【作者】 林闯；

【导师】 夏志忠；

【作者基本信息】 大连海事大学 ， 通信与信息系统， 2004， 硕士

【摘要】 本设计基于软件无线电的思想，使用软件的方法直接对短波信号进行处理，实现AM语音调制语音信号全数字解调。软件无线电(SR:Software Radio)的定义是将在天线后的信号进行数字化，所有的过程实现软件化、可编程化。但是由于A／D等器件的性能和处理器处理速度的限制，就出现了比软件无线电的更实际的解决方法，即SDR(software-defined radio)，也就是说，它的处理过程仍然对高频保留了模拟部分。SDR的模拟部分包括了混频和放大。而本设计由于A／D器件的输入信号幅度的限制，只对天线馈入信号进行滤波、放大后再进行数字化。 本设计接收频率范围为0MHZ~30MHZ短波信号，分为模拟射频处理部分和数字处理部分。模拟射频部分完成对信号的前置滤波和宽频放大；数字处理部分完成对信号的解调，主要由A／D，D／A，DSP，FPGA等组成，其中DSP为主控制器。外围接口控制包括：PCI、USB。其中的关键的技术有： 1 双A／D采样的时序控制 2 直接数字频率合成(DDS)的FPGA实现 3 积分梳状滤波器(CIC Filter)的FPGA实现 4 半带滤波器(HB Filter)的FPGA实现 5 PCI接口芯片驱动程序的设计 6 USB接口芯片DSP固件程序的设计 7 整个系统的上电自举 最后，本系统完成了对频率范围为0MHZ~30MHZ短波信号解调，以及上位机可以通过PCI控制芯片(PCI2040)，以及USB控制芯片(PDIUSBD12)与系统的主控制器(TMS320VC5402A)进行通信。更多还原

【Abstract】 In my design, signal is processed directly with software method based on software radio idea, which realizes the AM signal demodulation. The definition of Software Radio (SR) is that the signal is digitalized after antenna, make all processes programmable and make all processes be disposed by software. But with the limitation of performance of A/D and process speed of processor, the more effective method-SDR (Software-defined Radio) emerges, that is to say, SDR reserves the analog part of high frequency. The analog part of SDR includs mixing and magnification of signal from antenna. In my system, input signal from antenna is filtered and magnified and then digitalized.My system can receive the signal frequency from OMHZ to 30MHZ. The system can be divided into 2 parts - analog radio frequency processing part and digital processing pat. Analog radio frequency processing part mainly finishes filtering and magnifying signal from antenna. Digital processing part mainly finishes demodulation, which is made of A/D, D/A, DSP, FPGA. FPGA is the main process unity, and DSP is the main control unity. The peripheral interface is made of PCI interface and USB interface. The key technique of that is:1 Timing control of two ADCs;2 Realization of DDS in FPGA;3 Realization of CIC filter in FPGA;4 Realization of HB filter in FPGA;5 Driver program design of PCI interface chip;6 Firmware of DSP design of USB interface chip;7 Boot of the whole systemAt last, the complete SW signal decoding form OMHZ to 30MHZ and communication between DSP and personal computer through PCI interface and USB interface.更多还原