Generating and Processing Multi-User Data Units for WLAN

Patent metadata

Field	Value
Publication number	US-2016191127-A1
Application number	US-201615063218-A
Country	US
Kind code	A1
Filing date	Mar 7, 2016
Priority date	Oct 23, 2009
Publication date	Jun 30, 2016
Grant date	—

Abstract

A first field of a preamble includes a plurality of indications of respective numbers of spatial or space-time streams for respective receivers to enable each receiver among the multiple receivers to determine a respective set of one or more training sequences, in a plurality of training sequences, that corresponds to the receiver. A second field of the preamble includes respective modulation and coding scheme information for the respective receivers. The preamble is generated such that i) the first field is transmitted prior to the plurality of training sequences, and ii) the second field of the preamble is transmitted after the plurality of training sequences are transmitted. A data portion of the multi-user data unit is generated using respective modulation and coding schemes for the respective receivers. The multi-user data unit is transmitted such that data for the respective receivers are transmitted via respective sets of one or more spatial or space-time streams.

First claim

What is claimed is:

1 . A method for generating a multi-user data unit for transmission via a multiple input, multiple output (MIMO) communication channel, the method comprising:
generating, at a communication device, a plurality of training sequences to be included in a preamble of the multi-user data unit, the plurality of training sequences for facilitating multiple receivers to generate respective channel estimates; generating, at the communication device, a first field of the preamble to include a plurality of indications of respective numbers of spatial or space-time streams for respective receivers to enable each receiver among the multiple receivers to determine a respective set of one or more training sequences, in the plurality of training sequences, that corresponds to the receiver; generating, at the communication device, a second field of the preamble to include respective modulation and coding scheme information for the respective receivers; generating, at the communication device, the preamble such that i) the first field of the preamble will be transmitted prior to the plurality of training sequences being transmitted, and ii) the second field of the preamble will be transmitted after the plurality of training sequences are transmitted; generating, at the communication device, a data portion of the multi-user data unit using respective modulation and coding schemes for the respective receivers; and transmitting, with the communication device, the multi-user data unit such that data for the respective receivers are transmitted via respective sets of one or more spatial or space-time streams.

2 . The method of claim 1 , further comprising:
ordering, at the communication device, the plurality of indications of respective numbers of spatial or space-time streams according to an order.

3 . The method of claim 2 , further comprising:
generating, at the communication device, another data unit that includes information indicating the order; and transmitting, with the communication device, the other data unit prior to transmitting the multi-user data unit.

4 . The method of claim 1 , wherein transmitting the multi-user data unit comprises:
transmitting, with the communication device, the first field of the preamble in an omni-directional mode; and respectively beam-steering, with the communication device, the second field of the preamble to the multiple receivers.

5 . The method of claim 4 , wherein transmitting the multi-user data unit further comprises:
respectively beam-steering, with the communication device, the respective sets of one or more training sequences to the multiple receivers.

6 . An apparatus, comprising:
a wireless network interface device having one or more integrated circuits configured to:
generate a plurality of training sequences to be included in a preamble of a multi-user data unit, the plurality of training sequences for facilitating multiple receivers to generate respective channel estimates,
generate a first field of the preamble to include a plurality of indications of respective numbers of spatial or space-time streams for respective receivers to enable each receiver among the multiple receivers to determine a respective set of one or more training sequences, in the plurality of training sequences, that corresponds to the receiver,
generate a second field of the preamble to include respective modulation and coding scheme information for the respective receivers,
generate the preamble such that i) the first field of the preamble will be transmitted prior to the plurality of training sequences being transmitted, and ii) the second field of the preamble will be transmitted after the plurality of training sequences are transmitted,
generate a data portion of the multi-user data unit using respective modulation and coding schemes for the respective receivers, and
transmit the multi-user data unit such that data for the respective receivers are transmitted via respective sets of one or more spatial or space-time streams.

7 . The apparatus of claim 6 , wherein the one or more integrated circuits are further configured to:
order the plurality of indications of respective numbers of spatial or space-time streams according to an order.

8 . The apparatus of claim 7 , wherein the one or more integrated circuits are further configured to:
generate another data unit that includes information indicating the order; and transmit the other data unit prior to transmitting the multi-user data unit.

9 . The apparatus of claim 6 , wherein:
transmit the first field of the preamble in an omni-directional mode; and respectively beam-steer the second field of the preamble to the multiple receivers.

10 . The apparatus of claim 9 , wherein the one or more integrated circuits are configured to respectively beam-steer the respective sets of one or more training sequences to the multiple receivers.

11 . A method for processing a multi-user data unit received via a multiple input, multiple output (MIMO) communication channel, the method comprising:
processing, at a communication device, a plurality of indications, in a first field of a preamble of the multi-user data unit, of respective numbers of spatial or space-time streams for respective receivers of the multi-user data unit to determine a set of one or more training sequences among a plurality of training sequences in the preamble, wherein the set of one or more training sequences correspond to a set of one or more spatial or space-time streams, among a plurality of spatial or space-time streams of the multi-user data unit, that correspond to the communication device; generating, at the communication device, a channel estimate using the determined set of one or more training sequences among the plurality of training sequences, wherein the plurality of training sequences in the preamble are received after the first field of the preamble is received; using the channel estimate to process, at the communication device, a second field of the preamble that includes an indication of a modulation and coding scheme utilized for data, in a data portion of the multi-user data unit, intended for the communication device; and using, at the communication device, the indication of the modulation and coding scheme to decode data, in the data portion of the multi-user data unit, intended for the communication device.

12 . The method of claim 11 , further comprising:
using, at the communication device, other training sequences, among the plurality of training sequences in the preamble, to mitigate interference resulting from spatial or space-time streams to other receivers when processing the second field of the preamble.

13 . The method of claim 11 , wherein processing the plurality of indications of respective numbers of spatial or space-time streams for respective receivers of the multi-user data unit comprises:
determining, at the communication device, that one of the indications corresponds to the communication device based on an ordering.

14 . The method of claim 13 , further comprising:
receiving, at the communication device, another data unit that includes ordering information, wherein the other data unit is received prior to receiving the multi-user data unit; and determining, at the communication device, the ordering using the ordering information.

15 . The method of claim 14 , wherein the other data unit is one of:
a management packet; or a sounding packet.

16 . An apparatus, comprising
a wireless network interface device associated with a communication device,

Assignees

• Marvell World Trade Ltd

Inventors

• Zhang Hongyuan
• Banerjea Raja
• Liu Yong
• Yu Mao

Classifications

• H04W84/12

  WLAN [Wireless Local Area Networks] · CPC title

• H04B7/0452 Primary

  Multi-user MIMO systems · CPC title

• H04L5/005

  of common pilots, i.e. pilots destined for multiple users or terminals · CPC title

• H04B7/0669 Primary

  using different channel coding between antennas (space-time coding H04L1/0618) · CPC title

• H04L5/0023

  Time-frequency-space · CPC title