Blind multiuser detection for CDMA with multipath: a direct method

In this paper we consider the blind multiuser detection problem for asynchronous DS-CDMA systems operating in a multipath environment. Using only the spreading code of the desired user, we first estimate the column vector subspace of the channel matrix by multiple linear prediction. Then zero-forcing detectors and MMSE detectors with arbitrary delay can be obtained without explicit channel estimation. This avoids any channel estimation error and the resulting methods are therefore more robust and more accurate. The new algorithms are robust against timing estimation errors, and are extremely near-far resistant. Simulations show the effectiveness of these methods