A frequency domain sphericity test based approach for parsimonious rake receivers in CDMA systems

A frequency domain approach is presented for parsimonious channel estimation which can result in the implementation of a low complexity DS-CDMA RAKE receiver. We consider frequency selective slowly fading channels. A new approach is proposed to identify and estiamte only significant channel parameters. The approach uses the sphericity test and delay estimation methods based on averaged periodogram techniques. Simulations show that, with short training sequences and low signal to noise ratio, the proposed technique can correctly identify the significant channel parameters. Also the parsimonious RAKE receiver based on these estimates gives improved statistical as well as computational performance over classical methods.