TD-SCDMA集群系统中优先级退避算法研究  

Research on priority backoff algorithm of TD-SCDMA trunking system

作　　者：蒋青[1] 刘彰茂[1] 许泽文[1] 吴香林[1] 

机构地区：[1]重庆邮电大学移动通信技术重庆市重点实验室,重庆400065

出　　处：《计算机应用研究》2012年第4期1500-1503,共4页Application Research of Computers

基　　金：国家"863"计划资助项目(2009AA011302);国家教育部春晖计划资助项目(Z2007-1-63002);重庆市科委重点实验室专项经费资助项目

摘　　要：针对TD-SCDMA集群通信系统随机接入优先级用户快速建立呼叫响应的要求,提出了基于优先级退避算法的随机接入技术。该算法通过为各优先级用户分配相应的上行同步码资源,以及对不同优先级用户采用优先级退避处理来实现对其快速等级接入。MATLAB仿真结果表明,与优先级BEB退避算法相比,采用改进优先级指数退避算法的随机接入过程,在能保证高优先级用户成功接入的同时,还能明显提高中、低优先级用户的接入成功率,并且当用户接入压力较大时,该算法能有效地降低各优先级用户的平均接入时延。In order to make the priority users be able to set up a call quickly in TD-SCDMA trunking system,this paper proposed a random access technology which was based on priority backoff algorithm.By defining different priority users according to the allocation of the corresponding uplink synchronous code（SYNC_UL）resources and taking priority backoff methods for priority users to make them access fast by class.The simulation results on MATLAB software show that the improved priority exponential backoff algorithm in random access process could perform better for ensuring the successful access rate of high priority users than the priority BEB algorithm.And the successful access rate of medium and low priority users can be obviously increased.What＇s more,when the number of access users become large,its average access delay could be declined effectively.

关 键 词：TD-SCDMA集群系统 用户优先级 优先级退避 接入成功率 平均接入时延 

分 类 号：TP393.2[自动化与计算机技术—计算机应用技术]