CAJ | 학술논문

关于无线通信系统调频问题的研究,为了克服脉冲计数式鉴频法的不足,为提高调频的性能,提出利用叉积鉴频法对FM(Frequency Modulation)信号进行数字化解调实现方案.将前端预处理后的I/Q正交双路基带信号送入叉积鉴频器中,然后利用差积和点积来求得信号的近似反正切值.方法克服了脉冲计数式鉴频法由于计算原理复杂导致不能适用高速信号处理的局限,最大电路工作频率可达到206MHz,同时具有较好的抗载频失配特性.通过在Matlab上进行仿真和Modelsim硬件描述语言仿真,均具有较好的解调仿真效果,验证了方案的可行性.
관우무선통신계통조빈문제적연구,위료극복맥충계수식감빈법적불족,위제고조빈적성능,제출이용차적감빈법대FM(Frequency Modulation)신호진행수자화해조실현방안.장전단예처리후적I/Q정교쌍로기대신호송입차적감빈기중,연후이용차적화점적래구득신호적근사반정절치.방법극복료맥충계수식감빈법유우계산원리복잡도치불능괄용고속신호처리적국한,최대전로공작빈솔가체도206MHz,동시구유교호적항재빈실배특성.통과재Matlab상진행방진화Modelsim경건묘술어언방진,균구유교호적해조방진효과,험증료방안적가행성.
In order to eliminate the shortcoming of Pulse-type Counting Frequency Discriminator which applies only to signal with a slow velocity,a digital realization of FM signal demodulation based on Cross Product Frequency Discriminator is presented.The I/Q channels base signal is processed by the front preprocessing module.The approximate value of inverse tangent is solved by the dot product and cross product.The principle is easy and it is convenient to be implemented in FPGA,also it cost little of the system resource(991/72768).Its maximum circuit work frequency is 206MHz and it can resist the bad effect when the carrier frequency doesn't match.The results of Matlab simulation and Verilog HDL simulation on FPGA verify that the algorithm is feasible.