一种新的GMSK调制器的设计与实现方法  

A New Method for Realization of GMSK Modulator

作　　者：陈敬乔[1] 尚春杰 王力男[1] 王莉静[2] 

机构地区：[1]中国电子科技集团公司第五十四研究所,河北石家庄050081 [2]北京铁路局石家庄电务段,河北石家庄050000

出　　处：《无线电工程》2014年第7期79-82,共4页Radio Engineering

基　　金：国家部委基金资助项目

摘　　要：高斯最小相移键控(GMSK)调制信号具有相位连续、包络恒定的特点,且有较强的抗功放非线性的能力,适合应用于一些链路余量较小、功率受限的系统中。对GMSK调制器的总体设计进行了简要介绍,提出了一种新的产生相位轨迹的方法,并利用CORDIC算法产生调制载波。对GMSK调制器设计中需要解决的问题进行了分析,论述了新设计中采用的关键技术及实现方法。该方法实现流程简单、计算精度高。经过实际测试,当载波频率为1 200 MHz、输出电平为-10 dBm时,调制信号的EVM小于4.2%,符合系统实际要求。GMSK modulation not only has constant envelop and continuous phase,but also possesses a strong anti-nonlinear-am-plifier capability,suitable for systems in which the link margin is inadequate and the terminal transmittal power is limited.The design of GMSK modulator is introduced,a new method for generating phase trajectory is proposed,and the CORDIC method is used to generate modulation carrier wave.Questions needed to resolve in design are analysed,then,the key techniques and realization methods are dis-cussed.The proposed method has simpler process and higher precision.After actual testing,when the carrier frequency is 1 200 MHz and output power is -10 dBm,the EVM of modulation signals is smaller than 4.2%,which satisfies system requirements.

关 键 词：GMSK 正交调制 相位轨迹 CORDIC 

分 类 号：TN76[电子电信—电路与系统]