CPM Modulator Design Based on Modified Gaussian Pulse Shaping

In order to improve the bandwidth efficiency, CPM modulator design based on base-band pre-processing is presented in this paper, which uses modified Gaussian pulse as the base-band pre-processing pulse. The modified Gaussian pulse is obtained by passing the basic Gaussian pulse through certain low pass filter to restrain the side lobes. By adopting such design method, the output modulated signal owns better spectrum characteristics and suffers low distortion, compared with the basic Gaussian pulse shaping method. The traditional transmitter often uses an IF band-pass filter to control the signal spectrum, which results in high hardware complexity and serious signal distortion. The design method in this paper is simple and easy to apply, and owns good prospect in real applications.