Improved blind multiuser receiver employing genetic algorithms for CDMA systems with space-time block codes

An improved blind multiuser receiver employing the genetic algorithms (GA) for synchronous DS-CDMA systems with a space-time block coding (STBC) design in the Rayleigh flat-fading channels is proposed. The channel state information is blind to both the transmitter and the receiver. In the receiver only the spreading sequence for the desired user(s) and the timing are available. The proposed receiver has improved conventional Capon receiver. The roughly estimated signal acts as the seed chromosome of the initial population of the GA. Perturbing the seed chromosome randomly, the initial population is generated and leads to the following GA recombination operations. The simulation results show that the proposed GA converges quickly and performs well with a little more additional computational complexity for the GA operations is fairly small compared with the channel and signal estimation.