Methods for transmitting and receiving radio frames, data transmission equipment, and radio frame receiving equipment.

Abstract

The invention relates to methods and apparatus for transmitting and receiving empty packet message frames and computer-readable storage media, such that the method of transmitting radio frames comprises the following steps: creating, by the transmitting end, a radio frame, which includes one or more station information fields, each of which is 2K bytes long, where K is a natural number, and the value of bit B16j+11 in each station information field is set to 1, where j=1, 2, 3, …, K–1; and transmitting the radio frame.

Description

Method and apparatus for transmitting and receiving wireless frames This application claims the priority of a Chinese patent application filed with the Chinese Patent Office on May 10, 2016, with the application number 201610305870.9 and the invention title "Method and Apparatus for Transmitting and Receiving Wireless Frames", the entire content of which is incorporated herein by reference. Technical Field Embodiments of the present invention relate to communication technologies, and in particular, to a method and apparatus for transmitting and receiving wireless frames. Background Art OFDM (Orthogonal Frequency Division Multiplexing) is the basic transmission mode of current wireless communication and is widely used in wireless communication systems such as LTE, WiMAX, and WiFi. Moreover, OFDM is further applied to fixed network transmission, such as transmission modes of optical fiber, copper wire, and cable. The basic principle of OFDM is to compress the subcarrier spacing to the minimum within the range allowed by the orthogonality of the subcarriers. On the one hand, this can ensure the formation of multiple parallel and non-interfering channels, and at the same time, it can improve the frequency utilization efficiency of the system. Furthermore, due to the above characteristics of OFDM, if the non-interfering subcarriers of OFDM are allocated to multiple users, OFDM can be used to achieve multi-user access or data transmission. This is OFDMA (Orthogonal Frequency Division Multiple Access). The OFDMA method for sending data is that the sending end sends the data of multiple receiving ends to the receiving end associated with the subcarrier / subchannel through their respective corresponding subcarriers / subchannels. The sending mode of OFDMA requires that the data on the subcarrier / subchannel be sent synchronously, and the data of each user remains orthogonal through their respective subcarriers / subchannels during synchronous sending. Since OFDMA can flexibly and conveniently schedule multiple users to transmit simultaneously, it is beneficial to use OFDMA to achieve the effect of multi-user diversity; in addition, OFDMA can conveniently support multiple discrete subchannels, so OFDMA can more effectively utilize the blank frequency band. Similarly, as a way to support multi-user transmission using parallel channels, MU-MIMO (Multiple User-Multiple Input Multiple Output) uses the spatial dimension to implement parallel channels and provides them to multiple users as a transmission method. But this way The transmitting end (downlink, DL MU-MIMO) or the receiving end (uplink, UL MU-MIMIO) needs to have all or part of the channel information. Otherwise, it is impossible to correctly demodulate multiple valid signals at the receiving end, resulting in transmission failure. Among them, for DL MU-MIMO, the transmitting end uses the Channel State Information (CSI) to form a transmission beam and distinguish multiple spatial streams at the transmitting end; while UL MU-MIMO requires the receiving end to use the channel state information to form a receiving beam and distinguish multiple spatial streams at the receiving end. In particular, for the case of DL MU-MIMO, in order for the transmitting end to obtain the channel state information, the transmitting end needs to send a training sequence to enable multiple receiving ends to estimate the channel and feedback the estimated channel state information to the transmitting end. On the other hand, the sequential characteristic of WLAN (Wireless LAN) itself is a data transmission method based on frames. That is to say, a frame structure is needed to make full use of the characteristics of OFDMA for efficient transmission. Summary of the Invention An embodiment of the present invention provides a method for transmitting a wireless frame to solve the defects in the prior art and improve the efficiency of wireless frame communication. On the one hand, a method for transmitting a wireless frame is provided, including: the transmitting end generates a wireless frame, and the wireless frame includes: one or more station information fields, each station information field has a length of 2K bytes, where K is a natural number, and the value of bit B16j + 11 in each station information field is set to 1, where j = 1, 2, 3,..., K - 1; sending the wireless frame. Similarly, on the other hand, a method for transmitting a wireless frame includes: The transmitting end generates a wireless frame, and the wireless frame includes: one or more station information fields STA info field, each station information field has a length of 2K bytes, where K is a natural number, such as 1, 2, 3,..., and the value of bit B16j in each station information field is set to 1, where j = 1, 2, 3,..., K - 1; Sending the wireless frame. Correspondingly, a method for receiving a wireless frame is provided, including: Receiving a wireless frame, and the wireless frame includes: one or more station information fields, each station information field has a length of 2K bytes, where K is a natural number, and the value of bit B16j + 11 in each station information field is set to 1, where j = 1, 2, 3,..., K - 1; Parsing the wireless frame and performing processing according to the value of bit B16j + 11. Similarly, a method for receiving a wireless frame includes: Receiving a wireless frame, the wireless frame including: one or more station information fields (STA info field), each station information field having a length of 2K bytes, where K is a natural number, such as 1, 2, 3, …, and the value of bit B16j in each station information field is set to 1, where j = 1, 2, 3, …, K - 1; Parsing the wireless frame and performing processing according to the value of bit B16j. The embodiments of the present invention also correspondingly provide an apparatus for executing the foregoing method, such as a chip or a station, an access point. Description of the Drawings To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings. FIG. 1 is a schematic diagram of the system architecture of the embodiment of the present invention; FIG. 2 is a simple schematic diagram of the process of multi - user channel state information feedback; FIG. 3 is a simple schematic diagram of the format of an NDPA frame; FIG. 4 is a simple schematic diagram of the transmission process of uplink OFDMA / MU - MIMO; FIGS. 5 - 9 are respectively simple schematic diagrams of the format of a preferred NDPA frame; FIG. 10 is a simple schematic diagram of the format of a preferred trigger frame; FIGS. 11 - 12 are respectively simple schematic diagrams of an apparatus for implementing the embodiment of the present invention. Detailed Embodiments To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the drawings in the embodiments of the present invention. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art without creative efforts based on the embodiments of the present invention belong to the scope of protection of the present invention. Abbreviation and Definition of Key Terms: As shown in Figure 1, it is a simple schematic diagram of the structure of a wireless local area network WLAN, including an access station or access point 101, and one or more stations 102. Among them, referring to Figure 2, it is a simple schematic diagram of the process of multi-user channel state information feedback. The AP continuously sends NDPA (Null Data Packet Announcement) and NDP (Null Data Packet). The receiving end estimates the channel state information according to the indication of NDPA and the LTF (Long training field) of NDP, and generates a Beamforming Report (BF Report), and feeds back the estimated channel state information to the AP (Access Point). During the feedback process, the AP sends a Beamforming Report Poll frame to interrogate each STA (Station) indicated in NDPA one by one, and requests the BF Report from these STAs. This method of interrogating one by one will bring a large overhead. In addition, the format of an existing NDPA frame is shown in Figure 3. To reduce this overhead, as shown in Figure 4, it is a simple schematic diagram of the transmission process of uplink OFDMA / MU-MIMO, in which UL OFDMA is introduced to achieve parallel transmission of multiple user BF Reports. However, UL OFDMA requires a trigger frame to indicate information such as synchronization and uplink resource allocation. In the next-generation standard 802.11ax, the OFDMA feature is introduced, and the STA needs to measure partial channel information in the entire bandwidth. Therefore, the AP needs to indicate the bandwidth information required for the STA to measure in the NDPA frame, and this part of the information requires additional bits to indicate. However, the user information part of the current VHT NDPA frame only has 16 bits and all carry useful information. Therefore, in 802.11ax, a wireless frame compliant with the 802.11ax standard (such as a HE NDPA frame) is required to utilize the OFDMA feature to achieve efficient transmission. An embodiment of the present invention provides a method for sending a wireless frame, including: The sending end generates a wireless frame, and the wireless frame includes: one or more station information fields STA info field, the length of each station information field is 2K bytes, where K is a natural number, such as 1, 2, 3,..., and the value of its bit B16j+11 is set to 1, where j = 1, 2, 3,..., K-1; Send the wireless frame. In the above embodiment, the highest bit of the station information field is located on the right side. In another similar solution, the most significant bit of the station information field can also be on the left. In this case, similarly, a method for sending a wireless frame is provided, including The sending end generates a wireless frame, which includes: One or more station information fields (STA info field), each station information field having a length of 2K bytes, where K is a natural number, such as 1, 2, 3, …, and the value of its bit B16j is set to 1, where j = 1, 2, 3, …, K - 1; Send the wireless frame. In a specific example, the above wireless frame is an NDPA frame or a trigger frame. In particular, it is an NDPA frame or a trigger frame that follows the data structure specified by the 802.11ax standard. For example, it can be called HE NDPA or HE trigger. With the above frame structure, on the receiving side, a station that follows the 802.11ax standard parses the above wireless frame and performs subsequent processing after receiving it; for a station that does not follow the 802.11ax standard, such as a VHT STA, it is default set to 2 bytes for each STA Info field. It first reads the AID 12 information field. If the read value does not match its AID, it continues to read the next 2 bytes until it matches its AID, and then obtains the information sent to it from the subsequent 4 bits. When reading this frame, the VHT STA knows that the STA info field does not carry information related to the VHT STA by reading the value of the bit B16j + 11, or by reading the bit B16j, that is, the VHT STA can know that the STA info field does not carry information related to the VHT STA because the bit at the above position is 1, and thus can stop processing this STA info field. (Details will be described in the following examples.) The following details with HE NDPA as an example. Example 1: The sending end generates an HE NDPA frame, which contains n STA info fields, where n is a natural number. Each STA info field contains or is used to carry the three fields of AID12, Feedback Type, and NC Index; further, it can also contain or carry other fields, such as one or any combination of fields such as Nr Index, Codebook Information, Grouping Ng, and Partial BW info. Any combination. Referring to FIG. 5, it is a simple schematic diagram of a HE NDPA frame. In the example of the HE NDPA frame in FIG. 5, each STA info field contains 4 bytes. For the sake of illustration, we define the first 12 bits in the 3rd and 4th bytes of each STA info field as the first information field. Specifically, the value of the highest position in the first information field is set to 1, and the 28th bit (or B27) is set to 1 (when the highest bit is on the right side). When the highest bit is on the left side, then the highest bit is the 17th bit (B16). The remaining 11 bits of the first information field can carry other information, such as one or more of Nr Index, Codebook Information, Grouping Ng, or Partial BW info, etc. When the VHT STA receives and reads the HE NDPA frame, theoretically, the first information field is interpreted as the AID 12 field. However, in the embodiments of the present invention, the highest bit (Maximum Significant Bit, MSB) of the first information field is set to 1. In this way, when the VHT STA reads the first information field, the value of the first information field is greater than or equal to 2048. However, the value range of the AID is 1 - 2007. Therefore, the VHT STA will be implicitly indicated that this first information field is not the AID 12 field and does not need to continue processing this information, thus avoiding the situation of misreading by the VHT STA. In addition, the highest bit of the AID 12 information field in the STA info field can be set to 0 or 1. When it is set to 0, it means that the STA info field is the same as the STA info field in the VHT NDPA, that is, 2 bytes; when it is set to 1, it means that the STA info field carries the length of the TA info field specified by the 802.11ax standard. For example, in the embodiments of the present invention, it is 4 bytes. This bit can be called the VHT / HE field, as shown in FIG. 6. For the VHT / HE information field, it can also not be included in the STA info field, but be located in the common information part of the wireless frame (we call the part before all the STA Info fields the common information part). Preferably, the VHT / HE information field can be located in the Reserved field of the Sounding Dialog Token, as shown in FIG. 7. Since B27 is fixedly set to 1, the user information carried in the HE NDPA frame should be located at positions other than B27, i.e., B0 - B26 and B28 - B31. Another implementation is that regardless of the value of the VHT / HE field, the length of the STA info field is 4 bytes. When the receiver receives the HE NDPA frame, if the receiver is a VHT STA, it is default set to 2 bytes for each STA Info field. It first reads the AID 12 information field. If the read value does not match its AID, it continues to read the next 2 bytes until it matches its AID, and then obtains the information sent to it from the subsequent 4 bits. If the receiver is a HE STA, when the value of the VHT / HE field is 0, the reception is performed according to the reception process of the VHT STA; when the value of the VHT / HE field is 1, it reads in units of 4 bytes. It first reads the AID 12 information field. If the read value does not match its AID, it continues to read the next 4 bytes until it matches its AID, and then obtains the information sent to it from 19 bits out of the subsequent 20 bits excluding B27. Optionally, if it is found that the value in B27 is 0, the reception is stopped and the NDPA frame is discarded. Example 2: In the previous Example 1, the STA info field contains 4 bytes. Different from this, in this example, the STA info field of the HE NDPA frame can contain 6 bytes, 8 bytes, or 10 bytes, etc. In this example, similar to Example 1, except for the first 2 bytes, the MSB of the first 12 bits in each of the other 2 bytes is set to 1. For example, when the STA info field contains 6 bytes, B27 and B43 are set to 1, as shown in Figure 8, where the VHT / HE field in the example is located in the Reserved field of the common information part. Additionally, when the most significant bit is on the left, B16 and B32 are set to 1. When the receiver receives the HE NDPA frame, if the receiver is a VHT STA, it assumes that each STA Info field is 2 bytes. It first reads the AID 12 information field. If the read value does not match its AID, it continues to read the next 2 bytes until its AID is matched, and then obtains the information sent to it from the subsequent 4 bits. If the receiver is a HE STA, when the value of the VHT / HE field is 0, the reception is performed according to the reception process of the VHT STA; when the value of the VHT / HE field is 1, it reads in units of 6 bytes. It first reads the AID 12 information field. If the read value does not match its AID, it continues to read the next 6 bytes until its AID is matched, and then obtains the information sent to it from 34 bits out of the subsequent 36 bits, excluding B27 and B43. Optionally, if it is found that the value of B27 or B43 is 0, the reception is stopped and the NDPA frame is discarded. Example Three The main difference between Example One and Example Two is that the lengths of the STA info fields of the defined HE NDPA frames are different. However, compared with Example Three, the STA info fields in Example One and Example Two are of fixed length. In Example Three, a HE NDPA frame with an unspecified length is provided, and the length of its STA info field is variable, which can be 4 bytes, or 6 bytes, 8 bytes, or 10 bytes, etc. In order to enable the receiving end to know the length of the STA info field, the first indication information needs to be carried in the HE NDPA frame to indicate the length of the STA info field. The first indication information should be located before all the STA info fields. One implementation is that it can be located in the Reserved field of the Sounding Dialog Token. A more specific implementation is to take 1 bit from the Reserved field to carry the first indication information. Its value of 0 indicates that the length of the STA info field is 4 bytes, and its value of 1 indicates that the length of the STA info field is 6 bytes. As shown in Figure 9 below, the length field in Figure 9 is the first indication information. It should be noted that the first indication information (i.e., the length of the STA info field) refers to the length of the STA info field when the value of the VHT / HE field in the AID12 field (see Figure 6) is HE (specifically manifested as a bit value of 1 or a bit value of 0). Another implementation is that regardless of the value of the VHT / HE field, the first indication information indicates the length of the STA info field. Of course, the foregoing implementation is not limited to the NDPA frame, and may also be other frames other than the NDPA frame. The other frames have the following characteristics: including a common information part and a user information part, and the AID field in the user information part is the first information field. The trigger frame (TF) belongs to one of the other frames. As shown in FIG. 10. In the trigger frame, the same method as described above can be used to have different lengths of the STA Info field in the trigger frame. For example, if the STA info field contains M bytes before extension, and if it needs to be extended to MK bytes (K = 1, 2, 3,...), the bit B(8Mj + 11) can be set to 1 (j = 1, 2, 3,..., K - 1). The present invention also provides a data transmission device that can execute the foregoing method (including the method of sending or receiving). FIG. 11 is a transmission device for wireless local area network data provided by an embodiment of the present invention. Referring to FIG. 11, the device includes: a transmitter 1001, a receiver 1002, a memory 1003, and a processor 1004, which are used to execute the foregoing wireless local area network data sending method or receiving method. When the device is used on the sending side, it includes: The processor 1004 is used to construct or generate a wireless frame, and the wireless frame has at least the structure mentioned in the foregoing embodiment; The transmitter 1001 is used to send the wireless frame to the station STA associated with the AP. Alternatively, when the device is used on the receiving side, it includes a receiver 1002. The receiver 1002 is used to receive the wireless frame as described in the foregoing embodiment, and the processor is used to parse the wireless frame. The detailed processing can refer to the foregoing embodiment and will not be elaborated here. FIG. 12 is an example of a schematic structural diagram of the data transmission device provided in the embodiment of the present invention (for example, some devices in the figure such as an access point, a station, or a chip are optional). As shown in FIG. 12, the data transmission device 1200 can be implemented by a general bus architecture of a bus 1201. According to the specific application and overall design constraints of the data transmission device 1200, the bus 1201 may include any number of interconnected buses and bridges. The bus 1201 connects various circuits together, and these circuits include a processor 1202, a storage medium 1203, and a bus interface 1204. The data transmission device 1200 uses the bus interface 1204 to connect a network adapter 1205 and the like via the bus 1201. The network adapter 1205 can be used to implement the signal processing function of the physical layer in a wireless local area network, and realize the sending and receiving of radio frequency signals through an antenna 1207. The user interface 1206 can be connected to a user terminal, such as: a keyboard, a display, a mouse, a joystick, etc. The bus 1201 can also connect various other circuits, such as a timing source, peripheral devices, a voltage regulator, a power management circuit, etc. These circuits are well known in the art and will not be described in detail here. The data transmission device 1200 can also be configured as a general processing system, and the general processing system includes: one or more microprocessors providing processor functions; and an external memory providing at least a part of the storage medium 1203, and all of these are connected together with other support circuits through an external bus architecture. Alternatively, the data transmission device 1200 can be implemented by using the following: an ASIC (Application Specific Integrated Circuit) having a processor 1202, a bus interface 1204, and a user interface 1206; and at least a part of the storage medium 1203 integrated in a single chip or, the data transmission device 1200 can be implemented by using the following: one or more FPGAs (Field Programmable Gate Arrays), PLDs (Programmable Logic Devices), controllers, state machines, gate logic, discrete hardware components, any other suitable circuits, or any combination of circuits capable of performing various functions described throughout the present invention. The processor 1202 is responsible for managing the bus and general processing (including executing software stored in the storage medium 1203). The processor 1202 can be implemented by using one or more general-purpose processors and / or dedicated processors. Examples of the processor include a microprocessor, a microcontroller, a DSP processor, and other circuits capable of executing software. Software should be broadly interpreted as representing instructions, data, or any combination thereof, regardless of whether it is referred to as software, firmware, middleware, microcode, a hardware description language, or others. In FIG. 11, the storage medium 1203 is shown separated from the processor 1202. However, it will be readily understood by those skilled in the art that the storage medium 1203 or any part thereof may be located outside the data transmission device 1200. For example, the storage medium 1203 may include transmission lines, carrier waveforms modulated with data, and / or computer-made products separated from wireless nodes, all of which may be accessed by the processor 1202 through the bus interface 1204. Alternatively, the storage medium 1203 or any part thereof may be integrated into the processor 1202, for example, it may be a cache and / or a general-purpose register. The processor 1202 may execute the above embodiments, which will not be elaborated here. Those of ordinary skill in the art can understand that all or part of the steps to implement the above method embodiments can be completed by hardware related to program instructions. The foregoing program may be stored in a computer-readable storage medium. When the program is executed, it performs the steps including the above method embodiments; and the foregoing storage medium includes: various media such as ROM, RAM, magnetic disks, or optical discs that can store program codes.

Claims

1. A method for transmitting a wireless frame, comprising: The transmitting end generates a wireless frame, and the wireless frame includes: one or more station information fields, each of the station information fields having a length of 2K bytes, where K is a natural number, and the value of bit B16j+11 in each of the station information fields is set to 1, where j = 1, 2, 3, …, K-1; Transmit the wireless frame.

2. The method according to claim 1, wherein The wireless frame is an Null Data Packet Announcement (NDPA) frame or a trigger frame that follows the data structure specified by the 802.11ax standard; The value of bit B16j+11 is set to 1 to prevent a receiving end that does not follow the 802.11ax standard from misinterpreting the station information field.

3. The method according to claim 1 or 2, wherein Each of the station information fields has a length of 4 bytes; The value of bit B16j+11 is set to 1, specifically: the value of the 28th bit (i.e., bit B27) of the station information field is set to 1.

4. The method according to claim 3, wherein The value of bit B27 is set to 1 to prevent a receiving end that does not follow the 802.11ax standard from misinterpreting the first 12 bits in the 3rd and 4th bytes of the station information field.

5. A method for receiving a wireless frame, comprising: Receive a wireless frame, the wireless frame includes: one or more station information fields, each of the station information fields having a length of 2K bytes, where K is a natural number, and the value of bit B16j+11 in each of the station information fields is set to 1, where j = 1, 2, 3, …, K-1; Parse the wireless frame and process it according to the value of bit B16j+11.

6. The method according to claim 5, wherein The wireless frame is an Null Data Packet Announcement (NDPA) frame or a trigger frame that follows the data structure specified by the 802.11ax standard; The value of bit B16j+11 is set to 1 to prevent a receiving end that does not follow the 802.11ax standard from misinterpreting the station information field.

7. The method according to claim 5 or 6, wherein Each of the station information fields has a length of 4 bytes; The value of bit B16j+11 is set to 1, specifically: the 28 th bit (i.e., bit B27) of the station information field is set to 1.

8. The method according to claim 7, wherein The value of bit B27 is set to 1 to prevent a receiving end that does not follow the 802.11ax standard from misinterpreting the first 12 bits in the 3rd and 4th bytes of the station information field.

9. A data transmission device, comprising A module for generating a wireless frame, the wireless frame comprising: One or more station information fields, each of the station information fields having a length of 2K bytes, where K is a natural number, and the value of bit B16j+11 in each of the station information fields is set to 1, where j = 1, 2, 3, …, K-1; and, A module for transmitting the wireless frame.

10. The device according to claim 9, wherein The wireless frame is an Null Data Packet Announcement (NDPA) frame or a trigger frame that follows the data structure specified by the 802.11ax standard; The value of bit B16j+11 is set to 1 to prevent a receiving end that does not follow the 802.11ax standard from misinterpreting the station information field.

11. The device according to claim 9 or 10, wherein Each of the station information fields has a length of 4 bytes; The value of the bit B16j + 11 is set to 1, specifically: the value of the 28th bit (i.e., bit B27) of the station information field is set to 1.

12. The device according to claim 11, wherein The value of the bit B27 is set to 1 to prevent a receiving end that does not comply with the 802.11ax standard from misinterpreting the first 12 bits in the 3rd and 4th bytes of the station information field.

13. A device for receiving a wireless frame, comprising: A module for receiving a wireless frame, the wireless frame including: one or more station information fields, each of the station information fields having a length of 2K bytes, where K is a natural number, and the value of the bit B16j + 11 in each of the station information fields is set to 1, where j = 1, 2, 3,..., K - 1; Parse the wireless frame and process it according to the value of the bit B16j + 11.

14. The device according to claim 13, wherein The wireless frame is an empty data packet announcement NDPA frame or a trigger frame that follows a data structure specified by the 802.11ax standard; The value of the bit B16j + 11 is set to 1 to prevent a receiving end that does not comply with the 802.11ax standard from misinterpreting the station information field.

15. The device according to claim 13 or 14, characterized in that, Each of the station information fields has a length of 4 bytes; The value of the bit B16j + 11 is set to 1, specifically: the value of the 28th bit (i.e., bit B27) of the station information field is set to 1.

16. The device according to claim 7, characterized in that, The value of the bit B27 is set to 1 to prevent a receiving end that does not comply with the 802.11ax standard from misinterpreting the first 12 bits in the 3rd and 4th bytes of the station information field.

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