Padding for orthogonal frequency division multiplexing (ofdm) symbols in a wireless communication system

Patent metadata

Field	Value
Publication number	US-2020145268-A1
Application number	US-201916673523-A
Country	US
Kind code	A1
Filing date	Nov 4, 2019
Priority date	Jun 11, 2014
Publication date	May 7, 2020
Grant date	—

Abstract

A boundary within a last orthogonal frequency division multiplexing (OFDM) symbol of a PHY data unit is determined. Pre-encoder padding bits are added to a set of information bits to generate a set of padded information bits such that the set of padded information bits, after being encoded, fill one or more OFDM symbols up to the boundary within the last OFDM symbol. The set of padded information bits are encoded to generate a set of coded bits. A PHY preamble is generated to include a subfield that indicates the boundary. The one or more OFDM symbols are generated to include (i) the set of coded information bits in the one or more OFDM symbols up to the boundary to allow a receiving device to stop decoding the one or more OFDM symbols at the boundary, and (ii) post-encoder padding bits in the last OFDM symbol following the boundary.

First claim

What is claimed is:

1 . A method for generating a multi-user physical layer (PHY) data unit for transmission via a communication channel, the method comprising:
determining, at a first communication device, a number of orthogonal frequency division multiplexing (OFDM) symbols for the multi-user PHY data unit based on respective sets of information bits corresponding to respective second communication devices; determining, at the first communication device, a common boundary within a last OFDM symbol of the PHY data unit based on the respective sets of information bits corresponding to respective second communication devices; adding, at the first communication device, respective numbers of pre-encoder padding bits to the respective sets of information bits corresponding to respective second communication devices to generate respective sets of padded information bits corresponding to the respective second communication devices, wherein the respective numbers of pre-encoder padding bits are determined such that the padded information bits, after being encoded, fill one or more OFDM symbols up to the common boundary within the last OFDM symbol; encoding, at the first communication device, the respective sets of padded information bits to generate respective sets of coded bits; generating, at the first communication device, the one or more OFDM symbols of the PHY data unit to include (i) the respective sets of coded information bits in an initial portion of the one or more OFDM symbols up to the common boundary within the last OFDM symbol, and (ii) respective sets of post-encoder padding bits, added to the respective sets of coded bits, in a remaining portion of the last OFDM symbol following the common boundary; and including, at the first communication device, an indication of the common boundary in a PHY preamble of the PHY data unit to inform the second communication devices of the common boundary so that the second communication devices can stop decoding the one or more OFDM symbols after decoding the initial portion of the one or more OFDM symbols.

Assignees

• Nxp Usa Inc

Inventors

• Zhang Hongyuan
• Zheng Xiayu
• Cao Rui
• Xu Mingguang
• Srinivasa Sudhir
• Huang Jie

Classifications

• H04L1/0009

  by adapting the channel coding (H04L1/1812 takes precedence) · CPC title

• H04L5/0007

  the frequencies being orthogonal, e.g. OFDM(A) or DMT · CPC title

• H04B7/066

  Combined feedback for a number of channels, e.g. over several subcarriers like in orthogonal frequency division multiplexing [OFDM] · CPC title

• H04L5/0046

  Determination of the number of bits transmitted on different sub-channels · CPC title

• H04L27/2627

  Modulators · CPC title