Low-complexity transceiver design scheme based on channel null-space feedback

To reduce the negative impact of channel quantization errors, a low-complexity transceiver joint design scheme for both the transmit beamformers and receive combining vectors is proposed in the two-user multiple-input multiple-output (MIMO) system. In the scheme, the channel null-space quantization vector is used as the transmit beamformer of the interference user directly based on channel null-space feedback. Since the interference can be determined at the receiver, interference rejection combining (IRC) is jointly utilized to cancel the inter-user interference. Simulation results show that the proposed scheme can provide substantial sum-rate improvement especially at high SNR.