高阶差分幅度相移键控调制解调系统及仿真

【作者】 王志刚；

【导师】 钟洪声；

【作者基本信息】 电子科技大学 ， 电路与系统， 2007， 硕士

【摘要】 本文研究了高阶差分幅度相移键控调制解调(MDASPK)的算法。MDAPSK与具有高频谱利用率已实用化的QAM相比，MDAPSK是由差分幅度(DASK)和差分相移键控(DPSK)结合的一种调制方式。接收端可以采用非相干解调，有利于降低接收端的实现难度，而且不需要符号训练序列，可以提高系统的传输速率。本文仿真了MDPSK调制解调、MDAPSK调制解调以及双载波并行传输的MDAPSK调制解调的算法，并给出了各种算法的信噪比与误码率的对应关系。本文具体工作包括如下：首先，本文仿真了差分相位调制解调系统，包括π／4—DQPSK、8DPSK和16DPSK。分析比较8DPSK和16DPSK调制解调的误码率与信噪比的对应关系。其次，在DPSK调制解调的基础上，理解MDAPSK原理，推导MDAPSK的算法公式，根据算法公式设计了MDAPSK系统框架。在Matlab中仿真了MADPSK调制解调系统，包括16DAPSK、32DAPSK和64DAPSK。其中16DAPSK包括由2DASP与8DPSK结合的16DAPSK和4DASK和π／4—DQPSK结合成的16DAPSK。给出了多种调制解调的误码率与信噪比的对应关系，分析了不同M的MDAPSK调制信号频谱。再次，在理解了MDAPSK调制解调的原理上，本文以32(4A×8P)为例，在Matlab中仿真了简化差分幅度解调的MDAPSK调制解调系统，仿真中差分幅度阀值采用了几何平均数和代数平均数的常规MDAPSK的解调、差分幅度阀值采用代数平均数的简化幅度算法，对比本算法32DAPSK解调和常规32DAPSK解调系统，给出了其误码性能的比较。最后，本文采用双载波并行传输数据方法，仿真了两个载波并行传输16DAPSK系统，利用数字信号帧头实现同步的方式，在每一个载波的调制上加入特定的标码，仿真了误码率与信噪比的对应关系，并比较了与采用单载波传输调制信号的误码件能。更多还原

【Abstract】 This project study modulation arithmetic and demodulation arithmetic of multidifference amplitude and phase shift keying (MDAPSK). It is well known that QAMhas been used in many practical applications because it has high bandwidth efficiency.MDAPSK is combined by DASK and DPSK, non-coherent demodulation is adapted indemodulation module, the realization is easier than QAM, and the training sequence ofsymbol is not necessary. It can make the system transportation faster. The modulationand demodulation arithmetic is simulated in this paper, including MDPS29K、MDAPSKwith single carrier. MDAPSK modulation and demodulation with two carriers is alsosimulated in the paper. The relationship between SNR and EPR all modulation anddemodulation is depicted.The main contribution of this dissertation can be concluded as following.At first,difference phase shift keying is introduced,includingπ/4--DQPSK、8DPSK and 16DPSK. The relationship between EBR and SNR of 8DAPSK and16DAPSK is compared.Secondly, the modulation and demodulation theory and arithmetic of MDAPSK isstudied based on DPSK modulation and demodulation theory and arithmetic, the systemframework is designed according the theory and arithmetic. The modulation anddemodulation system of MDAPSK (M=16 32 64) is simulated in Matlab. 16DAPSK hastwo ways, one is 2DASP combine with 8DPSK, the other is 4DASK combine withπ/4--DQPSK. The relationship of SNR and BER is simulated and analyzed. Differenceof frequency according different M is studied.Thirdly, the simplified MDAPSK modulation and demodulation system isintroduced with 32DAPSK which is combined by 4DASK with 8DPSK based onMDAPSK modulation and demodulation. The two demodulation of 32DAPSK issimulated; they are the general 32DAPSK demodulation and the simplified 32DAPSKdemodulation, the adjudged valued can be algebraic average or geometrical average.The SNR performance of two 32DAPSK demodulation system is compared.At last, the modulation and demodulation system with two carriers is proposed to use in this paper, and the system is simulated in Matlab. The frame header can beused to realize synchronization; the identified codes are placed in modulate codes atevery carrier. The relationship of SNR and EBR is also simulated, and compare with thesingle carrier system.更多还原