串行级联CPM技术的研究-通信与信息系统专业论文.docx

摘要 提高信息传输的有效性和可靠性，一直是通信领域追求的目标。连续相位调 制（CPM）信号是一类包络恒定相位连续的调制信号，和其它调制技术相比，它 具有很高的功率利用率和频率利用率。CPM 信号已经广泛用于现代的军用和民用 移动通信领域中。信道编码技术的出现使信号在有噪信道下实现信息的可靠传输 成为现实。Turbo 码及其发展而来的串行级联卷积码（SCCC）以其优异的性能成 为近年来信道编码领域研究的热点。因此对 CPM 信号与 Turbo 码和 SCCC 的结合 进行研究具有重要的意义。 本文在介绍了 CPM 信号基本原理和 Turbo 码、SCCC 基本编译码结构的基础 上，重点研究了 CPM 信号与 SCCC 结合的串行级联连续相位调制（SCCPM）系 统的基本技术。首先我们给出了 SCCPM 系统的编译码结构，并对其交织器进行了 分析，仿真分析了卷积码、迭代次数、交织类型、交织长度等对系统性能的影响。 然后对 SCCPM 系统的正反馈现象进行了分析，提出了基于加权外信息交换的迭代 译码方法，有效改善了系统收敛程度，另外还对系统的迭代停止算法进行了分析 和仿真。最后介绍了 Laurent 分解技术，将 Laurent 分解特性应用到了 SCCPM 系 统中，有效地减少了匹配滤波器的数目和译码网格状态数，降低了 SCCPM 系统的 复杂度。 关键词：连续相位调制，交织器，迭代译码，停止准则 Abstract To improve the reliability and effectivity of information transmission is always the goal which we pursuit in the field of communication. Continuous phase modulation (CPM) is a kind modulation signal with constant envelope and continuous phase, compared with the other technologies of modulation, has a high efficiency of power and frequency. CPM signal is widely used in modern military communication and civil communication system. Channel encoding technology makes it true for non-error transmission of signal over the noisy channel. Turbo code and Serially concatenated convolutional code (SCCC) have become the hotspot in the field of channel coding because of its outstanding performance. So it is meaningful to study the combine between CPM signal and Turbo or SCCC. In this thesis, Serially Concatenated Continuous Phase Modulation(SCCPM) system is studied in detail based on the introduce of basic principles of CPM and basic structure of Turbo code、SCCC. The SCCPM system is based on Continuous Phase Modulation and SCCC technology. First, the system model of symbol interleaved SCCPM is given. Then we consider the interleaver in SCCPM system. And through the simulation of different systems, the influence of the convolution code, the interleave length, the number of iteration to the system performance are investigated. Second, phenomena of positive feedback