数字移动通信高斯最小移频键控调制器

Design Theory of GSM System GMSK Modulator

研究了泛欧蜂窝移动通信（ＧＳＭ）系统高斯最小移频键控（ＧＭＳＫ）调制器的设计理论。提出了：相位路径的理论计算；用数字信号处理方法实现ＧＭＳＫ调制器；用随机信号功率谱估计仿真方法，选择基带信号离散化的抽样个数及量化比特参数；推导出正交调制幅度和相位不平衡对已调信号功率谱影响的判据。根据上述理论，做出了硬件，其基带信号眼图及功率谱均符合ＧＳＭ建议的要求。

Present the theoretical calculation of the phase path and the GMSK modulator im-plemented with DSP method,discuss the simulation method of calculating the PSD powerspectrun density of GMSK signal in order to choose the proper parameter of the signal dis-cretization based on the estimation theory of random signal PSD,analyse the effect ofquadrature phase error and amplitude imbalance and derive its criterion,According to theabove theory,we obtain the hardware,Its eye pattern and PSD are consistent with the GSMrecommendation.