Subspace adaptive filtering techniques for multi-sensor DS-CDMA interference suppression

The performance of two subspace adaptive filtering techniques for multi-sensor DS-CDMA interference suppression is evaluated in the presence of frequency-selective fading. The first technique partially despreads (PD) the received signal, which is coherently combined with one of three different interference suppression filters: an exponential least squares (ELS) adaptive algorithm, a block least squares (BLS) adaptive algorithm, or an optimal MMSE filter to compute the filter coefficients. The second technique projects the received vectors onto an estimated signal subspace obtained by an appropriate eigendecomposition, which is coherently combined with a BLS adaptive algorithm.