WO2016058137A1 - Procédé d'émission de signal, extrémité d'émission et extrémité de réception dans un réseau local sans fil - Google Patents

Procédé d'émission de signal, extrémité d'émission et extrémité de réception dans un réseau local sans fil Download PDF

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WO2016058137A1
WO2016058137A1 PCT/CN2014/088606 CN2014088606W WO2016058137A1 WO 2016058137 A1 WO2016058137 A1 WO 2016058137A1 CN 2014088606 W CN2014088606 W CN 2014088606W WO 2016058137 A1 WO2016058137 A1 WO 2016058137A1
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frequency domain
subcarrier
subcarriers
domain signals
signal
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PCT/CN2014/088606
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English (en)
Chinese (zh)
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刘晟
卢伟山
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华为技术有限公司
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    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B7/00—Radio transmission systems, i.e. using radiation field
    • H04B7/02—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas
    • H04B7/04—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas
    • H04B7/06—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas at the transmitting station

Definitions

  • 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.
  • Orthogonal Frequency Division Multiplexing 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.
  • LTE Long-Term Evolution
  • WiMAX Worldwide Interoperability for Microwave Access
  • 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.
  • 802.11n and 802.11ac have supported single-user multiple input and multiple output (Single).
  • SU-MIMO User Multiple Input and Multiple Output
  • Multi-User MIMO Multi-User MIMO
  • the IEEE 802.11 standard organization has launched the standardization work of the new generation WLAN standard 802.11ax called High Efficiency WLAN (HEW).
  • HEW High Efficiency WLAN
  • uplink MU-MIMO is a key technology of 802.11ax.
  • an access point 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 Field, HE-LTF to obtain channel estimation for uplink MU-MIMO.
  • 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).
  • IFFT Inverse Fast Fourier Transform
  • FFT Fast Fourier Transform
  • 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.
  • a guard interval 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.
  • 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.
  • 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.
  • the overhead of HE-LTF is a major problem due to the use of 4 times longer OFDM symbols.
  • 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.
  • the HE-LTF needs to use 8 OFDM symbols in 8 spatial streams.
  • Embodiments of the present invention provide a method for signal transmission in a wireless local area network, which can reduce time overhead.
  • a method for signal transmission in a wireless local area network including:
  • 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,
  • i is any value between 0 and N-4
  • N is a positive integer power of 2;
  • 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;
  • a method for signal transmission in a wireless local area network including:
  • 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;
  • 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;
  • a method for signal transmission in a wireless local area network including:
  • 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
  • a sender including:
  • 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.
  • a sender 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;
  • 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 equal lengths 2 segments, intercepting any of the 2 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.
  • a receiving end 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 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 sender including:
  • 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;
  • a sending circuit configured to send the long training field.
  • a sender 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 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 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;
  • a sending circuit configured to send the long training field.
  • a receiving end 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 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 long training field is a high efficiency long training field HE-LTF in 802.11ax.
  • 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.
  • FIG. 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.
  • FIG. 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.
  • 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.
  • FIG. 1 illustrates a method of signal transmission in a wireless local area network when 4 times compression is employed.
  • FIG. 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:
  • the P frequency domain signals are converted into corresponding P first time domain signals by an N-point Fourier inverse transform IFFT.
  • 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 symbol consists of a second time domain signal of the P second time domain signals and a corresponding cyclic prefix CP.
  • 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.
  • the inverse Fourier transform may also be referred to as an inverse Fourier transform.
  • 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.
  • the long training field may be an HE-LTF.
  • the size of P is related to the number of spatial streams (Nss) of MIMO transmission.
  • Nss the number of spatial streams supported in the WLAN system.
  • the maximum number of spatial streams supported in the WLAN system is eight, that is, Nss ⁇ 8 and Nss is a positive integer.
  • 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 ⁇ s. Accordingly, the length of a first time domain signal is equal to 12.8 ⁇ s.
  • P frequency domain signals are generated based on the reference signal.
  • the reference signal is a reference signal corresponding to the spatial stream.
  • 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,
  • 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.
  • the subcarrier carrying the reference signal corresponding to the same spatial stream on the second frequency domain signal must not be the 0th.
  • the 3rd subcarrier for example, the 4th subcarrier or the 8th subcarrier.
  • the reference signal corresponding to the spatial stream is interleaved in two dimensions of time and frequency.
  • 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.
  • N 256, the length of the first time domain signal is 12.8 ⁇ s.
  • 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.
  • 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.
  • the length of the first and second time domain signals may be equal to 1/D ⁇ 12.8 ⁇ s.
  • the long training field includes P multiplex symbols, and each multiplex symbol has a length of 1/D ⁇ 12.8 ⁇ s+L CP .
  • 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.
  • N 256
  • the multiplex symbol is an OFDM symbol.
  • 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.
  • Fig. 2(a) indicates the serial number of the spatial stream.
  • the reference signal corresponding to the one spatial stream appears once every four subcarriers, and the signals of the remaining subcarriers are zero.
  • 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.
  • the growth training field includes one OFDM symbol, and the length of the one OFDM symbol is 3.2 ⁇ s+L CP . It can be understood that L CP is equal to 0.8 ⁇ s. It can be understood that the transmitting end can send the long training field as shown in FIG. 2(b) to the receiving end.
  • 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.
  • 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
  • the reference signal corresponding to the spatial stream with sequence number 2 appears once every 4 subcarriers
  • the signals of the remaining subcarriers are zero.
  • 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.
  • the long training field includes one OFDM symbol, and the length of the one OFDM symbol is 6.4 ⁇ s+L CP . It can be understood that L CP is equal to 0.8 ⁇ s. It can be understood that the transmitting end can send the long training field as shown in FIG. 3(b) to the receiving end.
  • 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.
  • 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.
  • 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)...
  • 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)...
  • the signals of the remaining subcarriers are zero.
  • the growth training field includes 3 OFDM symbols, and each OFDM symbol has a length of 3.2 ⁇ s+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.
  • 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
  • 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.
  • 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.
  • the growth training field includes 5 OFDM symbols, and each OFDM symbol has a length of 3.2 ⁇ s+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.
  • 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.
  • 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.
  • 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.
  • 5 subcarriers of every 12 consecutive subcarriers carry a reference signal corresponding to the spatial stream.
  • 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.
  • 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
  • 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
  • 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.
  • 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 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 signals of the remaining subcarriers are zero.
  • 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 ⁇ s, and the first time domain signal is completely completed by 2 segments.
  • the same length is 6.4 ⁇ s signal composition, therefore, the following one-segment repeated signal can be directly removed, leaving only the signal with a length of 6.4 ⁇ s 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 ⁇ s+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.
  • 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
  • the 12 subcarriers include the i th subcarrier to the i+3 subcarrier of each of the frequency domain signals.
  • 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 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 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 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 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 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).
  • the signals of the remaining subcarriers are zero.
  • 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 ⁇ s, and the first time domain signal is completely completed by 2 segments.
  • the same length is 6.4 ⁇ s signal composition, therefore, the following one-segment repeated signal can be directly removed, leaving only the signal with a length of 6.4 ⁇ s 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 ⁇ s+L CP . It can be understood that the sender sends a long training field as shown in FIG. 7(b) to the receiving end.
  • 101 includes: generating one frequency domain signal.
  • Each subcarrier of one frequency domain signal carries a reference signal corresponding to a spatial stream.
  • 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.
  • 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 ⁇ s, and is also added to the second time domain signal.
  • the CP can generate a long training field.
  • the long training field is composed of one OFDM symbol having a length of 12.8 ⁇ s+L CP .
  • L CP is equal to 0.8 ⁇ s.
  • the transmitting end sends the long training field as shown in FIG. 8(b) to the receiving end.
  • 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.
  • 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.
  • 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)...
  • 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 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 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 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 signals of the remaining subcarriers are zero.
  • 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 ⁇ s, and is also added to the second time domain signal.
  • the CP can generate a long training field.
  • the long training field is composed of two OFDM symbols having a length of 12.8 ⁇ s+L CP .
  • L CP is equal to 0.8 ⁇ s.
  • the transmitting end sends the long training field as shown in FIG. 9(b) to the receiving end.
  • 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.
  • 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 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)...
  • 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 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 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 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 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 signals of the remaining subcarriers are zero.
  • 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 ⁇ s, and is also added to the second time domain signal.
  • the CP can generate a long training field.
  • the long training field is composed of two OFDM symbols having a length of 12.8 ⁇ s+L CP .
  • L CP is equal to 0.8 ⁇ s.
  • the transmitting end sends the long training field as shown in FIG. 10(b) to the receiving end.
  • 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.
  • 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.
  • FIG. 11 shows a method of signal transmission in a wireless local area network when 2 times compression is employed.
  • FIG. 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:
  • 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.
  • 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 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.
  • 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.
  • the long training field may be an HE-LTF.
  • the size of P is related to the number of spatial streams (Nss) of MIMO transmission.
  • Nss the number of spatial streams supported in the WLAN system.
  • the maximum number of spatial streams supported in the WLAN system is eight, that is, Nss ⁇ 8 and Nss is a positive integer.
  • P ⁇ 8 and P is a positive integer.
  • 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 ⁇ s or 2.4 ⁇ s or 3.2 ⁇ s. Accordingly, the length of a first time domain signal is equal to 12.8 ⁇ s.
  • P frequency domain signals are generated based on the reference signal.
  • the reference signal is a reference signal corresponding to the spatial stream.
  • the spatial stream has a spatial stream number Nss. Then the value of P can be determined according to Nss.
  • 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.
  • 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...
  • the reference signal corresponding to the spatial stream is interleaved in two dimensions of time and frequency.
  • 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.
  • N 256, the length of the first time domain signal is 12.8 ⁇ s. .
  • 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.
  • 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.
  • the length of the first and second time domain signals may be equal to 1/2 x 12.8 ⁇ s.
  • a corresponding CP can be added before each second time domain signal obtained in 113, and a long training field can be generated.
  • the long training field includes P multiplex symbols, and each multiplex symbol has a length of 1/2 ⁇ 12.8 ⁇ s+L CP .
  • 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.
  • N 256
  • the multiplex symbol is an OFDM symbol.
  • 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
  • Fig. 12(a) indicates the serial number of the spatial stream.
  • the reference signal corresponding to the one spatial stream appears once, and the signals of the remaining subcarriers are zero.
  • 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.
  • the long training field is composed of one OFDM symbol having a length of 6.4 ⁇ s + L CP .
  • L CP can be equal to 1.6 ⁇ s or 2.4 ⁇ s or 3.2 ⁇ s.
  • 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.
  • 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.
  • 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 signals of the remaining subcarriers are zero.
  • the growth training field as shown in Fig. 13(b), consists of three OFDM symbols of length 6.4 ⁇ s + L CP . It will be appreciated that L CP can be equal to 1.6 ⁇ s or 2.4 ⁇ s or 3.2 ⁇ s. It can be understood that the transmitting end sends the long training field as shown in FIG. 13(b) to the receiving end.
  • 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.
  • 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.
  • 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.
  • 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 ⁇ s, and the first time domain signal is identical by two segments.
  • the signal is composed of a signal length of 6.4 ⁇ s. Therefore, the signal of the next segment can be directly removed, leaving only the signal of length 6.4 ⁇ s 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 ⁇ s + L CP . It will be appreciated that L CP can be equal to 1.6 ⁇ s or 2.4 ⁇ s or 3.2 ⁇ s. It can be understood that the transmitting end sends the long training field as shown in FIG. 14(b) to the receiving end.
  • 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.
  • 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.
  • 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.
  • 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.
  • the growth training field as shown in Fig. 15(b), consists of seven OFDM symbols of length 6.4 ⁇ s + L CP . It will be appreciated that L CP can be equal to 1.6 ⁇ s or 2.4 ⁇ s or 3.2 ⁇ s. It can be understood that the transmitting end sends the long training field as shown in FIG. 15(b) to the receiving end.
  • 101 includes: generating one frequency domain signal.
  • Each subcarrier of one frequency domain signal carries a reference signal corresponding to a spatial stream.
  • 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.
  • 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.
  • the long training field is composed of OFDM symbols having a length of 12.8 ⁇ s+L CP .
  • L CP can be equal to 1.6 ⁇ s or 2.4 ⁇ s or 3.2 ⁇ s. It can be understood that the transmitting end sends the long training field as shown in FIG. 16(b) to the receiving end.
  • 111 includes: generating two frequency domain signals.
  • Each subcarrier of the two frequency domain signals carries a reference signal corresponding to a spatial stream.
  • 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.
  • 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.
  • 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)...
  • 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 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.
  • the CP can generate a long training field.
  • the long training field consists of two OFDM symbols of length 12.8 ⁇ s + L CP .
  • L CP can be equal to 1.6 ⁇ s or 2.4 ⁇ s or 3.2 ⁇ s. It can be understood that the transmitting end sends the long training field as shown in FIG. 17(b) to the receiving end.
  • 111 includes: generating three frequency domain signals.
  • Each subcarrier of the three frequency domain signals carries a reference signal corresponding to a spatial stream.
  • 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.
  • 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.
  • 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.
  • 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 ⁇ s, and is also added to the second time domain signal.
  • the CP can generate a long training field.
  • the long training field consists of three OFDM symbols of length 12.8 ⁇ s + L CP .
  • L CP can be equal to 1.6 ⁇ s or 2.4 ⁇ s or 3.2 ⁇ s. It can be understood that the transmitting end sends the long training field as shown in FIG. 18(b) to the receiving end.
  • 111 includes: generating four frequency domain signals.
  • Each subcarrier of the four frequency domain signals carries a reference signal corresponding to a spatial stream.
  • 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.
  • 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.
  • 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.
  • the CP can generate a long training field.
  • the long training field is composed of three OFDM symbols having a length of 12.8 ⁇ s+L CP .
  • L CP can be equal to 1.6 ⁇ s or 2.4 ⁇ s or 3.2 ⁇ s. It can be understood that the transmitting end sends the long training field as shown in FIG. 19(b) to the receiving end.
  • 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:
  • 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.
  • 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.
  • the transmitting end generates P frequency domain signals by using a method of 4 times compression.
  • D 2 or 4; the transmitting end generates P frequency domain signals by using a method of 2 times compression.
  • D 2.
  • 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 ⁇ s. And, the first time domain signal is composed of signals having the same D segment.
  • 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.
  • 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 ⁇ s.
  • the transmitting end generates a long training field according to the P second time domain signals.
  • 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.
  • the length of the CP when 4 times compression is used, the length of the CP is 0.8 ⁇ s.
  • the length of the CP is 1.6 ⁇ s or 2.4 ⁇ s or 3.2 ⁇ s.
  • the CP between the multiplexed symbols can avoid interference between the multiplexed symbols.
  • the sender can send 304 the generated long training field, for example, can be sent to the receiving end.
  • FIG. 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:
  • 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.
  • 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.
  • 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.
  • 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
  • MME Mobility Management Entity
  • Gateway gateway
  • the long training field is a high efficiency long training field HE-LTF in 802.11ax.
  • N 256.
  • the multiplex symbol is an orthogonal frequency division multiplexing OFDM symbol.
  • the CP is the aforementioned guard interval GI.
  • 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.
  • 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:
  • 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.
  • 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.
  • 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.
  • FIG. 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.
  • 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.
  • the reference signal corresponding to the spatial stream is uniformly and uniformly carried on the subcarrier, thereby reducing the HE-LTF. Time overhead.
  • the first generating unit 1001 is specifically configured to:
  • the first generating unit 1001 is specifically configured to:
  • the first generating unit 1001 is specifically configured to:
  • the first generating unit 1001 is specifically configured to:
  • the first generating unit 1001 is specifically configured to:
  • 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.
  • the first generating unit 1001 is specifically configured to:
  • the length of the CP is 0.8 ⁇ s
  • the length of the first time domain signal is 12.8 ⁇ s.
  • N 256.
  • the long training field is a high efficiency long training field HE-LTF in 802.11ax.
  • the multiplex symbol is an orthogonal frequency division multiplexing OFDM symbol.
  • 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.
  • FIG. 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.
  • 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.
  • 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 first generating unit 1101 is specifically configured to:
  • the first generating unit 1101 is specifically configured to:
  • the first life The unit 1101 is specifically configured to:
  • the length of the CP is 1.6 ⁇ s or 2.4 ⁇ s or 3.2 ⁇ s, and the length of the first time domain signal is 12.8 ⁇ s.
  • N 256.
  • the long training field is a high efficiency long training field HE-LTF in 802.11ax.
  • the multiplex symbol is an orthogonal frequency division multiplexing OFDM symbol.
  • Nss ⁇ 8 and Nss is a positive integer
  • P ⁇ 8 and P is a positive integer
  • 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.
  • FIG. 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 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 receiving end performs the reverse operation after receiving the long training field, and can Used for channel estimation, and this approach reduces time overhead.
  • the long training field is a high efficiency long training field HE-LTF in 802.11ax.
  • N 256.
  • the multiplex symbol is an orthogonal frequency division multiplexing OFDM symbol.
  • Nss ⁇ 8 and Nss is a positive integer
  • P ⁇ 8 and P is a positive integer
  • 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.
  • FIG. 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 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 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.
  • bus system 1305 that includes, in addition to the data bus, a power bus, a control bus, and a status signal bus.
  • bus system 1305 includes, in addition to the data bus, a power bus, a control bus, and a status signal bus.
  • 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.
  • DSP digital signal processor
  • ASIC application specific integrated circuit
  • FPGA Field Programmable Gate Array
  • 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.
  • 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.
  • RAM Random Access Memory
  • 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).
  • 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.
  • the embodiments described herein can be implemented in hardware, software, firmware, middleware, microcode, or a combination thereof.
  • 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.
  • ASICs Application Specific Integrated Circuits
  • DSP Digital Signal Processing
  • DSP Device Digital Signal Processing Equipment
  • PLD programmable Programmable Logic Device
  • FPGA Field-Programmable Gate Array
  • 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.
  • 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.
  • the processor 1301 is specifically configured to:
  • the processor 1301 is specifically configured to:
  • the processor 1301 is specifically configured to:
  • the processor 1301 is specifically configured to:
  • the processor 1301 is specifically configured to:
  • the length of the CP is 0.8 ⁇ s
  • the first time domain signal The length of the number is 12.8 ⁇ s.
  • N 256.
  • the long training field is a high efficiency long training field HE-LTF in 802.11ax.
  • the multiplex symbol is an orthogonal frequency division multiplexing OFDM symbol.
  • Nss ⁇ 8 and Nss is a positive integer
  • P ⁇ 8 and P is a positive integer
  • 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.
  • FIG. 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 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.
  • bus system 1405 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.
  • DSP digital signal processor
  • ASIC application specific integrated circuit
  • FPGA field programmable gate array
  • 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.
  • 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.
  • RAM Random Access Memory
  • 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).
  • 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.
  • the embodiments described herein can be implemented in hardware, software, firmware, middleware, microcode, or a combination thereof.
  • 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.
  • ASICs Application Specific Integrated Circuits
  • DSP Digital Signal Processing
  • DSP Device Digital Signal Processing Equipment
  • PLD programmable Programmable Logic Device
  • FPGA Field-Programmable Gate Array
  • 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.
  • 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.
  • 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 processor 1401 is specifically configured to:
  • the length of the CP is 1.6 ⁇ s or 2.4 ⁇ s or 3.2 ⁇ s, and the length of the first time domain signal is 12.8 ⁇ s.
  • N 256.
  • the long training field is a high efficiency long training field HE-LTF in 802.11ax.
  • the multiplex symbol is an orthogonal frequency division multiplexing OFDM symbol.
  • Nss ⁇ 8 and Nss is a positive integer
  • P ⁇ 8 and P is a positive integer
  • 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.
  • FIG. 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 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 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.
  • bus system 1505 which in addition to the data bus includes a power bus, a control bus, and a status signal bus.
  • bus system 1505 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.
  • DSP digital signal processor
  • ASIC application specific integrated circuit
  • FPGA field programmable gate array
  • 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.
  • 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.
  • RAM random access memory
  • SRAM static random access memory
  • DRAM dynamic random access memory
  • DDR SDRAM Double Data Rate SDRAM
  • ESDRAM Enhanced Synchronous Dynamic Random Access Memory
  • SLDRAM Synchronous Connection Dynamic Random Access Memory
  • DR RAM direct memory bus random access memory
  • the embodiments described herein can be implemented in hardware, software, firmware, middleware, microcode, or a combination thereof.
  • 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.
  • ASICs Application Specific Integrated Circuits
  • DSP Digital Signal Processing
  • DSP Device Digital Signal Processing Equipment
  • PLD programmable Programmable Logic Device
  • FPGA Field-Programmable Gate Array
  • 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.
  • 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.
  • the long training field is a high efficiency long training field HE-LTF in 802.11ax.
  • N 256.
  • the multiplex symbol is orthogonal frequency division multiplexing (OFDM) symbol.
  • OFDM orthogonal frequency division multiplexing
  • Nss ⁇ 8 and Nss is a positive integer
  • P ⁇ 8 and P is a positive integer
  • 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.
  • the disclosed systems, devices, and methods may be implemented in other manners.
  • the device embodiments described above are merely illustrative.
  • the division of the unit is only a logical function division.
  • 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.
  • 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.
  • 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.
  • 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. .

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  • Mobile Radio Communication Systems (AREA)

Abstract

L'invention concerne un procédé d'émission de signal dans un réseau local sans fil, consistant à : générer P signaux de domaine fréquentiel, chaque signal de domaine fréquentiel parmi les P signaux de domaine fréquentiel comprenant N sous-porteuses, une sous-porteuse toutes les D sous-porteuses continues dans les N sous-porteuses portant un signal de référence correspondant à un flux spatial, le signal des (D-1) sous-porteuses restantes étant nul, et seulement une sous-porteuse de 4P sous-porteuses, comprenant d'une ième sous-porteuse à une (i+3)ème sous-porteuse de chaque signal de domaine fréquentiel, parmi les P signaux de domaine fréquentiel portant le signal de référence correspondant au même flux spatial ; convertir les P signaux de domaine fréquentiel en P premiers signaux de domaine temporel correspondants au moyen d'une IFFT à N points ; diviser chaque premier signal de domaine temporel parmi les P premiers signaux de domaine temporel en D sections de la même longueur, et intercepter une section quelconque parmi les D sections de sorte à obtenir P seconds signaux de domaine temporel ; générer un champ d'apprentissage long (LTF) conformément aux P seconds signaux de domaine temporel, le champ d'apprentissage long comprenant P symboles de multiplexage, et chaque symbole de multiplexage étant constitué d'un second signal de domaine temporel et d'un CP correspondant ; et émettre le champ d'apprentissage long. Lorsque les modes de réalisation de la présente invention font appel à des signaux de référence pour acquérir une estimation de canal de MIMO, les signaux de référence correspondant aux flux spatiaux sont portés de manière discontinue et uniforme sur les sous-porteuses, ce qui permet de réaliser des économies de temps de HE-LTF.
PCT/CN2014/088606 2014-10-15 2014-10-15 Procédé d'émission de signal, extrémité d'émission et extrémité de réception dans un réseau local sans fil WO2016058137A1 (fr)

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PCT/CN2014/088606 WO2016058137A1 (fr) 2014-10-15 2014-10-15 Procédé d'émission de signal, extrémité d'émission et extrémité de réception dans un réseau local sans fil

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PCT/CN2014/088606 WO2016058137A1 (fr) 2014-10-15 2014-10-15 Procédé d'émission de signal, extrémité d'émission et extrémité de réception dans un réseau local sans fil

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Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20080008258A1 (en) * 2006-07-05 2008-01-10 Yasuhiko Tanabe Wireless receiving apparatus and method
CN102379091A (zh) * 2009-03-30 2012-03-14 Lg电子株式会社 用于在无线通信系统中发送信号的方法和装置
EP2549748A2 (fr) * 2010-02-04 2013-01-23 LG Electronics Inc. Émetteur et récepteur de signaux de radiodiffusion et procédé d'émission et de réception de signaux de radiodiffusion

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20080008258A1 (en) * 2006-07-05 2008-01-10 Yasuhiko Tanabe Wireless receiving apparatus and method
CN102379091A (zh) * 2009-03-30 2012-03-14 Lg电子株式会社 用于在无线通信系统中发送信号的方法和装置
EP2549748A2 (fr) * 2010-02-04 2013-01-23 LG Electronics Inc. Émetteur et récepteur de signaux de radiodiffusion et procédé d'émission et de réception de signaux de radiodiffusion

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