降低信号峰均功率比算法研究
发布时间：2019-02-18 12:17
【摘要】：第四代移动通信系统的核心技术,正交频分复用(Orthogonal Frequency Division Multiplexing,OFDM)技术是由多载波调制(Multi-Carrier Modulation,MCM)发展而来,由于该技术拥能较好的抗多径衰落和抑制窄带干扰,是目前无线通信系统中实现复杂度低、应用最广的一种多载波传输方案。虽然OFDM系统带来更好的频谱利用率,但同时也存在较高的峰均功率比(PAPR)。高峰值信号在发射时会使大量信号进入高功率放大器(High Power Amplifier,HPA)的非线性区域,从而导致带外辐射和带内失真,破坏OFDM系统性能。所以,如何抑制OFDM系统的PAPR,是亟待解决的问题。本文从现有的抑制技术出发,首先分析了抑制OFDM系统PAPR的几类主要技术,尤其详细讨论了实用性较强的限幅技术和部分传输序列(PTS)技术的基本原理,并分析了这些技术各自的优缺点。最后发现传统OFDM限幅技术虽然能有效降低PAPR,但以牺牲BER性能为代价,针对这一问题,提出了基于优化模型的改进限幅算法,在保证PAPR性能的同时,降低误码率。为了达到更好的PAPR抑制效果,从PAPR产生的根本原因出发,将基于优化模型的改进限幅技术和PTS技术有机结合,从调幅和调相两方面出发,先使用PTS次优方法旋转信号相位,得到PAPR最优序列,降低高峰值出现概率,再用基于优化模型的限幅技术,限制信号幅度,进一步抑制PAPR,该方法兼顾了PAPR和BER性能。通过MATLAB软件仿真表明,基于优化模型的改进限幅和PTS联合技术与常规限幅技术和PTS技术相比,联合算法增强了系统性能且减少了计算量,对于抑制OFDM系统的PAPR来说,是一种有意义并且容易实现的新方法。
[Abstract]:The core technology of the fourth generation mobile communication system, orthogonal Frequency Division Multiplexing (Orthogonal Frequency Division Multiplexing,OFDM), is developed from multi-carrier modulation (Multi-Carrier Modulation,MCM), because it can resist multipath fading and suppress narrowband interference. It is one of the most widely used multi-carrier transmission schemes in wireless communication systems. Although the OFDM system brings better spectrum efficiency, there is also a higher peak-to-average power ratio (PAPR) to (PAPR). When the high peak signal is transmitted, a large number of signals will enter the nonlinear region of the high power amplifier (High Power Amplifier,HPA), which will lead to out-of-band radiation and in-band distortion, and destroy the performance of the OFDM system. Therefore, how to suppress the PAPR, of OFDM system is an urgent problem to be solved. Based on the existing suppression techniques, this paper first analyzes the main technologies of suppressing PAPR in OFDM system, especially discusses the practical limiting technology and the basic principle of partial transmission sequence (PTS) technology in detail. The advantages and disadvantages of these techniques are analyzed. Finally, it is found that the traditional OFDM limiting technique can effectively reduce PAPR, but at the expense of BER performance. In order to solve this problem, an improved limiter algorithm based on optimization model is proposed, which can guarantee the performance of PAPR and reduce the bit error rate (BER) at the same time. In order to achieve better PAPR suppression effect, starting from the root cause of PAPR, the improved limiting technique based on optimization model and the PTS technology are combined organically. From the aspects of amplitude modulation and phase modulation, we first use the PTS suboptimal method to rotate the phase of the signal. The optimal sequence of PAPR is obtained to reduce the probability of occurrence of high peak value, and then the amplitude of signal is limited by using the limiting technique based on optimization model, and the PAPR, is further suppressed. The method takes into account the performance of both PAPR and BER. The simulation results of MATLAB software show that compared with the conventional limiter technique and PTS technology, the improved clipping and PTS combination based on optimization model can enhance the system performance and reduce the computational complexity. For the PAPR suppression of OFDM system, the proposed algorithm can be used to suppress the PAPR of OFDM system. Is a meaningful and easy to implement a new approach.
【学位授予单位】：电子科技大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TN929.53
本文编号：2425827
[Abstract]:The core technology of the fourth generation mobile communication system, orthogonal Frequency Division Multiplexing (Orthogonal Frequency Division Multiplexing,OFDM), is developed from multi-carrier modulation (Multi-Carrier Modulation,MCM), because it can resist multipath fading and suppress narrowband interference. It is one of the most widely used multi-carrier transmission schemes in wireless communication systems. Although the OFDM system brings better spectrum efficiency, there is also a higher peak-to-average power ratio (PAPR) to (PAPR). When the high peak signal is transmitted, a large number of signals will enter the nonlinear region of the high power amplifier (High Power Amplifier,HPA), which will lead to out-of-band radiation and in-band distortion, and destroy the performance of the OFDM system. Therefore, how to suppress the PAPR, of OFDM system is an urgent problem to be solved. Based on the existing suppression techniques, this paper first analyzes the main technologies of suppressing PAPR in OFDM system, especially discusses the practical limiting technology and the basic principle of partial transmission sequence (PTS) technology in detail. The advantages and disadvantages of these techniques are analyzed. Finally, it is found that the traditional OFDM limiting technique can effectively reduce PAPR, but at the expense of BER performance. In order to solve this problem, an improved limiter algorithm based on optimization model is proposed, which can guarantee the performance of PAPR and reduce the bit error rate (BER) at the same time. In order to achieve better PAPR suppression effect, starting from the root cause of PAPR, the improved limiting technique based on optimization model and the PTS technology are combined organically. From the aspects of amplitude modulation and phase modulation, we first use the PTS suboptimal method to rotate the phase of the signal. The optimal sequence of PAPR is obtained to reduce the probability of occurrence of high peak value, and then the amplitude of signal is limited by using the limiting technique based on optimization model, and the PAPR, is further suppressed. The method takes into account the performance of both PAPR and BER. The simulation results of MATLAB software show that compared with the conventional limiter technique and PTS technology, the improved clipping and PTS combination based on optimization model can enhance the system performance and reduce the computational complexity. For the PAPR suppression of OFDM system, the proposed algorithm can be used to suppress the PAPR of OFDM system. Is a meaningful and easy to implement a new approach.
【学位授予单位】：电子科技大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TN929.53
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