Reduced complexity turbo equalization for space-time trellis coded systems

A reduced complexity turbo equalizer, TEQ-IQ, which uses the in-phase/quadrature-phase cancellation technique developed for single-transmitter and single-receiver systems, is proposed for space-time trellis coded (STTC) systems. The TEQ-IQ scheme is capable of approximating the performance of the conventional turbo equalizer (TEQ-CT), while achieving complexity reduction factors of 1.4 and 468.2 for a 4PSK 32-state STTC system communicating over two-path and five-path symbol-spaced and equal tap weight Rayleigh fading channels, respectively.