WO2016058137A1

WO2016058137A1 - Signal transmission method, transmitting end and receiving end in wireless local area network

Info

Publication number: WO2016058137A1
Application number: PCT/CN2014/088606
Authority: WO
Inventors: 刘晟; 卢伟山
Original assignee: 华为技术有限公司
Priority date: 2014-10-15
Filing date: 2014-10-15
Publication date: 2016-04-21

Abstract

Provided is a signal transmission method in a wireless local area network, comprising: generating P frequency-domain signals, wherein each frequency-domain signal of the P frequency-domain signals comprises N sub-carriers, one sub-carrier of every D continuous sub-carriers in the N sub-carriers bears a reference signal corresponding to a spatial flow, the signal of the remaining (D-1) sub-carriers is zero, and only one sub-carrier of 4P sub-carriers, comprising an ith sub-carrier to an (i+3)th sub-carrier of each frequency-domain signal, of the P frequency-domain signals bears the reference signal corresponding to the same spatial flow; converting the P frequency-domain signals into corresponding P first time-domain signals by means of N point IFFT; dividing each first time-domain signal of the P first time-domain signals into D sections of the same length, and intercepting any one section in the D sections to obtain P second time-domain signals; generating a long training field according to the P second time-domain signals, wherein the long training field comprises P multiplexing symbols, and each multiplexing symbol consists of one second time-domain signal and a corresponding CP; and transmitting the long training field. When the embodiments of the present invention utilize reference signals to acquire channel estimation of MIMO, the reference signals corresponding to spatial flows are discontinuously and uniformly borne on the sub-carriers, thus decreasing the time expenditure of HE-LTF.

Description

Signal transmission method, transmitting end and receiving end in wireless local area network

Technical field

Embodiments of the present invention relate to the field of communications, and, more particularly, to a method, a transmitting end, and a receiving end for signal transmission in a wireless local area network.

Background technique

Orthogonal Frequency Division Multiplexing (OFDM) is a multi-carrier modulation technology widely used in fourth-generation cellular communication systems, such as Long-Term Evolution (LTE) and global microwave interconnection. Worldwide Interoperability for Microwave Access (WiMAX) system.

The existing wireless local area network (WLAN) standard based on OFDM technology is composed of gradual evolution of 802.11a, 802.11n, 802.11ac, etc. Among them, 802.11n and 802.11ac have supported single-user multiple input and multiple output (Single). User Multiple Input and Multiple Output (SU-MIMO) and Downlink Multi-User Multiple Input Multiple Output (Multi-User MIMO, MU-MIMO). At present, the IEEE 802.11 standard organization has launched the standardization work of the new generation WLAN standard 802.11ax called High Efficiency WLAN (HEW). Among them, uplink MU-MIMO is a key technology of 802.11ax. For example, in the above MU-MIMO, an access point (AP) uses a high efficiency long training field in an uplink packet transmitted by each STA in order to demodulate signals from different stations (STAs). Field, HE-LTF) to obtain channel estimation for uplink MU-MIMO.

In an OFDM system, a transmitting end performs OFDM modulation on user data by an Inverse Fast Fourier Transform (IFFT) to generate a time domain OFDM symbol, and inserts a Cyclic Prefix (CP) before the time domain OFDM symbol. The receiving end performs a CP removal (CP removal) operation on the received user data, and performs OFDM demodulation by Fast Fourier Transform (FFT). In this implementation, each subcarrier in the frequency domain of the OFDM system is orthogonal to each other, and there is no mutual interference between the system subcarriers, so that the link performance is good.

Specifically, a guard interval (GI) is added to the transmitting end of the OFDM system, mainly to eliminate Inter-Symbol Interference (ISI) caused by multipath. Its The method is to fill the CP in the OFDM symbol guard interval to ensure that the number of waveform periods included in the delay copy of the OFDM symbol in the FFT period is also an integer, so that the signal with the delay less than the guard interval is not in the demodulation process. Generate ISI.

Existing WLAN systems based on the 802.11a, 802.11n, and 802.11ac standards employ OFDM symbols with a length of 4 us, including a GI of 0.8 us or CP. For smaller GI overhead and support for outdoor applications, the 802.11ax standard supports OFDM symbol lengths of 2x, 4x or longer. Taking the length of the 4x OFDM symbol as an example, the length of each OFDM symbol excluding the GI is 12.8us. In order to cope with the ISI caused by the large multipath delay in outdoor applications, the GI of 0.8us can also be used for 1.6us, 2.4us. Or a longer GI such as 3.2us, therefore, the total OFDM symbol length after including the GI will be 13.6us, 14.4us, 15.2us, and 16us, respectively.

In 802.11ax, the overhead of HE-LTF is a major problem due to the use of 4 times longer OFDM symbols. Specifically, the HE-LTF includes a plurality of OFDM symbols, the length of which is related to the number of spatial streams (Nss) of the MIMO transmission, and usually supports a maximum of 8 spatial streams in the WLAN system, if the prior art is still used. In the mode, the HE-LTF needs to use 8 OFDM symbols in 8 spatial streams. The length of the HE-LTF is 16us×8=128us, and the length of the whole packet is 1~3ms. This results in an excessive time overhead for the HE-LTF.

Summary of the invention

Embodiments of the present invention provide a method for signal transmission in a wireless local area network, which can reduce time overhead.

In a first aspect, a method for signal transmission in a wireless local area network is provided, including:

Generating P frequency domain signals, wherein each frequency domain signal of the P frequency domain signals comprises N subcarriers; and among the N subcarriers of each frequency domain signal, one sub of each D consecutive subcarriers The carrier carries a reference signal corresponding to a spatial stream, and the signals of the remaining D-1 subcarriers of each D consecutive subcarriers are zero, and among the total 4P subcarriers of the P frequency domain signals, One subcarrier carries a reference signal corresponding to the same spatial stream, and the 4P subcarriers include an i th subcarrier to an i+3 subcarrier of each frequency domain signal, D=2 or D=4, and P is a positive integer. , i is any value between 0 and N-4, and N is a positive integer power of 2;

Converting the P frequency domain signals into N corresponding first time domain signals by an N-point Fourier inverse transform IFFT;

Dividing each of the first time domain signals of the P first time domain signals into D segments of equal length, and intercepting any one of the D segments to obtain P second time domain signals;

Generating a long training field according to the P second time domain signals, wherein the long training field includes P multiplex symbols, each of the P multiplex symbols Forming a second time domain signal of the P second time domain signals and a corresponding cyclic prefix CP;

Send the long training field.

In a second aspect, a method for signal transmission in a wireless local area network is provided, including:

Generating P frequency domain signals, wherein each frequency domain signal of the P frequency domain signals includes N subcarriers; and one of every two consecutive subcarriers among the N subcarriers of each frequency domain signal The carrier carries a reference signal corresponding to one spatial stream, and the signal of the other subcarrier is zero, and among the 2P subcarriers of the P frequency domain signals, one and only one subcarrier carries a reference signal corresponding to the same spatial stream. The 2P subcarriers include an i th subcarrier to an i+1 th subcarrier of each frequency domain signal, P is a positive integer, i is any value between 0 and N-2, and N is 2. Positive integer power;

Dividing each of the first time domain signals of the P first time domain signals into two segments of equal length, and intercepting any one of the two segments to obtain P second time domain signals;

Send the long training field.

In a third aspect, a method for signal transmission in a wireless local area network is provided, including:

Receiving a long training field, wherein the long training field includes P multiplex symbols, each of the P multiplex symbols being subjected to a second time domain signal and a corresponding loop The prefix CP is composed, and P is a positive integer;

Performing a de-CP operation on the long training field to acquire P second time domain signals;

And repeating D segments for each second time domain signal of the P second time domain signals, to obtain P first time domain signals, where D=2 or D=4;

Converting the P first time domain signals into corresponding P frequency domain signals by an N-point Fourier transform, where N is a positive integer power of 2;

M-time interpolation is performed on the P frequency-domain signals to determine a channel estimation, where M represents a compression multiple, and M=2 or M=4.

In a fourth aspect, a sender is provided, including:

a first generating unit, configured to generate P frequency domain signals, where each frequency domain signal of the P frequency domain signals includes N subcarriers; in each of the N subcarriers of each frequency domain signal, each D One subcarrier of one consecutive subcarrier carries a reference signal corresponding to a spatial stream, the signals of the remaining D-1 subcarriers of each D consecutive subcarriers are zero, and a total of 4P in the P frequency domain signals Among the subcarriers, one and only one subcarrier carries a reference signal corresponding to the same spatial stream, and the 4P subcarriers include an i th subcarrier to an i+3 subcarrier of each frequency domain signal, D=2 or D = 4, P is a positive integer, i is any value between 0 and N-4, and N is a positive integer power of 2;

a converting unit, configured to convert the P frequency domain signals into N corresponding first time domain signals by an N-point inverse Fourier transform IFFT;

An intercepting unit, configured to divide each first time domain signal of the P first time domain signals into D segments of equal length, and intercept any one of the D segments to obtain P second time domain signals;

a second generating unit, configured to generate a long training field according to the P second time domain signals, where the long training field includes P multiplex symbols, where the P multiplex symbols Each multiplex symbol consists of a second time domain signal of the P second time domain signals and a corresponding cyclic prefix CP;

a sending unit, configured to send the long training field.

In a fifth aspect, a sender is provided, including:

a first generating unit, configured to generate P frequency domain signals, where each frequency domain signal of the P frequency domain signals includes N subcarriers; and each of the N subcarriers of each frequency domain signal One subcarrier of one consecutive subcarrier carries one reference signal corresponding to the spatial stream, the signal of the other subcarrier is zero, and one and only one subcarrier is carried in a total of 2P subcarriers of the P frequency domain signals a reference signal corresponding to the same spatial stream, where the 2P subcarriers include the i th subcarrier to the i+1 th subcarrier of each frequency domain signal, P is a positive integer, and i is between 0 and N-2 a value, N is a positive integer power of 2;

An intercepting unit, configured to divide each first time domain signal of the P first time domain signals into equal lengths 2 segments, intercepting any of the 2 segments to obtain P second time domain signals;

a sending unit, configured to send the long training field.

In a sixth aspect, a receiving end is provided, including:

a receiving unit, configured to receive a long training field, where the long training field includes P multiplex symbols, and each of the P multiplex symbols has a second time domain The signal is composed of a corresponding cyclic prefix CP, and P is a positive integer;

a first acquiring unit, configured to perform a de-CP operation on the long training field, to acquire P second time domain signals;

a second acquiring unit, configured to repeat D segments for each second time domain signal of the P second time domain signals, where P first time domain signals are obtained, where D=2 or D=4;

a converting unit, configured to convert the P second time domain signals into corresponding P frequency domain signals by an N-point Fourier transform, where N is a positive integer power of 2;

a determining unit, configured to perform M-time interpolation on the P frequency domain signals to determine a channel estimation, where M represents a compression multiple, and M=2 or M=4.

In a seventh aspect, a sender is provided, including:

a processor, configured to generate P frequency domain signals, where each frequency domain signal of the P frequency domain signals includes N subcarriers; in each of the N subcarriers of each frequency domain signal, each D consecutive One subcarrier of the subcarrier carries a reference signal corresponding to a spatial stream, the signals of the remaining D-1 subcarriers of each D consecutive subcarriers are zero, and a total of 4P subcarriers in the P frequency domain signals One and only one subcarrier carries a reference signal corresponding to the same spatial stream, and the 4P subcarriers include an i th subcarrier to an i+3 subcarrier of each frequency domain signal, D=2 or D=4 , P is a positive integer, i is any value between 0 and N-4, and N is a positive integer power of 2.

The processor is further configured to convert the P frequency domain signals into N corresponding first time domain signals by using an N-point Fourier inverse transform IFFT;

The processor is further configured to divide each first time domain signal of the P first time domain signals into D segments of equal length, and intercept any one of the D segments to obtain P second time domain signals;

The processor is further configured to generate a long training field according to the P second time domain signals, where The long training field includes P multiplex symbols, each of the P multiplex symbols being a second time domain signal of the P second time domain signals And the corresponding cyclic prefix CP;

And a sending circuit, configured to send the long training field.

In an eighth aspect, a sender is provided, including:

a processor, configured to generate P frequency domain signals, where each frequency domain signal of the P frequency domain signals includes N subcarriers; each of the N subcarriers of each frequency domain signal One subcarrier of one consecutive subcarrier carries one reference signal corresponding to the spatial stream, the signal of the other subcarrier is zero, and one and only one subcarrier is carried in a total of 2P subcarriers of the P frequency domain signals a reference signal corresponding to the same spatial stream, where the 2P subcarriers include the i th subcarrier to the i+1 th subcarrier of each frequency domain signal, P is a positive integer, and i is between 0 and N-2 a value, N is a positive integer power of 2;

The processor is further configured to divide each first time domain signal of the P first time domain signals into two segments of equal length, and intercept any one of the two segments to obtain P second time domain signals;

The processor is further configured to generate a long training field according to the P second time domain signals, where the long training field includes P multiplex symbols, and each of the P multiplex symbols Multiple multiplex symbols consisting of one of the P second time domain signals and a corresponding cyclic prefix CP;

And a sending circuit, configured to send the long training field.

In a ninth aspect, a receiving end is provided, including:

a receiving circuit, configured to receive a long training field, where the long training field includes P multiplex symbols, and each of the P multiplex symbols has a second time domain The signal is composed of a corresponding cyclic prefix CP, and P is a positive integer;

a processor, configured to perform a de-CP operation on the long training field, to acquire P second time domain signals;

The processor is further configured to repeat D segments for each second time domain signal of the P second time domain signals, where P first time domain signals are obtained, where D=2 or D=4;

The processor is further configured to convert the P second time domain signals into corresponding P frequency domain signals by using an N-point Fourier transform, where N is a positive integer power of 2;

The processor is further configured to perform M-time interpolation on the P frequency domain signals to determine a channel estimation, where M represents a compression multiple, and M=2 or M=4.

In conjunction with the ninth aspect, in a first possible implementation manner of the ninth aspect, the long training field is a high efficiency long training field HE-LTF in 802.11ax.

In the embodiment of the present invention, when the channel estimation of the MIMO is obtained by using the reference signal, the reference signal corresponding to the spatial stream is uniformly and uniformly carried on the subcarrier, so that the time overhead of the HE-LTF can be reduced.

DRAWINGS

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the embodiments or the prior art description will be briefly described below. Obviously, the drawings in the following description are only some of the present invention. For the embodiments, other drawings may be obtained from those skilled in the art without any inventive labor.

1 is a flow chart of a method of signal transmission in a wireless local area network according to an embodiment of the present invention.

2 is a diagram showing the structure of a frequency domain signal and the structure of a long training field when 4 times compressed and Nss=1 in the embodiment of the present invention.

3 is a diagram showing the structure of a frequency domain signal and the structure of a long training field when 4 times compressed and Nss=2 in the embodiment of the present invention.

4 is a diagram showing the structure of a frequency domain signal and the structure of a long training field when 4 times compressed and Nss=3 in the embodiment of the present invention.

FIG. 5 is a diagram showing the structure of a frequency domain signal and the structure of a long training field when 4 times compressed and Nss=5 according to an embodiment of the present invention.

6 is a diagram showing the structure of a frequency domain signal and the structure of a long training field when 4 times compressed and Nss=5 according to another embodiment of the present invention.

7 is a diagram showing the structure of a frequency domain signal and the structure of a long training field when 4 times compressed and Nss=6 in the embodiment of the present invention.

FIG. 8 is a diagram showing the structure of a frequency domain signal and the structure of a long training field when 4 times compressed and Nss=4 according to an embodiment of the present invention.

9 is a diagram showing the structure of a frequency domain signal and the structure of a long training field when 4 times compressed and Nss=7 in the embodiment of the present invention.

10 is a structure and long training of a frequency domain signal when 4 times compressed and Nss=8 according to an embodiment of the present invention; Practice the structure of the field.

11 is a flow chart of a method of signal transmission in a wireless local area network according to another embodiment of the present invention.

FIG. 12 is a diagram showing the structure of a frequency domain signal and the structure of a long training field when 2 times compressed and Nss=1 in the embodiment of the present invention.

FIG. 13 is a diagram showing the structure of a frequency domain signal and the structure of a long training field when 2 times compressed and Nss=3 according to an embodiment of the present invention.

14 is a diagram showing the structure of a frequency domain signal and the structure of a long training field when 2 times compressed and Nss=5 in the embodiment of the present invention.

Figure 15 is a diagram showing the structure of a frequency domain signal and the structure of a long training field when 2 times compressed and Nss = 7 in the embodiment of the present invention.

16 is a diagram showing the structure of a frequency domain signal and the structure of a long training field when 2 times compressed and Nss=2 in the embodiment of the present invention.

17 is a diagram showing the structure of a frequency domain signal and the structure of a long training field when 2 times compressed and Nss=4 in the embodiment of the present invention.

FIG. 18 is a diagram showing the structure of a frequency domain signal and the structure of a long training field when double compression and Nss=6 according to an embodiment of the present invention.

Fig. 19 is a diagram showing the structure of a frequency domain signal and the structure of a long training field when double compression and Nss = 8 in the embodiment of the present invention.

20 is a schematic diagram of a process of signal transmission in a wireless local area network according to an embodiment of the present invention.

21 is a flow chart of a method of signal transmission in a wireless local area network according to another embodiment of the present invention.

FIG. 22 is a schematic diagram of a process of signal transmission in a wireless local area network according to another embodiment of the present invention.

Figure 23 is a block diagram of a transmitting end of an embodiment of the present invention.

Figure 24 is a block diagram of a transmitting end of another embodiment of the present invention.

Figure 25 is a block diagram of a receiving end of one embodiment of the present invention.

Figure 26 is a block diagram of a transmitting end of another embodiment of the present invention.

Figure 27 is a block diagram of a transmitting end of another embodiment of the present invention.

Figure 28 is a block diagram of a receiving end of another embodiment of the present invention.

detailed description

The technical solutions in the embodiments of the present invention are clearly and completely described in the following with reference to the accompanying drawings in the embodiments of the present invention. It is obvious that the described embodiments are a part of the embodiments of the present invention, instead of All embodiments. All other embodiments obtained by a person of ordinary skill in the art based on the embodiments of the present invention without creative efforts are within the scope of the present invention.

Generally, when in an indoor channel environment, since the channel multipath delay is small, the channel changes slowly in the frequency domain. Therefore, channel estimation generally uses 4 times compression, that is, a subcarrier carrying each spatial stream reference signal. Every 4 subcarriers occur once, so that for each spatial stream, the receiving end first obtains the channel estimate on the subcarrier carrying the spatial stream reference signal, and then performs 4 times interpolation to obtain the spatial stream on all subcarriers. Channel estimation. Specifically, FIG. 1 illustrates a method of signal transmission in a wireless local area network when 4 times compression is employed.

1 is a flow chart of a method of signal transmission in a wireless local area network according to an embodiment of the present invention. The method shown in Figure 1 includes:

101. Generate P frequency domain signals, where each frequency domain signal of the P frequency domain signals includes N subcarriers; in each of the N subcarriers of each frequency domain signal, each D consecutive subcarriers One subcarrier carries a reference signal corresponding to a spatial stream, and signals of the remaining D-1 subcarriers of each D consecutive subcarriers are zero, and among the total 4P subcarriers of the P frequency domain signals, And only one subcarrier carries a reference signal corresponding to the same spatial stream, where the 4P subcarriers include an i th subcarrier to an i+3 subcarrier of each frequency domain signal, D=2 or D=4, P is A positive integer, i is any value between 0 and N-4, and N is a positive integer power of two.

102. The P frequency domain signals are converted into corresponding P first time domain signals by an N-point Fourier inverse transform IFFT.

103. Divide each first time domain signal of the P first time domain signals into D segments of equal length, and intercept any one of the D segments to obtain P second time domain signals.

104. Generate, according to the P second time domain signals, a long training field, where the long training field includes P multiplex symbols, and each of the P multiplex symbols is multiplexed The symbol consists of a second time domain signal of the P second time domain signals and a corresponding cyclic prefix CP.

105. Send the long training field.

It can be understood that the method shown in FIG. 1 is performed by the transmitting end.

It can be understood that in the embodiment of the present invention, the inverse Fourier transform may also be referred to as an inverse Fourier transform.

Optionally, in the embodiment of the present invention, the multiplex symbol may be an OFDM symbol, or may be other multiplex symbols, which is not limited by the present invention. It should be noted that the subsequent embodiments of the present invention are illustrated and described by taking an OFDM symbol as an example.

Optionally, in the embodiment of the present invention, the long training field may be an HE-LTF.

Optionally, in the embodiment of the present invention, the value of N may be equal to 64 or 256 or 1024, etc., which is not limited by the present invention. It should be noted that the subsequent embodiment of the present invention is illustrated and described by taking N=256 as an example.

It can be understood that, in the embodiment of the present invention, the size of P is related to the number of spatial streams (Nss) of MIMO transmission. Generally, the maximum number of spatial streams supported in the WLAN system is eight, that is, Nss ≤ 8 and Nss is a positive integer. Generally, P ≤ 8 and P is a positive integer.

The method shown in Figure 1 is for a case where 4x compression is employed, in which case the length of the CP can be equal to 0.8 μs. Accordingly, the length of a first time domain signal is equal to 12.8 μs. Among them, CP can also be understood as GI. If the length of the CP is expressed as L _CP , then L _CP = 0.8 μs.

Specifically, in 101, P frequency domain signals are generated based on the reference signal. The reference signal is a reference signal corresponding to the spatial stream. And the spatial stream has a spatial stream number Nss. Then the value of P and the value of D can be determined according to Nss. specifically,

When Nss=1, P=1, D=4;

When Nss=2, P=1, D=2;

When Nss=3, P=3, D=4;

When Nss=5, P=5, D=4;

When Nss=5 or Nss=6, P=3 and D=2.

Then, it can be understood that the reference signal corresponding to the spatial stream appears once every D subcarriers on each frequency domain signal. Moreover, in the range of 4×P subcarriers, the reference signal corresponding to the same spatial stream is carried by only one subcarrier.

For example, if the reference signal corresponding to a spatial stream is carried by the 0th subcarrier of the first frequency domain signal, the subcarrier carrying the reference signal corresponding to the same spatial stream on the second frequency domain signal must not be the 0th. To the 3rd subcarrier, for example, the 4th subcarrier or the 8th subcarrier...

Thus, it can be understood that the reference signal corresponding to the spatial stream is interleaved in two dimensions of time and frequency.

Further, in 102, a frequency domain signal can be converted into a first time domain signal by an IFFT of N points. That is to say, the P first time domain signals are in one-to-one correspondence with the P frequency domain signals. Optionally, N=256, the length of the first time domain signal is 12.8 μs.

It can be understood that each of the first time domain signals converted by 102 is composed of signals of the same D segment, and then in 103, each first time domain signal can be divided into D segments of equal length and intercepted. Each of the D segments obtains a corresponding second time domain signal. That is to say, a second time domain signal can be obtained by intercepting 1/D of a first time domain signal, and the P second time domain signals are in one-to-one correspondence with the P first time domain signals.

For example, the first segment of the D segment of the first time domain signal may be intercepted as the second time domain signal, or may be understood as the second D-1 segment in the D segment of the first time domain signal is removed as the second Time domain signal. And the length of the first and second time domain signals may be equal to 1/D×12.8 μs.

In this way, a corresponding CP can be added before each second time domain signal obtained by 103, and a long training field can be generated. Also, it can be understood that the long training field includes P multiplex symbols, and each multiplex symbol has a length of 1/D×12.8 μs+L _CP .

Specifically, FIG. 2 to FIG. 10 list the structure of the frequency domain signal at the time of 4 times compression and the structure of the long training field in the embodiment of the present invention. And, N = 256, and the multiplex symbol is an OFDM symbol.

Specifically, FIG. 2(a) shows the structure of a frequency domain signal when 4x compression and Nss=1, and FIG. 2(b) shows the structure of a long training field when 4x compression and Nss=1.

When the spatial stream number Nss=1, P=1, D=4, correspondingly, 101 includes: generating one frequency domain signal, wherein one of every four consecutive subcarriers of the one frequency domain signal The carrier carries a reference signal corresponding to a spatial stream, and the signals of the remaining 3 subcarriers of the 4 consecutive subcarriers are zero.

1 in Fig. 2(a) indicates the serial number of the spatial stream. And the reference signal corresponding to the one spatial stream appears once every four subcarriers, and the signals of the remaining subcarriers are zero. Specifically, the 0th subcarrier, the 4th subcarrier, and the 8th subcarrier... carry the reference signal corresponding to the spatial stream of sequence number 1, and the signals of the remaining subcarriers are zero.

Thus, after the structure of the frequency domain signal shown in FIG. 2(a) is transformed into the time domain by the 256-point IFFT, it becomes a first time domain signal having a length of 12.8 μs, and the first time domain signal is completely completed by four segments. The same length is 3.2μs signal composition, therefore, the following three segments of the repeated signal can be directly removed, only the signal with a length of 3.2μs is used as the second time domain signal, and the CP can be added before the second time domain signal. The growth training field, as shown in FIG. 2(b), includes one OFDM symbol, and the length of the one OFDM symbol is 3.2 μs+L _CP . It can be understood that L _CP is equal to 0.8 μs. It can be understood that the transmitting end can send the long training field as shown in FIG. 2(b) to the receiving end.

Specifically, FIG. 3(a) shows the structure of a frequency domain signal when 4 times compression and Nss=2, and FIG. 3(b) shows the structure of a long training field when 4 times compression and Nss=2.

When the number of spatial streams Nss=2, P=1, D=2, correspondingly, 101 includes: generating one frequency domain signal, wherein one of every two consecutive subcarriers of the one frequency domain signal The carrier carries a reference signal corresponding to one spatial stream, and the signal of the other subcarrier is zero, and one of the four consecutive subcarriers of the one frequency domain signal carries only one subcarrier corresponding to the same spatial stream. Reference signal.

1 and 2 in Fig. 3(a) indicate the sequence numbers of the spatial streams. The reference signal corresponding to the spatial stream with sequence number 1 appears once every 4 subcarriers, and the reference signal corresponding to the spatial stream with sequence number 2 appears once every 4 subcarriers, and the signals of the remaining subcarriers are zero. Moreover, the reference signal corresponding to the spatial stream of sequence number 1 and the reference signal corresponding to the spatial stream of sequence number 2 are separated by D=2 subcarriers. Specifically, the 0th subcarrier, the 4th subcarrier, and the 8th subcarrier include a reference signal corresponding to the spatial stream of sequence 1, the second subcarrier, the sixth subcarrier, and the 10th subcarrier. The reference signal corresponding to the spatial stream, and the signals of the remaining subcarriers are zero.

Thus, after the structure of the frequency domain signal shown in FIG. 3(a) is transformed into the time domain by the 256-point IFFT, it becomes a first time domain signal having a length of 12.8 μs, and the first time domain signal is completely completed by two segments. The same length is 6.4μs signal composition, therefore, the following one-segment repeated signal can be directly removed, leaving only the signal with a length of 6.4μs as the second time domain signal, and adding CP before the second time domain signal can be generated. In the growth training field, as shown in FIG. 3(b), the long training field includes one OFDM symbol, and the length of the one OFDM symbol is 6.4 μs+L _CP . It can be understood that L _CP is equal to 0.8 μs. It can be understood that the transmitting end can send the long training field as shown in FIG. 3(b) to the receiving end.

Specifically, FIG. 4(a) shows the structure of a frequency domain signal when 4 times compression and Nss=3, and FIG. 4(b) shows the structure of a long training field when 4 times compression and Nss=3.

When the number of spatial streams Nss=3, P=3, D=4, correspondingly, 101 includes: generating three frequency domain signals, wherein each of the three frequency domain signals has four consecutive channels of frequency domain signals. One of the subcarriers The subcarrier carries a reference signal corresponding to a spatial stream, and the signals of the remaining 3 subcarriers of the 4 consecutive subcarriers are zero, and among the 12 subcarriers of the 3 frequency domain signals, there are only one One subcarrier carries a reference signal corresponding to the same spatial stream, and the 12 subcarriers include an i th subcarrier to an i+3 subcarrier of each frequency domain signal.

Among them, the three frequency domain signals are (1), (2) and (3) in Fig. 4(a). 1, 2, and 3 in Fig. 4(a) indicate the sequence number of the spatial stream.

And the reference signal corresponding to the spatial stream with sequence number 1 appears once every 4 subcarriers, specifically, the 0th subcarrier of (1), the 4th subcarrier of (3), and the 8th subcarrier of (2) The reference signal corresponding to the spatial stream of sequence number 1.

The subcarrier corresponding to the spatial stream of sequence number 2 appears once every four subcarriers, specifically, the 0th subcarrier of (2), the 4th subcarrier of (1), and the 8th subcarrier of (3)... A reference signal corresponding to a spatial stream of 2.

The subcarrier corresponding to the spatial stream of sequence number 3 appears once every four subcarriers, specifically, the 0th subcarrier of (3), the 4th subcarrier of (2), and the 8th subcarrier of (1)... A reference signal corresponding to a spatial stream of 3.

The signals of the remaining subcarriers are zero.

Thus, after the structure of the frequency domain signal shown in FIG. 4(a) is transformed into the time domain by the 256-point IFFT, it becomes a first time domain signal having a length of 12.8 μs, and the first time domain signal is completely completed by 4 segments. The same length is 3.2μs signal composition, therefore, the following three segments of the repeated signal can be directly removed, only the signal with a length of 3.2μs is used as the second time domain signal, and the CP can be added before the second time domain signal. The growth training field, as shown in FIG. 4(b), includes 3 OFDM symbols, and each OFDM symbol has a length of 3.2 μs+L _CP . It can be understood that the transmitting end sends the long training field as shown in FIG. 4(b) to the receiving end.

Specifically, FIG. 5(a) shows the structure of a frequency domain signal when 4 times compression and Nss=5, and FIG. 5(b) shows the structure of a long training field when 4 times compression and Nss=5.

When the number of spatial streams Nss=5, P=5, D=4, correspondingly, 101 includes: generating five frequency domain signals, wherein each of the five frequency domain signals is continuous for every four consecutive frequency domain signals One of the subcarriers carries a reference signal corresponding to a spatial stream, the signals of the remaining 3 subcarriers of the 4 consecutive subcarriers are zero, and a total of 20 subcarriers in the 5 frequency domain signals In, there is And only one subcarrier carries a reference signal corresponding to the same spatial stream, and the 20 subcarriers include an ith subcarrier to an i+3th subcarrier of each frequency domain signal.

Among them, the five frequency domain signals are (1), (2), (3), (4) and (5) in Fig. 5(a). 1, 2, 3, 4, and 5 in Fig. 5(a) indicate the sequence numbers of the spatial streams.

And the reference signal corresponding to the spatial stream with sequence number 1 appears once every 4 subcarriers, specifically, the 0th subcarrier of (1), the 4th subcarrier of (5), the 8th subcarrier of (4), (3) The 12th subcarrier of (2), the 16th subcarrier of (2), ... carry a reference signal corresponding to the spatial stream of sequence number 1.

The reference signal corresponding to the spatial stream of sequence number 2 appears once every four subcarriers, specifically, the 0th subcarrier of (2), the 4th subcarrier of (1), the 8th subcarrier of (5), (4) The 12th subcarrier, the 16th subcarrier of (3), ... carry the reference signal corresponding to the spatial stream of sequence number 2.

The reference signal corresponding to the spatial stream of sequence number 3 appears once every four subcarriers, specifically, the 0th subcarrier of (3), the 4th subcarrier of (2), the 8th subcarrier of (1), (5) The 12th subcarrier, the 16th subcarrier of (4), carries the reference signal corresponding to the spatial stream of sequence number 3.

The reference signal corresponding to the spatial stream of sequence number 4 appears once every four subcarriers, specifically, the 0th subcarrier of (4), the 4th subcarrier of (3), the 8th subcarrier of (2), (1) The 12th subcarrier of the (5th) and the 16th subcarrier of (5) ... carry the reference signal corresponding to the spatial stream of sequence number 4.

The reference signal corresponding to the spatial stream of sequence number 5 appears once every four subcarriers, specifically, the 0th subcarrier of (5), the 4th subcarrier of (4), the 8th subcarrier of (3), (2) The 12th subcarrier, the 16th subcarrier of (1), carries the reference signal corresponding to the spatial stream of sequence number 5.

The signals of the remaining subcarriers are zero.

Thus, after the structure of the frequency domain signal shown in FIG. 5(a) is transformed into the time domain by the 256-point IFFT, it becomes a first time domain signal having a length of 12.8 μs, and the first time domain signal is completely completed by 4 segments. The same length is 3.2μs signal composition, therefore, the following three segments of the repeated signal can be directly removed, only the signal with a length of 3.2μs is used as the second time domain signal, and the CP can be added before the second time domain signal. The growth training field, as shown in FIG. 5(b), includes 5 OFDM symbols, and each OFDM symbol has a length of 3.2 μs+L _CP . It can be understood that the transmitting end sends the long training field as shown in FIG. 5(b) to the receiving end.

Specifically, FIG. 6(a) shows the structure of a frequency domain signal when 4 times is compressed and Nss=5, and FIG. 6(b) is 4 The structure of the long training field when the compression is doubled and Nss=5.

When the number of spatial streams Nss=5, P=3, D=2, correspondingly, 101 includes: generating three frequency domain signals, wherein each of the frequency domain signals of the three frequency domain signals is consecutively 12 consecutive The five subcarriers in the subcarrier carry a reference signal corresponding to the spatial stream, and the signals of the remaining 7 subcarriers of the 12 consecutive subcarriers are zero, and the 7 subcarriers include noncontiguous 4 groups of 1 subcarrier and one a group of three consecutive subcarriers; and, among the total of 12 subcarriers of the three frequency domain signals, one and only one subcarrier carries a reference signal corresponding to the same spatial stream, and the 12 subcarriers include the each frequency The i-th subcarrier of the domain signal to the i+3th subcarrier.

Or, it can be understood that, in the frequency domain signal of each of the three frequency domain signals, a signal of one of every two consecutive subcarriers of each of the 12 consecutive subcarriers is zero, and each of the twelve 5 subcarriers of the contiguous subcarriers other than the subcarriers whose signals are zero are respectively carried with reference signals corresponding to 5 spatial streams, except for the 5 subcarriers of the remaining 6 subcarriers. The signal of one subcarrier outside is zero.

Among them, the three HE-LTF symbols are (a), (b) and (c) in Fig. 6(a). 1, 2, 3, 4, and 5 in Fig. 6(a) indicate the sequence numbers of the spatial streams.

Wherein, 5 subcarriers of every 12 consecutive subcarriers carry a reference signal corresponding to the spatial stream. For example, in the dotted line frame 10 in FIG. 6(a), 12 subcarriers of (1) are included, wherein 5 subcarriers carry reference signals corresponding to spatial streams, and signals of the remaining 7 subcarriers are zero. Specifically, the 0th subcarrier carries a reference signal corresponding to the spatial stream of sequence number 1, the second subcarrier carries the reference signal corresponding to the spatial stream of sequence number 2, and the fourth subcarrier carries the reference signal corresponding to the spatial stream of sequence number 3. The sixth subcarrier carries a reference signal corresponding to the spatial stream of sequence number 4, and the eighth subcarrier carries a reference signal corresponding to the spatial stream of sequence number 5. The seven subcarriers include non-contiguous groups of 4 subcarriers and a set of three consecutive subcarriers: a first subcarrier, a third subcarrier, a fifth subcarrier, a seventh subcarrier, and a ninth to eleventh subcarrier.

And the reference signal corresponding to the spatial stream with sequence number 1 appears once every 4 subcarriers, specifically, the 0th subcarrier of (1), the 4th subcarrier of (3), and the 8th subcarrier of (2)... A reference signal corresponding to a spatial stream of 1.

The reference signal corresponding to the spatial stream of sequence number 2 appears once every four subcarriers, specifically, the second subcarrier of (1), the 6th subcarrier of (3), and the 10th subcarrier of (2)... The spatial stream corresponds to the reference signal of 2.

The reference signal corresponding to the spatial stream with sequence number 3 appears once every 4 subcarriers, specifically, (2) The 0th subcarrier, the 4th subcarrier of (1), and the 8th subcarrier of (3) ... carry a reference signal corresponding to the spatial stream of sequence number 3.

The reference signal corresponding to the spatial stream of sequence number 4 appears once every four subcarriers, specifically, the second subcarrier of (2), the 6th subcarrier of (1), and the 10th subcarrier of (3)... The spatial stream corresponding to the reference signal of 4.

The reference signal corresponding to the spatial stream of sequence number 5 appears once every four subcarriers, specifically, the 0th subcarrier of (3), the 4th subcarrier of (2), and the 8th subcarrier of (1)... The spatial stream corresponding to the reference signal of 5.

The signals of the remaining subcarriers are zero.

Thus, after the structure of the frequency domain signal shown in FIG. 6(a) is transformed into the time domain by the 256-point IFFT, it becomes a first time domain signal having a length of 12.8 μs, and the first time domain signal is completely completed by 2 segments. The same length is 6.4μs signal composition, therefore, the following one-segment repeated signal can be directly removed, leaving only the signal with a length of 6.4μs as the second time domain signal, and adding CP before the second time domain signal can be generated. The growth training field, as shown in FIG. 6(b), includes 3 OFDM symbols, and each OFDM symbol has a length of 6.4 μs+L _CP . It can be understood that the transmitting end sends the long training field as shown in FIG. 6(b) to the receiving end.

Specifically, FIG. 7(a) shows the structure of a frequency domain signal when 4 times compression and Nss=6, and FIG. 7(b) shows the structure of a long training field when 4 times compression and Nss=6.

When the number of spatial streams Nss=6, P=3, D=2, correspondingly, 101 includes: generating three frequency domain signals, wherein each of the three frequency domain signals is continuous for every two consecutive frequency domain signals One of the subcarriers carries a reference signal corresponding to one spatial stream, and the signal of the other subcarrier is zero, and one or only one subcarrier of the three frequency domain signals carries the same The spatial stream corresponds to the reference signal, and the 12 subcarriers include the i th subcarrier to the i+3 subcarrier of each of the frequency domain signals.

Among them, the three HE-LTF symbols are (a), (b) and (c) in Fig. 7(a). 1, 2, 3, 4, 5, and 6 in Fig. 7(a) indicate the sequence numbers of the spatial streams.

The reference signal corresponding to the spatial stream of sequence number 3 appears once every four subcarriers, specifically, the 0th subcarrier of (2), the 4th subcarrier of (1), and the 8th subcarrier of (3)... The spatial stream corresponding to the reference signal of 3.

The subcarrier corresponding to the spatial stream of sequence number 6 appears once every four subcarriers, specifically, the second subcarrier of (3), the 6th subcarrier of (2), and the 10th subcarrier of (1). A reference signal corresponding to a spatial stream of 6.

The signals of the remaining subcarriers are zero.

Thus, after the structure of the frequency domain signal shown in FIG. 7(a) is transformed into the time domain by the 256-point IFFT, it becomes a first time domain signal having a length of 12.8 μs, and the first time domain signal is completely completed by 2 segments. The same length is 6.4μs signal composition, therefore, the following one-segment repeated signal can be directly removed, leaving only the signal with a length of 6.4μs as the second time domain signal, and adding CP before the second time domain signal can be generated. The growth training field, as shown in FIG. 7(b), includes 3 OFDM symbols, and each OFDM symbol has a length of 6.4 μs+L _CP . It can be understood that the sender sends a long training field as shown in FIG. 7(b) to the receiving end.

In addition, for the case of Nss=4 or Nss=7 or Nss=8 at 4 times compression, a subcarrier interleaved HE-LTF scheme of D=1 can be employed.

Specifically, FIG. 8(a) shows the structure of a frequency domain signal when 4 times compression and Nss=4, and FIG. 8(b) shows the structure of a long training field when 4 times compression and Nss=4.

Wherein P=1, D=1, and correspondingly, 101 includes: generating one frequency domain signal. Each subcarrier of one frequency domain signal carries a reference signal corresponding to a spatial stream. In each of the 1 frequency domain signals Among the four subcarriers, one and only one subcarrier carries a reference signal corresponding to the same spatial stream. 1, 2, 3, and 4 in Fig. 8(a) indicate the sequence numbers of the spatial streams.

The reference signal corresponding to the spatial stream of sequence number 1 appears once every four subcarriers. Specifically, the 0th subcarrier, the 4th subcarrier, and the 8th subcarrier... carry a reference signal corresponding to the spatial stream of sequence number 1.

The reference signal corresponding to the spatial stream of sequence number 2 appears once every four subcarriers. Specifically, the first subcarrier, the fifth subcarrier, and the ninth subcarrier ... carry a reference signal corresponding to the spatial stream of sequence number 2.

The reference signal corresponding to the spatial stream of sequence number 3 appears once every four subcarriers. Specifically, the second subcarrier, the sixth subcarrier, and the tenth subcarrier ... carry a reference signal corresponding to the spatial stream of sequence number 3.

The reference signal corresponding to the spatial stream of sequence number 4 appears once every four subcarriers. Specifically, the third subcarrier, the seventh subcarrier, and the eleventh subcarrier ... carry a reference signal corresponding to the spatial stream of sequence number 4.

The signals of the remaining subcarriers are zero.

Thus, after the structure of the frequency domain signal shown in FIG. 8(a) is transformed into the time domain by the 256-point IFFT, it becomes a first time domain signal having a length of 12.8 μs, and is also added to the second time domain signal. The CP can generate a long training field. As shown in FIG. 8(b), the long training field is composed of one OFDM symbol having a length of 12.8 μs+L _CP . It can be understood that L _CP is equal to 0.8 μs. It can be understood that the transmitting end sends the long training field as shown in FIG. 8(b) to the receiving end.

Specifically, FIG. 9(a) shows the structure of a frequency domain signal when 4 times compression and Nss=7, and FIG. 9(b) shows the structure of a long training field when 4 times compression and Nss=7.

Wherein, P=2, D=1, correspondingly, 101 includes: generating two frequency domain signals, wherein each subcarrier of each frequency domain signal of the two frequency domain signals carries a reference signal corresponding to a spatial stream And, among the total of 8 subcarriers of the two frequency domain signals, one and only one subcarrier carries a reference signal corresponding to the same spatial stream, and the eight subcarriers include an ith sub-segment of each of the frequency domain signals Carrier to the i+3th subcarrier.

Among them, the two frequency domain signals are (1) and (2) in Fig. 9(a), respectively. 1, 2, 3, 4, 5, 6, and 7 in Fig. 9(a) indicate the serial number of the spatial stream.

And the reference signal corresponding to the spatial stream with sequence number 1 appears once every 4 subcarriers, specifically, the 0th subcarrier of (1), the 4th subcarrier of (2), and the 8th subcarrier of (1)... A reference signal corresponding to a spatial stream of 1.

The reference signal corresponding to the spatial stream of sequence number 2 appears once every four subcarriers, specifically, the first subcarrier of (1), the 5th subcarrier of (2), and the ninth subcarrier of (1)... The spatial stream corresponds to the reference signal of 2.

The reference signal corresponding to the spatial stream of sequence number 3 appears once every four subcarriers, specifically, the second subcarrier of (1), the 6th subcarrier of (2), and the 10th subcarrier of (1). The spatial stream corresponding to the reference signal of 3.

The reference signal corresponding to the spatial stream of sequence number 4 appears once every four subcarriers, specifically, the third subcarrier of (1), the 7th subcarrier of (2), and the 11th subcarrier of (1)... The spatial stream corresponding to the reference signal of 4.

The reference signal corresponding to the spatial stream of sequence number 5 appears once every four subcarriers, specifically, the 0th subcarrier of (2), the 4th subcarrier of (1), and the 8th subcarrier of (2)... The spatial stream corresponding to the reference signal of 5.

The reference signal corresponding to the spatial stream of sequence number 6 appears once every four subcarriers, specifically, the first subcarrier of (2), the 5th subcarrier of (1), and the 9th subcarrier of (2)... The spatial stream corresponds to a reference signal of 6.

The reference signal corresponding to the spatial stream of sequence number 7 appears once every four subcarriers, specifically, the second subcarrier of (2), the 6th subcarrier of (1), and the 10th subcarrier of (2)... The spatial stream corresponding to the reference signal of 7.

The signals of the remaining subcarriers are zero.

Thus, after the structure of the frequency domain signal shown in FIG. 9(a) is transformed into the time domain by the 256-point IFFT, it becomes a first time domain signal having a length of 12.8 μs, and is also added to the second time domain signal. The CP can generate a long training field. As shown in FIG. 9(b), the long training field is composed of two OFDM symbols having a length of 12.8 μs+L _CP . It can be understood that L _CP is equal to 0.8 μs. It can be understood that the transmitting end sends the long training field as shown in FIG. 9(b) to the receiving end.

FIG. 10 is a diagram showing the structure of a frequency domain signal and the structure of a long training field when 4 times compressed and Nss=8 according to an embodiment of the present invention.

Specifically, FIG. 10(a) shows the structure of a frequency domain signal when 4 times compression and Nss=8, and FIG. 10(b) shows the structure of a long training field when 4 times compression and Nss=8.

Among them, the two frequency domain signals are (1) and (2) in Fig. 10(a), respectively. 1, 2, 3, 4, 5, 6, 7, and 8 in Fig. 10(a) indicate the serial number of the spatial stream.

The reference signal corresponding to the spatial stream of sequence number 8 appears once every four subcarriers, specifically, the third subcarrier of (2), the 7th subcarrier of (1), and the 11th subcarrier of (2)... The spatial stream corresponding to the reference signal of 8.

The signals of the remaining subcarriers are zero.

Thus, after the structure of the frequency domain signal shown in FIG. 10(a) is transformed into the time domain by the 256-point IFFT, it becomes a first time domain signal having a length of 12.8 μs, and is also added to the second time domain signal. The CP can generate a long training field. As shown in FIG. 10(b), the long training field is composed of two OFDM symbols having a length of 12.8 μs+L _CP . It can be understood that L _CP is equal to 0.8 μs. It can be understood that the transmitting end sends the long training field as shown in FIG. 10(b) to the receiving end.

Thus, when located in an indoor channel environment, the HE-LTF structure as shown in FIGS. 2 to 10 can be employed to obtain channel estimation at MU-MIMO. And, accordingly, the length of the OFDM symbol used is short, which can reduce overhead.

Generally, when in an outdoor signal environment, since the channel multipath delay is large, the channel changes rapidly in the frequency domain. Therefore, channel estimation generally adopts 2 times compression, that is, each subcarrier carrying each spatial stream reference signal is used. Two subcarriers appear once, so that for each spatial stream, the receiving end first obtains the channel estimate on the subcarrier carrying the spatial stream reference signal, and then performs 2 times interpolation to obtain the spatial stream on all subcarriers. Channel estimation. Specifically, FIG. 11 shows a method of signal transmission in a wireless local area network when 2 times compression is employed.

11 is a flow chart of a method of signal transmission in a wireless local area network according to an embodiment of the present invention. The method shown in Figure 11 includes:

111. Generate P frequency domain signals, where each frequency domain signal of the P frequency domain signals includes N subcarriers; in each of the N subcarriers of each frequency domain signal, every 2 consecutive subcarriers One subcarrier carries a reference signal corresponding to one spatial stream, and the signal of the other subcarrier is zero, and among the total 2P subcarriers of the P frequency domain signals, one and only one subcarrier carries the same spatial stream corresponding to a reference signal, the 2P subcarriers include an i th subcarrier to an i+1 th subcarrier of each frequency domain signal, P is a positive integer, and i is any value between 0 and N-2, where N is A positive integer power of 2.

112. Convert the P frequency domain signals into N corresponding first time domain signals by an N-point Fourier inverse transform IFFT.

113. Split each first time domain signal of the P first time domain signals into two segments of equal length, and intercept any one of the two segments to obtain P second time domain signals.

114. Generate, according to the P second time domain signals, a long training field, where the long training field includes P multiplex symbols, and each of the P multiplex symbols is multiplexed Using a symbol from a second time domain signal of the P second time domain signals and a corresponding cyclic prefix CP group to make.

115. Send the long training field.

It can be understood that the method shown in FIG. 11 is performed by the transmitting end.

The method shown in Fig. 11 is for the case of using 2x compression, in which case the length of the CP can be equal to 1.6 μs or 2.4 μs or 3.2 μs. Accordingly, the length of a first time domain signal is equal to 12.8 μs. Among them, CP can also be understood as GI. If the length of the CP is expressed as L _CP , then L _CP = 1.6 μs or 2.4 μs or 3.2 μs.

Specifically, in 111, P frequency domain signals are generated based on the reference signal. The reference signal is a reference signal corresponding to the spatial stream. And the spatial stream has a spatial stream number Nss. Then the value of P can be determined according to Nss. specifically,

When Nss=1, P=1;

When Nss=3, P=3;

When Nss=5, P=5;

When Nss=7, P=7.

Then, it can be understood that the reference signal corresponding to the spatial stream appears once every 2 subcarriers on each frequency domain signal. Moreover, in the range of 4×P subcarriers, the reference signal corresponding to the same spatial stream is carried by only one subcarrier.

For example, if the reference signal corresponding to a spatial stream is carried by the 0th subcarrier of the first frequency domain signal, then the subcarrier of the reference signal corresponding to the same spatial stream is carried on the second frequency domain signal. It must not be the 0th subcarrier, and it is not necessarily the 1st subcarrier. For example, it can be the 2nd subcarrier or the 4th subcarrier...

Further, in 112, a frequency domain signal can be converted into a first time domain signal by an IFFT of N points. That is to say, the P first time domain signals are in one-to-one correspondence with the P frequency domain signals. Optionally, N=256, the length of the first time domain signal is 12.8 μs. .

It can be understood that each of the first time domain signals converted by 112 is composed of two identical signals, and in 113, each first time domain signal can be divided into two segments of equal length and intercepted. Each of the two segments obtains a corresponding second time domain signal. That is to say, a second time domain signal can be obtained by intercepting 1/2 of a first time domain signal, and the P second time domain signals are in one-to-one correspondence with the P first time domain signals.

For example, the first segment of the 2 segments of the first time domain signal may be intercepted as the second time domain signal, or may be understood as the second time domain after removing the next segment of the 2 segments of the first time domain signal. signal. And the length of the first and second time domain signals may be equal to 1/2 x 12.8 μs.

In this way, a corresponding CP can be added before each second time domain signal obtained in 113, and a long training field can be generated. And, it can be understood that the long training field includes P multiplex symbols, and each multiplex symbol has a length of 1/2×12.8 μs+L _CP .

Specifically, FIG. 12 to FIG. 19 list the structure of the frequency domain signal at the time of double compression and the structure of the long training field in the embodiment of the present invention. And, N = 256, and the multiplex symbol is an OFDM symbol.

Specifically, FIG. 12(a) shows the structure of a frequency domain signal when double compression and Nss=1, and FIG. 12(b) shows the structure of a long training field when double compression and Nss=1.

When the number of spatial streams Nss=1, P=1, correspondingly, 111 includes: generating one frequency domain signal, wherein one subcarrier of every two consecutive subcarriers of the one frequency domain signal carries one space The corresponding reference signal of the stream, the signal of the other subcarrier is zero

1 in Fig. 12(a) indicates the serial number of the spatial stream. And the reference signal corresponding to the one spatial stream appears once, and the signals of the remaining subcarriers are zero. Specifically, the 0th subcarrier, the 2nd subcarrier, and the 4th subcarrier... carry a reference signal corresponding to a spatial stream of sequence number 1, and the signals of the remaining subcarriers are zero.

Thus, after the structure of the frequency domain signal shown in FIG. 12(a) is transformed into the time domain by the 256-point IFFT, it becomes a first time domain signal having a length of 12.8 μs, and the first time domain signal is completely completed by 2 segments. The same length is 6.4μs signal composition, therefore, the following one-segment repeated signal can be directly removed, leaving only the signal with a length of 6.4μs as the second time domain signal, and adding CP before the second time domain signal can be generated. In the growth training field, as shown in Fig. 12(b), the long training field is composed of one OFDM symbol having a length of 6.4 μs + L _CP . It will be appreciated that L _CP can be equal to 1.6 μs or 2.4 μs or 3.2 μs. It can be understood that the transmitting end sends the long training field as shown in FIG. 12(b) to the receiving end.

Specifically, FIG. 13(a) shows the structure of a frequency domain signal when double compression and Nss=3, and FIG. 13(b) shows the structure of a long training field when double compression and Nss=3.

When the number of spatial streams Nss=3, P=3, correspondingly, 111 includes: generating three frequency domain signals, wherein each of the three frequency domain signals is in every two consecutive subcarriers of the frequency domain signal One subcarrier carries a reference signal corresponding to one spatial stream, and the signal of the other subcarrier is zero, and among the total of 6 subcarriers of the three frequency domain signals, one and only one subcarrier carries the same spatial stream corresponding to a reference signal, the 6 subcarriers including an i th subcarrier to an i+1 th subcarrier of each frequency domain signal.

Among them, the three frequency domain signals are (1), (2) and (3) in Fig. 13(a). 1, 2, and 3 in Fig. 13(a) indicate the sequence numbers of the spatial streams.

And the reference signal corresponding to the spatial stream with sequence number 1 appears once every two subcarriers, specifically, the 0th subcarrier of (1), the 2nd subcarrier of (3), and the 4th subcarrier of (2)... A reference signal corresponding to a spatial stream of 1.

The reference signal corresponding to the spatial stream of sequence number 2 appears once every two subcarriers, specifically, the 0th subcarrier of (2), the 2nd subcarrier of (1), and the 4th subcarrier of (3)... The spatial stream corresponds to the reference signal of 2.

The reference signal corresponding to the spatial stream of sequence number 3 appears once every two subcarriers, specifically, the 0th subcarrier of (3), the 2nd subcarrier of (2), and the 4th subcarrier of (1)... The spatial stream corresponding to the reference signal of 3.

The signals of the remaining subcarriers are zero.

Thus, after the structure of the frequency domain signal shown in FIG. 13(a) is transformed into the time domain by the 256-point IFFT, it becomes a first time domain signal having a length of 12.8 μs, and the first time domain signal is completely completed by 2 segments. The same length is 6.4μs signal composition, therefore, the following one-segment repeated signal can be directly removed, leaving only the signal with a length of 6.4μs as the second time domain signal, and adding CP before the second time domain signal can be generated. The growth training field, as shown in Fig. 13(b), consists of three OFDM symbols of length 6.4 μs + L _CP . It will be appreciated that L _CP can be equal to 1.6 μs or 2.4 μs or 3.2 μs. It can be understood that the transmitting end sends the long training field as shown in FIG. 13(b) to the receiving end.

Specifically, FIG. 14(a) shows the structure of a frequency domain signal when double compression and Nss=5, and FIG. 14(b) shows the structure of a long training field when double compression and Nss=5.

When the number of spatial streams Nss=5, P=5, correspondingly, 111 includes: generating five frequency domain signals, wherein each of the five frequency domain signals is in every two consecutive subcarriers of the frequency domain signal One subcarrier carries a reference signal corresponding to one spatial stream, and the signal of the other subcarrier is zero, and among the total 10 subcarriers of the 5 frequency domain signals, only one subcarrier carries the same spatial stream corresponding to a reference signal, the 10 subcarriers including an i th subcarrier to an i+1 th subcarrier of each frequency domain signal.

Among them, the five frequency domain signals are (1), (2), (3), (4) and (5) in Fig. 14(a). 1, 2, 3, 4, and 5 in Fig. 14(a) indicate the serial number of the spatial stream.

And the reference signal corresponding to the spatial stream with sequence number 1 appears once every 2 subcarriers, specifically, the 0th subcarrier of (1), the 2nd subcarrier of (5), the 4th subcarrier of (4), (3) The sixth subcarrier of (2), the eighth subcarrier of (2), and the reference signal corresponding to the spatial stream of sequence number 1.

The reference signal corresponding to the spatial stream of sequence number 2 appears once every two subcarriers, specifically, the 0th subcarrier of (2), the 2nd subcarrier of (1), the 4th subcarrier of (5), (4) The sixth subcarrier, the eighth subcarrier of (c), carries the reference signal corresponding to the spatial stream of sequence number 2.

The reference signal corresponding to the spatial stream of sequence number 3 appears once every two subcarriers, specifically, the 0th subcarrier of (3), the 2nd subcarrier of (2), the 4th subcarrier of (1), (5) The sixth subcarrier, the eighth subcarrier of (4), carries the reference signal corresponding to the spatial stream of sequence number 3.

The reference signal corresponding to the spatial stream of sequence number 4 appears once every two subcarriers, specifically, the 0th subcarrier of (4), the 2nd subcarrier of (3), the 4th subcarrier of (2), (1) The sixth subcarrier, the eighth subcarrier of (f), carries the reference signal corresponding to the spatial stream of sequence number 4.

The reference signal corresponding to the spatial stream of sequence number 5 appears once every two subcarriers, specifically, the 0th subcarrier of (5), the 2nd subcarrier of (4), the 4th subcarrier of (3), (2) 6th The subcarrier, the 8th subcarrier of (1), carries the reference signal corresponding to the spatial stream of sequence number 5.

The signals of the remaining subcarriers are zero.

Thus, after the 256-point IFFT of the frequency domain signal shown in FIG. 14(a) is transformed into the time domain, it becomes a first time domain signal having a length of 12.8 μs, and the first time domain signal is identical by two segments. The signal is composed of a signal length of 6.4 μs. Therefore, the signal of the next segment can be directly removed, leaving only the signal of length 6.4 μs as the second time domain signal, and adding CP before the second time domain signal can generate long The training field, as shown in Figure 14(b), consists of five OFDM symbols of length 6.4 μs + L _CP . It will be appreciated that L _CP can be equal to 1.6 μs or 2.4 μs or 3.2 μs. It can be understood that the transmitting end sends the long training field as shown in FIG. 14(b) to the receiving end.

Specifically, FIG. 15(a) shows the structure of a frequency domain signal when double compression and Nss=7, and FIG. 15(b) shows the structure of a long training field when double compression and Nss=7.

When the number of spatial streams Nss=7, P=7, correspondingly, 111 includes: generating 7 frequency domain signals, wherein each of the 7 frequency domain signals is in every 2 consecutive subcarriers of the frequency domain signal One subcarrier carries a reference signal corresponding to one spatial stream, and the signal of the other subcarrier is zero, and among the total of 14 subcarriers of the seven frequency domain signals, one and only one subcarrier carries the same spatial stream corresponding to The reference signal, the 14 subcarriers include an i th subcarrier to an i+1 th subcarrier of each frequency domain signal.

Among them, the seven frequency domain signals are (1), (2), (3), (4), (5), (6) and (7) in Fig. 15(a). 1 to 7 in Fig. 15(a) indicate the serial number of the spatial stream.

And the reference signal corresponding to the spatial stream of sequence number 1 appears once every two subcarriers, specifically, the 0th subcarrier of (1), the 2nd subcarrier of (7), the 4th subcarrier of (6), (5) The sixth subcarrier of the ) and the eighth subcarrier of (four) ... carry the reference signal corresponding to the spatial stream of sequence number 1.

The reference signal corresponding to the spatial stream of sequence number 2 appears once every two subcarriers, specifically, the 0th subcarrier of (2), the 2nd subcarrier of (1), the 4th subcarrier of (7), (6) The sixth subcarrier, the eighth subcarrier of (f), and the reference signal corresponding to the spatial stream of sequence number 2.

The reference signal corresponding to the spatial stream of sequence number 3 appears once every two subcarriers, specifically, the 0th subcarrier of (3), the 2nd subcarrier of (2), the 4th subcarrier of (1), (7) The sixth subcarrier, the eighth subcarrier of (six), carries the reference signal corresponding to the spatial stream of sequence number 3.

The reference signal corresponding to the spatial stream with sequence number 4 appears once every 2 subcarriers, specifically, (4) The 0th subcarrier, the third subcarrier of (3), the 4th subcarrier of (2), the 6th subcarrier of (1), and the 8th subcarrier of (7) ... bear the spatial stream corresponding to the sequence number 4. Reference signal.

The reference signal corresponding to the spatial stream of sequence number 5 appears once every two subcarriers, specifically, the 0th subcarrier of (5), the 2nd subcarrier of (4), the 4th subcarrier of (3), (2) The sixth subcarrier, the eighth subcarrier of (1), carries the reference signal corresponding to the spatial stream of sequence number 5.

The reference signal corresponding to the spatial stream of sequence number 6 appears once every two subcarriers, specifically, the 0th subcarrier of (6), the 2nd subcarrier of (5), the 4th subcarrier of (4), (3) The 6th subcarrier, the 8th subcarrier of (2), and the reference signal corresponding to the spatial stream of sequence number 6.

The reference signal corresponding to the spatial stream of sequence number 7 appears once every two subcarriers, specifically, the 0th subcarrier of (7), the 2nd subcarrier of (6), the 4th subcarrier of (5), (4) The sixth subcarrier, the eighth subcarrier of (c), carries the reference signal corresponding to the spatial stream of sequence number 7.

The signals of the remaining subcarriers are zero.

Thus, after the structure of the frequency domain signal shown in FIG. 15(a) is transformed into the time domain by the 256-point IFFT, it becomes a first time domain signal having a length of 12.8 μs, and the first time domain signal is completely completed by 2 segments. The same length is 6.4μs signal composition, therefore, the following one-segment repeated signal can be directly removed, leaving only the signal with a length of 6.4μs as the second time domain signal, and adding CP before the second time domain signal can be generated. The growth training field, as shown in Fig. 15(b), consists of seven OFDM symbols of length 6.4 μs + L _CP . It will be appreciated that L _CP can be equal to 1.6 μs or 2.4 μs or 3.2 μs. It can be understood that the transmitting end sends the long training field as shown in FIG. 15(b) to the receiving end.

In addition, when 2x compression is used, in the case where Nss is even, that is, Nss=2 or Nss=4 or Nss=6 or Nss=8, a subcarrier interleaving HE-LTF scheme of D=1 can be employed.

Specifically, FIG. 16(a) shows the structure of a frequency domain signal when double compression and Nss=2, and FIG. 16(b) shows the structure of a long training field when double compression and Nss=2.

Wherein P=1, correspondingly, 101 includes: generating one frequency domain signal. Each subcarrier of one frequency domain signal carries a reference signal corresponding to a spatial stream. Among every two subcarriers of the one frequency domain signal, one and only one subcarrier carries a reference signal corresponding to the same spatial stream. 1 and 2 in Fig. 16(a) indicate the sequence numbers of the spatial streams.

And the reference signal corresponding to the spatial stream with sequence number 1 appears once every 2 subcarriers, specifically, the 0th subcarrier, the 2nd subcarrier, the 4th subcarrier, ... the spatial stream pair with the sequence number 1 The reference signal should be.

The reference signal corresponding to the spatial stream of sequence number 2 appears once every two subcarriers. Specifically, the first subcarrier, the third subcarrier, and the fifth subcarrier ... carry a reference signal corresponding to the spatial stream of sequence number 2.

The signals of the remaining subcarriers are zero.

Thus, after the structure of the frequency domain signal shown in FIG. 16(a) is transformed into the time domain by the 256-point IFFT, it becomes a first time domain signal having a length of 12.8 μs, and is also a second time domain signal, and Adding a CP can generate a long training field. As shown in FIG. 16(b), the long training field is composed of OFDM symbols having a length of 12.8 μs+L _CP . It will be appreciated that L _CP can be equal to 1.6 μs or 2.4 μs or 3.2 μs. It can be understood that the transmitting end sends the long training field as shown in FIG. 16(b) to the receiving end.

Specifically, FIG. 17(a) shows the structure of a frequency domain signal when double compression and Nss=4, and FIG. 17(b) shows the structure of a long training field when double compression and Nss=4.

Wherein P=2, correspondingly, 111 includes: generating two frequency domain signals. Each subcarrier of the two frequency domain signals carries a reference signal corresponding to a spatial stream. Among the total of four subcarriers of the two frequency domain signals, one and only one subcarrier carries a reference signal corresponding to the same spatial stream, and the four subcarriers include the i th subcarrier of each frequency domain signal to the first i+1 subcarriers.

Among them, the two frequency domain signals are (a) and (b) in Fig. 17 (a). 1, 2, 3, and 4 in Fig. 17(a) indicate the sequence numbers of the spatial streams.

And the reference signal corresponding to the spatial stream with sequence number 1 appears once every two subcarriers, specifically, the 0th subcarrier of (1), the 2nd subcarrier of (2), and the 4th subcarrier of (1)... A reference signal corresponding to a spatial stream of 1.

The reference signal corresponding to the spatial stream of sequence number 2 appears once every two subcarriers, specifically, the first subcarrier of (1), the third subcarrier of (2), and the 5th subcarrier of (1)... The spatial stream corresponds to the reference signal of 2.

The reference signal corresponding to the spatial stream of sequence number 3 appears once every two subcarriers, specifically, the 0th subcarrier of (2), the 2nd subcarrier of (1), and the 4th subcarrier of (2)... The spatial stream corresponding to the reference signal of 3.

The reference signal corresponding to the spatial stream of sequence number 4 appears once every two subcarriers, specifically, the first subcarrier of (2), the 3rd subcarrier of (1), and the 5th subcarrier of (2)... 4 The spatial stream corresponds to the reference signal.

The signals of the remaining subcarriers are zero.

Thus, after the structure of the frequency domain signal shown in FIG. 17(a) is transformed into the time domain by the 256-point IFFT, it becomes a first time domain signal having a length of 12.8 μs, and is also added to the second time domain signal. The CP can generate a long training field. As shown in Figure 17(b), the long training field consists of two OFDM symbols of length 12.8 μs + L _CP . It will be appreciated that L _CP can be equal to 1.6 μs or 2.4 μs or 3.2 μs. It can be understood that the transmitting end sends the long training field as shown in FIG. 17(b) to the receiving end.

Specifically, FIG. 18(a) shows the structure of a frequency domain signal when double compression and Nss=6, and FIG. 18(b) shows the structure of a long training field when double compression and Nss=6.

Wherein P=3, correspondingly, 111 includes: generating three frequency domain signals. Each subcarrier of the three frequency domain signals carries a reference signal corresponding to a spatial stream. Among the total of 6 subcarriers of the three frequency domain signals, one and only one subcarrier carries a reference signal corresponding to the same spatial stream, and the six subcarriers include the i th subcarrier of each frequency domain signal to the first i+1 subcarriers.

Among them, the three frequency domain signals are (1), (2) and (3) in Fig. 18(a). 1 to 6 in Fig. 18(a) indicate the serial number of the spatial stream.

And the reference signal corresponding to the spatial stream with sequence number 1 appears once every two subcarriers, specifically, the 0th subcarrier of (1), the 2nd subcarrier of (3), and the 4th subcarrier of (2), (1) The sixth subcarrier of the ... carries the reference signal corresponding to the spatial stream of sequence number 1.

The reference signal corresponding to the spatial stream of sequence number 2 appears once every two subcarriers, specifically, the first subcarrier of (1), the 3rd subcarrier of (3), the 5th subcarrier of (2), (1) The 7th subcarrier... carries the reference signal corresponding to the spatial stream of sequence number 2.

The reference signal corresponding to the spatial stream of sequence number 3 appears once every two subcarriers, specifically, the 0th subcarrier of (2), the 2nd subcarrier of (1), the 4th subcarrier of (3), (2) The sixth subcarrier... carries the reference signal corresponding to the spatial stream of sequence number 3.

The reference signal corresponding to the spatial stream of sequence number 4 appears once every two subcarriers, specifically, the first subcarrier of (2), the 3rd subcarrier of (1), the 5th subcarrier of (3), (1) The 7th subcarrier... carries the reference signal corresponding to the spatial stream of sequence number 4.

The reference signal corresponding to the spatial stream of sequence number 5 appears once every two subcarriers, specifically, the 0th subcarrier of (3), the 2nd subcarrier of (2), the 4th subcarrier of (1), (3) 6th The subcarriers ... carry the reference signal corresponding to the spatial stream of sequence number 5.

The reference signal corresponding to the spatial stream of sequence number 6 appears once every two subcarriers, specifically, the first subcarrier of (3), the 3rd subcarrier of (2), the 5th subcarrier of (1), (3) The 7th subcarrier... carries the reference signal corresponding to the spatial stream of sequence number 6.

The signals of the remaining subcarriers are zero.

Thus, after the structure of the frequency domain signal shown in FIG. 18(a) is transformed into the time domain by the 256-point IFFT, it becomes a first time domain signal having a length of 12.8 μs, and is also added to the second time domain signal. The CP can generate a long training field. As shown in Figure 18(b), the long training field consists of three OFDM symbols of length 12.8 μs + L _CP . It will be appreciated that L _CP can be equal to 1.6 μs or 2.4 μs or 3.2 μs. It can be understood that the transmitting end sends the long training field as shown in FIG. 18(b) to the receiving end.

Specifically, FIG. 19(a) shows the structure of a frequency domain signal when double compression and Nss=8, and FIG. 19(b) shows the structure of a long training field when double compression and Nss=8.

Wherein P=4, correspondingly, 111 includes: generating four frequency domain signals. Each subcarrier of the four frequency domain signals carries a reference signal corresponding to a spatial stream. Among the total of 8 subcarriers of the four frequency domain signals, one and only one subcarrier carries a reference signal corresponding to the same spatial stream, and the eight subcarriers include the i th subcarrier of each frequency domain signal to the first i+1 subcarriers.

Among them, the three frequency domain signals are (1), (2), (3) and (4) in Fig. 19(a). 1 to 8 in Fig. 19(a) indicate the serial number of the spatial stream.

And the reference signal corresponding to the spatial stream with sequence number 1 appears once every 2 subcarriers, specifically, the 0th subcarrier of (1), the 2nd subcarrier of (4), the 4th subcarrier of (3), (2) The sixth subcarrier, the eighth subcarrier of (a), ... carries a reference signal corresponding to the spatial stream of sequence number 1.

The reference signal corresponding to the spatial stream of sequence number 2 appears once every two subcarriers, specifically, the first subcarrier of (1), the 3rd subcarrier of (4), the 5th subcarrier of (3), and (2) The seventh subcarrier, the ninth subcarrier of (1), carries the reference signal corresponding to the spatial stream of sequence number 2.

The reference signal corresponding to the spatial stream of sequence number 3 appears once every two subcarriers, specifically, the 0th subcarrier of (2), the 2nd subcarrier of (1), the 4th subcarrier of (4), (3) The 6th subcarrier, the 8th subcarrier of (2), and the reference signal corresponding to the spatial stream of sequence number 3.

The reference signal corresponding to the spatial stream of sequence number 4 appears once every two subcarriers, specifically, the first subcarrier of (2), the 3rd subcarrier of (1), the 5th subcarrier of (4), and (3) 7th The subcarrier, the ninth subcarrier of (2), carries the reference signal corresponding to the spatial stream of sequence number 4.

The reference signal corresponding to the spatial stream of sequence number 5 appears once every two subcarriers, specifically, the 0th subcarrier of (3), the 2nd subcarrier of (2), the 4th subcarrier of (1), (4) The sixth subcarrier, the eighth subcarrier of (c), carries the reference signal corresponding to the spatial stream of sequence number 5.

The reference signal corresponding to the spatial stream of sequence number 6 appears once every two subcarriers, specifically, the first subcarrier of (3), the 3rd subcarrier of (2), the 5th subcarrier of (1), (4) The 7th subcarrier and the ninth subcarrier of (3) carry the reference signal corresponding to the spatial stream of sequence number 6.

The reference signal corresponding to the spatial stream of sequence number 7 appears once every two subcarriers, specifically, the 0th subcarrier of (4), the 2nd subcarrier of (3), the 4th subcarrier of (2), (1) The sixth subcarrier, the eighth subcarrier of (four) ... carries the reference signal corresponding to the spatial stream of sequence number 7.

The reference signal corresponding to the spatial stream of sequence number 8 appears once every two subcarriers, specifically, the first subcarrier of (4), the third subcarrier of (3), the 5th subcarrier of (2), (1) The 7th subcarrier, the ninth subcarrier of (4), carries the reference signal corresponding to the spatial stream of sequence number 8.

The signals of the remaining subcarriers are zero.

Thus, after the structure of the frequency domain signal shown in FIG. 19(a) is transformed into the time domain by the 256-point IFFT, it becomes a first time domain signal having a length of 12.8 μs, and is also added to the second time domain signal. The CP can generate a long training field. As shown in FIG. 19(b), the long training field is composed of three OFDM symbols having a length of 12.8 μs+L _CP . It will be appreciated that L _CP can be equal to 1.6 μs or 2.4 μs or 3.2 μs. It can be understood that the transmitting end sends the long training field as shown in FIG. 19(b) to the receiving end.

Thus, when located in an outdoor channel environment, the HE-LTF structure as shown in FIGS. 12 to 19 can be employed to obtain channel estimation of uplink/downlink MU-MIMO. And, accordingly, the length of the OFDM symbol used is short, which can reduce overhead.

The processing flow of the signal at the transmitting end can be as shown in FIG. 20, including:

301. The transmitting end generates P frequency domain signals according to the reference signal, where each frequency domain signal of the P frequency domain signals includes N subcarriers. One of the D consecutive subcarriers of the N subcarriers carries a reference signal corresponding to one spatial stream, and the signals of the remaining D-1 subcarriers are zero.

Specifically, the transmitting end generates P frequency domain signals by using a method of 4 times compression. For example, the foregoing embodiment of FIG. 1 to FIG. 10, D=2 or 4; the transmitting end generates P frequency domain signals by using a method of 2 times compression. Referring to the aforementioned embodiment of Figures 11 to 19, D = 2.

302. The transmitting end converts the P frequency domain signals into corresponding P first time domain signals by using an N-point Fourier inverse transform IFFT.

The length of the first time domain signal is 12.8 μs. And, the first time domain signal is composed of signals having the same D segment.

303. The transmitting end divides each first time domain signal of the P first time domain signals into D segments of equal length, and intercepts any one of the D segments to obtain P second time domain signals.

Alternatively, it can be considered that the transmitting end directly removes the following D-1 segment of the D segment signal of the first time domain signal. It can be understood that the length of one second time domain signal is 1/D×12.8 μs.

304. The transmitting end generates a long training field according to the P second time domain signals. Wherein the long training field includes P multiplex symbols, and each of the P multiplex symbols is used by a second one of the P second time domain signals The domain signal consists of the corresponding CP.

Among them, when 4 times compression is used, the length of the CP is 0.8 μs. When using 2x compression, the length of the CP is 1.6μs or 2.4μs or 3.2μs.

It can be understood that in the long training field, the CP between the multiplexed symbols can avoid interference between the multiplexed symbols.

In this way, the sender can send 304 the generated long training field, for example, can be sent to the receiving end.

21 is a flow chart of a method of signal transmission in a wireless local area network according to another embodiment of the present invention. The method shown in Figure 20 includes:

401. Receive a long training field, where the long training field includes P multiplex symbols, and each of the P multiplex symbols is configured by a second time domain signal and corresponding The cyclic prefix CP is composed, and P is a positive integer.

402. Perform a de-CP operation on the long training field to obtain P second time domain signals.

403. Repeat D segments for each second time domain signal of the P second time domain signals, where P first time domain signals are obtained, where D=2 or D=4.

404. Convert the P first time domain signals into corresponding P frequency domain signals by an N-point Fourier transform, where N is a positive integer power of 2.

405. Perform M-time interpolation on the P frequency domain signals to determine a channel estimation, where M represents a compression multiple, and M=2 or M=4.

In this way, in the embodiment of the present invention, the receiving end performs the inverse operation after receiving the long training field, and can be used for channel estimation, and the method reduces the time overhead.

It can be understood that, in the embodiment of the present invention, the method shown in FIG. 21 is the inverse process of the method shown in FIG. 1 and FIG. 20, and details are not described herein again to avoid repetition.

It can be understood that the method shown in FIG. 21 is performed by the receiving end. The receiving end may be referred to as a receiving end device or a receiver, and refers to a receiving end device of a MIMO-OFDM system, which may be a base station, a Mobility Management Entity (MME), a gateway (Gateway) or other network element, and the present invention The embodiment does not limit this.

Optionally, in the embodiment of the present invention, the long training field is a high efficiency long training field HE-LTF in 802.11ax.

Optionally, in the embodiment of the present invention, N=256.

Optionally, in the embodiment of the present invention, the multiplex symbol is an orthogonal frequency division multiplexing OFDM symbol.

It should be noted that in the embodiment of the present invention, when M=4, D=2 or D=4; when M=2, D=2.

It can be understood that, in the embodiment of the present invention, the CP is the aforementioned guard interval GI.

If the long training field in 401 is generated by the M=4 times compression, the receiving end may use the P frequency domain signals in 403 to obtain the reference signal corresponding to the spatial stream on the corresponding subcarrier. Channel estimation. And further, 4 times interpolation is performed, and channel estimation of the reference signal corresponding to the spatial stream on all subcarriers can be obtained.

If the long training field in 401 is generated by the M=2 times compression of the transmitting end, then in 404, the receiving end may use the P frequency domain signals in 403 to obtain the reference signal corresponding to the spatial stream on the corresponding subcarrier. Channel estimation. Further, by performing 2x interpolation, channel estimation of the reference signal corresponding to the spatial stream on all subcarriers can be obtained.

The processing flow of the signal at the receiving end can be as shown in FIG. 22, including:

501. Remove the received long training field from the CP.

It can be understood that the received long training field includes P multiplex symbols, and the CP of each of the P multiplex symbols is removed.

A multiplex symbol after removing the CP may be referred to as a second time domain signal, and then 501 generates P second time domain signals according to the long training field.

502. Repeat the D-1 time of the second time domain signal.

Specifically, D=2 or D=4.

Specifically, each second time domain signal is repeated D-1 times, so that P first time domain signals can be obtained according to the P second time domain signals. The first time domain signal is D times longer than the second time domain signal. For details, refer to the foregoing scenarios shown in FIG. 1 to FIG. 19. To avoid repetition, details are not described herein again.

503. Convert, through the N-point FFT, P first time domain signals into P frequency domain signals.

Here, N is a positive integer power of 2, for example, N=64 or N=256.

504. Acquire, according to the P frequency domain signals, channel estimates of the reference signals corresponding to the spatial streams on the corresponding subcarriers.

505. Perform M-time interpolation to obtain channel estimates of all reference signals corresponding to spatial streams on all subcarriers.

Specifically, M=2 or M=4.

Thus, in the embodiment of the present invention, the receiving end receives the transmission signal signal from the transmitting end, and obtains the channel estimation of the MIMO system through the reverse operation.

Figure 23 is a block diagram of a transmitting end of an embodiment of the present invention. The transmitting end 1000 shown in FIG. 23 includes a first generating unit 1001, a converting unit 1002, an intercepting unit 1003, a second generating unit 1004, and a transmitting unit 1005.

a first generating unit 1001, configured to generate P frequency domain signals, where each frequency domain signal of the P frequency domain signals includes N subcarriers; and each of the N subcarriers of each frequency domain signal One subcarrier of D consecutive subcarriers carries a reference signal corresponding to a spatial stream, and signals of the remaining D-1 subcarriers of each D consecutive subcarriers are zero, and a total of signals in the P frequency domain Among the 4P subcarriers, one and only one subcarrier carries a reference signal corresponding to the same spatial stream, and the 4P subcarriers include the i th subcarrier to the i+3 subcarrier of each frequency domain signal, D=2 or D=4, P is a positive integer, i is any value between 0 and N-4, and N is a positive integer power of 2;

The converting unit 1002 is configured to convert the P frequency domain signals into corresponding P first time domain signals by using an N-point Fourier inverse transform IFFT;

The intercepting unit 1003 is configured to divide each first time domain signal of the P first time domain signals into D segments of equal length, and intercept any one of the D segments to obtain P second time domain signals;

a second generating unit 1004, configured to generate a long training field according to the P second time domain signals, where the long training field includes P multiplex symbols, where the P multiplex symbols are Each multiplex symbol consists of a second time domain signal of the P second time domain signals and a corresponding cyclic prefix CP;

The sending unit 1005 is configured to send the long training field.

In the embodiment of the present invention, when the channel estimation of the MIMO is obtained by using the reference signal, the reference signal corresponding to the spatial stream is uniformly and uniformly carried on the subcarrier, thereby reducing the HE-LTF. Time overhead.

Optionally, as an embodiment, when the number of spatial streams Nss=1, P=1, D=4, the first generating unit 1001 is specifically configured to:

Generating a frequency domain signal, wherein one of every four consecutive subcarriers of the one frequency domain signal carries a reference signal corresponding to a spatial stream, and the remaining three of the four consecutive subcarriers The carrier signal is zero.

Optionally, as another embodiment, when the number of spatial streams Nss=2, P=1, D=2, the first generating unit 1001 is specifically configured to:

Generating a frequency domain signal, wherein one of every two consecutive subcarriers of the one frequency domain signal carries a reference signal corresponding to one spatial stream, and the signal of the other subcarrier is zero, and the Among every 4 consecutive subcarriers of a frequency domain signal, only one subcarrier carries a reference signal corresponding to the same spatial stream.

Optionally, as another embodiment, when the number of spatial streams Nss=3, P=3, D=4, the first generating unit 1001 is specifically configured to:

Generating three frequency domain signals, wherein one of every four consecutive subcarriers of each frequency domain signal of the three frequency domain signals carries a reference signal corresponding to a spatial stream, the four consecutive contigs The signals of the remaining three subcarriers in the carrier are zero, and among the total of 12 subcarriers of the three frequency domain signals, one and only one subcarrier carries a reference signal corresponding to the same spatial stream, and the 12 subcarriers include The i-th subcarrier of each frequency domain signal to the i+3th subcarrier.

Optionally, as another embodiment, when the number of spatial streams Nss=5, P=5, D=4, the first generating unit 1001 is specifically configured to:

Generating 5 frequency domain signals, wherein one of every 4 consecutive subcarriers of each frequency domain signal of the 5 frequency domain signals carries a reference signal corresponding to a spatial stream, the 4 consecutive contigs The signals of the remaining 3 subcarriers in the carrier are zero, and among the 20 subcarriers of the 5 frequency domain signals, only one subcarrier carries a reference signal corresponding to the same spatial stream, and the 20 subcarriers include The i-th subcarrier of each frequency domain signal to the i+3th subcarrier.

Optionally, as another embodiment, when the number of spatial streams Nss=5, P=3, D=2, the first generating unit 1001 is specifically configured to:

Generating three frequency domain signals, wherein a signal of one of every two consecutive subcarriers of each of the four consecutive frequency carriers of each of the three frequency domain signals is zero, each of 5 out of 12 consecutive subcarriers except the subcarrier with zero signal The carriers respectively carry reference signals corresponding to the five spatial streams, and the signals of one of the remaining six subcarriers except the five subcarriers are zero; and, a total of 12 subcarriers in the three frequency domain signals Among the carriers, one and only one subcarrier carries a reference signal corresponding to the same spatial stream, and the 12 subcarriers include an i th subcarrier to an i+3 subcarrier of each frequency domain signal.

Optionally, as another embodiment, when the number of spatial streams Nss=6, P=3, D=2, the first generating unit 1001 is specifically configured to:

Generating three frequency domain signals, wherein one of every two consecutive subcarriers of each frequency domain signal of the three frequency domain signals carries a reference signal corresponding to a spatial stream, and the signal of the other subcarrier is Zero, and, among the total of 12 subcarriers of the three frequency domain signals, one and only one subcarrier carries a reference signal corresponding to the same spatial stream, and the 12 subcarriers include the i th of each frequency domain signal Subcarriers to the i+3th subcarrier.

Optionally, as another embodiment, the length of the CP is 0.8 μs, and the length of the first time domain signal is 12.8 μs.

Alternatively, as another embodiment, N=256.

Optionally, as another embodiment, the long training field is a high efficiency long training field HE-LTF in 802.11ax.

Optionally, as another embodiment, the multiplex symbol is an orthogonal frequency division multiplexing OFDM symbol.

Alternatively, Nss ≤ 8 and Nss is a positive integer, P ≤ 8 and P is a positive integer.

The transmitting end 1000 can implement various processes implemented by the transmitting end in the embodiments of FIG. 1 to FIG. 10, and details are not described herein again to avoid repetition.

Figure 24 is a block diagram of a transmitting end of another embodiment of the present invention. The transmitting end 1100 shown in FIG. 24 includes a first generating unit 1101, a converting unit 1102, a truncating unit 1103, a second generating unit 1104, and a transmitting unit 1105.

a first generating unit 1101, configured to generate P frequency domain signals, where each frequency domain signal of the P frequency domain signals includes N subcarriers; among the N subcarriers of each frequency domain signal One subcarrier of every two consecutive subcarriers carries a reference signal corresponding to one spatial stream, the signal of the other subcarrier is zero, and one or only one of a total of 2P subcarriers of the P frequency domain signals The subcarriers carry reference signals corresponding to the same spatial stream, and the 2P subcarriers include an i th subcarrier to an i+1 th subcarrier of each frequency domain signal, P is a positive integer, and i is 0 to N-2. Any value between, N is a positive integer power of 2;

The converting unit 1102 is configured to convert the P frequency domain signals into N corresponding first time domain signals by using an N-point inverse Fourier transform IFFT;

The intercepting unit 1103 is configured to divide each first time domain signal of the P first time domain signals into two segments of equal length, and intercept any one of the two segments to obtain P second time domain signals;

a second generating unit 1104, configured to generate a long training field according to the P second time domain signals, where the long training field includes P multiplex symbols, where the P multiplex symbols are included Each multiplex symbol consists of a second time domain signal of the P second time domain signals and a corresponding cyclic prefix CP;

The sending unit 1105 is configured to send the long training field.

Optionally, as an embodiment, when the number of spatial streams Nss=1, P=1, the first generating unit 1101 is specifically configured to:

A frequency domain signal is generated, wherein one of every two consecutive subcarriers of the one frequency domain signal carries a reference signal corresponding to one spatial stream, and the signal of the other subcarrier is zero.

Optionally, as another embodiment, when the number of spatial streams Nss=3, P=3, the first generating unit 1101 is specifically configured to:

Generating three frequency domain signals, wherein one of every two consecutive subcarriers of each frequency domain signal of the three frequency domain signals carries a reference signal corresponding to a spatial stream, and the signal of the other subcarrier is Zero, and, among the total of 6 subcarriers of the three frequency domain signals, one and only one subcarrier carries a reference signal corresponding to the same spatial stream, and the six subcarriers include the i th of each of the frequency domain signals Subcarriers to the i+1th subcarrier.

Optionally, as another embodiment, when the number of spatial streams Nss=5, P=5, the first generating unit 1101 is specifically configured to:

Generating five frequency domain signals, wherein one of every two consecutive subcarriers of each frequency domain signal of the five frequency domain signals carries a reference signal corresponding to a spatial stream, and the signal of the other subcarrier is Zero, and, among the total of 10 subcarriers of the five frequency domain signals, one and only one subcarrier carries a reference signal corresponding to the same spatial stream, and the ten subcarriers include the i th of each of the frequency domain signals Subcarriers to the i+1th subcarrier.

Optionally, as another embodiment, when the number of spatial streams Nss=7, P=7, the first life The unit 1101 is specifically configured to:

Generating 7 frequency domain signals, wherein one of every two consecutive subcarriers of each frequency domain signal of the seven frequency domain signals carries a reference signal corresponding to a spatial stream, and the signal of the other subcarrier is Zero, and, among the total of 14 subcarriers of the seven frequency domain signals, one and only one subcarrier carries a reference signal corresponding to the same spatial stream, and the 14 subcarriers include an ith of each of the frequency domain signals Subcarriers to the i+1th subcarrier.

Optionally, as another embodiment, the length of the CP is 1.6 μs or 2.4 μs or 3.2 μs, and the length of the first time domain signal is 12.8 μs.

Alternatively, as another embodiment, N=256.

The transmitting end 1100 can implement various processes implemented by the transmitting end in the embodiment of FIG. 11 to FIG. 20, and details are not described herein again to avoid repetition.

Figure 25 is a block diagram of a receiving end of one embodiment of the present invention. The receiving end 1200 shown in FIG. 25 includes a receiving unit 1201, a first acquiring unit 1202, a second obtaining unit 1203, a converting unit 1204, and a determining unit 1205.

The receiving unit 1201 is configured to receive a long training field, where the long training field includes P multiplex symbols, and each of the P multiplex symbols is a second time The domain signal is composed of a corresponding cyclic prefix CP, and P is a positive integer;

The first obtaining unit 1202 is configured to perform a de-CP operation on the long training field to obtain P second time domain signals.

The second obtaining unit 1203 is configured to repeat D segments for each second time domain signal of the P second time domain signals, where P first time domain signals are obtained, where D=2 or D=4;

The converting unit 1204 is configured to convert the P second time domain signals into corresponding P frequency domain signals by using an N-point Fourier transform, where N is a positive integer power of 2;

The determining unit 1205 is configured to perform M-time interpolation on the P frequency domain signals to determine a channel estimation, where M represents a compression multiple, and M=2 or M=4.

Thus, in the embodiment of the present invention, the receiving end performs the reverse operation after receiving the long training field, and can Used for channel estimation, and this approach reduces time overhead.

Optionally, as an embodiment, the long training field is a high efficiency long training field HE-LTF in 802.11ax.

Alternatively, as another embodiment, N=256.

The receiving end 1200 can implement the various processes implemented by the receiving end in the embodiment of FIG. 21 to FIG. 22, and details are not described herein again to avoid repetition.

Figure 26 is a block diagram of a transmitting end of another embodiment of the present invention. The transmitting end 1300 shown in FIG. 26 includes a processor 1301, a receiving circuit 1302, a transmitting circuit 1303, and a memory 1304.

The processor 1301 is configured to generate P frequency domain signals, where each frequency domain signal of the P frequency domain signals includes N subcarriers, and each of the N subcarriers of each frequency domain signal One subcarrier of the contiguous subcarrier carries a reference signal corresponding to a spatial stream, the signals of the remaining D-1 subcarriers of each D consecutive subcarriers are zero, and a total of 4P sub-carriers in the P frequency domain signals Among the carriers, one and only one subcarrier carries a reference signal corresponding to the same spatial stream, and the 4P subcarriers include an i th subcarrier to an i+3 subcarrier of each frequency domain signal, D=2 or D= 4, P is a positive integer, i is any value between 0 and N-4, and N is a positive integer power of 2.

The processor 1301 is further configured to convert the P frequency domain signals into N corresponding first time domain signals by using an N-point Fourier inverse transform IFFT;

The processor 1301 is further configured to divide each first time domain signal of the P first time domain signals into D segments of equal length, and intercept any one of the D segments to obtain P second time domain signals;

The processor 1301 is further configured to generate a long training field according to the P second time domain signals, where the long training field includes P multiplex symbols, where the P multiplex symbols Each multiplex symbol consists of a second time domain signal of the P second time domain signals and a corresponding cyclic prefix CP;

The sending circuit 1303 is configured to send the long training field.

The various components in the transmit end 1300 are coupled together by a bus system 1305 that includes, in addition to the data bus, a power bus, a control bus, and a status signal bus. However, for clarity of description, various buses are labeled as bus system 1305 in FIG.

The method disclosed in the foregoing embodiments of the present invention may be applied to the processor 1301 or implemented by the processor 1301. The processor 1301 may be an integrated circuit chip with signal processing capabilities. In the implementation process, each step of the foregoing method may be completed by an integrated logic circuit of hardware in the processor 1301 or an instruction in a form of software. The processor 1301 may be a general-purpose processor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a Field Programmable Gate Array (FPGA), or the like. Programmable logic devices, discrete gates or transistor logic devices, discrete hardware components. The methods, steps, and logical block diagrams disclosed in the embodiments of the present invention may be implemented or carried out. The general purpose processor may be a microprocessor or the processor or any conventional processor or the like. The steps of the method disclosed in the embodiments of the present invention may be directly implemented by the hardware decoding processor, or may be performed by a combination of hardware and software modules in the decoding processor. The software module can be located in a conventional storage medium such as random access memory, flash memory, read only memory, programmable read only memory or electrically erasable programmable memory, registers, and the like. The storage medium is located in the memory 1304, and the processor 1301 reads the information in the memory 1304 and completes the steps of the above method in combination with its hardware.

It is to be understood that the memory 1304 in the embodiments of the present invention may be a volatile memory or a non-volatile memory, or may include both volatile and non-volatile memory. The non-volatile memory may be a read-only memory (ROM), a programmable read only memory (PROM), an erasable programmable read only memory (Erasable PROM, EPROM), or an electric Erase programmable read only memory (EEPROM) or flash memory. The volatile memory can be a Random Access Memory (RAM) that acts as an external cache. By way of example and not limitation, many forms of RAM are available, such as static random access memory (SRAM), dynamic random access memory (DRAM), synchronous dynamic random access memory (Synchronous DRAM). SDRAM), Double Data Rate SDRAM (DDR SDRAM), Enhanced Synchronous Dynamic Random Access Memory (ESDRAM), Synchronous Connection Dynamic Random Access Memory (Synchlink DRAM, SLDRAM) And direct memory bus random access memory (Direct Rambus RAM, DR RAM). The memory 1304 of the systems and methods described herein is intended to comprise, without being limited to, these and any other suitable types of memory.

It will be appreciated that the embodiments described herein can be implemented in hardware, software, firmware, middleware, microcode, or a combination thereof. For hardware implementation, the processing unit can be implemented in one or more Application Specific Integrated Circuits (ASICs), Digital Signal Processing (DSP), Digital Signal Processing Equipment (DSP Device, DSPD), programmable Programmable Logic Device (PLD), Field-Programmable Gate Array (FPGA), general purpose processor, controller, microcontroller, microprocessor, other for performing the functions described herein In an electronic unit or a combination thereof.

When the embodiments are implemented in software, firmware, middleware or microcode, program code or code segments, they can be stored in a machine readable medium such as a storage component. A code segment can represent a procedure, a function, a subprogram, a program, a routine, a subroutine, a module, a software group, a class, or any combination of instructions, data structures, or program statements. A code segment can be combined into another code segment or hardware circuit by transmitting and/or receiving information, data, arguments, parameters or memory contents. Information, arguments, parameters, data, etc. can be communicated, forwarded, or transmitted using any suitable means including memory sharing, messaging, token passing, network transmission, and the like.

For a software implementation, the techniques described herein can be implemented by modules (eg, procedures, functions, and so on) that perform the functions described herein. The software code can be stored in a memory unit and executed by the processor. The memory unit can be implemented in the processor or external to the processor, in the latter case the memory unit can be communicatively coupled to the processor via various means known in the art.

Optionally, as an embodiment, when the number of spatial streams Nss=1, P=1, D=4, the processor 1301 is specifically configured to:

Optionally, as another embodiment, when the number of spatial streams Nss=2, P=1, D=2, the processor 1301 is specifically configured to:

Optionally, as another embodiment, when the number of spatial streams Nss=3, P=3, D=4, the processor 1301 is specifically configured to:

Optionally, as another embodiment, when the number of spatial streams Nss=5, P=5, D=4, the processor 1301 is specifically configured to:

Optionally, as another embodiment, when the number of spatial streams Nss=5, P=3, D=2, the processor 1301 is specifically configured to:

Generating three frequency domain signals, wherein a signal of one of every two consecutive subcarriers of each of the four consecutive frequency carriers of each of the three frequency domain signals is zero, each of 5 of the 12 consecutive subcarriers except the subcarriers whose signals are zero are respectively carrying reference signals corresponding to 5 spatial streams, except for the 5 subcarriers. The signal of one subcarrier other than the carrier is zero; and, among the total of 12 subcarriers of the three frequency domain signals, one and only one subcarrier carries a reference signal corresponding to the same spatial stream, and the 12 subcarriers include The i-th subcarrier of each frequency domain signal to the i+3th subcarrier.

Optionally, as another embodiment, when the number of spatial streams Nss=6, P=3, D=2, the processor 1301 is specifically configured to:

Optionally, as another embodiment, the length of the CP is 0.8 μs, and the first time domain signal The length of the number is 12.8 μs.

Alternatively, as another embodiment, N=256.

The sending end 1300 can implement various processes implemented by the sending end in the embodiment of FIG. 1 to FIG. 10, and details are not described herein again to avoid repetition.

Figure 27 is a block diagram of a transmitting end of another embodiment of the present invention. The transmitting end 1400 shown in FIG. 27 includes a processor 1401, a receiving circuit 1402, a transmitting circuit 1403, and a memory 1404.

The processor 1401 is configured to generate P frequency domain signals, where each frequency domain signal of the P frequency domain signals includes N subcarriers, and each of the N subcarriers of each frequency domain signal One subcarrier of two consecutive subcarriers carries a reference signal corresponding to one spatial stream, and the signal of the other subcarrier is zero, and one or only one subcarrier among a total of 2P subcarriers of the P frequency domain signals Carrying a reference signal corresponding to the same spatial stream, where the 2P subcarriers include an i th subcarrier to an i+1 th subcarrier of each frequency domain signal, P is a positive integer, and i is between 0 and N-2 Any value, N is a positive integer power of 2;

The processor 1401 is further configured to convert the P frequency domain signals into N corresponding first time domain signals by using an N-point inverse Fourier transform IFFT;

The processor 1401 is further configured to divide each first time domain signal of the P first time domain signals into two segments of equal length, and intercept any one of the two segments to obtain P second time domain signals;

The processor 1401 is further configured to generate a long training field according to the P second time domain signals, where the long training field includes P multiplex symbols, where the P multiplex symbols Each multiplex symbol consists of a second time domain signal of the P second time domain signals and a corresponding cyclic prefix CP;

The sending circuit 1403 is configured to send the long training field.

The various components in the transmitting end 1400 are coupled together by a bus system 1405, wherein the bus system In addition to the data bus, the system 1405 includes a power bus, a control bus, and a status signal bus. However, for clarity of description, various buses are labeled as bus system 1405 in FIG.

The method disclosed in the foregoing embodiment of the present invention may be applied to the processor 1401 or implemented by the processor 1401. The processor 1401 may be an integrated circuit chip with signal processing capabilities. In the implementation process, each step of the foregoing method may be completed by an integrated logic circuit of hardware in the processor 1401 or an instruction in a form of software. The processor 1401 may be a general-purpose processor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA), or the like. Programmable logic devices, discrete gates or transistor logic devices, discrete hardware components. The methods, steps, and logical block diagrams disclosed in the embodiments of the present invention may be implemented or carried out. The general purpose processor may be a microprocessor or the processor or any conventional processor or the like. The steps of the method disclosed in the embodiments of the present invention may be directly implemented by the hardware decoding processor, or may be performed by a combination of hardware and software modules in the decoding processor. The software module can be located in a conventional storage medium such as random access memory, flash memory, read only memory, programmable read only memory or electrically erasable programmable memory, registers, and the like. The storage medium is located in the memory 1404, and the processor 1401 reads the information in the memory 1404 and completes the steps of the above method in combination with its hardware.

It is to be understood that the memory 1404 in the embodiments of the present invention may be a volatile memory or a non-volatile memory, or may include both volatile and non-volatile memory. The non-volatile memory may be a read-only memory (ROM), a programmable read only memory (PROM), an erasable programmable read only memory (Erasable PROM, EPROM), or an electric Erase programmable read only memory (EEPROM) or flash memory. The volatile memory can be a Random Access Memory (RAM) that acts as an external cache. By way of example and not limitation, many forms of RAM are available, such as static random access memory (SRAM), dynamic random access memory (DRAM), synchronous dynamic random access memory (Synchronous DRAM). SDRAM), Double Data Rate SDRAM (DDR SDRAM), Enhanced Synchronous Dynamic Random Access Memory (ESDRAM), Synchronous Connection Dynamic Random Access Memory (Synchlink DRAM, SLDRAM) ) and direct memory bus random access memory (DR RAM). The memory 1404 of the systems and methods described herein is intended to include, but is not limited to, these and any Other suitable types of memory.

Optionally, as an embodiment, when the number of spatial streams Nss=1, P=1, the processor 1401 is specifically configured to:

Optionally, as another embodiment, when the number of spatial streams Nss=3, P=3, the processor 1401 is specifically configured to:

Optionally, as another embodiment, when the number of spatial streams Nss=5, P=5, the processor 1401, Specifically used for:

Optionally, as another embodiment, when the number of spatial streams Nss=7, P=7, the processor 1401 is specifically configured to:

Alternatively, as another embodiment, N=256.

The sending end 1400 can implement the various processes implemented by the sending end in the embodiment of FIG. 11 to FIG. 20, and details are not described herein again to avoid repetition.

Figure 28 is a block diagram of a receiving end of one embodiment of the present invention. The receiving end 1500 shown in FIG. 28 includes a processor 1501, a receiving circuit 1502, a transmitting circuit 1503, and a memory 1504.

a receiving circuit 1502, configured to receive a long training field, where the long training field includes P multiplex symbols, and each of the P multiplex symbols is a second time The domain signal is composed of a corresponding cyclic prefix CP, and P is a positive integer;

The processor 1501 is configured to perform a de-CP operation on the long training field to obtain P second time domain signals.

The processor 1501 is further configured to: weight each second time domain signal of the P second time domain signals Complex D segments, obtaining P first time domain signals, wherein D=2 or D=4;

The processor 1501 is further configured to convert the P second time domain signals into corresponding P frequency domain signals by using an N-point Fourier transform, where N is a positive integer power of 2;

The processor 1501 is further configured to perform M-time interpolation on the P frequency domain signals to determine a channel estimation, where M represents a compression multiple, and M=2 or M=4.

The various components in the receiving end 1500 are coupled together by a bus system 1505, which in addition to the data bus includes a power bus, a control bus, and a status signal bus. However, for clarity of description, various buses are labeled as bus system 1505 in FIG.

The method disclosed in the foregoing embodiments of the present invention may be applied to the processor 1501 or implemented by the processor 1501. The processor 1501 may be an integrated circuit chip with signal processing capabilities. In the implementation process, each step of the foregoing method may be completed by an integrated logic circuit of hardware in the processor 1501 or an instruction in a form of software. The processor 1501 may be a general-purpose processor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA), or the like. Programmable logic devices, discrete gates or transistor logic devices, discrete hardware components. The methods, steps, and logical block diagrams disclosed in the embodiments of the present invention may be implemented or carried out. The general purpose processor may be a microprocessor or the processor or any conventional processor or the like. The steps of the method disclosed in the embodiments of the present invention may be directly implemented by the hardware decoding processor, or may be performed by a combination of hardware and software modules in the decoding processor. The software module can be located in a conventional storage medium such as random access memory, flash memory, read only memory, programmable read only memory or electrically erasable programmable memory, registers, and the like. The storage medium is located in the memory 1504, and the processor 1501 reads the information in the memory 1504 and completes the steps of the above method in combination with its hardware.

It is to be understood that the memory 1504 in the embodiments of the present invention may be a volatile memory or a non-volatile memory, or may include both volatile and non-volatile memory. The non-volatile memory may be a read-only memory (ROM), a programmable read only memory (PROM), an erasable programmable read only memory (Erasable PROM, EPROM), or an electric Erase programmable read only memory (EEPROM) or flash memory. The volatile memory can be a random access memory (Random Access Memory, RAM), which is used as an external cache. By way of example and not limitation, many forms of RAM are available, such as static random access memory (SRAM), dynamic random access memory (DRAM), synchronous dynamic random access memory (Synchronous DRAM). SDRAM), Double Data Rate SDRAM (DDR SDRAM), Enhanced Synchronous Dynamic Random Access Memory (ESDRAM), Synchronous Connection Dynamic Random Access Memory (Synchlink DRAM, SLDRAM) ) and direct memory bus random access memory (DR RAM). The memory 1504 of the systems and methods described herein is intended to comprise, without being limited to, these and any other suitable types of memory.

Alternatively, as another embodiment, N=256.

Optionally, as another embodiment, the multiplex symbol is orthogonal frequency division multiplexing (OFDM) symbol.

The receiving end 1500 can implement the various processes implemented by the receiving end in the embodiment of FIG. 21 to FIG. 22, and to avoid repetition, details are not described herein again.

Those of ordinary skill in the art will appreciate that the elements and algorithm steps of the various examples described in connection with the embodiments disclosed herein can be implemented in electronic hardware or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the solution. A person skilled in the art can use different methods for implementing the described functions for each particular application, but such implementation should not be considered to be beyond the scope of the present invention.

A person skilled in the art can clearly understand that for the convenience and brevity of the description, the specific working process of the system, the device and the unit described above can refer to the corresponding process in the foregoing method embodiment, and details are not described herein again.

In the several embodiments provided by the present application, it should be understood that the disclosed systems, devices, and methods may be implemented in other manners. For example, the device embodiments described above are merely illustrative. For example, the division of the unit is only a logical function division. In actual implementation, there may be another division manner, for example, multiple units or components may be combined or Can be integrated into another system, or some features can be ignored or not executed. In addition, the mutual coupling or direct coupling or communication connection shown or discussed may be an indirect coupling or communication connection through some interface, device or unit, and may be in an electrical, mechanical or other form.

The units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, may be located in one place, or may be distributed to multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of the embodiment.

In addition, each functional unit in each embodiment of the present invention may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit.

The functions may be stored in a computer readable storage medium if implemented in the form of a software functional unit and sold or used as a standalone product. Based on such understanding, the technical solution of the present invention, which is essential or contributes to the prior art, or a part of the technical solution, may be embodied in the form of a software product, which is stored in a storage medium, including Several instructions are used to make a computer device (which can be a personal computer, a server, Or a network device or the like) performing all or part of the steps of the method of the various embodiments of the present invention. The foregoing storage medium includes: a U disk, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk, or an optical disk, and the like, which can store program codes. .

The above is only a specific embodiment of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art can easily think of changes or substitutions within the technical scope of the present invention. It should be covered by the scope of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

A method for signal transmission in a wireless local area network, comprising:

Generating P frequency domain signals, wherein each frequency domain signal of the P frequency domain signals comprises N subcarriers; and among the N subcarriers of each frequency domain signal, one sub of each D consecutive subcarriers The carrier carries a reference signal corresponding to a spatial stream, and the signals of the remaining D-1 subcarriers of each D consecutive subcarriers are zero, and among the total 4P subcarriers of the P frequency domain signals, One subcarrier carries a reference signal corresponding to the same spatial stream, and the 4P subcarriers include an i th subcarrier to an i+3 subcarrier of each frequency domain signal, D=2 or D=4, and P is a positive integer. , i is any value between 0 and N-4, and N is a positive integer power of 2;

Converting the P frequency domain signals into N corresponding first time domain signals by an N-point Fourier inverse transform IFFT;

Dividing each of the first time domain signals of the P first time domain signals into D segments of equal length, and intercepting any one of the D segments to obtain P second time domain signals;

Generating a long training field according to the P second time domain signals, wherein the long training field includes P multiplex symbols, each of the P multiplex symbols Forming a second time domain signal of the P second time domain signals and a corresponding cyclic prefix CP;

Send the long training field.
The method according to claim 1, wherein when the number of spatial streams Nss=1, P=1, D=4, the generating P frequency domain signals includes:

Generating a frequency domain signal, wherein one of every four consecutive subcarriers of the one frequency domain signal carries a reference signal corresponding to a spatial stream, and the remaining three of the four consecutive subcarriers The carrier signal is zero.
The method according to claim 1, wherein when the number of spatial streams Nss=2, P=1, D=2, the generating P frequency domain signals comprises:

Generating a frequency domain signal, wherein one of every two consecutive subcarriers of the one frequency domain signal carries a reference signal corresponding to one spatial stream, and the signal of the other subcarrier is zero, and the Among every 4 consecutive subcarriers of a frequency domain signal, only one subcarrier carries a reference signal corresponding to the same spatial stream.
The method according to claim 1, wherein when the number of spatial streams Nss=3, P=3, D=4, the generating P frequency domain signals comprises:

Generating three frequency domain signals, wherein each of the three frequency domain signals has four frequency domain signals One of the consecutive subcarriers carries a reference signal corresponding to a spatial stream, the signals of the remaining 3 subcarriers of the 4 consecutive subcarriers are zero, and a total of 12 subcarriers in the 3 frequency domain signals Among the carriers, one and only one subcarrier carries a reference signal corresponding to the same spatial stream, and the 12 subcarriers include an i th subcarrier to an i+3 subcarrier of each frequency domain signal.
The method according to claim 1, wherein when the number of spatial streams Nss=5, P=5, D=4, the generating P frequency domain signals comprises:

Generating 5 frequency domain signals, wherein one of every 4 consecutive subcarriers of each frequency domain signal of the 5 frequency domain signals carries a reference signal corresponding to a spatial stream, the 4 consecutive contigs The signals of the remaining 3 subcarriers in the carrier are zero, and among the 20 subcarriers of the 5 frequency domain signals, only one subcarrier carries a reference signal corresponding to the same spatial stream, and the 20 subcarriers include The i-th subcarrier of each frequency domain signal to the i+3th subcarrier.
The method according to claim 1, wherein when the number of spatial streams Nss=5, P=3, D=2, the generating P frequency domain signals comprises:

Generating three frequency domain signals, wherein a signal of one of every two consecutive subcarriers of each of the four consecutive frequency carriers of each of the three frequency domain signals is zero, each of 5 of the 12 consecutive subcarriers except the subcarriers whose signals are zero are respectively carrying reference signals corresponding to 5 spatial streams, except for the 5 subcarriers. The signal of one subcarrier other than the carrier is zero; and, among the total of 12 subcarriers of the three frequency domain signals, one and only one subcarrier carries a reference signal corresponding to the same spatial stream, and the 12 subcarriers include The i-th subcarrier of each frequency domain signal to the i+3th subcarrier.
The method according to claim 1, wherein when the number of spatial streams Nss=6, P=3, D=2, the generating P frequency domain signals comprises:

Generating three frequency domain signals, wherein one of every two consecutive subcarriers of each frequency domain signal of the three frequency domain signals carries a reference signal corresponding to a spatial stream, and the signal of the other subcarrier is Zero, and, among the total of 12 subcarriers of the three frequency domain signals, one and only one subcarrier carries a reference signal corresponding to the same spatial stream, and the 12 subcarriers include the i th of each frequency domain signal Subcarriers to the i+3th subcarrier.
The method according to any one of claims 1 to 7, wherein the length of the CP is 0.8 μs and the length of the first time domain signal is 12.8 μs.
Method according to any of claims 1 to 8, characterized in that N = 256.
Method according to any one of claims 1 to 9, characterized in that said long training The field is the high efficiency long training field HE-LTF in 802.11ax.
The method according to any one of claims 1 to 10, wherein the multiplex symbol is an Orthogonal Frequency Division Multiplexing OFDM symbol.
A method for signal transmission in a wireless local area network, comprising:

Generating P frequency domain signals, wherein each frequency domain signal of the P frequency domain signals includes N subcarriers; and one of every two consecutive subcarriers among the N subcarriers of each frequency domain signal The carrier carries a reference signal corresponding to one spatial stream, and the signal of the other subcarrier is zero, and among the 2P subcarriers of the P frequency domain signals, one and only one subcarrier carries a reference signal corresponding to the same spatial stream. The 2P subcarriers include an i th subcarrier to an i+1 th subcarrier of each frequency domain signal, P is a positive integer, i is any value between 0 and N-2, and N is 2. Positive integer power;

Converting the P frequency domain signals into N corresponding first time domain signals by an N-point Fourier inverse transform IFFT;

Dividing each of the first time domain signals of the P first time domain signals into two segments of equal length, and intercepting any one of the two segments to obtain P second time domain signals;

Generating a long training field according to the P second time domain signals, wherein the long training field includes P multiplex symbols, each of the P multiplex symbols Forming a second time domain signal of the P second time domain signals and a corresponding cyclic prefix CP;

Send the long training field.
The method according to claim 12, wherein when the number of spatial streams Nss=1, P=1, the generating P frequency domain signals comprises:

A frequency domain signal is generated, wherein one of every two consecutive subcarriers of the one frequency domain signal carries a reference signal corresponding to one spatial stream, and the signal of the other subcarrier is zero.
The method according to claim 12, wherein when the number of spatial streams Nss=3, P=3, the generating P frequency domain signals comprises:

Generating three frequency domain signals, wherein one of every two consecutive subcarriers of each frequency domain signal of the three frequency domain signals carries a reference signal corresponding to a spatial stream, and the signal of the other subcarrier is Zero, and, among the total of 6 subcarriers of the three frequency domain signals, one and only one subcarrier carries a reference signal corresponding to the same spatial stream, and the six subcarriers include the i th of each of the frequency domain signals Subcarriers to the i+1th subcarrier.
The method according to claim 12, wherein when the number of spatial streams Nss = 5, P=5, the generating P frequency domain signals, including:

Generating five frequency domain signals, wherein one of every two consecutive subcarriers of each frequency domain signal of the five frequency domain signals carries a reference signal corresponding to a spatial stream, and the signal of the other subcarrier is Zero, and, among the total of 10 subcarriers of the five frequency domain signals, one and only one subcarrier carries a reference signal corresponding to the same spatial stream, and the ten subcarriers include the i th of each of the frequency domain signals Subcarriers to the i+1th subcarrier.
The method according to claim 12, wherein when the number of spatial streams Nss=7, P=7, the generating P frequency domain signals comprises:

Generating 7 frequency domain signals, wherein one of every two consecutive subcarriers of each frequency domain signal of the seven frequency domain signals carries a reference signal corresponding to a spatial stream, and the signal of the other subcarrier is Zero, and, among the total of 14 subcarriers of the seven frequency domain signals, one and only one subcarrier carries a reference signal corresponding to the same spatial stream, and the 14 subcarriers include an ith of each of the frequency domain signals Subcarriers to the i+1th subcarrier.
The method according to any one of claims 12 to 16, wherein the length of the CP is 1.6 μs or 2.4 μs or 3.2 μs, and the length of the first time domain signal is 12.8 μs.
A method according to any one of claims 12 to 17, wherein N = 256.
The method according to any one of claims 12 to 18, wherein the long training field is a high efficiency long training field HE-LTF in 802.11ax.
The method according to any one of claims 12 to 19, wherein the multiplex symbol is an Orthogonal Frequency Division Multiplexing OFDM symbol.
A method for signal transmission in a wireless local area network, comprising:

Receiving a long training field, wherein the long training field includes P multiplex symbols, each of the P multiplex symbols being subjected to a second time domain signal and a corresponding loop The prefix CP is composed, and P is a positive integer;

Performing a de-CP operation on the long training field to acquire P second time domain signals;

And repeating D segments for each second time domain signal of the P second time domain signals, to obtain P first time domain signals, where D=2 or D=4;

Converting the P first time domain signals into corresponding P frequency domain signals by an N-point Fourier transform, where N is a positive integer power of 2;

M-time interpolation is performed on the P frequency-domain signals to determine a channel estimation, where M represents a compression multiple, and M=2 or M=4.
The method of claim 21 wherein said long training field is a high efficiency long training field HE-LTF in 802.11ax.
Method according to claim 21 or 22, characterized in that N = 256.
The method according to any one of claims 21 to 23, wherein the multiplex symbol is an orthogonal frequency division multiplexing OFDM symbol.
A transmitting end, comprising:

a first generating unit, configured to generate P frequency domain signals, where each frequency domain signal of the P frequency domain signals includes N subcarriers; in each of the N subcarriers of each frequency domain signal, each D One subcarrier of one consecutive subcarrier carries a reference signal corresponding to a spatial stream, the signals of the remaining D-1 subcarriers of each D consecutive subcarriers are zero, and a total of 4P in the P frequency domain signals Among the subcarriers, one and only one subcarrier carries a reference signal corresponding to the same spatial stream, and the 4P subcarriers include an i th subcarrier to an i+3 subcarrier of each frequency domain signal, D=2 or D = 4, P is a positive integer, i is any value between 0 and N-4, and N is a positive integer power of 2;

a converting unit, configured to convert the P frequency domain signals into N corresponding first time domain signals by an N-point inverse Fourier transform IFFT;

An intercepting unit, configured to divide each first time domain signal of the P first time domain signals into D segments of equal length, and intercept any one of the D segments to obtain P second time domain signals;

a second generating unit, configured to generate a long training field according to the P second time domain signals, where the long training field includes P multiplex symbols, where the P multiplex symbols Each multiplex symbol consists of a second time domain signal of the P second time domain signals and a corresponding cyclic prefix CP;

a sending unit, configured to send the long training field.
The transmitting end according to claim 25, wherein when the number of spatial streams Nss=1, P=1, D=4, the first generating unit is specifically configured to:

Generating a frequency domain signal, wherein one of every four consecutive subcarriers of the one frequency domain signal carries a reference signal corresponding to a spatial stream, and the remaining three of the four consecutive subcarriers The carrier signal is zero.
The transmitting end according to claim 25, wherein when the number of spatial streams Nss=2, P=1, D=2, the first generating unit is specifically configured to:

Generating one frequency domain signal, wherein each of the two consecutive subcarriers of the one frequency domain signal One subcarrier carries a reference signal corresponding to one spatial stream, and the signal of the other subcarrier is zero, and one of the four consecutive subcarriers of the one frequency domain signal carries one and only one subcarrier carries the same spatial stream. Corresponding reference signal.
The transmitting end according to claim 25, wherein when the number of spatial streams Nss=3, P=3, D=4, the first generating unit is specifically configured to:

Generating three frequency domain signals, wherein one of every four consecutive subcarriers of each frequency domain signal of the three frequency domain signals carries a reference signal corresponding to a spatial stream, the four consecutive contigs The signals of the remaining three subcarriers in the carrier are zero, and among the total of 12 subcarriers of the three frequency domain signals, one and only one subcarrier carries a reference signal corresponding to the same spatial stream, and the 12 subcarriers include The i-th subcarrier of each frequency domain signal to the i+3th subcarrier.
The transmitting end according to claim 25, wherein when the number of spatial streams Nss=5, P=5, D=4, the first generating unit is specifically configured to:

Generating 5 frequency domain signals, wherein one of every 4 consecutive subcarriers of each frequency domain signal of the 5 frequency domain signals carries a reference signal corresponding to a spatial stream, the 4 consecutive contigs The signals of the remaining 3 subcarriers in the carrier are zero, and among the 20 subcarriers of the 5 frequency domain signals, only one subcarrier carries a reference signal corresponding to the same spatial stream, and the 20 subcarriers include The i-th subcarrier of each frequency domain signal to the i+3th subcarrier.
The transmitting end according to claim 25, wherein when the number of spatial streams Nss=5, P=3, D=2, the first generating unit is specifically configured to:

Generating three frequency domain signals, wherein a signal of one of every two consecutive subcarriers of each of the four consecutive frequency carriers of each of the three frequency domain signals is zero, each of 5 of the 12 consecutive subcarriers except the subcarriers whose signals are zero are respectively carrying reference signals corresponding to 5 spatial streams, except for the 5 subcarriers. The signal of one subcarrier other than the carrier is zero; and, among the total of 12 subcarriers of the three frequency domain signals, one and only one subcarrier carries a reference signal corresponding to the same spatial stream, and the 12 subcarriers include The i-th subcarrier of each frequency domain signal to the i+3th subcarrier.
The transmitting end according to claim 25, wherein when the number of spatial streams Nss=6, P=3, D=2, the first generating unit is specifically configured to:

Generating three frequency domain signals, wherein one of every two consecutive subcarriers of each frequency domain signal of the three frequency domain signals carries a reference signal corresponding to a spatial stream, and the signal of the other subcarrier is Zero, and one or only one of a total of 12 subcarriers of the three frequency domain signals The subcarriers carry reference signals corresponding to the same spatial stream, and the 12 subcarriers include an ith subcarrier to an i+3th subcarrier of each frequency domain signal.
The transmitting end according to any one of claims 25 to 31, wherein the length of the CP is 0.8 μs, and the length of the first time domain signal is 12.8 μs.
The transmitting end according to any one of claims 25 to 32, wherein N = 256.
The transmitting end according to any one of claims 25 to 33, wherein the long training field is a high efficiency long training field HE-LTF in 802.11ax.
The transmitting end according to any one of claims 25 to 34, wherein the multiplex symbol is an orthogonal frequency division multiplexing OFDM symbol.
A transmitting end, comprising:

a first generating unit, configured to generate P frequency domain signals, where each frequency domain signal of the P frequency domain signals includes N subcarriers; and each of the N subcarriers of each frequency domain signal One subcarrier of one consecutive subcarrier carries one reference signal corresponding to the spatial stream, the signal of the other subcarrier is zero, and one and only one subcarrier is carried in a total of 2P subcarriers of the P frequency domain signals a reference signal corresponding to the same spatial stream, where the 2P subcarriers include the i th subcarrier to the i+1 th subcarrier of each frequency domain signal, P is a positive integer, and i is between 0 and N-2 a value, N is a positive integer power of 2;

a converting unit, configured to convert the P frequency domain signals into N corresponding first time domain signals by an N-point inverse Fourier transform IFFT;

An intercepting unit, configured to divide each first time domain signal of the P first time domain signals into two segments of equal length, and intercept any one of the two segments to obtain P second time domain signals;

a second generating unit, configured to generate a long training field according to the P second time domain signals, where the long training field includes P multiplex symbols, where the P multiplex symbols Each multiplex symbol consists of a second time domain signal of the P second time domain signals and a corresponding cyclic prefix CP;

a sending unit, configured to send the long training field.
The transmitting end according to claim 36, wherein when the number of spatial streams Nss=1, P=1, the first generating unit is specifically configured to:

A frequency domain signal is generated, wherein one of every two consecutive subcarriers of the one frequency domain signal carries a reference signal corresponding to one spatial stream, and the signal of the other subcarrier is zero.
The transmitting end according to claim 36, wherein when the number of spatial streams is Nss = 3 When P=3, the first generating unit is specifically configured to:

Generating three frequency domain signals, wherein one of every two consecutive subcarriers of each frequency domain signal of the three frequency domain signals carries a reference signal corresponding to a spatial stream, and the signal of the other subcarrier is Zero, and, among the total of 6 subcarriers of the three frequency domain signals, one and only one subcarrier carries a reference signal corresponding to the same spatial stream, and the six subcarriers include the i th of each of the frequency domain signals Subcarriers to the i+1th subcarrier.
The transmitting end according to claim 36, wherein when the number of spatial streams Nss=5, P=5, the first generating unit is specifically configured to:

Generating five frequency domain signals, wherein one of every two consecutive subcarriers of each frequency domain signal of the five frequency domain signals carries a reference signal corresponding to a spatial stream, and the signal of the other subcarrier is Zero, and, among the total of 10 subcarriers of the five frequency domain signals, one and only one subcarrier carries a reference signal corresponding to the same spatial stream, and the ten subcarriers include the i th of each of the frequency domain signals Subcarriers to the i+1th subcarrier.
The transmitting end according to claim 36, wherein when the number of spatial streams Nss=7, P=7, the first generating unit is specifically configured to:

Generating 7 frequency domain signals, wherein one of every two consecutive subcarriers of each frequency domain signal of the seven frequency domain signals carries a reference signal corresponding to a spatial stream, and the signal of the other subcarrier is Zero, and, among the total of 14 subcarriers of the seven frequency domain signals, one and only one subcarrier carries a reference signal corresponding to the same spatial stream, and the 14 subcarriers include an ith of each of the frequency domain signals Subcarriers to the i+1th subcarrier.
The transmitting end according to any one of claims 36 to 40, wherein the length of the CP is 1.6 μs or 2.4 μs or 3.2 μs, and the length of the first time domain signal is 12.8 μs.
The transmitting end according to any one of claims 36 to 41, wherein N = 256.
The transmitting end according to any one of claims 36 to 42, wherein the long training field is a high efficiency long training field HE-LTF in 802.11ax.
The transmitting end according to any one of claims 36 to 43, wherein the multiplex symbol is an orthogonal frequency division multiplexing OFDM symbol.
A receiving end, comprising:

a receiving unit, configured to receive a long training field, where the long training field includes P multiplex symbols, and each of the P multiplex symbols has a second time domain The signal is composed of a corresponding cyclic prefix CP, and P is a positive integer;

a first acquiring unit, configured to perform a de-CP operation on the long training field, to acquire P second time domain signals;

a second acquiring unit, configured to repeat D segments for each second time domain signal of the P second time domain signals, where P first time domain signals are obtained, where D=2 or D=4;

a converting unit, configured to convert the P second time domain signals into corresponding P frequency domain signals by an N-point Fourier transform, where N is a positive integer power of 2;

a determining unit, configured to perform M-time interpolation on the P frequency domain signals to determine a channel estimation, where M represents a compression multiple, and M=2 or M=4.
The receiving end according to claim 45, wherein the long training field is a high efficiency long training field HE-LTF in 802.11ax.
A receiving end according to claim 45 or 46, wherein N = 256.
The receiving end according to any one of claims 45 to 47, wherein the multiplex symbol is an orthogonal frequency division multiplexing OFDM symbol.