WLAN baseband chip and FDMA PPDU generation method

Patent metadata

Field	Value
Publication number	US-11558233-B2
Application number	US-202117142015-A
Country	US
Kind code	B2
Filing date	Jan 5, 2021
Priority date	Jan 6, 2020
Publication date	Jan 17, 2023
Grant date	Jan 17, 2023

Abstract

A WLAN baseband chip and an FDMA PPDU generation method are disclosed. The WLAN baseband chip obtains a subcarrier coefficient corresponding to a subcarrier set, m LDR SYNC sequences, and n−m HDR SYNC sequences. The WLAN baseband chip performs duplicating processing on m data streams in n data streams, to obtain m data sequences on which the duplicating processing has been performed and n−m remaining data streams. The WLAN baseband chip obtains m pieces of to-be-modulated data based on the m LDR SYNC sequences and the m data sequences on which the duplicating processing has been performed, and obtains n−m pieces of to-be-modulated data based on the n−m HDR SYNC sequences and the n−m remaining data streams, to obtain n pieces of to-be-modulated data. The WLAN baseband chip performs postprocessing to obtain a frequency-domain symbol sequence, to obtain an FDMA PPDU.

First claim

What is claimed is:

1. A wireless local area network (WLAN) baseband chip, wherein the WLAN baseband chip comprises a memory and an inverse fast Fourier transform (IFFT) circuit, and the WLAN baseband chip is configured to:
obtain, based on a subcarrier coefficient sequence in the memory, a subcarrier coefficient corresponding to a subcarrier set, wherein the subcarrier set comprises n subcarrier groups, each subcarrier group comprises a plurality of continuous subcarriers, each subcarrier group is discontinuous from other subcarrier groups of the n subcarrier groups, all subcarriers in the subcarrier set are in one frequency band, n is an integer greater than or equal to 2, and the n subcarrier groups correspond to n WLAN devices respectively;
obtain, based on SYNC sequences stored in the memory, n SYNC sequences of the n WLAN devices, wherein each SYNC sequence corresponds to one WLAN device, and the n SYNC sequences comprise m low data rate (LDR) SYNC sequences and n−m high data rate (HDR) SYNC sequences, and m is a positive integer less than or equal to n;
obtain n data streams corresponding to the n WLAN devices respectively, and perform duplicating processing on m data streams in the n data streams to obtain m data sequences on which the duplicating processing has been performed and n−m remaining data streams, wherein the duplicating processing performed on a data stream comprises: duplicating each bit of the data stream to obtain a respective duplicate bit, and inserting the respective duplicate bit next to each corresponding bit;
obtain m pieces of to-be-modulated data based on the m LDR SYNC sequences and the m data sequences on which the duplicating processing has been performed, and obtain n−m pieces of to-be-modulated data based on the n−m HDR SYNC sequences and the n−m remaining data streams, to obtain n pieces of to-be-modulated data respectively corresponding to the n WLAN devices; and
perform postprocessing on the n pieces of to-be-modulated data to obtain a frequency division multiple access (FDMA) physical layer convergence procedure protocol data unit (PPDU), wherein the postprocessing comprises: sequentially and respectively modulating bits in the n pieces of to-be-modulated data to the respective n subcarrier groups of the n WLAN devices based on the subcarrier coefficient to obtain a frequency-domain symbol sequence, and processing each symbol in the frequency-domain symbol sequence using the IFFT circuit to obtain a corresponding time-domain symbol.

2. The WLAN baseband chip according to claim 1 , wherein every two non-zero coefficients in the subcarrier coefficient sequence are spaced by at least one zero coefficient.

3. The WLAN baseband chip according to claim 2 , wherein the subcarrier coefficient sequence comprises p subcarrier coefficients, p is an odd number, values of a 2j th subcarrier coefficient and a center subcarrier coefficient are zero, a value of a (2j+1) th subcarrier coefficient other than the center subcarrier coefficient is a non-zero value, j<p, and both j and p are positive integers.

4. The WLAN baseband chip according to claim 2 , wherein the postprocessing further comprises intercepting a half of a time domain symbol to obtain a short time-domain symbol.

5. The WLAN baseband chip according to claim 1 , wherein the subcarrier coefficient comprises n subcarrier coefficient sets corresponding to the n WLAN devices; and
the WLAN baseband chip is configured to perform on off keying (OOK) modulation, in response to a piece of to-be-modulated data corresponding to each WLAN device being a SYNC sequence, based on a subcarrier coefficient set and a first SYNC sequence of the n SYNC sequences that correspond to a target WLAN device, to modulate the first SYNC sequence to a subcarrier group corresponding to the target WLAN device, to obtain the frequency-domain symbol sequence, wherein the target WLAN device is one of the n WLAN devices; or
the WLAN baseband chip is configured to perform OOK modulation, in response to a SYNC sequence of the n SYNC sequences corresponding to a piece of to-be-modulated data being an HDR SYNC sequence, based on a subcarrier coefficient set and first modulation data that correspond to a target WLAN device, to modulate the first modulation data to a subcarrier group corresponding to the target WLAN device, to obtain the frequency-domain symbol sequence, wherein the first modulated data comprises a SYNC sequence and/or a data sequence.

6. The WLAN baseband chip according to claim 1 , wherein the subcarrier coefficient comprises n subcarrier coefficient sets corresponding to the n WLAN devices;
the WLAN baseband chip is configured to perform extension processing on the subcarrier coefficient to obtain an extended subcarrier coefficient, wherein the extended subcarrier coefficient comprises a primary subcarrier coefficient and a secondary subcarrier coefficient, and the secondary subcarrier coefficient is determined based on the primary subcarrier coefficient; and
the WLAN baseband chip is configured to perform OOK modulation, in response to a piece of to-be-modulated data comprising a data sequence whose corresponding SYNC sequence is an LDR SYNC sequence, based on an extended subcarrier coefficient set and first modulation data that correspond to a target WLAN device, to modulate the first modulation data to a subcarrier group corresponding to the target WLAN device, to obtain the frequency-domain symbol sequence, the first modulation data comprises a SYNC sequence and/or a data sequence, and the target WLAN device is a WLAN device in the n WLAN devices.

7. The WLAN baseband chip according to claim 1 , wherein the WLAN baseband chip is further configured to perform random processing on second modulation data, to obtain modulation data on which the random processing has been performed, the random processing comprises randomization processing and cyclic shift randomization processing, and the second modulation data comprises a SYNC sequence or a data sequence; and
the WLAN baseband chip is configured to perform OOK modulation on the modulation data on which the random processing has been performed and the subcarrier coefficient, to modulate the modulation data on which the random processing has been performed to a subcarrier group corresponding to a target WLAN device, to obtain the frequency-domain symbol sequence.

8. The WLAN baseband chip according to claim 7 , wherein the WLAN baseband chip is further configured to perform extension processing on the subcarrier coefficient, to obtain an extended subcarrier coefficient, the extended subcarrier coefficient comprises a primary subcarrier coefficient and a secondary subcarrier coefficient, and the secondary subcarrier coefficient is determined based on the primary subcarrier coefficient; and
the WLAN baseband chip is configured to perform the OOK modulation on the modulation data on which the random processing has been performed and the extended subcarrier coefficient, to modulate the modulation data on which the random processing has been performed to the subcarrier group corresponding to the target WLAN device, to obtain the frequency-domain symbol sequence.

9. The WLAN baseband chip according to claim 7 , wherein the WLAN baseband chip is configured to perform the OOK modulation on a subcarrier coefficient set corresponding to the target WLAN device and a cyclic shift diversity (CSD) value, to obtain the frequency-domain symbol sequence, the target WLAN device is a WLAN device in the n WLAN devices, and the CSD value Y meets:
Y=s i m i exp( j 2π kΔ F,WUR (− T CSD n tx −T CSR,i )),

where s i is an i th data value in a piece of to-be-modulated data corresponding to the target WLAN device,

Assignees

• Huawei Tech Co Ltd

Inventors

• Wang Shengsen
• Zhang Li

Classifications

• H04L27/2692

  with preamble design, i.e. with negotiation of the synchronisation sequence with transmitter or sequence linked to the algorithm used at the receiver · CPC title

• H04W84/12

  WLAN [Wireless Local Area Networks] · CPC title

• H04B1/40 Primary

  Circuits · CPC title

• H04L27/2628 Primary

  Inverse Fourier transform modulators, e.g. inverse fast Fourier transform [IFFT] or inverse discrete Fourier transform [IDFT] modulators (H04L27/2634 takes precedence) · CPC title

• Y02D30/70

  in wireless communication networks · CPC title