基于Ptolemy的通用CPM调制器的建模与仿真

Modeling and Simulation of General CPM Modulator Based on Ptolemy

连续相位调制(CPM)是一类具有良好频谱利用率和恒包络特性的调制方式,非常适合应用于带宽及功率都受限的无线环境中,然而建模与仿真工具的缺乏大大限制了这类调制方式的应用。文中采用递归的方法,在ADSPtolemy环境下定制出CPM调制器的核心模块--通用相位产生模块,并结合库中已有模块,实现了对一个通用CPM调制器的建模,最后给出了不同调制参数下CPM信号的频谱及与测试仪表协同仿真的结果。从仿真得出的频谱和仪表观察的波形可以看出,模型具有良好的通用性,适合对各种CPM调制方式的建模和仿真。

Continuous Phase Modulation （CPM）is attractive for power and bandwidth -limited wireless environments because of its constant - envelop and high bandwidth - efficiency feature. However, the lack of proper modeling and simulation tools limits the application of CPM. In this paper, the kernel model of CPM - - General Phase Generation Model is created in ADS Ptolemy based on recursive method, and a general CPM modulator based on the kernel model and other models in the library is realized. Finally, the spectrums of CPM signal at different modulation parameters and the results of co - simulation with measurement instruments are presented. From the spectrums and wavcforms, we can conclude that the model has good generality and can be applied to modeling and simulation of various CPM modulators.