基于OCC选择的高效UWB空间调制系统研究

发布时间：2018-01-10 11:05

本文关键词：基于OCC选择的高效UWB空间调制系统研究　出处：《山东大学》2017年硕士论文　论文类型：学位论文

【摘要】：超宽带(UWB,Ultra Wideband)通信最早用在军事领域中,2002年美国联邦通信委员会(FCC)批准民用后,其凭借低功耗、高速率、易实现性以及较好的抗干扰性等特点成为了短距离高速无线通信领域的关键组成之一。UWB技术的频带范围定义在3.1-10.6GHz,根据香农信道公式,在同样信噪比下带宽越大即可带来更高的信道容量,因此UWB技术具有较其他窄带通信技术更快的传输速度。UWB通信因其具有诸多优点已广泛应用于无线个域网和无线体域网中,UWB通信的研究对未来无线通信技术的发展起着重要作用。随着人们对通信速度的要求逐渐提高,频谱资源的有效利用成为更为重要的研究课题,高效UWB传输方案的设计也引起了广泛关注,其关键要求是更高的频谱效率,更低的复杂度和更稳定的抵抗信道衰落的鲁棒性。关于高效UWB传输方案的相关研究主要分为两种,一种是在系统发送端采取更高阶的脉冲调制方式,通过调节脉冲幅度、相位和形状等因素传输更多信息比特;另一种是增加信号发送天线数目,通过多天线同时发送UWB信号起到提高频谱效率的作用。目前高效UWB传输方案的设计存在实现复杂度高和系统性能差等缺点,为了设计出能够优化系统频谱效率和系统误码率性能的高效UWB传输方案,本论文主要进行了下面三部分研究工作。首先,为了提高系统发送速率,增加了每个用户的备选码集数目,给出了多径信道下基于正交互补码(OCC,Orthogonal Complementary Code)选择的高效UWB传输方案的分析与仿真,在提高频谱效率的同时降低了多径干扰对系统性能的影响,使该方案更加适用于复杂的信道传输环境,同时兼顾了系统的有效性和可靠性。针对该传输方案的性能分析,给出了基于矩生成函数(MGF,Moment Generating Function)的理论分析方法,并在两种不同多径信道模型下得出仿真结果,验证了该方案相比传统传输结构的性能优越性。其次,针对多天线UWB系统的高效传输研究,提出了超宽带空间调制传输方案,充分利用多天线的空间优势,利用从多根发送天线中选择一根激活发送天线的方式增多每次传输的比特数目,同时利用多接收天线优化了系统性能,分别在加性高斯白噪声(AWGN,Additive White Gaussian Noise)信道和多径信道下得到了所提方案的仿真结果。最后,为了进一步提高系统频谱效率,同时降低超宽带空间调制系统的误码率,提出了基于OCC选择的高效超宽带空间调制传输方案,该方案结合了 OCC选择调制和超宽带空间调制的技术特点,充分利用了扩频码集资源和空间资源,在发送端采用三种方式发送数据,相比前两种方案获得了更高的发送速率。在系统性能方面,基于MGF分析方法得出了系统误比特率表达式,仿真比较了此方案与超宽带空间调制方案的误比特率性能,结果显示出该方案可获得更好的系统可靠性,实现了对高效超宽带传输方案速率和性能的综合优化。
[Abstract]:UWB Ultra Wideband (UWB) communication was first used in the military field. In 2002, the Federal Communications Commission (FCC) approved the civil use, and its power consumption was low. The characteristics of high rate, easy realization and good anti-jamming have become one of the key components of short-range high-speed wireless communication. The frequency band of UWB technology is defined in the range of 3.1-10.6GHz. According to Shannon channel formula, the higher the bandwidth is, the higher the channel capacity will be under the same SNR. Therefore, UWB technology has a faster transmission speed than other narrowband communication technology. Because of its many advantages, UWB technology has been widely used in wireless personal area network and wireless body area network. The research of UWB communication plays an important role in the development of wireless communication technology in the future. With the increasing demand of communication speed, the effective use of spectrum resources becomes a more important research topic. The design of efficient UWB transmission scheme has also attracted wide attention, and the key requirement is higher spectrum efficiency. Lower complexity and more stable robustness against channel fading. The research on efficient UWB transmission schemes is mainly divided into two types, one is to adopt higher-order pulse modulation at the system transmitter. More bits are transmitted by adjusting pulse amplitude, phase and shape. The other is to increase the number of signal-transmitting antennas. Transmission of UWB signals through multiple antennas plays a role in improving spectrum efficiency. At present, the design of efficient UWB transmission scheme has the shortcomings of high complexity and poor system performance. In order to design an efficient UWB transmission scheme which can optimize the spectrum efficiency and BER performance of the system, this paper mainly studies the following three parts. Firstly, in order to improve the transmission rate of the system. The number of alternative code sets per user is increased, and the OCC based on orthogonal complementary codes is given in multipath channel. The analysis and simulation of the efficient UWB transmission scheme selected by Orthogonal Complementary Code. The spectrum efficiency is improved and the influence of multipath interference on the system performance is reduced, which makes the scheme more suitable for the complex channel transmission environment. At the same time, the effectiveness and reliability of the system are taken into account. According to the performance analysis of the transmission scheme, the moment generating function (MGF) is given. The theoretical analysis method of Moment Generating function is presented, and the simulation results are obtained under two different multipath channel models. The performance of this scheme compared with the traditional transmission structure is verified. Secondly, the UWB spatial modulation transmission scheme is proposed to make full use of the spatial advantages of multi-antenna UWB system. The number of bits per transmission is increased by selecting one active transmit antenna from multiple transmit antennas, and the system performance is optimized by using multiple receiving antennas, respectively, in the additive Gao Si white noise and AWGN. The simulation results of the proposed scheme in Additive White Gaussian Noise) channel and multipath channel are obtained. Finally, in order to further improve the spectral efficiency of the system. At the same time, the BER of UWB spatial modulation system is reduced, and an efficient UWB spatial modulation transmission scheme based on OCC selection is proposed. This scheme combines the technical characteristics of OCC selective modulation and ultra-wideband spatial modulation, makes full use of the spread spectrum code set resources and space resources, and transmits data in three ways at the transmitter. Compared with the former two schemes, the transmission rate is higher. In terms of system performance, the system bit error rate (BER) expression is obtained based on the MGF analysis method. The BER performance of this scheme is compared with that of UWB spatial modulation scheme. The results show that the proposed scheme can achieve better system reliability and achieve a comprehensive optimization of the rate and performance of the UWB transmission scheme.
【学位授予单位】：山东大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TN925

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