Patent ID: 9712223
Date: 2017-07-18
CPC Classifications: H04B

Claim:
1. A frame transmission method for use in a multiuser, multiple input and multiple output (MIMO) WiFi system comprising a transmitter with a plurality of antennas and receivers that are respectively associated with users, the method comprising: constructing a sounding frame in which a first portion comprises at least one symbol for synchronizing destination receivers and a second portion comprises at least as many precoded pilot symbols as there are destination receivers; transmitting the sounding frame in a broadcast mode for its first portion and in a directional mode for its second portion to each of the destination receivers, within the MIMO WiFi system; and constructing a respective data frame for sending to each of the destination receivers, which takes account feedback information coming from the destination receivers and, for each destination receiver, interference between destination receivers, and wherein, for a given destination receiver, the feedback information codes solely an identifier for that one of the interfering destination receivers that is generating the highest level of interference between destination receivers from among the various interferences between destination receivers received by the given destination receiver.