Iterative detection with soft input for virtual layered space-frequency receivers

In this study, we develop a virtual layered space-frequency communication architecture. This architecture enables the decoding of transmitted OFDM (Orthogonal Frequency Division Multiplexing)-QPSK signals even if the number of antennas at the transmitter is twice the number of antennas at the receiver over multipath fading channels. Furthermore, in order to improve the performance of this architecture, we propose an iteration with prior probability in which the receiver decodes the detected signals; through such iteration, this architecture can obtain path diversity and achieve high performance. When the transmitter has four antennas and receiver has two antennas, the proposed architecture achieves BER of 8×10^-4 at E_b/N₀ = 13.5 dB. Furthermore, by performing more iterations, it provides additional gains of 5 dB. The performance of the proposed architecture is verified using computer simulations.