Performance comparison of HSDPA downlink equalizers

To restore the orthogonality of the spreading code, an equalizer is adopted at the receiving site for a HSDPA system. In this paper, BER performance and complexity analysis of various equalizers are compared under different outdoor channels. Results show that with tapering technique, the fast FFT-circulant and Expand-truncate equalizers can ease the condition number problem at a high SNR multipath channel. Simulations also show that the CG method has a satisfactory BER improvement. However, its performance depends notably on the number of iterations.