RAKE receiver structures for differential and pilot symbol-assisted detection of DS-CDMA signals in frequency-selective Rayleigh fading channels

The capacity of a CDMA system is a function of the bit error rate performance of individual users. Therefore it is important to optimize the individual links before proceeding to system level analysis. This is particularly true for operating in a fading channel where the performance without diversity reception is rather poor. This paper compares the BER performance of differential detection and pilot symbol-assisted coherent detection of a direct-sequence spread spectrum signal on a frequency-selective Rayleigh fading channel using RAKE reception. Both equal gain and maximal ratio combining are considered, and the effect of convolutional coding with interleaving is studied.