CoMP系统中反馈比特分配及用户调度算法研究

发布时间：2018-07-03 15:16

本文选题：协同多点传输 + 有限反馈　；参考：《哈尔滨工程大学》2014年硕士论文

【摘要】：协同多点传输(Coordinated multi-point,CoMP)技术因为其卓越的抗小区间干扰能力被公认为LTE-A通信的关键技术之一。在实际CoMP系统中,各个协作基站必须通过本小区用户反馈回来的瞬时信道信息来获知本地信道状态信息(Channel State Information, CSI),所以由于有限反馈而产生的误差会严重影响系统性能,必须加以考虑。本文基于CoMP联合传输(Joint Processing, JP)系统的下行链路传输模型,考虑有限反馈和信道时延,研究了有限反馈比特分配方案及用户调度算法。为了减小非完全CSI给系统带来的性能影响,论文提出了基于差分进化算法的有限反馈比特分配算法。该算法通过使用差分进化算法对分配反馈比特进行优化,从而最大限度的降低因为有限反馈而给系统所带来的速率损失。仿真结果表明,在总反馈比特数相同时,本文所提出的算法不仅能够与穷举法比特分配算法同样地实现系统总传输速率的最大化,而且比穷举法比特分配算法计算复杂度更小,更利于实现。在实际系统中,CSI都是非完全可知的,所以在实际系统的设计时一定要要考虑有限反馈和信道时延给系统性能带来的影响。针对这一问题,本文研究了有限反馈和信道时延条件下的CoMP-JP反馈比特分配问题,计算得出了由非完全CSI而引起的系统速率损失,并得出终端所需要反馈给本服务基站和相邻基站的最佳反馈比特数值。在此基础上,本文研究了 CoMP联合传输系统下行链路中的用户调度算法,对比分析了基于系统容量最大化准则、基于用户信道相关因子最小化准则和基于用户公平性准则的三种用户调度算法。算法仿真结果表明在本文所讨论的三种改进算法中,基于系统容量最大化准则的用户调度算法性能更优,基于用户信道相关因子最小化准则的用户调度算法的各用户之间信道相关性最好。
[Abstract]:Coordinated multi-point transfer (coop) technology is recognized as one of the key technologies for LTE-A communication because of its excellent anti-inter-cell interference capability. In the actual comp system, each cooperative base station must obtain the local channel state information (CSI) through the instantaneous channel information returned by the local user, so the error caused by the limited feedback will seriously affect the performance of the system. It must be considered. Based on the downlink transmission model of comp (Joint processing, JP) system, a limited feedback bit allocation scheme and a user scheduling algorithm are studied in this paper, taking into account the limited feedback and channel delay. In order to reduce the effect of incomplete CSI on the performance of the system, a finite feedback bit allocation algorithm based on differential evolution algorithm is proposed in this paper. The algorithm optimizes the allocation of feedback bits by using differential evolution algorithm to minimize the rate loss caused by finite feedback. Simulation results show that when the total feedback bit number is the same, the proposed algorithm can not only maximize the total transmission rate of the system as the exhaustive bit allocation algorithm, but also have less computational complexity than the exhaustive bit allocation algorithm. It is more conducive to realization. CSI is not completely knowable in practical systems, so the effect of limited feedback and channel delay on system performance must be considered in the design of practical systems. In order to solve this problem, the CoMP-JP feedback bit allocation problem under the condition of limited feedback and channel delay is studied, and the system rate loss caused by incomplete CSI is calculated. The optimal feedback bit value of the terminal to the serving base station and the adjacent base station is obtained. On this basis, the user scheduling algorithm in the downlink of comp joint transmission system is studied, and the system capacity maximization criterion is compared and analyzed. Three user scheduling algorithms based on user channel correlation factor minimization criterion and user fairness criterion. The simulation results show that among the three improved algorithms discussed in this paper, the performance of the user scheduling algorithm based on the system capacity maximization criterion is better. The user scheduling algorithm based on the minimization criterion of user channel correlation factor has the best channel correlation among users.
【学位授予单位】：哈尔滨工程大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TN929.5

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