A MIMO-OFDM System with Simple Bit Allocation and Spatial Resource Grouping Based Beamforming

Abstract

We propose a spatial resource grouping based beamforming scheme for performance improvement and feedback information reduction in MIMO-OFDM (multi-input multi-output-orthogonal frequency division multiplexing) systems with SBA (simple bit allocation). In the proposed scheme, to improve performance of MIMO-OFDM systems with the SBA, we consider an effective CSI (channel state information) calculation procedure based on spatial resource grouping, which is adequate for the combination of MRT (maximum ratio transmission) in the transmitter and MRC (maximum ratio combining) in the receiver. Moreover, to reduce feedback information for the beamforming, we also apply QEGT (quantized equal gain transmission) based on quantization of amplitudes and phases of beam weights that are multiplied by each data symbol for beamforming in the transmitter. Simulation results show that the proposed MIMO-OFDM system can achieve closely comparable performance of the ideal case, while effectively reducing the feedback information of the CSI for the SBA based on the beamforming