π/4-DQPSK基带差分解调技术研究及数据传输实现

【作者】 黄松；

【导师】 钟洪声；

【作者基本信息】 电子科技大学 ， 信号与信息处理， 2006， 硕士

【摘要】 本课题对π/4-DQPSK的全数字调制解调技术进行研究,利用π/4-DQPSK数字调制和基带差分解调技术实现数字信号的传输,实现传输码率500kbps,调制中频2MHz。π/4-DQPSK是QPSK改进方式,它是一种线性窄带数字调制技术,被广泛应用于移动通信和卫星通信中,其突出特点是频带利用率高、频谱特性好、抗衰落性能强、可进行非相干解调。本文中介绍了π/4-DQPSK的调制解调原理,着重介绍了成形滤波器,位同步实现,并对调制解调的全过程进行Matlab仿真并用Verilog硬件描述语言设计实现各个模块。为验证模块的正确性,不但通过Quartus和ModelSim进行软件仿真,还设计制作了基于FPGA的PCB板,并完成了电路调试。通过对FPGA芯片下载运行编制的程序,验证了本π/4-DQPSK调制解调系统能正确工作,完成了预定的目标。更多还原

【Abstract】 This project study the all-digital modulation and demodulation ofπ/4 offset differentially encoded quadrature phase shift keying (π/4-DQPSK). Then useπ/4-DQPSK digital modulation and baseband differential demodulation technology to implement digital signal transmission. The bite rate is 500Kb/s and the intermediate frequency is 2MHz.π/4-DQPSK which is a modification of QPSK modulation. It is a linear narrowband technology which has been widely employed in mobile communication system, satellite communication system. It possesses features of high spectrum utilization ratio, better spectrum specification, stronger anti-fading performance and applicability to non-coherent detection.The paper introduces the modulation and demodulation theory ofπ/4-DQPSK. Recommended pulse shaping filter and bit synchronization detailed. Then author use Matlab software to simulate the whole process of modulation and demodulation and use Verilog Hardware Description Language to design the module. To validate the correctness of each module, author use Quartus and ModelSim software to implement software simulation , designed the PCB board based on FPGA chip and finished circuit debug. Through download designed program to FPGA chip and run it ,the modulation and demodulation system ofπ/4-DQPSK proved to be run correctly and the target goal is completed.更多还原