Patent ID: 8862075

Claim:
A method of transmitting from a transmitter to a receiver over a channel using a transmit diversity scheme whereby data transmitted from one of multiple transmit antennas of the transmitter is the same as data transmitted from others of the multiple transmit antennas, the same data being transmitted with different relative weightings, the method comprising: for each of a plurality of time intervals, receiving power-related information fed back from the receiver to the transmitter, relating to a combined power from the multiple antennas as received at the receiver over said channel, wherein the power-related information is fed back for a primary purpose other than transmit diversity to control a function of the transmitter relating to the primary purpose, the primary purpose comprises at least one of: controlling the combined power of the channel, and adaptive modulation; at the transmitter, applying a recursive filter to generate channel state information relating to the transmit diversity of the channel for each of said plurality of time intervals, wherein the application of the recursive filter comprises estimating the channel state information for a current time interval based on the estimated channel state information from a previous time interval, and refining the estimated channel state information for the current time interval using the power-related information for the current time interval; and using the generated channel state information to control the relative weightings for subsequent transmission to the receiver from the multiple transmit antennas of the transmitter.