A low-complexity rate-one MIMO scheme with four transmit antennas and phase feedback

In this paper we propose a low-complexity rate-one multiple-input multiple-output (MIMO) scheme with four transmit antennas and phase feedback. A preprocessor design based on phase feedback information enables the proposed scheme to achieve full diversity order as well as a coding advantage. Signal-to-noise ratio (SNR) analysis is performed and it is used to find the optimal (non-quantized) phases in the sense of maximizing the instantaneous SNR. A quantized feedback analysis of the proposed scheme for quasi-static flat Rayleigh fading channels is also considered. Monte Carlo simulations are performed for different closed-loop space-time block codes with four transmit antennas and unitary transmission rate. Simulation results illustrate that the proposed scheme achieves full diversity order and outperforms other good schemes in terms of coding gain and decoding delay.