自适应调制混合ARQ系统中低时延冗余递增策略的研究

The Study of Low-Delay Incremental Redundancy Hybrid ARQ Schemes in Adaptive Modulation System

冗余递增混合ARQ能提供较高的数据通过率,但也带来了较大的传输时延。该文提出一种具备低时延冗余递增策略的混合ARQ系统并与自适应调制系统相结合,不但根据不同的接收信噪比,选取不同的调制方式,而且还选择不同的冗余递增策略。仿真和计算结果表明,与采用固定冗余递增策略的自适应调制混合ARQ系统相比,该系统在保证较高的数据通过率的前提下,大大降低了系统传输时延。

The incremental redundancy hybrid ARQ scheme can provide high throughput efficiency. Meanwhile, it also leads to high transmission delay. This paper presents a Low-Delay Incremental Redundancy hybrid ARQ scheme with Adaptive Modulation （AM-LD-IR）. It adopts different strategy of incremental redundancy and constellation size according to the received Signal-to-Noise Ratio （SNR）. The calculation and＇simulation results in the paper show, comparing to the ordinary incremental redundancy hybrid ARQ systems with adaptive modulation, the AM-LD-IR system can provide a little higher throughput efficiency and can reduce much transmission delay.