Communication method and apparatus

Abstract

The present application relates to the technical field of communications, and in particular to a communication method and apparatus. The present application can be applied to the IEEE 802.11ax standard, the 802.11be standard, the 802.11bn standard, etc., and other standards in the IEEE 802.11 series, such as the 802.15 standard, the 802.11bf standard, the IMMW standard, and the NearLink standard. The present application designs a new LTF sequence, which can reduce the PAPR of an LTF field. The LTF sequence comprises a non-zero LTF sequence value, which corresponds to a subcarrier. The LTF sequence may satisfy: an LTF sequence value corresponding to a first subcarrier group is opposite to an LTF sequence value corresponding to a second subcarrier group, and an LTF sequence value corresponding to a third subcarrier group is the same as an LTF sequence value corresponding to a fourth subcarrier group.

Description

Communication method and apparatus

[0001] This application claims priority to the Chinese patent application No. 202411401070.8, filed on September 30, 2024, with the State Intellectual Property Office of China, and the Chinese patent application No. 202411401070.8 has the title of “Communication method and apparatus”, the whole content of which is incorporated herein by reference. TECHNICAL FIELD

[0002] The present application relates to the field of communication technology, in particular to a communication method and apparatus. BACKGROUND

[0003] Wireless local area network (WLAN) starts from 802.11a / b / g, goes through 802.11n, 802.11ac, 802.11ax, 802.11be and 802.11bn. Among them, the 802.11a / b / g standards are collectively referred to as non high throughput (non-HT), the 802.11n standard is referred to as high throughput (HT), the 802.11ac standard is referred to as very high throughput (VHT), the 802.11ax standard is referred to as high efficient (HE), the 802.11be standard is referred to as extremely high throughput (EHT), and the 802.11bn standard is referred to as ultra high reliability (UHR).

[0004] As the number of WLAN-based internet of things (IoT) devices increases, and it is difficult to deploy multiple access points (APs) in a home environment, the demand for WLAN to support long-distance transmission is increasing. The 802.11b standard adopts a direct-sequence spread spectrum (DSSS) modulation method to convert digital signals into analog signals with a wider frequency width to enhance the reliability of data transmission. However, the frequency spectrum efficiency of the long-distance transmission scheme based on the 802.11b standard is low, and the standard is relatively old, making network management difficult. Therefore, in the 802.11bn or subsequent standards, long-distance transmission, such as enhanced long range (ELR) transmission based on orthogonal frequency division multiplexing (OFDM) modulation, has become one of the research hotspots.

[0005] LTF sequence is an important part for channel estimation in WLAN network, and is also a current research hotspot. SUMMARY

[0006] Embodiments of the present application provide a communication method and device, which can effectively reduce the PAPR of a long training field (LTF) field, or the PAPR of an LTF sequence.

[0007] In a first aspect, embodiments of the present application provide a communication method, which is applied to a first station. The first station can be a Wi-Fi device, or a chip or functional module in the Wi-Fi device. The Wi-Fi device includes, but is not limited to, an IoT device. The method includes:

[0008] generating an LTF field according to an LTF sequence, the LTF sequence satisfying at least one of the following conditions: an LTF sequence value corresponding to a first subcarrier group is opposite to an LTF sequence value corresponding to a second subcarrier group, and an LTF sequence value corresponding to a third subcarrier group is the same as an LTF sequence value corresponding to a fourth subcarrier group; and transmitting an enhanced long range physical protocol data unit (ELR-PPDU) including the LTF field.

[0009] In other words, an LTF sequence value corresponding to an i-th subcarrier in the first subcarrier group is opposite to an LTF sequence value corresponding to the i-th subcarrier in the second subcarrier group, and an LTF sequence value corresponding to the i-th subcarrier in the third subcarrier group is the same as an LTF sequence value corresponding to the i-th subcarrier in the fourth subcarrier group.

[0010] The number of subcarriers in the first to fourth subcarrier groups is the same. The LTF field includes one or more OFDM symbols.

[0011] In embodiments of the present application, the LTF sequence value corresponding to each subcarrier in each subcarrier group 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.

[0012] In a second aspect, embodiments of the present application provide a communication method, which is applied to a second station. The second station can be a Wi-Fi device, or a chip or functional module in the Wi-Fi device. The Wi-Fi device includes, but is not limited to, an IoT device. The method includes:

[0013] receiving an ELR-PPDU, the ELR-PPDU comprising a LTF field; performing channel estimation according to a LTF sequence and the LTF field, the LTF sequence satisfying at least one of: LTF sequence values corresponding to the first subcarrier group are opposite to LTF sequence values corresponding to the second subcarrier group, LTF sequence values corresponding to the third subcarrier group are same as LTF sequence values corresponding to the fourth subcarrier group.

[0014] The LTF sequence values corresponding to the subcarriers in each of the subcarrier groups are 1 or -1. The beneficial effects of the second aspect are similar to the first aspect, and will not be repeated here.

[0015] In a possible implementation of the first aspect or the second aspect, the LTF sequence is a 2x LTF sequence pattern. That is, the LTF sequence can also be referred to as a 2x LTF sequence. There are at least 1 zero between two adjacent non-zero elements in the LTF sequence.

[0016] In a possible implementation of the first aspect or the second aspect, the LTF sequence values corresponding to the first subcarrier group are [1 1 -1 -1 1 1 1 1 1 1 1 -1 -1], or the LTF sequence values corresponding to the first subcarrier group are LTF sequence values after processing [1 1 -1 -1 1 1 1 1 1 1 1 -1 -1]. The processing manner includes at least one of: reverse order, all elements negation, and partial elements negation.

[0017] In a possible implementation of the first aspect or the second aspect, the LTF sequence values corresponding to the first subcarrier group are [1 1 -1 -1 1 1 1 1 1 1 1 -1 -1], or the LTF sequence values corresponding to the first subcarrier group are [-1 -1 1 1 -1 -1 -1 -1 -1 -1 -1 1 1], or the LTF sequence values corresponding to the first subcarrier group are [-1 1 1 -1 -1 1 -1 1 -1 1 -1 -1 1], or the LTF sequence values corresponding to the first subcarrier group are [1 -1 -1 1 1 -1 1 -1 1 -1 1 1 -1].

[0018] In a possible implementation of the first aspect or the second aspect, the LTF sequence values corresponding to the third subcarrier group are [-1 -1 -1 1 1 1 -1 -1 1 1 1 1 1], or the LTF sequence values corresponding to the third subcarrier group are LTF sequence values after processing [-1 -1 -1 1 1 1 -1 -1 1 1 1 1 1]. The processing manner includes at least one of: reverse order, all elements negation, and partial elements negation.

[0019] In a possible implementation manner of the first aspect or the second aspect, 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].

[0020] In a possible implementation manner of the first aspect or the second aspect, the index of the subcarrier in the first subcarrier group to the fourth subcarrier group is less than 0, or the index of the subcarrier in the first subcarrier group to the fourth subcarrier group is greater than 0.

[0021] In a possible implementation manner of the first aspect or the second aspect, when the index of the subcarrier in the first subcarrier group to the fourth subcarrier group is less than 0, the non-zero LTF sequence value corresponding to the subcarrier with the 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 value corresponding to the subcarrier in the first subcarrier group to the fourth subcarrier group; or when the index of the subcarrier in the first subcarrier group to the fourth subcarrier group is greater than 0, the non-zero LTF sequence value corresponding to the subcarrier with the 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 value corresponding to the subcarrier in the first subcarrier group to the fourth subcarrier group.

[0022] In a possible implementation manner of the first aspect or the second aspect, the index of the subcarrier in the first subcarrier group is [-120:2:-96], the index of the subcarrier in the second subcarrier group is [-68:2:-44], or the index of the subcarrier in the second subcarrier group is [-42:2:-18]; the index of the subcarrier in the third subcarrier group is [-94:2:-70], the index of the subcarrier in the fourth subcarrier group is [-42:2:-18], or the index of the subcarrier in the fourth subcarrier group is [-68:2:-44].

[0023] Alternatively, the indexes of the subcarriers in the first subcarrier group are [120:-2:96], the indexes of the subcarriers in the second subcarrier group are [68:-2:44], or the indexes of the subcarriers in the second subcarrier group are [42:-2:18]; the indexes of the subcarriers in the third subcarrier group are [94:-2:70], the indexes of the subcarriers in the fourth subcarrier group are [42:-2:18], or the indexes of the subcarriers in the fourth subcarrier group are [68:-2:44].

[0024] With reference to the first aspect or the second aspect, in a possible implementation, in the case that the indexes of the subcarriers in the first subcarrier group to the fourth subcarrier group are less than 0, the LTF sequence values corresponding to the remaining subcarriers other than the subcarriers in the first subcarrier group to the fourth subcarrier group in the subcarriers with indexes less than 0 are 0.

[0025] With reference to the first aspect or the second aspect, in a possible implementation, in the case that the indexes of the subcarriers in the first subcarrier group to the fourth subcarrier group are greater than 0, the LTF sequence values corresponding to the remaining subcarriers other than the subcarriers in the first subcarrier group to the fourth subcarrier group in the subcarriers with indexes greater than 0 are 0.

[0026] With reference to the first aspect or the second aspect, in a possible implementation, the bandwidth for transmitting the ELR-PPDU is 20MHz. Taking a subcarrier spacing of 78.125KHz as an example, there are 256 subcarriers in 20MHz, and the index range is [-128:127].

[0027] With reference to the first aspect or the second aspect, in a possible implementation, the ELR-PPDU further comprises an ELR-data (ELR-data) field, and the RU corresponding to the ELR-data field is 4 52-tone RUs. That is, the data information of the ELR-data field is transmitted on 4 52-tone RUs.

[0028] With reference to the first aspect or the second aspect, in a possible implementation, the ELR-PPDU further comprises an ELR signaling (signal, SIG) (ELR-SIG), and the RU corresponding to the ELR-SIG field is 4 52-tone RUs. That is, the signaling information of the ELR-SIG field is transmitted on 4 52-tone RUs.

[0029] With reference to the first aspect or the second aspect, in a possible implementation, the RU corresponding to the LTF field is 4 52-tone RUs. That is, the signaling information of the LTF field is transmitted on 4 52-tone RUs.

[0030] In a third aspect, an embodiment of the present application provides a communication method, which is applied to a first station. The first station can be a Wi-Fi device, or a chip or functional module in the Wi-Fi device. The Wi-Fi device includes, but is not limited to, an IoT device. The method includes:

[0031] obtaining an LTF sequence, which is a sequence in each of the subsequent embodiments; and transmitting the LTF sequence.

[0032] In a fourth aspect, an embodiment of the present application provides a communication method, which is applied to a second station. The second station can be a Wi-Fi device, or a chip or functional module in the Wi-Fi device. The Wi-Fi device includes, but is not limited to, an IoT device. The method includes:

[0033] receiving a PPDU, which is an ELR-PPDU. The ELR-PPDU includes an LTF field;

[0034] obtaining an LTF sequence as a reference sequence for channel estimation, which is a sequence in each of the subsequent embodiments;

[0035] performing channel estimation according to the LTF field and the LTF sequence.

[0036] In a fifth aspect, an embodiment of the present application provides a first station, which is configured to perform the method in the first aspect or the third aspect or any possible implementation manner. The first station includes a module configured to perform the method in the first aspect or the third aspect or any possible implementation manner.

[0037] In a sixth aspect, an embodiment of the present application provides a second station, which is configured to perform the method in the second aspect or the fourth aspect or any possible implementation manner. The second station includes a module configured to perform the method in the second aspect or the fourth aspect or any possible implementation manner.

[0038] In a seventh aspect, an embodiment of the present application provides a first station, which includes a processor configured to cause the first station to perform the method in the first aspect or the third aspect or any possible implementation manner. Alternatively, the processor is configured to execute a computer program stored in a memory, and when the computer program is executed, the method in the first aspect or the third aspect or any possible implementation manner is performed.

[0039] In a possible implementation manner, the memory is located outside the first station.

[0040] In a possible implementation manner, the memory is located inside the first station.

[0041] In the embodiments of the present application, the processor and the memory can also be integrated in one device, i.e., the processor and the memory can also be integrated together. For example, the first station can be a chip.

[0042] In a possible implementation, the first station further includes a transceiver, configured to receive a signal or send a signal. For example, the transceiver can be further configured to send the ELR-PPDU. For example, the first station can be a WLAN device.

[0043] In the eighth aspect, the embodiments of the present application provide a second station, which includes a processor configured to cause the second station to perform the method in the second aspect or the fourth aspect or any possible implementation.

[0044] In a possible implementation, the memory is located outside the second station.

[0045] In a possible implementation, the memory is located inside the second station.

[0046] In the embodiments of the present application, the processor and the memory can also be integrated in one device, i.e., the processor and the memory can also be integrated together. For example, the second station can be a chip.

[0047] In a possible implementation, the second station further includes a transceiver, configured to receive a signal or send a signal. For example, the transceiver can be configured to receive the ELR-PPDU. For example, the second station can be a WLAN device.

[0048] In the ninth aspect, the embodiments of the present application provide a first station, which includes a logic circuit and an interface, coupled with each other; the interface is configured to input and / or output information, and the logic circuit is configured to cause the first station to perform the method in the first aspect or the fourth aspect or any possible implementation.

[0049] For example, the interface configured to output information can include that the interface is configured to input the ELR-PPDU. For example, the logic circuit configured to generate the LTF field according to the LTF sequence.

[0050] In the tenth aspect, the embodiments of the present application provide a second station, which includes a logic circuit and an interface, coupled with each other; the interface is configured to input and / or output information, and the logic circuit is configured to cause the second station to perform the method in the second aspect or the fourth aspect or any possible implementation.

[0051] Exemplarily, the interface for outputting information comprises: an interface for outputting the ELR-PPDU. Exemplarily, the logic circuit is configured to perform channel estimation according to the LTF sequence and the LTF field.

[0052] In an eleventh aspect, an embodiment of the present application provides a computer readable storage medium for storing a computer program, which, when executed on a computer (such as the station shown above), causes the method shown in any one of the first aspect to the fourth aspect or any possible implementation manner to be performed.

[0053] In a twelfth aspect, an embodiment of the present application provides a computer program product comprising a computer program, which, when executed on a computer (such as the station shown above), causes the method shown in any one of the first aspect to the fourth aspect or any possible implementation manner to be performed.

[0054] In a thirteenth aspect, an embodiment of the present application provides a computer program, which, when executed on a computer, causes the method shown in any one of the first aspect to the fourth aspect or any possible implementation manner to be performed.

[0055] In a fourteenth aspect, an embodiment of the present application provides a communication system comprising a first station and a second station, wherein the first station is configured to perform the method shown in the first aspect or the third aspect or any possible implementation manner, and the second station is configured to perform the method shown in the second aspect or the fourth aspect or any possible implementation manner. BRIEF DESCRIPTION OF DRAWINGS

[0056] FIG. 1 is a schematic diagram of an architecture of a communication system according to an embodiment of the present application;

[0057] FIG. 2a is a schematic diagram of a format of an ELR-PPDU according to an embodiment of the present application;

[0058] FIG. 2b is a schematic diagram of a format of an ELR-PPDU according to an embodiment of the present application;

[0059] FIG. 3 is a schematic diagram of an RU for transmitting an ELR-SIG field and an ELR data field according to an embodiment of the present application;

[0060] FIG. 4a and FIG. 4b are schematic diagrams of HE LTF sequences in a 20MHz bandwidth according to an embodiment of the present application;

[0061] FIG. 5 is a schematic diagram of a flow of a communication method according to an embodiment of the present application;

[0062] FIG. 6 is a schematic diagram of a flow of a communication method according to an embodiment of the present application;

[0063] Fig. 7 is a schematic diagram of a structure of a communication apparatus according to an embodiment of the present application;

[0064] Fig. 8 is a schematic diagram of another structure of a communication apparatus according to an embodiment of the present application;

[0065] Fig. 9 is a schematic diagram of a structure of a chip according to an embodiment of the present application. DETAILED DESCRIPTION

[0066] For the purpose of understanding the technical solutions of the present application, the present application will be further described below with reference to the drawings.

[0067] The terms "first" and "second" and the like in the specification of the present application, claims, and drawings are used only to distinguish different objects, and are not used to describe a particular order. In addition, the terms "include" and "have" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or device, etc. including a series of steps or units is not limited to the listed steps or units, but can optionally include other steps or units not listed, or can optionally include other steps or units inherent to the process, method, product, or device, etc.

[0068] In this document, "embodiment" means that the specific features, structures, or characteristics described in connection with the embodiment can be included in at least one embodiment of the present application. The appearance of this phrase in various places in the specification does not necessarily mean the same embodiment is referred to, nor does it mean that the embodiments are mutually exclusive or alternative to each other. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with each other.

[0069] In the present application, "at least one" means one or more, "multiple" means two or more, "at least two" means two or three and more, and "and / or" is used to describe the association relationship of the associated objects, which means that there can be three relationships, for example, "A and / or B" can mean: only A, only B, and A and B exist at the same time, where A and B can be singular or plural. "Or" means that there can be two relationships, such as only A, only B; when A and B are not mutually exclusive, it can also mean that there are three relationships, such as only A, only B, and A and B exist at the same time. The character " / " generally represents an "or" relationship between the associated objects before and after it. "At least one of the following" or similar expressions means any combination of these items. For example, at least one 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".

[0070] It can be understood that, for the convenience of subsequent reference, some implementations or some examples of the present application are numbered.

[0071] The following describes the communication system involved in the embodiments of this application.

[0072] The technical solutions provided in the embodiments of the present application can be applied to a wireless local area network (WLAN) system, such as Wi-Fi and the like. The method provided in the embodiments of the present application can be applicable to the institute of electrical and electronics engineers (IEEE) 802.11 series standards, for example, the 802.11be standard, the 802.11bn standard (or also referred to as Wi-Fi 8, and also referred to as ultra high reliability (UHR) or ultra high reliability and throughput (UHRT), etc.), or a next-generation standard of the 802.11bn standard or a standard supporting ambient power (AMP), and the like. The technical solutions provided in the embodiments of the present application can also be applied to a wireless personal area network (WPAN) based on integrated millimeter wave (IMMW), ultra wideband (UWB) technology, and the like. The method provided in the embodiments of the present application can be applicable to the IEEE 802.15 series standards, for example, the 802.15.4a standard, the 802.15.4z standard or the 802.15.4ab standard, or a future generation UWB WPAN standard, and the like. The technical solutions provided in the embodiments of the present application can also be applied to a spark link or nearlink standard. The technical solutions provided in the embodiments of the present application can also be applied to a communication system, for example, can be an internet of things (IoT) system, a vehicle-to-everything (V2X, X can represent any thing) system, a device-to-device (D2D) system, a narrow band IoT (NB-IoT) system, a long term evolution (LTE) system, a 5th-generation (5G) communication system, and a new communication system to be appeared in future communication development, and the like.For example, the V2X can include vehicle to vehicle (V2V), vehicle to infrastructure (V2I), vehicle to pedestrian (V2P) or vehicle to network (V2N) communication, etc.

[0073] The WLAN system can provide high-rate and low-latency transmission. With the continuous evolution of WLAN application scenarios, the WLAN system will be applied to more scenarios or industries, such as the Internet of Things industry, the Internet of Vehicles industry, or the banking industry, enterprise offices, stadiums and exhibition halls, concert halls, hotel rooms, dormitories, wards, classrooms, supermarkets, squares, streets, manufacturing workshops, and warehouses, etc. Of course, the devices (such as access points or stations) supporting WLAN communication or sensing can be sensor nodes in smart cities (such as smart water meters, smart electricity meters, and smart air detection nodes), smart devices in smart homes (such as smart cameras, projectors, display screens, televisions, sound systems, refrigerators, washing machines, etc.), nodes in the Internet of Things, entertainment terminals (such as augmented reality (AR), virtual reality (VR), etc. wearable devices), smart devices in smart offices (such as printers, projectors, amplifiers, sound systems, etc.), Internet of Vehicles devices in the Internet of Vehicles, infrastructure in daily life scenarios (such as vending machines, self-service navigation stations in supermarkets, self-service checkout devices, self-service ordering machines, etc.), and devices in large sports and music venues, etc.

[0074] Although the embodiments of the present application mainly take WLAN as an example, especially the network applied to the IEEE 802.11 series standard, but the various aspects involved in the embodiments of the present application can be extended to other networks using 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 now known or later developed networks.

[0075] In a possible implementation, the method provided by the embodiments of the present application 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).

[0076] An AP is a device with wireless communication capability, which supports communication or sensing or energy transfer using WLAN standards, and has the capability to communicate or sense with or transfer energy to other devices in a WLAN network, such as non-AP stations (non-AP STAs) or other access points. Alternatively, an access point is equivalent to a bridge connecting wired and wireless networks, and mainly functions to connect various wireless network clients together, and then access the wireless network to the Ethernet. In a WLAN system, an access point can be referred to as an access point station (AP STA). An AP is a device that provides services for non-AP STAs, and can support 802.11 series standards or subsequent standards, etc. For example, an access point can be an access point for a terminal (such as a mobile phone) to enter a wired (or wireless) network, and is mainly deployed in homes, buildings, and parks, with a typical coverage radius of tens of meters to hundreds of meters, and can also be deployed outdoors. For another example, an AP can be a communication server, a router, a switch, a network bridge, or the like. An AP can include various forms of macro base stations, micro base stations, relay stations, and the like. An AP can be a whole device (such as a WLAN device or a Wi-Fi device or an IoT device, etc.), or can be a chip, a processing system, or a functional module installed in a whole device, and the device in which the chip, the processing system, or the functional module is installed can implement the methods and functions of the embodiments of the present application under the control of the chip, the processing system, or the functional module.

[0077] A STA is a device with wireless communication capability, which supports communication or sensing or energy transfer using WLAN standards, and has the capability to communicate or sense with or transfer energy to other non-AP STAs or access points in a WLAN network. In a WLAN system, a station can be referred to as a non-AP station (non-access point station, non-AP STA). For example, a STA is any user communication device that allows a user to communicate or sense or transfer energy with an AP and then communicate with a WLAN. For example, a STA can be a wireless communication chip, a wireless sensor, or a wireless communication terminal, and can also be referred to as a user. For another example, a STA can be a mobile phone supporting Wi-Fi communication functions, a tablet computer supporting Wi-Fi communication functions, a set-top box supporting Wi-Fi communication functions, a smart television supporting Wi-Fi communication functions, a smart wearable device supporting Wi-Fi communication functions, a vehicle-mounted communication device supporting Wi-Fi communication functions, and a computer supporting Wi-Fi communication functions, etc. A STA can be a whole device (such as a WLAN device or a Wi-Fi device or an IoT device, etc.), or can be a chip, a processing system, or a functional module installed in a whole device, and the device in which the chip, the processing system, or the functional module is installed can implement the methods and functions of the embodiments of the present application under the control of the chip, the processing system, or the functional module.

[0078] The communication system can include an access point and a station. For example, embodiments of the present application can be applied to a scenario of communication or sensing between an AP and a STA, between an AP and an AP, or between a STA and a STA in a WLAN, and the present application is not limited in this regard. Optionally, an AP can communicate or sense with a single STA, or an AP can simultaneously communicate or sense with multiple STAs. Specifically, the AP communicating or sensing with multiple STAs can be divided into downlink transmission in which the AP simultaneously sends signals to multiple STAs, and uplink transmission in which multiple STAs send signals to the AP. The AP and the STA, the AP and the AP, and the STA and the STA can support a WLAN communication standard, which can include standards of the IEEE 802.11 series, such as the 802.11bn standard, and of course also standards after the 802.11bn standard.

[0079] FIG. 1 is a schematic diagram of an architecture of a communication system according to an embodiment of the present application. The communication system can include one or more APs and one or more STAs. As shown in FIG. 1, two APs, such as AP1 and AP2, and three STAs, such as STA1, STA2, and STA3, are shown. As an example, the method provided by embodiments of the present application can be applied to data communication or sensing between an AP and one or more STAs, such as the communication between AP1 and STA1 shown in FIG. 1. As another example, the method provided by embodiments of the present application can be applied to communication between an AP and an AP, such as the communication or sensing between AP1 and AP2 shown in FIG. 1. As yet another example, the method provided by embodiments of the present application can be applied to communication or sensing between a STA and a STA, such as the communication or sensing between STA2 and STA3 shown in FIG. 1.

[0080] In FIG. 1, a STA is taken as a mobile phone and an AP is taken as a router as an example, which does not limit the types of the AP and the STA in embodiments of the present application. Meanwhile, the number of APs and the number of STAs shown in FIG. 1 are only examples, and the number of APs or STAs can be more or less in a specific implementation, which is not limited in the present application.

[0081] From different perspectives of sending and receiving signals, the first station shown below can be understood as a communication device that sends a PPDU, and the second station can be understood as a communication device that receives a PPDU.

[0082] From the perspective of different devices, as an example, the first station can be an AP, and the second station can be a non-AP STA. As another example, the first station and the second station can both be non-AP STAs or both be APs. As yet another example, the first station can be a non-AP STA, and the second station can be an AP. Specific forms of the first station and the second station are not listed one by one here.

[0083] Embodiments of the present application are described from the perspective of the first station and the second station, but the first station and the second station can also forward the signal through other devices in the process of transmitting the signal, such as forwarding the signal between the first station and the second station through a forwarding device. Embodiments of the present application do not limit other devices other than the first station and the second station.

[0084] The method related to embodiments of the present application is introduced below.

[0085] For the time domain, the amplitude of the wireless signal is constantly changing, so the transmission power of the wireless signal is not constant. PAPR refers to the ratio of the peak power of the signal in a period of time to the average power of the signal. Since the OFDM symbol is superimposed by a plurality of independently modulated subcarrier signals, when the phases of the subcarriers are the same or similar, the superimposed signal will be modulated by the same initial phase signal, thereby generating a larger instantaneous power peak, which further brings a higher PAPR. Since the dynamic range of a general power amplifier is limited, an OFDM symbol with a large peak-to-average ratio is easy to enter the nonlinear region of the power amplifier, causing nonlinear distortion of the signal, causing significant spectral spread interference and in-band signal distortion, resulting in a serious decline in the performance of the entire system.

[0086] The format of the ELR-PPDU related to embodiments of the present application is illustrated below:

[0087] FIG. 2a is a format diagram of an ELR-PPDU provided by embodiments of the present application. As shown in FIG. 2a, the ELR-PPDU includes the following fields: a legacy preamble (or called a legacy preamble code), an ELR preamble (or called an ELR preamble code), and ELR data. The legacy preamble field can be used to indicate that a legacy device avoids transmitting the ELR-PPDU. That is, through the legacy preamble field, the legacy device can avoid transmitting a PPDU in the transmission time of the ELR-PPDU. The ELR preamble field is used for detection of the ELR-PPDU, channel estimation, and indication of the modulation and coding information of the ELR data field. The ELR data field can carry data.

[0088] Fig. 2b is a format diagram of the ELR-PPDU according to an embodiment of the present application. As shown in Fig. 2b, the ELR-PPDU includes at least one of the following fields: a legacy-short training field (L-STF), a legacy-long training field (L-LTF) (or a legacy-channel estimation field (L-CEF), a legacy signal (L-SIG), a repetition legacy signal (RL-SIG), a universal signal (U-SIG) 1, a U-SIG 2, an ELR-mark 1, an ELR-mark 2, an ELR-STF, an ELR-LTF, an ELR-SIG, or an ELR data. Fig. 2b also shows the power gain of the L-STF, the L-STF, the ELR-STF, and the ELR-LTF, which is +3dB as shown in Fig. 2b.

[0089] The L-STF can be used for discovery, coarse synchronization, automatic gain control (AGC), etc. of the ELR-PPDU. The L-LTF can be used for fine synchronization, channel estimation, etc. The L-SIG and the RL-SIG can be used to carry information related to the length of the ELR-PPDU, etc. The U-SIG can carry a physical layer version indication, etc. The ELR-STF can be used for automatic gain control of the subsequent fields, etc. For the descriptions of other fields, refer to the above, which will not be repeated here.

[0090] It can be understood that the order or position between the fields shown in Fig. 2b is only an example, and is not a limitation to the embodiments of the present application. With the development of the standard, the ELR-PPDU can also have other formats, and the format of the ELR-PPDU shown in Fig. 2b is not limited by the embodiments of the present application. The transmission distance of the ELR-PPDU can be greater than a certain threshold. With the development of the standard, the PPDU including the LTF field can also have other functions, or have other names, as long as the relationship between the LTF field and the LTF sequence included in the PPDU conforms to the relationship shown in the embodiments of the present application, the PPDU is within the protection scope of the embodiments of the present application.

[0091] Optionally, to increase the transmission distance of the ELR-PPDU, the station can transmit the ELR-SIG field and / or the ELR data field according to the 4 52-tone RUs. The data on one 52-tone RU is copied to the other three 52-tone RUs, and the data on part of the RUs is phase-rotated in the manner shown in FIG. 3, so as to reduce the PAPR of the ELR-SIG field and the ELR data field.

[0092] FIG. 3 is a schematic diagram of an RU for transmitting an ELR-SIG field and an ELR data field according to an embodiment of the present application. The subcarrier range of the 4 52-tone RUs shown in FIG. 3 can refer to Table 1. The data on the third 52-tone RU and the fourth 52-tone RU can be phase-rotated. [1 1 1 1 -1 1 1 -1] in FIG. 3 represents the case of phase rotation, 1 represents no phase rotation, and -1 represents phase rotation.

[0093] Table 1 exemplarily shows 4 52-tone RUs and corresponding subcarrier ranges. The subcarrier indices of the respective RUs are shown in Table 1:

[0094] Table 1

[0095] In the prior art, there are LTF sequences corresponding to 20 MHz as shown in FIG. 4a and FIG. 4b. An implementation of the present application before has an ELR-LTF field that can be generated based on the LTF sequence shown in FIG. 4a or FIG. 4b. The LTF sequence value corresponding to the subcarriers in the RUs (such as the 4 52-tone RUs described above) for transmitting information is the value at the corresponding position of the LTF sequence in FIG. 4a or FIG. 4b, and the value corresponding to the subcarriers other than the above RUs is 0.

[0096] FIG. 4a and FIG. 4b are schematic diagrams of HE LTF sequences in a 20 MHz bandwidth according to an embodiment of the present application. Taking a subcarrier spacing of 78.125 KHz as an example, the 20 MHz bandwidth can correspond to 256 subcarriers, whose indices are denoted as [-128:127]. FIG. 4a shows a 2x LTF sequence, and FIG. 4b shows a 4x LTF sequence. FIG. 4a and FIG. 4b exemplarily show the LTF sequence values on subcarriers with indices [-122:122], and the values of the subcarriers not shown in the indices are 0.

[0097] Table 2 exemplarily shows the PAPR of the LTF sequence shown in FIG. 4a or FIG. 4b. 2x ELR-LTF represents the PAPR when the ELR-LTF field is generated based on the 2x LTF sequence. 4x ELR-LTF represents the PAPR when the ELR-LTF field is generated based on the 4x LTF sequence.

[0098] Table 2

[0099] As can be seen from Table 2, the PAPR of the ELR-LTF field is larger than that of the ELR-STF field, and since the ELR-PPDU needs to amplify the power of the ELR-LTF field by 3dB, the problem of large PAPR is more serious. The large PAPR of the ELR-LTF field is prone to cause more nonlinear distortion, and also reduces the efficiency of the power amplifier, thereby affecting the system performance.

[0100] In view of the problem that directly multiplexing the HE-LTF sequence in the ELR-LTF field causes large PAPR of the ELR-LTF field, the present application designs a new LTF sequence, which can improve the overall performance of the ELR system.

[0101] FIG. 5 is a flowchart of a communication method according to an embodiment of the present application. The first station and the second station involved in the method are described with reference to FIG. 1, which will not be described here. As shown in FIG. 5, the method comprises:

[0102] 501. The first station generates an LTF field according to an LTF sequence.

[0103] The LTF sequence values in the LTF sequence are mapped to corresponding subcarriers, and the values carried by the subcarriers form the LTF field of the OFDM symbol in the time domain after inverse Fourier transform (and other processing operations). The 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. The LTF field can also be referred to as an ELR-LTF field, or as an ELR-LTF.

[0104] The kth subcarrier in the bandwidth corresponds to the kth LTF sequence value LTF k For example, if the bandwidth is 20MHz and the subcarrier spacing is 78.125KHz, there are 256 subcarriers in the 20MHz. The indices of the 256 subcarriers are [-128:127].

[0105] In the embodiments of the present application, [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 taken depends on whether c-a is exactly an integer multiple of b. If not, the element c is not included. When b is equal to 1, [a:c] can usually be used to represent [a:1:c]. For example, [-128:127] represents -128, -127, -126, -125, …, 125, 126, 127.

[0106] As a possible implementation manner 1, the length of the LTF sequence is 256, that is, the LTF sequence includes 256 LTF sequence values, and the 256 LTF sequence values correspond to 256 subcarriers in sequence. The LTF sequence is represented as LTF -128:127 , or ELR LTF -128:127 . The LTF sequence values corresponding to the guard subcarriers and the direct current subcarriers in the 256 subcarriers are 0. The LTF sequence values corresponding to the null subcarriers in the 256 subcarriers are 0.

[0107] As another possible implementation manner 2, the length of the LTF sequence is 241, that is, the LTF sequence includes 241 LTF sequence values, and the 241 LTF sequence values correspond to 241 subcarriers in sequence. The indexes of the 241 subcarriers are [-120:120]. The LTF sequence is represented as LTF - 120:120 , or ELR LTF -120:120 . The LTF sequence values corresponding to the subcarriers other than [-120:120] in [-128:127] are 0.

[0108] As still another possible implementation manner 3, the length of the LTF sequence is 243, that is, the LTF sequence includes 243 LTF sequence values, and the 243 LTF sequence values correspond to 243 subcarriers in sequence. The indexes of the 243 subcarriers are [-121:121]. The LTF sequence is represented as LTF - 121:121 , or ELR LTF -121:121 . The LTF sequence values corresponding to the subcarriers other than [-121:121] in [-128:127] are 0.

[0109] The implementation manners 1 to 3 exemplarily show different expressions of the LTF sequence. In a specific implementation, the length of the LTF sequence can also be greater than 240 and less than 256, and the expressions of the LTF sequence are not listed one by one.

[0110] As a possible implementation 4, the LTF sequence value corresponding to the kth subcarrier is the kth LTF sequence value in the LTF sequence. The value of k refers to the above-mentioned implementation 1~implementation 3. For example, the LTF sequence is designed according to the resource unit (resource allocation, RU) used to transmit information. The values corresponding to the remaining subcarriers in the LTF sequence except the above-mentioned RU are all 0. The information includes but is not limited to at least one of the ELR-data field or the ELR-SIG field. For example, the RU used to transmit information is the 4 52-tone RUs shown in Table 1 above. The LTF sequence defines the LTF sequence value corresponding to each subcarrier in the above-mentioned RU1~RU4 (as shown in Table 1), and the LTF sequence value corresponding to the above-mentioned subcarriers not shown is 0.

[0111] As another possible implementation 5, the LTF sequence value corresponding to the kth subcarrier is determined according to the kth LTF sequence value in the LTF sequence and whether the kth subcarrier belongs to the subcarrier in the RU used to transmit the LTF field. The value of k refers to the above-mentioned implementation 1~implementation 3. For example, if the kth subcarrier belongs to the subcarrier in the RU used to transmit the LTF field, the LTF sequence value corresponding to the kth subcarrier is the kth LTF sequence value in the LTF sequence. For another example, if the kth subcarrier does not belong to the subcarrier in the RU used to transmit the LTF field, the LTF sequence value corresponding to the kth subcarrier is 0. In addition to defining the LTF sequence value corresponding to each subcarrier in the above-mentioned RU1~RU4, the LTF sequence also defines the LTF sequence value corresponding to the above-mentioned subcarriers not shown, which may be 0, 1, or -1.

[0112] In a possible implementation, the first station determines the LTF sequence.

[0113] As the first station determines the LTF sequence according to the sequence mode, the sequence mode includes a 1x LTF sequence mode (or referred to as a 1x LTF sequence), a 2x LTF sequence mode (or referred to as a 2x LTF sequence), or a 4x LTF sequence mode (or referred to as a 4x LTF sequence). In the 1x LTF sequence, there are at least 3 zeros between two adjacent non-zero elements, in the 2x LTF sequence, there is at least 1 zero between two adjacent non-zero elements, and in the 4x LTF sequence, there can be consecutive non-zero elements. The non-zero elements of the 4x LTF sequence are the most dense, and thus the estimation of the channel is the most accurate.

[0114] Optionally, for the ELR-PPDU, the LTF sequence can only have a 2x LTF sequence mode, so that the first station can directly generate the LTF field according to the 2x LTF sequence.

[0115] For example, the first station determines the LTF sequence according to the bandwidth. For example, the LTF sequence can be designed for each bandwidth, i.e., different bandwidths can correspond to different LTF sequences. For example, the LTF sequence corresponding to 20MHz is different from the LTF sequence corresponding to 40MHz.

[0116] Optionally, for the ELR-PPDU, the bandwidth of the ELR-PPDU can only be 20MHz, so that the first station can directly generate the LTF field according to the LTF sequence. Optionally, the first station can transmit the ELR-PPDU in units of 20MHz.

[0117] For example, the first station determines the LTF sequence according to the sequence mode and the bandwidth. The sequence mode and the bandwidth are described above, and will not be described here.

[0118] For example, the first station determines the LTF sequence according to the type of the PPDU. The type of the PPDU includes the ELR-PPDU, or the non-ELR-PPDU. For the ELR-PPDU, the LTF sequence can be the sequence in the following embodiments. For the non-ELR-PPDU, the LTF sequence can be the sequence shown in FIG. 4a or FIG. 4b. The non-ELR-PPDU can also correspond to other sequences, which are not limited by the embodiments of the present application.

[0119] Alternatively, the first station determines the LTF sequence according to whether the PPDU is the ELR-PPDU.

[0120] Other descriptions of the LTF sequence can also be referred to below, which will not be described here.

[0121] 502. The first station transmits the ELR-PPDU including the LTF field. Correspondingly, the second station receives the ELR-PPDU.

[0122] The ELR-PPDU can also include an ELR data (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 the four 52-tone RUs shown in Table 1.

[0123] The ELR-PPDU can also include an ELR signal (SIG) field (or ELR-SIG). For example, the RUs corresponding to the ELR-SIG field and the ELR data field are the same as the RUs corresponding to the LTF field. For example, the RUs can be the four 52-tone RUs shown in Table 1.

[0124] Optionally, in order to better perform channel estimation and improve the performance of channel estimation, the LTF field can also have a power gain of 3dB. For example, the first station can perform a power gain of 3dB relative to the data field when transmitting the LTF field.

[0125] Optionally, the ELR-PPDU can further comprise a flag field, which is used to identify whether the PPDU comprising the flag field is a PPDU of the current cell. Optionally, the flag field is used to identify whether the PPDU comprising the flag field is an ELR-PPDU. Optionally, the flag field is used to identify whether the PPDU comprising the flag field is an ELR-PPDU of the current cell.

[0126] The description of the ELR-PPDU is described with reference to FIG. 2a and FIG. 2b, which will not be repeated here.

[0127] 503. The second station performs channel estimation according to the LTF sequence and the LTF field.

[0128] The second station can decode the ELR-SIG field and the ELR data field according to the channel estimation result.

[0129] The description of the LTF sequence can refer to step 201, or the following, which will not be repeated here.

[0130] The LTF sequence provided by the embodiments of the present application can effectively reduce the PAPR of the LTF field and improve the system performance.

[0131] FIG. 6 is a flow diagram of a communication method provided by an embodiment of the present application. The description of the first station and the second station involved in the method refers to FIG. 1, which will not be repeated here. As shown in FIG. 6, the method comprises:

[0132] 601. The first station acquires an LTF sequence.

[0133] The first station acquires the LTF sequence according to a sequence mode. The sequence mode comprises a 1x LTF sequence mode (or 1x LTF sequence), a 2x LTF sequence mode (or 2x LTF sequence) or a 4x LTF sequence mode (or 4x LTF sequence). In the 1x LTF sequence, there are at least 3 zeros between two adjacent non-zero elements. In the 2x LTF sequence, there are at least 1 zero between two adjacent non-zero elements. In the 4x LTF sequence, there can be continuous non-zero elements. The non-zero elements of the 4x LTF sequence are the most dense, so the channel estimation is the most accurate.

[0134] Optionally, for the ELR-PPDU, the LTF sequence can only have a 2x LTF sequence mode, so that the first station can directly acquire a 2x LTF sequence.

[0135] For example, the first station acquires the LTF sequence according to the bandwidth. For example, the LTF sequence can be designed for each bandwidth, i.e., different bandwidths can correspond to different LTF sequences. For example, the LTF sequence corresponding to 20MHz is different from the LTF sequence corresponding to 40MHz.

[0136] Optionally, for the ELR-PPDU, the bandwidth of the ELR-PPDU can only be 20MHz, so that the first station can directly acquire the LTF sequence under 20MHz. Optionally, the first station can transmit the ELR-PPDU in units of 20MHz.

[0137] For example, the first station determines the LTF sequence according to the sequence mode and the bandwidth. The description of the sequence mode and the bandwidth is referred to the above, which will not be described here in detail.

[0138] For example, the first station determines the LTF sequence according to the type of the PPDU. The description of step 601 is referred to step 501 in the above, which will not be described here in detail.

[0139] The other description of the LTF sequence can be referred to the below, which will not be described here in detail.

[0140] 602、The first station transmits the LTF sequence.

[0141] Correspondingly, the second station receives the PPDU, and the PPDU includes the LTF field.

[0142] For steps 601 and 602, the first station acquires the LTF and transmits the LTF sequence, including at least one of (a)-(g):

[0143] (a) Sequence generation: generating the LTF sequence in the frequency domain on the bandwidth.

[0144] (b) Matrix mapping: applying the P matrix to the data subcarriers of the LTF sequence, and applying the R matrix to the pilot subcarriers of the EHT-LTF sequence.

[0145] (c) Cyclic shift delay (CSD): applying CSD to each spatial stream.

[0146] (d) Spatial mapping: applying the Q matrix.

[0147] (e) Inverse discrete fourier transform (IDFT): calculating the inverse discrete fourier transform.

[0148] (f) Insertion of cyclic prefix and application of windowing: inserting GI and applying windowing.

[0149] (g) Analog and RF: converting complex baseband waveforms associated with each transmit chain to RF signals and transmitting according to the center frequency of the desired channel.

[0150] Optionally, the number of spatial streams for transmitting the LTF sequence is one. In this case, the process of transmitting the LTF sequence can not include the above-mentioned step (b) and step (d).

[0151] Optionally, the bandwidth for transmitting the LTF sequence is only 20MHz. Alternatively, the LTF sequence is transmitted in units of 20MHz.

[0152] The specific descriptions of (a)-(g) can also refer to the descriptions of the 802.11 standard, which will not be described in detail here.

[0153] 603、The second station acquires the LTF sequence as a reference sequence for channel estimation, and performs channel estimation according to the LTF field and the LTF sequence.

[0154] The descriptions of other contents related to FIG. 6 can refer to FIG. 5 or the following, and the details are similar, which will not be described in detail here.

[0155] The LTF sequence provided by the embodiments of the present application can effectively reduce the PAPR of the LTF field and improve the system performance.

[0156] The following introduces the characteristics satisfied by the LTF sequence related to the embodiments of the present application.

[0157] As a possible implementation manner, 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.

[0158] The number of subcarriers in the first subcarrier group to the fourth subcarrier group is the same. The LTF sequence value corresponding to the i th subcarrier in the first subcarrier group is opposite to 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.

[0159] Optionally, the subcarriers in the first and third subcarrier groups are determined according to an RU used for transmitting information. For example, the subcarriers in the first and third subcarrier groups can be subcarriers in RU1. For another example, the subcarriers in the first and third subcarrier groups can be subcarriers in RU4.

[0160] Optionally, the subcarriers in the second and fourth subcarrier groups are determined according to an RU used for transmitting information. For example, the subcarriers in the second and fourth subcarrier groups can be subcarriers in RU2. For another example, the subcarriers in the second and fourth subcarrier groups can be subcarriers in RU3.

[0161] The descriptions of RU1-RU4 are referred to the foregoing, and will not be described in detail herein.

[0162] It can be understood that the subcarrier groups can also be referred to as subcarrier bands or subcarrier intervals. For example, the first subcarrier group is referred to as the first subcarrier band or the first subcarrier interval. In order to describe the characteristics met by the LTF sequence, the embodiments of the present application distinguish the first to fourth subcarrier groups, and divide the subcarriers into groups. However, in a specific implementation, the subcarriers can not be divided into groups.

[0163] As an example a, the indexes of the subcarriers in the first to fourth subcarrier groups are all less than 0.

[0164] For example, the indexes of the subcarriers in the first subcarrier group are [-120:2:-96], the indexes of the subcarriers in the second subcarrier group are [-68:2:-44], the indexes of the subcarriers in the third subcarrier group are [-94:2:-70], and the indexes of the subcarriers in the fourth subcarrier group are [-42:2:-18].

[0165] For another example, the indexes of the subcarriers in the first subcarrier group are [-120:2:-96], the indexes of the subcarriers in the second subcarrier group are [-42:2:-18], the indexes of the subcarriers in the third subcarrier group are [-94:2:-70], and the indexes of the subcarriers in the fourth subcarrier group are [-68:2:-44].

[0166] Optionally, the LTF sequence values corresponding to the subcarriers other than the subcarriers in the first to fourth subcarrier groups among the subcarriers with indexes less than 0 are 0.

[0167] For example, the LTF sequence values corresponding to the first subcarrier group correspond to the 13 elements in sequence a1 in turn, and the LTF sequence values corresponding to the third subcarrier group correspond to the 13 elements in sequence a2 in turn. The non-zero LTF sequence values other than 0 (i.e., the LTF sequence value is 0) in the LTF sequence values corresponding to the subcarriers with an index less than 0 are [a1, a2, -a1, a2] in turn, or [a1, a2, a1, -a2].

[0168] In the embodiments of the present application, the LTF sequence values corresponding to the subcarriers with an index less than 0 can be sequence [a1, a2], and by copying the 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 form a Gray complementary pair sequence, the PAPR of the copied subsequence can also be low. At the same time, by using the above design method, the storage space requirement of the LTF sequence can also be reduced. For example, the station can store a short sequence such as [a1, a2] and the corresponding rotation coefficients, and the LTF sequence values corresponding to the subcarriers with an index less than 0 can be obtained, and the LTF sequence can also be obtained.

[0169] For example a, the non-zero LTF sequence values corresponding to the subcarriers with an index greater than 0 are 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 subcarrier group to the fourth subcarrier group. 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] in turn. 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] in turn.

[0170] For example, the LTF sequence values corresponding to the subcarriers in the first to fourth subcarrier groups are the 52 elements in the following sequence in order: [a1, a2, a1, -a2]. The non-zero LTF sequence values in the LTF sequence values corresponding to the subcarriers with index greater than 0 are, in order: the 1st element in a1, the 3rd element in a1, the 5th element in a1, and so on, the 13th element in a1; the 2nd element in a2, the 4th element in a2, and so on, the 12th element in a2; the 1st element in a1, the 3rd element in a1, the 5th element in a1, and so on, the 13th element in a1; the 2nd element in -a2, the 4th element in -a2, and so on, the 12th element in -a2; and the 2nd element in a1, the 4th element in a1, the 6th element in a1, and so on, the 12th element in a1; the 1st element in a2, the 3rd element in a2, and so on, the 13th element in a2; the 2nd element in a1, the 4th element in a1, the 6th element in a1, and so on, the 12th element in a1; the 1st element in -a2, the 3rd element in -a2, and so on, the 13th element in -a2. As another example, the non-zero LTF sequence values in the LTF sequence values corresponding to the subcarriers with index greater than 0 are, in order: the 2nd element in a1, the 4th element in a1, the 6th element in a1, and so on, the 12th element in a1; the 1st element in a2, the 3rd element in a2, and so on, the 13th element in a2; the 2nd element in a1, the 4th element in a1, the 6th element in a1, and so on, the 12th element in a1; the 1st element in -a2, the 3rd element in -a2, and so on, the 13th element in -a2; and the 1st element in a1, the 3rd element in a1, the 5th element in a1, and so on, the 13th element in a1; the 2nd element in a2, the 4th element in a2, and so on, the 12th element in a2; the 1st element in a1, the 3rd element in a1, the 5th element in a1, and so on, the 13th element in a1; the 2nd element in -a2, the 4th element in -a2, and so on, the 12th element in -a2.

[0171] Or, the non-zero LTF sequence values corresponding to the subcarriers with index greater than 0 are obtained by sampling the LTF sequence values corresponding to the subcarriers with index [-120:2:-20] with a sampling step of 2, and then sampling the LTF sequence values corresponding to the subcarriers with index [-118:2:-18] with a sampling step of 2. Or, the non-zero LTF sequence values corresponding to the subcarriers with index greater than 0 are obtained by sampling the LTF sequence values corresponding to the subcarriers with index [-118:2:-18] with a sampling step of 2, and then sampling the LTF sequence values corresponding to the subcarriers with index [-120:2:-20] with a sampling step of 2.

[0172] Alternatively, the sampling step can also be 3 or 4, and the like, which are not listed one by one here.

[0173] In the embodiments of the present application, in the first to fourth subcarrier groups, the LTF sequence values corresponding to the odd-numbered subcarriers are odd-symmetric, and the LTF sequence values corresponding to the even-numbered subcarriers are even-symmetric, or the LTF sequence values corresponding to the even-numbered subcarriers are odd-symmetric, and the LTF sequence values corresponding to the odd-numbered subcarriers are even-symmetric. The time domain signal corresponding to the odd-symmetric LTF sequence values only has an imaginary part, and the time domain signal corresponding to the even-symmetric LTF sequence values only has a real part, and when the two are superimposed together, the power of the corresponding time domain signal is equal to the sum of the powers of the two. When designing the LTF sequence values corresponding to the subcarriers on the negative half axis, the time domain signal thereof contains both real and imaginary parts, and when the LTF sequence values are random, the real and imaginary parts are approximately independently distributed. According to the law of large numbers and the Pisar theorem, 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, through the relationship between the LTF sequence values corresponding to the subcarriers with index less than 0 and the LTF sequence values corresponding to the subcarriers with index greater than 0 shown in the embodiments of the present application, the PAPR of the LTF sequence values corresponding to the subcarriers with index greater than 0 and the PAPR of the LTF sequence values corresponding to the subcarriers with index less than 0 can have approximate PAPR distribution, avoiding the problem that the PAPR of the LTF sequence becomes large due to the increase in the number of subcarriers.

[0174] As another example b, the indexes of the subcarriers in the first to fourth subcarrier groups are all greater than 0.

[0175] For example, the indexes of the subcarriers in the first subcarrier group are [120:-2:96], the indexes of the subcarriers in the second subcarrier group are [68:-2:44], the indexes of the subcarriers in the third subcarrier group are [94:-2:70], and the indexes of the subcarriers in the fourth subcarrier group are [42:-2:18].

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

[0177] Optionally, the LTF sequence values corresponding to the subcarriers other than the subcarriers in the first to fourth subcarrier groups among the subcarriers with indexes greater than 0 are 0.

[0178] The details are similar to those in the first to fourth subcarrier groups, and are not described here again.

[0179] For example b, the non-zero LTF sequence values corresponding to the subcarriers with indexes less than 0 are determined according to the first odd LTF sequence value and the second even LTF sequence value 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 indexes less than 0 are the LTF sequence values corresponding to [120:-4:18] and the LTF sequence values corresponding to [118:-4:18] in turn. For another example, the non-zero LTF sequence values corresponding to the subcarriers with indexes less than 0 are the LTF sequence values corresponding to [118:-4:18] and the LTF sequence values corresponding to [120:-4:18] in turn.

[0180] Alternatively, the non-zero LTF sequence values corresponding to the subcarriers with indexes less than 0 are obtained by sampling the LTF sequence values corresponding to the subcarriers with indexes [120:-2:20] with a sampling step of 2, and then sampling the LTF sequence values corresponding to the subcarriers with indexes [118:-2:18] with a sampling step of 2. Alternatively, the non-zero LTF sequence values corresponding to the subcarriers with indexes greater than 0 are obtained by sampling the LTF sequence values corresponding to the subcarriers with indexes [118:-2:18] with a sampling step of 2, and then sampling the LTF sequence values corresponding to the subcarriers with indexes [120:-2:20] with a sampling step of 2.

[0181] The details of the non-zero LTF sequence values corresponding to the subcarriers with indexes less than 0 can be referred to example a, and the details are similar and are not described here again.

[0182] For the 2xELR-LTF sequence, [120:2:-18, 18:2:120] corresponds to the LTF sequence values with non-zero values. For example, [-120:2:-70] corresponds to the LTF sequence values forming a sequence a with a length of 26 (i.e., 26 LTF sequence values), and the sequence a is split into two equal-length subsequences, i.e., a = [a1, a2]. [-68:2:-44] corresponds to the LTF sequence values forming a sequence -a1 (or a1), and the subcarriers [-42:2:-18] correspond to the LTF sequence values forming a sequence a2 (or -a2). A sequence b = [a1, a2, -a1, a2], and the elements in the sequence b are divided into two equal-length subsequences b1 and b2 according to the first odd-numbered element and the first even-numbered element. [120:-4:20] corresponds to the LTF sequence values forming a sequence -b1, and [118:-4:18] corresponds to the LTF sequence values forming a sequence b2. Thus, the sequence a is traversed, the PAPR of the corresponding sequence is calculated, and the sequence with the lowest PAPR is selected as the 2xELR-LTF sequence.

[0183] The LTF sequence satisfying the characteristics shown in the embodiments of the present application and the LTF sequence obtained by the search method shown below are both within the protection scope of the embodiments of the present application.

[0184] By designing to map and expand the short sequence, a longer sequence is constructed, and the long sequence with the lowest PAPR is selected as the ELR-LTF sequence by traversing the short sequence, so that the constructed ELR-LTF sequence has a lower PAPR.

[0185] For the above example a and example b, the following introduces the LTF sequence values corresponding to the first to fourth subcarrier groups.

[0186] 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 1 -1 -1] in turn, and the LTF sequence values corresponding to the second subcarrier group are [-1 -1 1 1 -1 -1 -1 -1 -1 -1 -1 1 1] in turn. The subcarrier indexes corresponding to the LTF sequence values shown here are referred to the example a or example b described above, and will not be described in detail here.

[0187] As another example d, the LTF sequence values corresponding to the first subcarrier group are the LTF sequence values 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: reverse order, all elements negation, and partial element negation.

[0188] 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] in sequence.

[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 -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] in sequence.

[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], 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] in sequence.

[0191] 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 index corresponding to each LTF sequence value shown here is referred to the example a or example b described above, and will not be described in detail here.

[0192] As another example f, the LTF sequence value corresponding to the third subcarrier group is the LTF sequence value processed from [-1 -1 -1 1 1 1 -1 -1 1 1 1 1 1]. The processing manner includes at least one of the following: reverse order, all element negation, and partial element negation.

[0193] 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].

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

[0196] In combination with the above examples c-d, and the relationship between the LTF sequence value corresponding to the subcarrier with an index less than 0 and the LTF sequence value corresponding to the subcarrier with an index greater than 0 shown in examples a and b, the LTF sequence can be obtained. The LTF sequence shown below is only an example, and other LTF sequences can also be obtained in combination with the method shown above, and the following will not be listed one by one.

[0197] The LTF sequence related to the embodiments of the present application is introduced below. Each LTF sequence shown below satisfies the characteristics of the LTF sequence shown above.

[0198] As an example, the LTF sequence is:

[0199] Alternatively, the LTF sequence is -121:121

[0200] The above examples show three expressions of the LTF sequence, and other expressions are not listed one by one.

[0201] It can be understood that one or more of the following operations on the above LTF sequence does not change the PAPR of the LTF sequence, and therefore the new sequence obtained from the above LTF sequence is still within the protection scope of the embodiments of the present application: taking the inverse of the above LTF sequence as a whole, reversing the above LTF sequence, taking the inverse of the LTF sequence value corresponding to the subcarrier [-120:4:120] in the above LTF sequence, and taking the inverse of the LTF sequence value corresponding to the subcarrier [-118:4:118] in the above LTF sequence.

[0202] As another example, the LTF sequence is:

[0203] Alternatively,

[0204] Alternatively,

[0205] As another example, the LTF sequence is:

[0206] Alternatively,​

[0207] or,

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

[0209] or,

[0210] or,

[0211] The LTF sequence provided by the embodiments of the present application has a lower PAPR, which can effectively reduce nonlinear distortion, improve work efficiency, improve channel estimation accuracy, and thus improve system performance.

[0212] Table 3 exemplarily shows the PAPR comparison between the LTF sequence provided by the present application and the HE-LTF sequence. In combination with the description of Table 2, the 52-tone RU repeated 4 times transmission mode is equivalent to constructing a new multi-resource unit (MRU), which does not consider the PAPR of the corresponding LTF field when designing the LTF sequence, so the first station may have a large PAPR when transmitting the LTF field. However, the LTF sequence provided by the present application not only reduces the PRAP, but also has a gain of 1.48dB relative to the HE-LTF sequence.

[0213] Table 3

[0214] The communication device provided by the embodiments of the present application will be introduced below.

[0215] The present application divides the functional modules of the communication device according to the above-mentioned method embodiments, for example, each functional module can be divided according to each function, or two or more functions can be integrated into one processing module. The integrated module can be realized in the form of hardware or in the form of a software functional module. It should be noted that the division of the modules in the present application is illustrative, and is only a logical function division. When actually implemented, there can be another division manner. The communication device of the embodiments of the present application will be described in detail below with reference to FIGS. 7-9.

[0216] Figure 7 is a structural schematic diagram of a communication apparatus provided in an embodiment of the present application. As shown in Figure 7, the communication apparatus 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 configured to implement corresponding processing functions. The transceiver module 702 can also be referred to as an interface, a communication interface, or a communication module, etc.

[0217] In some embodiments of the present application, the communication apparatus can be configured 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 a functional module configured in the device, etc. The transceiver module 702 is configured to perform the transceiving related operations of the first station in the above method embodiments, and the processing module 701 is configured to perform the processing related operations of the first station in the above method embodiments.

[0218] The processing module 701 can obtain the LTF sequence.

[0219] The transceiver module 702 can be configured to send or output the PPDU.

[0220] Alternatively,

[0221] The processing module 701 is configured to generate the LTF field according to the LTF sequence.

[0222] The transceiver module 702 is configured to send or output the PPDU including the LTF field. Multiplex Figure 7, in another embodiment of the present application, the communication apparatus can be configured 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 a functional module configured in the device, etc. The transceiver module 702 is configured to perform the transceiving related operations of the second station in the above method embodiments, and the processing module 701 is configured to perform the processing related operations of the second station in the above method embodiments.

[0223] The transceiver module 702 can be configured to receive the PPDU including the LTF field.

[0224] The processing module 701 can be configured to perform channel estimation according to the LTF sequence and the LTF field.

[0225] For example, the transceiver module 702 described above can be an antenna module. For another example, the transceiver module 702 described above can be an input / output module. Optionally, in each of the above embodiments, the communication apparatus can further include a storage module, which can be configured to store instructions and / or data. The processing module 701 can read the instructions and / or data in the storage module, so that the communication apparatus implements the above method embodiments.

[0226] In the above embodiments, the specific description of each term or noun or step can refer to the introduction in the method embodiments, and will not be described in detail.

[0227] The specific description of the transceiver module and the processing module in the above embodiments is only an example. For the specific function or executed step of the transceiver module and the processing module, refer to the method embodiments, and will not be described in detail.

[0228] It can be understood that the division of the modules in the above device is only a logical function division. Each function can correspond to a function module, or two or more functions can be integrated into one function module. In actual implementation, all or part of the modules can be integrated into one physical entity, or can be distributed in different physical entities. In addition, the function modules can be implemented in the form of hardware, software, or a combination of hardware and software.

[0229] In one example, the functional units in any of the above devices can be one or more integrated circuits configured to implement the above method, 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.

[0230] The above introduces the communication device of the embodiment of the application, and the following introduces the possible product form of the communication device. Any form of product with the function of the communication device described in FIG. 7 falls within the protection scope of the embodiment of the application. The following introduction is only an example, and does not limit the product form of the communication device of the embodiment of the application.

[0231] In a possible implementation, in the communication apparatus shown in FIG. 7, 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 sending module and a receiving module, the sending module can be a transmitter, and the receiving module can be a receiver, and the sending module and the receiving module are integrated in one device, for example, a transceiver. In the embodiments of the present application, the processor and the transceiver can be coupled, and the connection manner of the processor and the transceiver is not limited in the embodiments of the present application. In the process of executing the above method, the process of sending information in the above method can be the process of outputting the above information by the processor. When the above information is output, the processor outputs the above information to the transceiver, so that the transceiver transmits. After the above information is output by the processor, the above information can also need to be processed further, and then reaches the transceiver. Similarly, the process of receiving information in the above method can be the process of receiving inputted above information by the processor. When the processor receives the inputted information, the transceiver receives the above information and inputs it to the processor. Furthermore, after the transceiver receives the above information, the above information can need to be processed further, and then inputs the processor.

[0232] FIG. 8 is another structural schematic diagram of a communication apparatus provided by the embodiments of the present application. As shown in FIG. 8, the communication apparatus 80 includes one or more processors 820 and a transceiver 810.

[0233] In some embodiments of the present application, the communication apparatus can be used to execute the steps or methods or functions performed by the first station, for example, the processor 820 can be used to execute the functions or steps implemented by the processing module 701 shown in FIG. 7, and the transceiver 810 can be used to execute the functions or steps implemented by the transceiver module 702 shown in FIG. 7. The specific description of the processor 820 and the transceiver 810 can refer to FIG. 7 or the method embodiments shown above, and will not be described in detail here.

[0234] In some embodiments of the present application, the communication apparatus can be used to execute the steps or methods or functions performed by the first station, for example, the processor 820 can be used to execute the functions or steps implemented by the processing module 701 shown in FIG. 7, and the transceiver 810 can be used to execute the functions or steps implemented by the transceiver module 702 shown in FIG. 7. The specific description of the processor 820 and the transceiver 810 can refer to FIG. 7 or the method embodiments shown above, and will not be described in detail here.

[0235] In each implementation of the communication apparatus shown in FIG. 8, the transceiver can include a receiver and a transmitter, the receiver is configured to perform the function (or operation) of receiving, and the transmitter is configured to perform the function (or operation) of transmitting. And the transceiver is configured to communicate with other devices / apparatuses through a transmission medium.

[0236] Optionally, the communication device 80 can 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 between the various components in the embodiments of the present application can be indirect coupling or communication connection between the communication devices, units or modules, which can be electrical, mechanical or other form, for information interaction between the communication devices, units or modules. The processor 820 can operate in cooperation with the memory 830. The processor 820 can execute the program instructions stored in the memory 830. Optionally, at least one of the one or more memories can be included in the processor.

[0237] The specific connection medium between the transceiver 810, the processor 820 and the memory 830 in the embodiments of the present application is not limited. In FIG. 8, the memory 830, the processor 820 and the transceiver 810 are connected through the bus 840, and the bus is represented by a thick line in FIG. 8. The connection mode between other components is only schematically illustrated and is not limited. The bus can be divided into an address bus, a data bus, a control bus, etc. For convenience of representation, only one thick line is used in FIG. 8, but it does not mean that there is only one bus or only one type of bus.

[0238] In the embodiments of the present application, the processor can be a general processor, a digital signal processor, an application specific integrated circuit, a field programmable gate array or other programmable logic device, a discrete gate or transistor logic device, a discrete hardware component, etc., which can implement or execute the disclosed methods, steps and logic block diagrams in the embodiments of the present application. The general processor can be a microprocessor or any conventional processor, etc. The steps of the method disclosed in conjunction with the embodiments of the present application can be directly embodied as execution completed by a hardware processor, or executed by a combination of hardware and software modules in the processor, etc.

[0239] The memory in the embodiments of the present application can include, but is not limited to, a non-volatile memory such as a hard disk drive (HDD) or a solid-state drive (SSD), a random access memory (RAM), an erasable programmable ROM (EPROM), a read-only memory (ROM), a compact disc read-only memory (CD-ROM), and the like. The memory is any storage medium that can be used to carry or store program codes in the form of instructions or data structures and can be read and / or written by a computer (such as the communication device shown in the present application and the like). The memory in the embodiments of the present application can also be a circuit or any other device capable of realizing a storage function, used for storing program instructions and / or data.

[0240] The processor 820 is mainly used for processing communication protocols and communication data, controlling the whole communication device, executing software programs, and processing data of the software programs. The memory 830 is mainly used for storing software programs and data. The transceiver 810 can include a control circuit and an antenna, and the control circuit is mainly used for converting baseband signals and radio frequency signals and processing the radio frequency signals. The antenna is mainly used for receiving and transmitting radio frequency signals in the form of electromagnetic waves. The input and output device, such as a touch screen, a display screen, a keyboard, and the like, is mainly used for receiving user input data and outputting data to the user.

[0241] 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 circuit. The radio frequency circuit converts the baseband signal into a radio frequency signal, and transmits the radio frequency signal in the form of electromagnetic waves through the antenna. When data is transmitted to the communication device, the radio frequency circuit receives the radio frequency signal through the antenna, converts the radio frequency 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.

[0242] In another implementation, the radio frequency circuit and the antenna can be arranged independently of the processor performing baseband processing, for example, in a distributed scenario, the radio frequency circuit and the antenna can be arranged remotely from the communication device.

[0243] The communication apparatus shown in the embodiments of the present application can also have more components than those shown in FIG. 8, and the embodiments of the present application do not limit this. The method performed by the processor and the transceiver shown above is only an example, and the steps specifically performed by the processor and the transceiver can refer to the method described above. The dashed part in FIG. 8 represents an option.

[0244] In another possible implementation, in the communication apparatus shown in FIG. 7, the processing module 701 can be one or more logic circuits, and the transceiving module 702 can be an input / output interface, also referred to as a communication interface, or an interface circuit, or an interface, etc. Alternatively, the transceiving module 702 can also be a sending module and a receiving module, the sending module can be an output interface, and the receiving module can be an input interface, and the sending module and the receiving module are integrated into one module, for example, an input / output interface.

[0245] FIG. 9 is a structural schematic diagram of a chip provided by the embodiments of the present application. As shown in FIG. 9, the chip shown in FIG. 9 includes a logic circuit 901 and an interface 902. That is, the processing module 701 can be implemented by the logic circuit 901, and the transceiving module 702 can be implemented by the interface 902. The logic circuit 901 can be a chip, a processing circuit, an integrated circuit, or a system on chip (SoC) chip, etc., and the interface 902 can be a communication interface, an input / output interface, a pin, etc. For example, FIG. 9 is shown by taking the above communication apparatus as an example, and the chip includes the logic circuit 901 and the interface 902.

[0246] In the embodiments of the present application, the logic circuit and the interface can also be coupled to each other. The embodiments of the present application do not limit the specific connection mode of the logic circuit and the interface. For example, the logic circuit 901 can be used to perform the functions or steps implemented by the processing module 701 shown in FIG. 7, and the interface 902 can be used to perform the functions or steps implemented by the transceiving module 702 shown in FIG. 7. For specific descriptions of the logic circuit 901 and the interface 902, refer to FIG. 7 or the method embodiments shown above, which will not be described in detail here.

[0247] The communication apparatus shown in the embodiments of the present application can implement the method provided by the embodiments of the present application in the form of hardware, or implement the method provided by the embodiments of the present application in the form of software, etc., and the embodiments of the present application do not limit this.

[0248] In addition, the embodiments of the present application also provide a communication system, which includes a first station and a second station, and the first station and the second station can be used to perform the method in any of the preceding embodiments.

[0249] The present application also provides a computer program for implementing the operations and / or processes performed by each station in the method provided by the present application.

[0250] The application further provides a computer readable storage medium, wherein computer code is stored in the computer readable storage medium, and when the computer code is run on a computer, the computer code causes the computer to perform operations and / or processes performed by each communication device in the method provided by the application.

[0251] The application further provides a computer program product, which comprises computer code or a computer program, and when the computer code or the computer program is run on a computer, operations and / or processes performed by each in the method provided by the application are performed.

[0252] In several embodiments provided by the application, it should be understood that the disclosed system, communication device and method can be implemented in other manners. For example, the embodiments of the communication device described above are merely schematic; for example, the division of the modules is merely a logical function division; an actual implementation can be another division manner, for example, multiple modules or components can be combined or integrated into another system, or some features can be ignored or not executed. In addition, the displayed or discussed mutual couplings or direct couplings or communication connections between different modules can be indirect couplings or communication connections through some interfaces, communication devices or modules, and can be electrical, mechanical or other forms.

[0253] The modules illustrated as separated components can or can not be physically separated, and the components illustrated as modules can or can not be physical modules, i.e., can be located in one place, or can be distributed on multiple network modules. According to actual needs, some or all of the modules can be selected to achieve the technical effects of the scheme provided by the embodiments of the application.

[0254] In addition, each functional module in each embodiment of the application can be integrated in one processing module, or each module can exist physically independently, or two or more modules can be integrated in one module. The integrated module can be implemented in the form of hardware or in the form of a software functional module.

[0255] The integrated module, if implemented in the form of a software function module and sold or used as an independent product, can be stored in a computer readable storage medium. Based on such understanding, the technical solutions of the present application essentially or say the part that contributes to the prior art, or the whole or part of the technical solutions can be embodied in the form of a software product. The computer software product is stored in a readable storage medium, includes a plurality of instructions to make a computer device (which can be a personal computer, a server, or a network device, etc.) execute all or part of the steps of the method described in various embodiments of the present application. The aforementioned readable storage medium includes: a U disk, a mobile hard disk, a read-only memory (read-only memory, ROM), a random access memory (random access memory, RAM), a magnetic disk or an optical disk, and various media that can store program codes.

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 1 0 1 0 1 0 -1 0 -1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 -1 0 -1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 -1 0 -1 0 1 0 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 1 0 1 0 -1 0 1 0 -1 0 1 0 -1 0 1 0 1 0 -1 0 -1 0 1 0 -1 0 1 0 -1 0 1 0 -1 0 -1 0 1 0 1 0 -1 0 1 0 1 0 -1 0 1 0 -1 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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