Performance analysis of different HSDPA equalizers under the measured outdoor channels

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 of various equalizer methods are compared and analyzed under measured outdoor channels. Besides, a FFT-circulant with tapering equalization approach is proposed for the downlink HSDPA receiver. Results show that with tapering technique, the fast FFT-circulant equalizer can ease its high conditional 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 its iterative number and requires higher computational complexity than the FFT-circulant with tapering method.