Pilot aided channel estimation for short-code DS-CDMA

This paper investigates pilot based channel estimation techniques for short code DS-CDMA in a multipath environment. It is shown that the conventional correlative estimation algorithm is biased and very sensitive to multiuser interference Therefore, we suggest two advanced estimation algorithms. The first one eliminates the inherent path crosstalk and yields an unbiased estimate while still suffering from MUI. The second approach suppresses the influence of the MUI by incorporating a linear interference suppression into the channel estimation algorithm. It is shown that significant performance improvements can be achieved with the proposed algorithms especially under extreme near-far conditions.