Patent ID: 7376192

Claim:
A receiver unit comprising: a receiver for receiving a pilot signal from a transmit antenna located at a transmitter unit; and a processor for performing the following steps: computing a channel estimate of a real part of a complex coefficient of a channel tap associated with a channel corresponding to the transmit antenna: generating a reconstructed channel estimate of the real part of the complex coefficient of the channel tap associated with the channel corresponding to the transmit antenna using feedback bits that were sent in the past to the transmitter unit; determining a difference between the channel estimate and the reconstructed channel estimate; quantizing the difference between the channel estimate and the reconstructed channel estimate to generate a feedback bit to be sent to the transmitter unit; said processor also performing the computing, generating, determining and quantizing steps to generate a feedback bits for an imaginary part of the complex coefficient of the channel tap associated with the channel of the pilot signal; a transmitter for sending the two feedback bits corresponding to a channel tap over a feedback channel to the transmitter unit which uses the feedback bits to optimize the subsequent transmission of data to the receiver; wherein said processor uses more than two feedback bits per channel tap to send a more complete channel estimate to the transmitter unit 1) during an initial synchronization between the receiver and the transmitter unit; 2) when said transmitter unit requests a resynchronization between the receiver and the transmitter unit; 3) when said processor decides to send the more complete channel estimate to said transmitter unit; or 4) at periodic intervals.