Patent ID: 8923425

Claim:
A channel feedback method for use in a communication apparatus, wherein the communication apparatus is used in a multi-input multi-output (MIMO) network comprising at least one communication system, the communication apparatus has a first antenna, the communication system has a plurality of second antennae, the communication apparatus and the communication system communicate via the first antenna and the second antennae respectively, and a plurality of first sounding signals and a plurality of second sounding signals are defined between the communication apparatus and the communication system, the channel feedback method comprising the steps of: (a) enabling the communication apparatus to receive a plurality of pilot messages from the communication system and determine a plurality of corresponding first channel responses according to the pilot messages; (b) enabling the communication apparatus to determine a plurality of corresponding phases according to the first channel responses; (c) enabling the communication apparatus to append the phases to the first sounding signals respectively and transmit the first sounding signals to the communication system via the first sounding channels; and (d) enabling the communication apparatus to transmit the second sounding signals to the communication system via a plurality of second sounding channels so that the communication system determines a plurality of corresponding second channel responses according to the second sounding signals and calculates the phases according to the first sounding signals and the second channel responses.