MISO antenna array OC pre-RAKE transmitter with MRC post-RAKE receiver

Abstract

The optimal independent space independent time (ISIT) pre-correction transmit equalizer solution is derived for a multiple-in single-out (MISO) antenna array wireless communication system using an input referred noise model. A combined time division multiplexed (TDM) spread spectrum (SS) system is analyzed. Using knowledge of the channel state, the transmit equalizer solution combats frequency selective channel induced multipath (MP) interchip interference (ICI). The time invariant subset of the optimal ISIT solution is defined equal to the optimal combining (OC) pre-RAKE equalizer. The maximum of the OC pre-RAKE weights is proposed as a spatial only transmit weight, suitable for a multiuser CDMA downlink, and compared to a weight based upon the maximum eigenmode of the channel state. Bit error rate (BER) simulations illustrate that pre-correction weights derived from the optimal ISIT solution outperform the maximal ratio combining (MRC) pre-RAKE and the eigenmode based solution.