高阶高速率OFDM水声通信技术的研究

发布时间：2018-03-07 12:27

本文选题：高阶编码　切入点：差分编码　出处：《哈尔滨工程大学》2014年硕士论文　论文类型：学位论文

【摘要】：随着海洋领域开发的不断深入,水下信息传输系统中的各种数据信息量急速增加。近年来水声通信对于高速率、可靠及可行性高的传输技术的研究越发引人关注。OFDM被视为一种可以有效抗频率选择性衰落的、高速且有效的传输技术,被广泛应用于近程的高速率水声通信。本文在简要介绍OFDM通信系统关键技术的基础上,通过理论概述与实验仿真完成了对于高阶编码技术以及纠错码在OFDM通信系统中的性能分析。详细论证了 OFDM系统中的各种差分调制技术,对于时域差分、频域差分、时频混合差分的性能与适用环境进行了分析。通过仿真分析了四进制相移键控(QPSK)和四进制差分相移键控(QDPSK)的性能,证明了各种差分编码的优越性,提高了水声通信系统的稳健性。并通过水池实验以及湖上实验对于不同的差分方案的误码性能和通信速率进行了对比分析,验证了不同差分方案的优劣性。高阶差分幅度相移键控(MDAPSK)技术是基于差分思想提出来的一种新的调制方式,它由差分幅度(DASK)和差分相移键控(DPSK)结合而成,具有高频谱利用率,大大提高了通信速率,接收端采用相干解调,不需要加入训练序列,降低了系统的复杂度。本文在Matlab中仿真了 MDAPSK调制解调系统,包括16DAPSK和64DAPSK,给出了信噪比和误码率的对应关系,并对64DAPSK提出一种简化解调算法,比较了其误码性能。
[Abstract]:With the development of the ocean field, the amount of all kinds of data in underwater information transmission system is increasing rapidly. The research of reliable and feasible transmission technology has attracted more and more attention. OFDM is regarded as an effective anti-frequency selective fading, high-speed and efficient transmission technology. It is widely used in high speed underwater acoustic communication in short range. This paper briefly introduces the key technologies of OFDM communication system. The performance analysis of high-order coding and error-correcting codes in OFDM communication system is completed by theoretical overview and experimental simulation. Various differential modulation techniques in OFDM system are demonstrated in detail, and the difference in time domain and frequency domain is discussed in detail. The performance of QPSK and QDPSK are analyzed by simulation, and the advantages of various differential codes are proved. The robustness of underwater acoustic communication system is improved, and the error performance and communication rate of different differential schemes are compared and analyzed through tank experiment and lake experiment. High order differential amplitude phase shift keying (MDAPSKK) is a new modulation method based on difference thought. It is composed of differential amplitude shift keying (DASK) and differential phase shift keying (DPSK), and has high spectral efficiency. The communication rate is greatly improved, the receiver adopts coherent demodulation, the training sequence is not added, and the complexity of the system is reduced. In this paper, the MDAPSK modulation and demodulation system is simulated in Matlab. Including 16DAPSK and 64DAPSKK, the corresponding relation between SNR and bit error rate is given, and a simplified demodulation algorithm for 64DAPSK is proposed, and its error performance is compared.
【学位授予单位】：哈尔滨工程大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TN929.3

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