摘要
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(FrequencyModu lation)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。
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.
出处
《计算机仿真》
CSCD
北大核心
2010年第3期353-356,共4页
Computer Simulation
