基于Ⅲ型HARQ的多播系统跨层设计  

Cross-layer Design of Multicast System Based on Type-Ⅲ HARQ

作　　者：谢川[1] 黄生叶[1] 

机构地区：[1]湖南大学计算机与通信学院,长沙410082

出　　处：《计算机工程》2011年第1期104-106,共3页Computer Engineering

基　　金：湖南省自然科学基金资助项目(06JJ20030)

摘　　要：提出一种基于Ⅲ型混合自动重传请求(HARQ)的自适应多播系统跨层设计方法。结合链路层HARQ和物理层的自适应调制与编码技术,在给定系统延时性能和残余误包率的条件下,使用曲线拟合法计算在不同限定条件下的自适应调制阈值,推导多播系统分层设计与跨层设计的频谱效率表达式。仿真实验结果表明,与II型HARQ和分层设计方法相比,该方法能有效提高系统的频谱效率,使其随最大传输次数的增加而提升。A cross-layer design of adaptive multicast transmission system based on Type-Ill HARQ is proposed. This paper combines Type-III HARQ at the data link and Adaptive Modulation and Coding（AMC） schedule at the physical layer. The curve fitting method of packet error rate is used to compute the adaptive threshold in order to maximize spectral efficiency when under given constraint. The closed-form expressions of the average spectral efficiency of multieast transmission in cross-layer design and layered design are derived. Simulation results show that this cross-layer design can improve obviously in spectral efficiency comparing to the layered design and Typel/HARQ, and spectral efficiency increase with the maxtransmission time grows.

关 键 词：混合自动重传请求 多播传输 跨层设计 分层设计 自适应调制与编码 

分 类 号：TP393[自动化与计算机技术—计算机应用技术]