Transmitter precoding based on partial equalization for downlink TDD MC-CDMA systems

A linear transmitter precoding technique based on partial equalization receiver (TP-PER) is proposed for time-duplex division (TDD) downlink multi-carrier code-division multiple-access (MC-CDMA) systems to pre-suppress multiple access interference (MAI) in frequency selective Rayleigh fading channels. Given that the channel state information (CSI) is known to the transmitter and the channel is slowly varying, the proposed transmitter precoding algorithm can outperform conventional precoding schemes, such as transmitter precoding with equal gain combining (TP-EGC), transmitter precoding with maximum ratio combining (TP-MRC), and the linear equalization receiver. Numerical results show that the proposed algorithm achieves optimal performance by using an appropriate partial equalization factor that depends on the system specification