基于信道状态信息预测的中继选择方法研究

发布时间：2018-04-04 10:45

本文选题：中继选择　切入点：信道预测　出处：《广西师范大学》2016年硕士论文

【摘要】：协作中继技术是一种重要的无线通信技术,它可以带来空间分集,提升频谱效率、链路可靠性,以及网络配置的灵活性等,具有很大的应用潜力。在其中的各关键技术中,中继选择方法直接关系到协作通信系统性能的好坏,因此受到广泛关注。一般的协作中继选择方法往往利用过时的信道状态信息作为中继选择的主要依据,这种过时是由于中继选择和数据转发之间存在时延造成的,基于过时CSI的中继选择未必具有理想的系统性能。本文希望通过信道预测为中继选择提供更精确的信道状态信息,因此开展基于信道预测的中继选择方法研究,具体贡献如下：(1)提出了一种基于斜率预测的信道状态信息预测算法及中继选择方法。该预测算法将预测范围切割成若干个足够小的时间片段,在这些小的时间片段内使用FIR维纳预测器连续预测信道一阶线性函数的斜率。同时,分析了基于该预测算法的中继选择性能。数值结果表明,与基于过时信道状态信息的中继选择方法相比,所提方法能有效降低协作通信系统的误码率。(2)为了在信道预测复杂度和精度之间取得平衡,提出了在测量信噪比基础上增加服从特定分布的随机数以获得预测信噪比,并利用预测信噪比进行中继选择的低复杂度中继选择方法,并对方法性能进行了分析,得到了系统中断概率和平均误码率的表达式。数值结果表明,所提方法在中断和误码率性能上优于基于最小均方误差预测的中继选择方法,且复杂度远低于后者。尤其在高信道相关性时,所提方法降低系统平均误码率和中断概率的效果更明显。(3)从单用户场景扩展到多用户场景,考虑多用户通信中的干扰问题,提出了一种基于预测信干噪比的多用户中继选择方法。首先产生具有特定分布的随机数,再将该随机数与测量信干噪比结合生成预测信干噪比,进而根据预测信干噪比进行中继选择。同时,分析了基于该方法的多用户协作通信系统的平均误码率和中断概率。数值结果表明,所提方法在上述性能上优于基于过时信干噪比的多用户中继选择方法,从而验证了该方法的有效性。
[Abstract]:Cooperative relay technology is an important wireless communication technology. It can bring spatial diversity, improve spectral efficiency, link reliability, and network configuration flexibility. It has great application potential.Among the key technologies, relay selection is directly related to the performance of cooperative communication systems.General cooperative relay selection methods often use outdated channel state information as the main basis for relay selection, which is caused by the delay between relay selection and data forwarding.Relay selection based on outmoded CSI may not have ideal system performance.This paper hopes to provide more accurate channel state information for relay selection through channel prediction, so the research of relay selection method based on channel prediction is carried out.A channel state information prediction algorithm based on slope prediction and relay selection method are presented.The prediction algorithm cuts the prediction range into several small enough time segments in which the FIR Wiener predictor is used to continuously predict the slope of the first-order linear function of the channel.At the same time, the performance of relay selection based on the prediction algorithm is analyzed.Numerical results show that compared with the relay selection method based on outdated channel state information, the proposed method can effectively reduce the bit error rate (BER) of cooperative communication systems in order to achieve a balance between the complexity and accuracy of channel prediction.Based on the measurement of SNR, a low complexity relay selection method is proposed, which adds random numbers from a specific distribution to obtain the predictive signal-to-noise ratio, and makes use of the predictive signal-to-noise ratio to select the relay. The performance of the method is analyzed.The expressions of system interrupt probability and average bit error rate are obtained.Numerical results show that the proposed method is superior to the relay selection method based on least mean square error prediction in interrupt and bit error rate performance, and the complexity of the proposed method is much lower than that of the latter.Especially in the case of high channel correlation, the proposed method can reduce the average bit error rate (BER) and the outage probability of the system more obviously. The proposed method extends from a single user scenario to a multi-user scenario, and considers the interference problem in multi-user communication.A multiuser relay selection method based on predictive signal-to-noise ratio is proposed.First, a random number with a special distribution is generated. Then, the random number is combined with the measured signal-to-interference noise ratio to generate a predictive signal-to-noise ratio, and then relay selection is carried out according to the predictive signal-to-noise ratio.At the same time, the average bit error rate and interrupt probability of multi-user cooperative communication system based on this method are analyzed.Numerical results show that the proposed method is superior to the multiuser relay selection method based on outdated signal-to-noise ratio, and the effectiveness of the proposed method is verified.
【学位授予单位】：广西师范大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TN92

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