Sensitivity of blind adaptive LMMSE single-user receivers to path delay and phase estimation errors in multipath fading channel

Carrier frequency, carrier phase, multipath profile, delay values as well as fading characteristics are important for coherent detection. Several DS-CDMA receivers have been investigated, but mainly with the assumption of perfect estimation of those parameters. This paper deals with the impact of channel phase and path delay estimation errors to the performance of pre and post-combining blind adaptive linear minimum mean square error (LMMSE) receivers. Comparisons are made also with the conventional RAKE receiver. The results show that channel phase estimation errors degrade almost equally the performance of blind adaptive LMMSE and RAKE receivers. Delay estimation errors by over 20% of chip time cause the loss of advantages of LMMSE detection.