TDD系统容量的提升和同信道干扰的避免

System Capacity Promotion and Co-Channel Interference Avoidance in TDD Wireless Communication System

对时分双工（TDD）方式面临的问题进行了分析,讨论了TDD方式下必须解决的单蜂窝、大覆盖范围的无线区域网络（WRAN）系统中由往返时延引起的系统容量损失问题,以及多蜂窝环境中由于同信道干扰导致的性能下降问题.在WRAN系统中,基于用户驻地设备（CPE）与基站的距离,利用空闲时间发送信号来减少容量损失.仿真结果表明,上行容量至少提升5%;在多蜂窝系统中,提出一种改进的时隙分配算法.在1%中断概率下,改进后算法比不使用优化算法的信号干扰比性能优11-12 dB;虽然比基于时隙分配算法的性能差2.5-3 dB,但系统复杂度至少降低到（M2-M）/2.

Two limited factors in time division duplex（TDD）： capacity loss caused by round-trip delay in sole cell,large region wireless region access network（WRAN） system and performance degradation caused by co-channel interference in multi-cell environment are analyzed.In WRAN system,capacity loss was reduced by signal transmission in idle time on the basis of distance between customer premises equipment（CPE） and base station.Simulation results show that uplink capacity increase at least by 5%.In multi-cell system, an improved time slot allocation method is put forward. It shows that at 1% outage probability, 11- 12 dB signal-to-interference ratio （SIR） performance is improved compared with no optimization situation, and 2.5 - 3 dB performance is degraded compared with original time slot allocation method, but system complexity is reduced to （M2- M）/2.