A chip semiblind receiver based on an adaptive mixing parameter for STBC downlink MC-CDMA with CPICH systems

This paper proposes a time domain space-time chip semiblind receiver for MIMO STBC downlink MC-CDMA with CPICH systems and without CP. The receiver distinctively exploits advantage of information from training and blind modes in the updated algorithm. Combination between two modes is achieved by using an adaptive mixing parameter. The adaptive mixing parameter LMS and AS-LMS are incorporated in a semiblind updated function, which in turn improves the performance of the receiver in frequency-selective fading channel where the number of activated user in the system is varying. The receiver restores efficiently the orthogonality of the userspsila signal and suppresses MAI by means of a time domain space-time chip equalisation. Detection of the desired user requires only the knowledge of the desired user code matrix. The simulation results show that the proposed receiver outperforms in the MSE more than semiblind receiver with fixed mixing parameter and has achieved an improved gain of the transmitted power over the space-time chip training-based and existing semiblind receivers in outdoor propagation scenario 3GPP2 MIMO modified Pedestrian A channel model. Moreover, the receiver has lower computational complexity than existing space-time chip receivers.