【作者】 侯猛；

【导师】 周正；

【作者基本信息】 北京邮电大学 ， 通信与信息系统， 2013， 硕士

【摘要】 现代无线通信高数据量、大数据流和大带宽的无线通信服务,极大推动了全世界范围内对60GHz毫米波频段通信技术的研究,60GHz毫米波通信发展的主要推动力是该频段高富余的频段资源,能够使得Gbps数量级的数据传输变为现实,同时该频段在世界范围内无需授权,因此吸引了大量的知名的设备制造厂商和有关学者的研究。本研究课题,从具体现实需求出发叙述了压缩感知的逻辑流程,指出了其对于高达60GHz频段数据传输的适用性。然后从压缩感知的具体步骤入手,详细阐述了其理论核心,最后总结了将该理论应用于实际所带来的巨大价值。接着,我们着重介绍了60GHz毫米波通信在信道估计方面的必要性,深入剖析了60GHz毫米波通信信道的特殊表征：60GHz无线通信占据了极大的通信带宽,但是由于其信道具有高度离散和稀疏分布的实际特点,我们考虑将压缩感知的信号处理方式引入到60GHz毫米波通信系统中来。此外,在研究分析中,我们总结分析了60GHz无线信道的特殊性,发现其与窄带系统有显著差别,除了整体表现出的稀疏外,在稀疏值的分布上也表现出了独特的一面,将这种特点加以抽象,我们提出了基于团簇的压缩感知算法——基于簇的压缩感知算法(Cluster Sparsity Compressive Sensing CS-CS),并对其在60GHz通信信道估计中的适应性做了仿真,结果也表明了其卓越的性能。文章最后对CS-CS算法和以往较为典型算法CS-ROMP、CS-OMP和CS-DS算法分别进行了MALTAB平台下的实验仿真。最后对60GHz毫米波通信系统和压缩感知的研究方向做了展望。本文的剩余部分组织如下：第一章,绪论,简要介绍了60GHz毫米波通信的发展由来,总结了该项技术的优点和创新性解决方案；由60GHz通信的理论难点,引出了压缩感知,并简要介绍其由来和背景。第二章,着重介绍了压缩感知的历史发展,详细论述了其关键技术与核心步骤,对其商业化应用做出总结。第三章,着重介绍了60GHz毫米波通信系统信道的数学模型,介绍了相关标准和技术特征,为下一章压缩感知应用做了铺垫。第四章,是本文的重点内容,本章完成了将压缩感知应用于60GHz信道估计的任务,对其应用性能做了实验仿真,对于各种传统算法性能也进行了仿真分析。第五章,是本文的创新点,基于60GHz毫米波通信信道的具体分析,提出了基于簇的压缩感知算法,并对应用性能做了仿真分析。文章最后对本文研究课题做了总结,对60GHz毫米波通信和压缩感知做了展望。更多还原

【Abstract】 The growing demands for high-speed data streams and broadband wireless services have significantly driven the worldwide researches on60GHz millimeter-wave frequency band communications, which is mainly designed for the wireless accessing network such as the Pico-cellular mobile systems, the wireless local area networksand wireless personal area networks. In order to achieve the targeted ultra-high throughput in the next generation WLAN systems, the new WLAN/WPAN standards are currently developed by the IEEE802standardization committee. The main motivation for60GHz millimeter-wave communications is the availability of abundant unauthorized spectrum resources, which enables the realization of Gbps transmission as well as the worldwide broader market of60GHz products and therefore attracts a large number of famous manufacturers.We may notice from the60GH millimeter-wave channels that, dramatically different from the narrow-band systems, except for the overall sparsity of channel MPCs that attenuated by following an exponent decay function, the local sparse property introduced by the cluster phenomenon may greatly facilitate the practical designs of efficient reconstruction algorithm. Based on the cluster identification results, the local sparsity can be observed, i.e. the few nonzero coefficients occurring in each cluster, which may be are referred to as the block cluster-sparsity. By explicitly taking such a specific block structures into account, both in terms of the recovery algorithm and in terms of the measure that are used to characterize the performance, a novel cluster sparsity compressive sensing (CS-CS) algorithm for60GHz channel estimation is proposed. The reconstruction performance (i.e. reconstruction error and iterative convergence) is compared with the classical ROMP algorithms based on the extensive experimental simulations. It has been shown that the proposed CS-CS algorithm can significantly enhances the accuracy of60GHz channel estimations, and simultaneously exhibits a much faster iteration behavior. The advantage of such a new CS-CS may be essentially attributed to the full exploitation the specific cluster-sparsity, except for the overall sparsity as in conventional sense.The remainder of this paper is organized as follows. In Section I, we discussed60GHz channeling model and the simulated60GHz millimeter CIRs, for both the line-of-sight (LOS) and non-line-of-sight (NLOS) scenarios in typical short-range indoor applications, have been plotted. In Section Ⅱ, we highlighted that the60GHz multipath channel is relatively special, which may show quite different characteristics and we briefly introduced the classical CS theory. In Section Ⅲ, we analyze the60GHz multipath channel and then draw the conclusion that Attributed to the enormous emission bandwidth (typically surpassing2GHz) and the resulting fair time resolution as well as the involved many objects in operation environments, the60GHz propagation is always intensive multipath channel, which also assumes the received resolvable MPCs arrive in clusters. That is, the rays within a cluster (or a group) may have independent phases as well as independent amplitudes distribution whose variances decay exponentially with cluster and rays delays. In Section IV and V, block sparsity embodied by the multiple clusters is developed, and on this basis, the more competitive cluster-sparsity based compressed sensing algorithm for the channel estimations of60GHz millimeter-wave is developed. Then the comprehensive experimental simulations and comparative performance analysis are provided. Finally, we conclude the whole investigation in Section VI.更多还原