Frequency domain channel estimation for asynchronous CDMA signals

Channel estimation, particularly delay estimation in asynchronous CDMA channel, is essential for most receivers. The correlated time domain data sequence will become asymptotically uncorrelated in the frequency domain. By taking the discrete Fourier transform (DFT) of the received signals, we can take advantage of this asymptotical property to simplify the estimation algorithm. The proposed scheme can jointly estimate the path delay and the complex channel response with lower computational complexity. Even with such a simplified channel estimation, performance results are shown to be better.