LPLC通信中HARQ与组合译码方法的研究与实现

发布时间：2019-06-25 11:03

【摘要】：电力线载波通信技术发展迅速,已经成为当前科技领域的研究热点。但是电力线信道特性突出表现为信号干扰大、噪声种类复杂、信号衰减强,而且其具有频率选择性衰落特性和时变性强等特点,严重影响了数据的可靠通信。差错控制技术是建立可靠的低压电力线载波通信系统的关键技术之一。因此,本课题主要研究适用于PLC系统的差错控制技术。本课题在分析、对比相关的调制/解调技术后,提出一种基于DSTFT的2FSK解调改进算法,并利用MATLAB对常规DFT算法和改进的DFT算法进行仿真比较,验证了该改进算法的有效性。此改进算法能在简化系统硬件结构的前提下,提高系统的实时性。根据噪声对低压PLC系统的影响,对现有的差错控制技术进行理论分析与MATLAB仿真,包括CRC检错码、纠错码、HARQ和组合译码技术。利用MATLAB对电力线通信系统进行建模仿真,通过对纠错码模块、组合译码模块及其ARQ模块的不同组合的研究,来设计可靠性更高的电力线载波系统。这些关键技术实现复杂度低,在时延要求不严格、载波频率不高、数据传输率较低的PLC应用场合中,具有较好的抗干扰性能。采用TI公司高性能32位定点DSP芯片TMS320F2812作为核心控制平台,编程实现PLC差错控制系统中主要模块的核心算法,包括纠错码、HARQ、组合译码和CRC检错码等模块,以及串口收发模块、调制解调模块。每个子模块均为各自独立的API函数,以便于系统主程序的调用。并设计相应的外围电路,包括发送功放、耦合、谐振滤波和接收信号放大电路等。整个系统具有结构简单、灵活等特点。这些关键技术实现复杂度低,当应用于低压电力线通信时,具有较好的抗干扰性能。在实际的应用中可以根据不同的应用需求和软硬件资源配置,设计适用于低压PLC的差错控制方案,以达到低成本、易于实现且高可靠通信的要求。搭建了低压PLC实验系统并对实验系统进行测试和分析,实验数据表明,所设计的差错控制方案可以有效抵抗信道噪声造成的随机错误和突发错误,提高载波通信系统的抗干扰能力。所研究的适合于PLC的差错控制技术为提高电力线载波通信的可靠性提供一种备选方案。
[Abstract]:With the rapid development of power line carrier communication technology, it has become a hot research topic in the field of science and technology. However, the characteristics of power line channel are large signal interference, complex noise types, strong signal attenuation, and its frequency selective fading characteristics and strong time variability, which seriously affect the reliable communication of data. Error control technology is one of the key technologies to establish reliable low voltage power line carrier communication system. Therefore, this paper mainly studies the error control technology suitable for PLC system. In this paper, after analyzing and comparing the related modulation / demodulation technology, an improved 2FSK demodulation algorithm based on DSTFT is proposed, and the conventional DFT algorithm and the improved DFT algorithm are simulated and compared by MATLAB to verify the effectiveness of the improved algorithm. This improved algorithm can improve the real-time performance of the system on the premise of simplifying the hardware structure of the system. According to the influence of noise on low voltage PLC system, the existing error control technologies are analyzed theoretically and simulated by MATLAB, including CRC error detection code, error correction code, HARQ and combined decoding technology. The power line communication system is modeled and simulated by MATLAB, and the power line carrier system with higher reliability is designed by studying the different combinations of error correction code module, combined decoding module and its ARQ module. These key technologies have low implementation complexity and good anti-interference performance in PLC applications where delay requirements are not strict, carrier frequency is not high and data transmission rate is low. Using TI high performance 32-bit fixed-point DSP chip TMS320F2812 as the core control platform, the core algorithm of the main modules of PLC error control system is programmed, including error correction code, HARQ, combination decoding and CRC error detection code, as well as serial port transceiver module, modulation and demodulation module. Each sub-module is a separate API function to facilitate the call of the main program of the system. The corresponding peripheral circuits, including transmitting power amplifier, coupling, resonance filtering and receiving signal amplification circuit, are designed. The whole system has the characteristics of simple structure, flexibility and so on. These key technologies have low complexity and good anti-interference performance when used in low-voltage power line communication. In practical application, according to different application requirements and hardware and software resource allocation, an error control scheme suitable for low voltage PLC can be designed to meet the requirements of low cost, easy to implement and high reliable communication. A low voltage PLC experimental system is built and tested and analyzed. The experimental data show that the designed error control scheme can effectively resist random errors and burst errors caused by channel noise and improve the anti-interference ability of carrier communication system. The error control technology suitable for PLC provides an alternative for improving the reliability of power line carrier communication.
【学位授予单位】：福州大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TN913.6

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