采用8QAM调制的GSM/EDGE移动通信系统

8QAM Modulation Scheme for GSM/EDGE Mobile Communication System

在与现有GSM/EDGE系统兼容,且不改变该系统发送和接收滤波器的基础上,为了改善基于8PSK调制方案的GSM/EDGE的性能,建议将GSM/EDGE的8PSK调制方式改为8QAM调制方式。并给出相位旋转的方法,解决了功率放大器非线性引起的频谱再生问题。同时,调整了8QAM星座图上的信号点位置,保持了原有EDGE系统发送和接收滤波器。在Matlab仿真实验中表明,相对于现有的GSM/EDGE 8PSK调制方案,GSM/EDGE的8QAM调制方案能够在达到相同误码率的情况下,信噪比提高约5dB。

To improve the property of current GSM/EDGE based on 8PSK modulation scheme, we change 8PSK modulation scheme into 8QAM modulation scheme for GSM/EDGE, which is compatible with present system and using the same pulse-shaping filter and receive filter. And the phase revolves method is presented for solving the frequency spectrum regeneration problem caused by the power amplifier non-linearity. We also adjust the signal position on 8QAM constellation for no change on the transmission and receive filter in the EDGE system. The simulation results show us the remarkable difference between 8QAM and 8-PSK is that 8QAM scheme can improve 5 dB under the same SNR.