带内全双工多用户MIMO系统中的用户选择

User Selection of Multiuser MIMO Systems Using In-Band Full-Duplex Transmission

考虑一种多用户MIMO的传输设计,配置发射天线阵列和接收天线阵列的蜂窝基站可以工作在带内全双工传输模式。在该全双工通信方案中,基站的下行发射信号对基站的上行接收产生显著的干扰,即自干扰。这里,下行预编码处理和上行发射协方差矩阵处理将被依次进行,以简化全双工的设计。其次,为了进一步改善上、下行信道的和速率性能,我们提出一种尝试性的下行用户选择方案,其基本思想是:当某一个下行用户的信道矩阵的范数较小时,关闭该下行用户的数据流。计算机仿真结果表明,在基站下行总发射功率受限时,在低的和中等的下行信噪比区域,用户选择有助于提高下行和速率;在高的上行信噪比区域,简化的用户选择使得上行和速率明显提高。

A transmission design of multiuser MIMO system is considered. One cellular base station configured with a transmit antennas array and a receive antennas array operates in in-band full-duplex transmission mode. To mitigate the effect of the self-interference（SI） on the uplink in such systems,the signal processing including the downlink precoding and the subsequent uplink transmit covariance matrix calculating is considered. To enhance the uplink sum rate,we propose a tentative downlink user selection. The basic idea is turning off data streams of one downlink user whose channel matrix norm is relatively smaller. Computer simulation results show that under the constraint of downlink total transmission power at the base station,the simple user selection scheme increases the downlink rate in low and moderate downlink SNR region. In addition,the downlink user selection can remarkably increase the uplink sum rate in high uplink SNR region.