单载波频域均衡系统设计与实现

发布时间：2018-04-11 14:02

  本文选题：单载波频域均衡 + 线性均衡　； 参考：《哈尔滨工业大学》2016年硕士论文

【摘要】：单载波频域均衡(Single Carrier Frequency Domain Equalization,SC-FDE)技术在保证高速率、大容量通信的同时具有较强的对抗频率选择性衰落信道的能力。与时域均衡对比拥有计算复杂度低的优势,与正交频分复用技术(Orthogonal Frequency Division Multiplexing,OFDM)相比可以降低峰值平均功率比,由此可以降低接收端对功率放大器的要求。目前,单载波频域均衡系统作为OFDM强有力的竞争对手在宽带无线系统得到越来越的使用。本文首先阐述了无线信道的基本特性,为后续研究提供信道模型。接着对单载波频域均衡系统进行数学描述;分析时域均衡和频域均衡的计算复杂度和单载波频域均衡系统与OFDM系统的峰值平均功率比与信道容量;论述了系统中的传输模式和信道估计的有关算法。其次对单载波频域均衡系统中的线性均衡器进行详细的介绍,分析两者的优缺点,对比两者的误比特性能;分析了载波跟踪性能对单载波频域均衡系统的影响,其中载波频域偏移和相位噪声会对系统的性能产生一定的的影响。设计了一种基于线性均衡器的单载波频域均衡系统,并实验验证了设计的正确性。最后重点对非线性均衡器进行介绍,其中详细介绍了时频混合反馈判决均衡器,块迭代判决反馈均衡器(Iterative Block Decision Feedback Equalizer,IBFDE)等的基本原理。其中,IBFDE是通过有效次迭代来消除码间干扰,其均前馈及反馈滤波器均在频域进行;但是,IBFDE均衡器的前馈滤波器和反馈滤波器系数中需要计算相关因子,且每一迭代需要计算新的相关因子且更新系数,随着迭代次数的增长计算量也会增大;本文从IBFDE均衡器系数的推导过程中入手对IBFDE均衡器进行改进,利用最小均方误差准则得到相应滤波器系数,撤销了相关因子的计算,在保证与传统算法相似的性能的同时降低了复杂度。
[Abstract]:Single Carrier Frequency Domain Equalization (SC-FDE) technique can guarantee high speed and large capacity communication, and it can resist frequency selective fading channel.Compared with time-domain equalization, it has the advantage of low computational complexity. Compared with orthogonal Frequency Division multiplexing OFDM (orthogonal Frequency Division Multiplexing OFDM), it can reduce the peak-to-average power ratio (PAPR), thus reducing the requirement of receiver for power amplifier.At present, single carrier frequency domain equalization system, as a strong competitor of OFDM, has been used more and more in broadband wireless systems.In this paper, the basic characteristics of wireless channel are introduced, and the channel model is provided for further research.Then the single-carrier frequency-domain equalization system is described, the computational complexity of time-domain equalization and frequency-domain equalization is analyzed, and the peak-to-average power ratio and channel capacity of single-carrier frequency-domain equalization system and OFDM system are analyzed.The transmission mode and channel estimation algorithms in the system are discussed.Secondly, the linear equalizer in single-carrier frequency domain equalization system is introduced in detail, the advantages and disadvantages of the two are analyzed, and the bit error performance is compared, and the influence of carrier tracking performance on single-carrier frequency domain equalization system is analyzed.Carrier frequency offset and phase noise will affect the performance of the system.A single carrier frequency domain equalization system based on linear equalizer is designed, and the correctness of the design is verified by experiments.Finally, the nonlinear equalizer is introduced in detail, including the basic principles of time-frequency mixed feedback decision equalizer, block iterative Block Decision Feedback equalizer and so on.IBFDE eliminates inter-symbol interference by effective iteration, and its feedforward and feedback filters are carried out in frequency domain, but the feedforward filter and feedback filter coefficients of IBFDE equalizer need to calculate correlation factors.And each iteration needs to calculate new correlation factors and update the coefficients, with the number of iterations will increase the amount of calculation. This paper from the IBFDE equalizer coefficient derivation process to improve the IBFDE equalizer,The filter coefficients are obtained by using the least mean square error criterion, and the calculation of correlation factors is cancelled, which ensures the performance similar to the traditional algorithm and reduces the complexity.
【学位授予单位】：哈尔滨工业大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TN911.5
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本文编号：1736304