0 -1 0 1 0 -1 0 1 0 -1 0 1 0 1 0 - ...

[0204] LTF -128:127 =

[0205] [0 0 0 0 0 0 0 0 1 0 1 0 -1 0 -1 0 1 0 1 0 1 0 1 0 1 0 1 0 -1 0 -1 0 -1 0 -1 0 -1 0 1 0 1 0 1 0 -1 0 -1 0 1 0 1 0 1 0 1 0 1 0 1 0 -1 0 -10 1 0 1 0 1 0 1 0 1 0 -1 0 -1 0 1 0 1 0 1 0 -1 0 -1 0 -1 0 1 0 1 0 1 0 -1 0 -1 0 -1 0 -1 0 -1 0 -1 0 -1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 -1 0 1 0 -1 0 1 0 1 0 -1 0 -1 0 1 0 -1 0 -1 0 1 0 -1 0 -1 0 10 1 0 -1 0 1 0 -1 0 1 0 -1 0 1 0 -1 0 1 0 -1 0 -1 0 1 0 1 0 1 0 -1 0 1 0 1 0 -1 0 1 0 -1 0 1 0 -1 0 1 0 1 0 -1 0 1 0 -1 0 1 0 1 0 -1 0 -1 0 1 0 1 0 -1 0 -1 0 1 0 0 0 0 0 0 0].

[0206] The above examples illustrate three expressions for LTF sequences; other expressions will not be listed here.

[0207] It is understood that performing one or more of the following operations on the above LTF sequence will not change the PAPR of the LTF sequence. Therefore, the new sequence obtained based on the above LTF sequence is still within the protection scope of the embodiments of this application: inverting the entire above LTF sequence, reversing the above LTF sequence, inverting the LTF sequence value corresponding to the subcarrier [-120:4:120] in the above LTF sequence, and inverting the LTF sequence value corresponding to the subcarrier [-118:4:118] in the above LTF sequence.

[0208] As another example, the LTF sequence is:

[0209] LTF -120:120 =

[0210] [-1 0 -1 0 1 0 1 0 -1 0 -1 0 -1 0 -1 0 -1 0 -1 0 1 0 1 0 1 0 1 01 0 -1 0 -1 0 -1 0 1 0 1 0 -1 0 -1 0 -1 0 -1 0 -1 0 -1 0 1 0 1 0 - ... 0 0 0 0 0 0 0 0 0 0 0 0 00 0 -1 0 1 0 -1 0 1 0 -1 0 -1 0 1 0 1 0 -1 0 1 0 1 0 -1 0 1 0 1 0 -1 0 -1 0 10 -1 0 1 0 -1 0 1 0 -1 0 -1 0 1 0 1 0 -1 0 1 0 -1 0 1 0 -1 0 -1 0 1 0 1 0 -1 0 -1 0 1 0 -1 0 -1 0 1 0 -1 0 1 0 -1 0 -1 0 1 0 -1 0 -1 0 1 0 -1 0 -1 0 1 01 0-1].

[0211] Or, LTF -121:121 =

[0212] [0 -1 0 -1 0 1 0 1 0 -1 0 -1 0 -1 0 -1 0 -1 0 -1 0 1 0 1 0 1 0 1 0 1 0 -1 0 -1 0 1 0 10 -1 0 -1 0 -1 0 1 0 1 0 - ... 0 0 0 0 0 0 0 0 0 0 0 0 00 0 0 -1 0 1 0 -1 0 1 0 -1 0 -1 0 1 0 1 0 -1 0 1 0 1 0 -1 0 1 0 1 0 -1 0 -1 01 0 -1 0 1 0 -1 0 -1 0 1 0 -1 0 -1 0 1 0 1 0 -1 0 1 0 -1 0 -1 0 1 0 -1 0 -1 0 1 0 -1 0 -1 0 1 0 -1 0 -1 0 1 0 -1 0 -1 0 1 0 -1 0 -1 0 1 0 -1 0 -1 0 1 0 -1 0 -1 0 1 010 -1 0 ...

[0213] Or, LTF -128:127 =

[0214] [0 0 0 0 0 0 0 0 -1 0 -1 0 1 0 1 0 -1 0 -1 0 -1 0 -1 0 -1 0 -1 0 -1 01 0 1 0 1 0 1 0 -1 0 -1 0 -1 0 1 0 1 0 -1 0 -1 0 -1 0 -1 0 -1 0 -1 01 0 1 0 -1 0 -1 0 -1 0 -1 0 -1 0 -1 0 -1 0 1 0 1 0 -1 0 -1 0 -1 0 1 0 1 0 -1 0 -1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 -1 0 1 0 -1 0 1 0 -1 0 -1 0 1 0 1 0 -1 0 1 0 1 0 -1 0 1 01 0 -1 0 -1 0 1 0 -1 0 1 0 -1 0 1 0 -1 0 -1 0 1 0 1 0 -1 0 1 0 -1 0 1 0 -1 0 1 0 -1 0 1 0 -1 0 1 0 -1 0 1 0 -1 0 1 0 -1 0 1 0 -1 0 1 0 -1 0 1 0 -1 0 1 0 -1 0 1 0 -1 0 1 0 -1 0 1 0 -1 0 1 0 -1 0 1 0 -1 0 1 0 -1 0 1 0 -1 0 0 0 0 0 0 0].

[0215] As yet another example, the LTF sequence is:

[0216] LTF -120:120 =

[0217] [-1 0 1 0 1 0 -1 0 -1 0 1 0 -1 0 1 0 -1 0 1 0 -1 0 -1 0 1 0 -1 0 1 0-1 0 -1 0 1 0 -1 0 -1 0 1 0 1 0 -1 0 1 0 -1 0 1 0 -1 0 1 0 1 0 -1 0 -1 0 1 0-1 0 1 0 -1 0 1 0 -1 0 -1 0 1 0 -1 0 -1 0 1 0 1 0 1 0 -1 0 -1 0 ... 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 1 0 1 0 1 0 1 0 -1 0 -1 0 1 0 1 0 1 0 -1 0 -1 0 -1 0 1 0 1 0 -1 0 -1 0 -1 0 -1 0 -1 0 -1 0 -1 0 1 0 1 0 -1 0 -1 0 -1 0 -1 0 -1 0 -1 0 1 0 1 0 -1 0 -1 0 -1 0 -1 0 1 0 1 0 1 0 1 0 1 0 -1 0 -1 0 -1 0 -1 0 -1 0 -1 0 -1 0 -1 0 1 0 1 0 -1 0 -1 0 -1 0 -1 0 -1 0 1 0 1 0 -1 0 -1 0 -1 0 -1 0 -1 0 1 0 1 0 -1 0 -1 0 -1].

[0218] Or, LTF -121:121 =

[0219] [0 -1 0 1 0 1 0 -1 0 -1 0 1 0 -1 0 1 0 -1 0 1 0 -1 0 -1 0 1 0 -1 0 10 -1 0 -1 0 1 0 -1 0 -1 0 1 0 1 0 -1 0 1 0 -1 0 1 0 -1 0 1 0 1 0 -1 0 -1 0 10 -1 0 1 0 -1 0 -1 0 ... 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 1 0 1 0 1 0 1 0 -1 0 -1 0 1 0 1 0 1 0 -1 0 -1 0 -1 0 1 0 1 0 -1 0 -1 0 -1 0 -1 0 -1 0 -1 0 -1 0 1 0 1 0 -1 0 -1 0 -1 0 -1 0 -1 0 -1 0 1 0 1 0 -1 0 -1 0 -1 0 -1 0 1 0 1 0 1 0 1 0 1 0 -1 0 -1 0 -1 0 -1 0 -1 0 -1 0 -1 0 -1 0 ...

[0220] Or, LTF -128:127 =

[0221] [0 0 0 0 0 0 0 0 -1 0 1 0 1 0 -1 0 -1 0 1 0 -1 0 1 0 -1 0 -10 1 0 -1 0 1 0 -1 0 -1 0 1 0 -1 0 -1 0 1 0 1 0 -1 0 1 0 -1 0 1 0 1 0 -1 0 1 0 1 0 -1 0 1 0 -1 0 1 0 1 0 -1 0 1 0 1 0 -1 0 1 0 1 0 1 0 -1 0 1 0 1 0 -1 0 -1 0 1 0 -1 0 1 0 -1 0 1 0 -1 0 1 0 -1 0 1 0 -1 0 1 0 -1 0 1 0 -1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 1 0 1 0 1 0 1 0 -1 0 -1 0 1 0 1 0 1 0 -1 0 -1 0 -1 0 10 1 0 -1 0 -1 0 -1 0 -1 0 -1 0 -1 0 1 0 1 0 -1 0 -1 0 -1 0 -1 0 -1 0 -1 0 1 0 1 0 -1 0 -1 0 -1 0 -1 0 1 0 1 0 1 0 1 0 1 0 -1 0 -1 0 -1 0 -1 0 -1 0 -1 0 -1 0 -1 0 1 0 1 0 -1 0 -1 0 0 0 0 0 0 0].

[0222] As yet another example, the LTF sequence is:

[0223] LTF -120:120 =

[0224] [1 0 -1 0 -1 0 1 0 1 0 -1 0 1 0 -1 0 1 0 -1 0 1 0 1 0 -1 0 1 0 1 0 1 0 -1 0 1 0 1 0 -1 0 -1 0 1 0 -1 0 1 0 -1 0 1 0 -1 0 -1 0 1 0 1 0 -1 0 1 0-1 0 1 0 - ... 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0-1 0 -1 0 -1 0 -1 0 -1 0 1 0 1 0 -1 0 -1 0 -1 0 1 0 1 0 1 0 -1 0 -1 0 1 0 1 0 1 0 1 0 1 0 1 0 -1 0 -1 0 1 0 1 0 1 0 1 0 1 0 -1 0 -1 0 1 0 1 0 1 0 -1 0 -1 0 1 0 1 0 -1 0 -1 0 -1 0 -1 0 -1 0 1 0 1 0 1 0 1 0 1 0 1 0 - ...

[0225] Or, LTF -121:121 =

[0226] [0 1 0 -1 0 -1 0 1 0 1 0 -1 0 1 0 -1 0 1 0 1 0 -1 0 1 0 -1 0 1 0 -1 01 0 1 0 -1 0 1 0 1 0 -1 0 -1 0 1 0 -1 0 1 0 -1 0 -1 0 1 0 1 0 -1 0 10 -1 0 1 ... 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 00 -1 0 -1 0 -1 0 -1 0 -1 0 1 0 1 0 -1 0 -1 0 -1 0 1 0 1 0 1 0 -1 0 -1 0 1 0 10 1 0 1 0 1 0 1 0 -1 0 -1 0 1 0 1 0 1 0 1 0 1 0 -1 0 -1 0 1 0 1 0 1 0 -1 0 -1 0 -1 0 -1 0 -1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 - ...

[0227] Or, LTF -128:127 =

[0228] [0 0 0 0 0 0 0 0 1 0 -1 0 -1 0 1 0 1 0 -1 0 1 0 -1 0 1 0 -1 0 1 0 1 0-1 0 1 0 -1 0 1 0 1 0 -1 0 1 0 1 0 -1 0 -1 0 1 0 -1 0 1 0 -1 0 -1 0 1 0 1 0 -1 0 -1 0 1 0 -1 0 1 0 -1 0 1 0 -1 0 -1 0 1 0 -1 0 -1 0 1 0 -1 0 -1 0 1 0 1 0 -1 0 -1 0 1 0 -1 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 -1 0 -1 0 -1 0 -1 0 -1 0 1 0 1 0 -1 0 -1 0 -1 0 1 0 1 0 1 0 -1 0 -1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 -1 0 -1 0 1 0 1 0 1 0 1 0 -10 -1 0 1 0 1 0 1 0 -1 0 -1 0 -1 0 -1 0 -1 0 -1 0 1 0 1 0 1 0 1 0 1 0 1 0 -1 0-1 0 1 0 1 0 0 0 0 0 0 0].

[0229] The LTF sequence provided in this application embodiment has a low PAPR, which can effectively reduce nonlinear distortion, improve working efficiency, improve channel estimation accuracy, and thus improve system performance.

[0230] Table 3 exemplarily illustrates the PAPR comparison between the LTF sequence and the HE-LTF sequence provided in this application. Referring to the explanation in Table 2, repeating the transmission of the 52-tone RU four times is equivalent to constructing a new multi-resource unit (MRU). This MRU did not consider the PAPR of its corresponding LTF field when designing the LTF sequence; therefore, the first station may have a high PAPR when transmitting the LTF field. However, the LTF sequence provided in this application not only reduces PRAP but also has a gain of 1.48 dB compared to the HE-LTF sequence.

[0231] Table 3

[0232]

[0233] The following describes the communication device provided in the embodiments of this application.

[0234] This application divides the communication device into functional modules according to the above-described method embodiments. For example, each function can be divided into its own functional modules, or two or more functions can be integrated into one processing module. The integrated modules can be implemented in hardware or as software functional modules. It should be noted that the module division in this application is illustrative and represents only one logical functional division; other division methods may be used in actual implementation. The following will combine... Figures 7 to 9 The communication device of the present application embodiment is described in detail.

[0235] Figure 7 This is a schematic diagram of a communication device provided in an embodiment of this application. For example... Figure 7 As shown, the communication device includes a processing module 701 and a transceiver module 702. The transceiver module 702 can implement corresponding communication functions, and the processing module 701 is used to implement corresponding processing functions. The transceiver module 702 can also be referred to as an interface, communication interface, or communication module, etc.

[0236] In some embodiments of this application, the communication device can be used to perform the actions performed by the first station in the above method embodiments. In this case, the first station can be the device itself or a chip or functional module configurable in the device. The transceiver module 702 is used to perform the transceiver-related operations of the first station in the above method embodiments, and the processing module 701 is used to perform the processing-related operations of the first station in the above method embodiments.

[0237] Processing module 701 can acquire LTF sequences;

[0238] The transceiver module 702 can be used to send or output the PPDU.

[0239] or,

[0240] Processing module 701 is used to generate an LTF field based on the LTF sequence;

[0241] The transceiver module 702 is used to send or output PPDUs including the LTF field. Multiplexing. Figure 7 In other embodiments of this application, the communication device can be used to perform the actions performed by the second station in the above method embodiments. In this case, the second station can be the device itself or a chip or functional module configurable in the device. The transceiver module 702 is used to perform the transceiver-related operations of the second station in the above method embodiments, and the processing module 701 is used to perform the processing-related operations of the second station in the above method embodiments.

[0242] The transceiver module 702 can be used to receive PPDUs, which include an LTF field.

[0243] The processing module 701 can be used to perform channel estimation based on the LTF sequence and the LTF field.

[0244] For example, the transceiver module 702 described above can be an antenna module. Alternatively, the transceiver module 702 can be an input / output module. Optionally, in the above embodiments, the communication device may further include a storage module, which can be used to store instructions and / or data. The processing module 701 can read the instructions and / or data from the storage module to enable the communication device to implement the aforementioned method embodiments.

[0245] For details regarding the specific explanations of each term, noun, or step in the above embodiments, please refer to the descriptions in the above method embodiments; they will not be detailed here.

[0246] The specific descriptions of the transceiver module and processing module shown in the above embodiments are merely examples. For the specific functions or execution steps of the transceiver module and processing module, please refer to the above method embodiments, which will not be described in detail here.

[0247] It is understandable that the module division in the above-mentioned device is merely a logical functional division. Each function can correspond to a functional module, or two or more functions can be integrated into one functional module. In actual implementation, all or some modules can be integrated into one physical entity, or they can be distributed across different physical entities. Furthermore, the above-mentioned functional modules can be implemented in hardware, software, or a combination of both.

[0248] In one example, the functional unit in any of the above devices may be one or more integrated circuits configured to implement the above methods, such as: one or more application-specific integrated circuits (ASICs), or one or more central processing units (CPUs), one or more microcontroller units (MCUs), one or more digital signal processors (DSPs), or one or more field-programmable gate arrays (FPGAs), or a combination of at least two of these integrated circuit forms.

[0249] The communication device according to the embodiments of this application has been described above. The following describes the possible product forms of the communication device. Any device possessing the above-described... Figure 7Any form of the communication device described herein falls within the protection scope of the embodiments of this application. The following description is merely illustrative and does not limit the product form of the communication device in the embodiments of this application to this.

[0250] In one possible implementation, Figure 7 In the communication device shown, the processing module 701 can be one or more processors, and the transceiver module 702 can be a transceiver, or the transceiver module 702 can also be a transmitting module and a receiving module. The transmitting module can be a transmitter, and the receiving module can be a receiver. The transmitting module and the receiving module are integrated into one device, such as a transceiver. In the embodiments of this application, the processor and the transceiver can be coupled, etc., and the connection method between the processor and the transceiver is not limited in the embodiments of this application. In the process of executing the above method, the process of sending information in the above method can be the process of the processor outputting the above information. When outputting the above information, the processor outputs the above information to the transceiver so that the transceiver can transmit it. After the above information is output by the processor, it may need to undergo other processing before reaching the transceiver. Similarly, the process of receiving information in the above method can be the process of the processor receiving the above information input. When the processor receives the input information, the transceiver receives the above information and inputs it into the processor. Furthermore, after the transceiver receives the above information, the above information may need to undergo other processing before being input into the processor.

[0251] Figure 8 This is another structural schematic diagram of the communication device provided in the embodiments of this application. For example... Figure 8 As shown, the communication device 80 includes one or more processors 820 and transceivers 810.

[0252] In some embodiments of this application, the communication device can be used to execute the steps, methods, or functions performed by the first station, such as the processor 820 being used to perform... Figure 7 The transceiver 810 can be used to perform the functions or steps implemented by the processing module 701 shown. Figure 7 The transceiver module 702 shown illustrates the functions or steps implemented by this module. For detailed information on the processor 820 and transceiver 810, please refer to [link / reference needed]. Figure 7 Alternatively, the method embodiments shown above will not be described in detail here.

[0253] In other embodiments of this application, the communication device is used to execute the steps, methods, or functions performed by the second station, such as the processor 820 being used to perform... Figure 7 The transceiver 810 can be used to perform the functions or steps implemented by the processing module 701 shown. Figure 7The transceiver module 702 shown illustrates the functions or steps implemented by this module. For detailed information on the processor 820 and transceiver 810, please refer to [link / reference needed]. Figure 7 Alternatively, the method embodiments shown above will not be described in detail here.

[0254] exist Figure 8 In various implementations of the communication apparatus shown, the transceiver may include a receiver for performing a receiving function (or operation) and a transmitter for performing a transmitting function (or operation). The transceiver is also used to communicate with other devices / appliances via a transmission medium.

[0255] Optionally, the communication device 80 may further include one or more memories 830 for storing program instructions and / or data. The memory 830 is coupled to the processor 820. The coupling in this embodiment is an indirect coupling or communication connection between communication devices, units, or modules, and can be electrical, mechanical, or other forms, used for information exchange between the communication devices, units, or modules. The processor 820 may operate in conjunction with the memory 830. The processor 820 can execute program instructions stored in the memory 830. Optionally, at least one of the above-mentioned memories may be included in the processor.

[0256] This application embodiment does not limit the specific connection medium between the transceiver 810, processor 820, and memory 830. This application embodiment... Figure 8 The memory 830, processor 820, and transceiver 810 are connected via a bus 840, and the bus is in... Figure 8 The connections between other components are shown in bold and are for illustrative purposes only, not as limiting information. The bus can be divided into address bus, data bus, control bus, etc. For ease of illustration, Figure 8 The bus is represented by a single thick line, but this does not mean that there is only one bus or one type of bus.

[0257] In the embodiments of this application, the processor may be a general-purpose processor, a digital signal processor, an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc., and can implement or execute the various methods, steps, and logic block diagrams disclosed in the embodiments of this application. The general-purpose processor may be a microprocessor or any conventional processor. The steps of the methods disclosed in the embodiments of this application can be directly manifested as being executed by a hardware processor, or being executed by a combination of hardware and software modules within the processor.

[0258] In this application embodiment, the memory may include, but is not limited to, non-volatile memory such as hard disk drive (HDD) or solid-state drive (SSD), random access memory (RAM), erasable programmable read-only memory (EPROM), read-only memory (ROM), or compact disc read-only memory (CD-ROM), etc. Memory is any storage medium capable of carrying or storing program code in the form of instructions or data structures, and capable of being read and / or written by a computer (such as the communication device shown in this application), but is not limited to this. The memory in this application embodiment may also be a circuit or any other device capable of implementing storage functions, used to store program instructions and / or data.

[0259] The processor 820 is primarily used for processing communication protocols and data, controlling the entire communication device, executing software programs, and processing software program data. The memory 830 is primarily used for storing software programs and data. The transceiver 810 may include control circuitry and an antenna. The control circuitry is primarily used for converting baseband signals to radio frequency signals and processing radio frequency signals. The antenna is primarily used for transmitting and receiving radio frequency signals in the form of electromagnetic waves. Input / output devices, such as touchscreens, displays, and keyboards, are primarily used for receiving user input data and outputting data to the user.

[0260] When the communication device is powered on, the processor 820 can read the software program in the memory 830, interpret and execute the instructions of the software program, and process the data of the software program. When data needs to be transmitted wirelessly, the processor 820 performs baseband processing on the data to be transmitted and outputs the baseband signal to the radio frequency (RF) circuit. The RF circuit processes the baseband signal and transmits the RF signal outward in the form of electromagnetic waves through the antenna. When data is sent to the communication device, the RF circuit receives the RF signal through the antenna, converts the RF signal into a baseband signal, and outputs the baseband signal to the processor 820. The processor 820 converts the baseband signal into data and processes the data.

[0261] In another implementation, the radio frequency circuitry and antenna can be set up independently of the processor performing baseband processing. For example, in a distributed scenario, the radio frequency circuitry and antenna can be arranged remotely, independent of the communication device.

[0262] The communication device shown in the embodiments of this application may also have a higher... Figure 8This application does not limit the use of other components or other related elements. The methods performed by the processor and transceiver shown above are merely examples; the specific steps performed by the processor and transceiver can be found in the methods described above. Figure 8 The dashed section indicates that it is optional.

[0263] In another possible implementation Figure 7 In the communication device shown, the processing module 701 can be one or more logic circuits, and the transceiver module 702 can be an input / output interface, or a communication interface, or an interface circuit, or an interface, etc. Alternatively, the transceiver module 702 can also be a transmitting module and a receiving module. The transmitting module can be an output interface, and the receiving module can be an input interface. The transmitting module and the receiving module are integrated into one module, such as an input / output interface.

[0264] Figure 9 This is a schematic diagram of a chip structure provided in an embodiment of this application. For example... Figure 9 As shown, Figure 9 The chip shown includes logic circuitry 901 and interface 902. That is, the processing module 701 can be implemented using logic circuitry 901, and the transceiver module 702 can be implemented using interface 902. The logic circuitry 901 can be a chip, processing circuit, integrated circuit, or system-on-a-chip (SoC) chip, etc., and the interface 902 can be a communication interface, input / output interface, pins, etc. For example, Figure 9 The above-mentioned communication device is used as an example of a chip, which includes a logic circuit 901 and an interface 902.

[0265] In this embodiment, the logic circuit and the interface can also be coupled to each other. The specific connection method between the logic circuit and the interface is not limited in this embodiment. For example, the logic circuit 901 can be used to perform... Figure 7 The processing module 701 shown implements the functions or steps, and the interface 902 can be used to execute such functions or steps. Figure 7 The transceiver module 702 shown herein implements the functions or steps. For detailed descriptions of the logic circuit 901 and interface 902, please refer to [link / reference needed]. Figure 7 Alternatively, the method embodiments shown above will not be described in detail here.

[0266] The communication device shown in the embodiments of this application can implement the method provided in the embodiments of this application in hardware form, or it can implement the method provided in the embodiments of this application in software form, etc., and the embodiments of this application do not limit it in this way.

[0267] Furthermore, embodiments of this application also provide a communication system, which includes a first station and a second station, the first station and the second station being used to perform the methods in any of the foregoing embodiments.

[0268] This application also provides a computer program for implementing the operations and / or processes performed by various sites in the methods provided in this application.

[0269] This application also provides a computer-readable storage medium storing computer code that, when executed on a computer, causes the computer to perform the operations and / or processes performed by various communication devices in the methods provided in this application.

[0270] This application also provides a computer program product comprising computer code or a computer program that, when run on a computer, causes the operations and / or processes performed by various entities in the method provided in this application to be executed.

[0271] In the embodiments provided in this application, it should be understood that the disclosed systems, communication devices, and methods can be implemented in other ways. For example, the communication device embodiments described above are merely illustrative. For instance, the division of modules is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple modules or components may be combined or integrated into another system, or some features may be ignored or not executed. In addition, the mutual coupling or direct coupling or communication connection shown or discussed may be indirect coupling or communication connection through some interfaces, communication devices, or modules, or it may be an electrical, mechanical, or other form of connection.

[0272] The modules described as separate components may or may not be physically separate. The components shown as modules may or may not be physical modules; that is, they may be located in one place or distributed across multiple network modules. Some or all of the modules can be selected according to actual needs to achieve the technical effects of the solutions provided in the embodiments of this application.

[0273] Furthermore, the functional modules in the various embodiments of this application can be integrated into one processing module, or each module can exist physically separately, or two or more modules can be integrated into one module. The integrated modules described above can be implemented in hardware or as software functional modules.

[0274] If the integrated module is implemented as a software functional module and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a readable storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this application. The aforementioned readable storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

Claims

1. A communication method characterized by comprising: The method comprises: obtaining an LTF sequence, the LTF sequence satisfying at least one of: an LTF sequence value corresponding to a first subcarrier group being opposite to an LTF sequence value corresponding to a second subcarrier group, an LTF sequence value corresponding to a third subcarrier group being same as an LTF sequence value corresponding to a fourth subcarrier group, the LTF sequence value being 1 or -1; sending the LTF sequence.

2. A communication method characterized by comprising: The method comprises: receiving a physical layer protocol data unit (PPDU), the PPDU comprising a long training field (LTF) field; obtaining an LTF sequence as a reference sequence for channel estimation, the LTF sequence satisfying at least one of: an LTF sequence value corresponding to a first subcarrier group being opposite to an LTF sequence value corresponding to a second subcarrier group, an LTF sequence value corresponding to a third subcarrier group being same as an LTF sequence value corresponding to a fourth subcarrier group, the LTF sequence value being 1 or -1; performing channel estimation according to the LTF sequence and the LTF field.

3. The method according to claim 1 or 2, characterized in that, The LTF sequence is a 2x LTF sequence.

4. The method of any one of claims 1-3, wherein the LTF sequence value corresponding to the first subcarrier group is [1 1 -1 -1 1 1 1 1 1 1 1 -1 -1], or the LTF sequence value corresponding to the first subcarrier group is [-1 -1 1 1 -1 -1 -1 -1 -1 -1 -1 1 1], or the LTF sequence value corresponding to the first subcarrier group is [-1 1 1 -1 -1 1 -1 1 -1 1 -1 -1 1], or the LTF sequence value corresponding to the first subcarrier group is [1 -1 -1 1 1 -1 1 -1 1 -1 1 1 -1].

5. The method of any one of claims 1-4, wherein the LTF sequence value corresponding to the third subcarrier group is [-1 -1 -1 1 1 1 -1 -1 1 1 1 1 1], or the LTF sequence value corresponding to the third subcarrier group is [1 1 1 -1 -1 -1 1 1 -1 -1 -1 -1 -1], or the LTF sequence value corresponding to the third subcarrier group is [1 -1 1 1 -1 1 1 -1 -1 1 -1 1 -1], or the LTF sequence value corresponding to the third subcarrier group is [-1 1 -1 -1 1 -1 -1 1 1 -1 1 -1 1].

6. The method according to any one of claims 1 to 5, characterized in that, an index of a subcarrier in the first subcarrier group to the fourth subcarrier group is less than 0, or an index of a subcarrier in the first subcarrier group to the fourth subcarrier group is greater than 0.

7. The method of claim 6, wherein In a case where the index of the subcarriers in the first to fourth subcarrier groups is less than 0, the non-zero LTF sequence value corresponding to the subcarrier with an index greater than 0 is determined according to the first odd LTF sequence value and the second even LTF sequence value in the LTF sequence values corresponding to the subcarriers in the first to fourth subcarrier groups; or, In a case where the index of the subcarriers in the first to fourth subcarrier groups is greater than 0, the non-zero LTF sequence value corresponding to the subcarrier with an index less than 0 is determined according to the first odd LTF sequence value and the second even LTF sequence value in the LTF sequence values corresponding to the subcarriers in the first to fourth subcarrier groups.

8. The method of any one of claims 1-7, wherein, the index of the subcarriers in the first subcarrier group is [-120:2:-96], and the index of the subcarriers in the second subcarrier group is [-68:2:-44], or the index of the subcarriers in the second subcarrier group is [-42:2:-18]; the index of the subcarriers in the third subcarrier group is [-94:2:-70], and the index of the subcarriers in the fourth subcarrier group is [-42:2:-18], or the index of the subcarriers in the fourth subcarrier group is [-68:2:-44]; or, the index of the subcarriers in the first subcarrier group is [120:-2:96], and the index of the subcarriers in the second subcarrier group is [68:-2:44], or the index of the subcarriers in the second subcarrier group is [42:-2:18]; the index of the subcarriers in the third subcarrier group is [94:-2:70], and the index of the subcarriers in the fourth subcarrier group is [42:-2:18], or the index of the subcarriers in the fourth subcarrier group is [68:-2:44].

9. The method according to any one of claims 1 to 8, characterized in that, The LTF sequence is: [1 0 1 0 -1 0 -1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 -1 0 -1 0 -1 0 -1 0 -1 0 10 1 0 1 0 -1 0 -1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 -1 0 -1 0 1 0 1 0 1 0 1 0 1 01 0 1 0 -1 0 -1 0 1 0 1 0 1 0 -1 0 -1 0 -1 0 1 0 1 0 -1 0 -1 0 -1 0 -1 0 -1 00 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 -1 01 0 -1 0 1 0 1 0 -1 0 -1 0 1 0 -1 0 -1 0 1 0 -1 0 -1 0 1 0 1 0 -1 0 1 0 -1 01 0 -1 0 1 0 1 0 -1 0 -1 0 1 0 -1 0 1 0 -1 0 1 0 -1 0 -1 0 1 0 1 0 -1 0 1 0 10 -1 0 1 0 -1 0 1 0 1 0 -1 0 1 0 -1 0 1 0 -1 0 1 0 1 0 -1 0 -1 0 1]。 10. A communications device, characterized by The apparatus comprises a module for performing the method of any one of claims 1-9.

11. A communications device, characterized by The apparatus comprises a processor configured to cause the communication device to implement the method of any one of claims 1-9.

12. A computer-readable storage medium, characterized in that, The computer readable storage medium is configured to store a computer program, which, when executed by a communication device, causes the method of any one of claims 1-9 to be implemented.

13. A computer program product, characterised in that, The computer program product, when executed by a computer, causes the method of any one of claims 1-9 to be performed.

14. A communication system, characterized by The apparatus comprises a first station configured to perform the method of any one of claims 1, 3-9, and a second station configured to perform the method of any one of claims 2-9.

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