Patent ID: 7260056

Claim:
A method for estimating a channel experienced by a plurality of communication bursts transmitted substantially simultaneously in a time slot of a time division duplex/code division multiple access communication system, each burst having an assigned midamble, each midamble being a shifted version of a basic midamble code having a period of P, the communication system having a maximum number K of midamble shifts, the method comprising: receiving a combined signal, the combined signal including a received version of each of the communication burst's midambles; constructing a P by P square circulant matrix including the K midamble shifts; and determining a channel response for each of the K midamble shifts using a prime factor algorithm (PFA) discrete Fourier transform (DFT) algorithm, the received combined signal and the P by P square circulant matrix, the PFA DFT algorithm having a plurality of stages, each stage having P inputs.