Research On The Implementation Of Digital Receiver Of Differential Frequency Hopping HF Radio

Differential Frequency Hopping (DFH) is a new type of communicationtechnique, which growing up in these years. Compared with the conventionalFrequency Hopping technique, DFH can achieve desirable performance feature ofhigh hopping rate, spectral re-use, multi-path fading mitigation, and interferenceresistance, furthermore, DFH system need less hardware, implementing easily. With the developing of high-speed ADC and ultra-speed DSP , Software DefinedRadio (SDR) based on DSP can be implemented at present, the conventionalcommunication system frame is challenged. SDR affect the design of newcommunication system. Now, research on DFH radio based on SDR is hotspot inmilitary communication system . This paper will talk more about how to implementDFH radio receiver based on SDR, focus on the hardware design and demodulationalgorithms. In this paper , the implementation of DFH system receiver is target. IntermediateFrequency (IF) sampling digitial scheme is given. Expatiate on the channel from RFto IF, the IF processing module, and main board design based on DSP. The paperintroduce more about IF processing module based on AD6644, which is up to 65MHzsampling rate and 14-bit precision. After test of the module by using the methods ofFFT and histogram, the request of ADC module can be meet. The hardware design ofmain board based on TMS320C6201 is pivot in this paper, the detail is given,onboard,including SBSRAM,SDRAM,FLASH,DPRAM and so on. As a daughter board , theIF processing module can link to main board by slot , Two main board also can linktogether for dual-DSP parallel processing. The value of register in DSP is given. Themain board not only fit to the need of this system,but also provide hardware space forupdating in future. The demodulation optimized algorithms of DFH based on DSP is presented,introducing a new optional hopping synchronization method, optimizing the FFTalgorithms, and giving a method of demodulate frequency hopping pattern. At last,using the hadware platform above, dumodulating data stream from IF frequencyhopping sequenc is implemented.