Patent ID: 7639643

Claim:
A method for channel estimation in an OFDM system, the method comprising: quantizing a channel response function of a signal received from a transmitter or a residual value of the channel response function, wherein the channel response function is represented by M complex numbers, wherein a channel estimate is subtracted from the channel response function to provide the residual value; limiting the channel response function to N complex numbers where N is less than M, wherein the N complex numbers are limited to values having time delays less than a predetermined delay spread; converting the signal from a frequency domain representation of the signal to a time domain representation of the signal prior to said quantizing; and generating a channel state information packet to be transmitted back to the transmitter, wherein the packet includes the quantized channel response function when the packet is a first feedback packet sent to the transmitter or a first feedback packet sent after a channel interruption, and includes the quantized residual value of the channel response function otherwise, and wherein the channel state information permits the transmitter to obtain a channel state estimation.