A frequency domain based approach for low complexity RAKE receivers in CDMA systems

A frequency domain approach is presented for parsimonious channel estimation resulting in an efficient implementation of the RAKE receiver in CDMA systems. The multi-path frequency selective slowly fading channel is modeled as an FIR filter of unknown length with taps located at integer values of the chip duration. Following estimation of the full channel model by averaged periodogram and modified delay estimation techniques, F-tests are applied to identify the model order and the significant taps. Simulations show the proposed technique correctly identifies the true channel model and the subsequent RAKE receiver shows improved performance over classical methods.