A novel rake receiver design for wideband wireless communications

In this paper a novel RAKE receiver design is proposed. Its main characteristic is its non-uniform taps distribution. A wide-sense stationary uncorrelated scattering (WSSUS) frequency-selective Rayleigh fading channel is assumed. Uniform and exponential power delay profiles (PDPs) are considered. Taps positions optimization is done according to the Maximum Power Minimum Correlation (MPMC) criterion. This implies the simultaneous maximization of the sum of squares of total average signal power received in each finger and minimization of the sum of squares of autocorrelation between each pair of fingers. Robustness of the technique with respect to errors in channel estimation or in the optimum taps placement is also studied. Several simulation examples of the proposed receiver show its superior performance comparing with other implementations. Finally analytical expressions for the correlation coefficients at the branches outputs of a RAKE receiver for rectangular chip waveforms are derived.