多用户MIMO-OFDM系统的子信道可变速率算法

Variable-rate algorithm of subchannel based on multi-user diversity MIMO-OFDM system

联合考虑随机波束成形和自适应调制建立了MIMO-OFDM系统的自适应多用户分集系统模型,提出了随机波束成形QR接收机的子信道可变速率算法,推导了在最小化系统误码率情况下系统的误码性能。仿真结果表明,该算法在用户数很小时使系统性能收敛到特征波束成形系统的性能;当用户数增多时,采用天线分配算法的多用户分集系统能获得比特征波束成形系统更好的性能;将自适应编码调制技术运用到多用户分集系统,从而提高系统的实际吞吐量和误码性能。

A model of adaptive multi-user diversity based on random beamforming and adaptive modulation MIMO-OFDM system was established. A variable-rate algorithm of subchannel, which combines random beam-former and linear QR receiver, was proposed. The BER performance of the system under the condition of minimal system BER was deduced. Simulation results show that the algorithm can make the system performance to approach that of eigen beamforming system even the user number is small. When user number increases, multi-user diversity with antenna allocation can achieve better performance than that of eigen-beamforming system. Application of adaptive subchannel coded modulation to multi-user diversity system can further improve the system throughput and BER performance.