改进的基于每天线速率控制机制的多数据流多输入多输出系统收发机结构

摘要

每天线速率控制(per-antenna rate control,PARC)技术能有效提高多数据流多输入多输出(multiple-input multiple-output,MIMO)系统的吞吐量.然而,在时变信道下,反馈到发射端的信道质量指示(channel quality indicator,CQI)已经过期,这意味着发射端选择的传输机制与实际情况不匹配,从而导致系统性能下降.考虑到信道延迟对CQI反馈的影响,提出一种改进的多数据流PARC收发机结构.该结构使用基于导频符号辅助调制(pilot symbol assisted modulation,PSAM)的最小均方误差(minimum mean square error,MMSE)信道预测器对信道进行预测,补偿了传输延迟带来的性能下降,使发射机可以更准确地通过改变编码调制(modulation and coding set,MCS)方案来进行速率控制.仿真结果表明,该结构能有效提高基于PARC机制的多数据流MIMO系统性能.%Per-antenna rate control ( PARC ) is an efficient way to increase throughput of multi-stream multiple-input multiple-output (MIMO) systems. In time-varying channels, however, the channel quality indicator ( CQI) fed back to the transmitter becomes is outdated. There is a mismatch between the selected transmission scheme and actual situation. Therefore, the system performance may be degraded. We propose an improved transceiver structure for PARC based multi-stream MIMO system considering the channel delay effects of CQI feedback. The minimum mean square error ( MMSE ) channel predictor based on pilot symbol assisted modulation ( PSAM) for MIMO systems is used for prediction. This scheme compensates for the performance degradation caused by transmission delay and offers a more precise application of the modulation and coding set ( MCS ) selection scheme for modulation and rate control.Simulations are performed to demonstrate the performance for the proposed system.