自适应调制编码系统门限调整算法研究

Threshold Controlling Algorithm for Adaptive Modulation and Coding System

从保证自适应编码调制系统目标误帧率的角度出发,提出了一种保证实时误帧率的优化门限值算法(ITA).此算法根据移动台反馈的信道估计值和上一帧数据的对错,实时调整每种调制编码方式的下门限.数值和链路仿真表明,ITA比第3代合作伙伴计划(3GPP)提案中的门限调整方法能更稳定地保证系统误帧率;当反馈时延超过10 ms时,ITA算法采用自回归(AR)模型进行信道预测比采用瞬时值预测,有更高的系统吞吐量和更稳定的误帧率性能.

An improved threshold adjustment （ITA） algorithm is proposed, it can precisely guarantee the predefined frame error rate （FER） for pilot-assisted adaptive modulation and coding （AMC）. An autoregressive （AR） model is introduced to improve the link prediction performance of ITA. Numerical and link level simulation show that ITA can converge to the predefined FER, while threshold adjustment AMC algorithm proposed by the 3rd generation partnership project （3GPP） deviate the predefined FER. When feedback delay is large than 10 ms. ITA algorithm with AR prediction could obtain higher throughput and more accurate FER performance than the one without AR prediction.