The implement of synchronization and differential demodulation algorithm of GMSK signal

Abstract

GMSK has the advantages of constant envelope, continuous phase, and concentrated power spectral density, and is widely used in the field of digital communication with limited frequency bands. Aiming at the multi-channel receiver system with limited hardware resources, an algorithm for obtaining bit synchronization information based on the phase characteristics and waveform characteristics of the GMSK signal is proposed, which has a simple structure, occupies less hardware resources, has a low sampling rate, and is easy to implement by engineering. And combined with the 2-bit of 10Mpbs, the bit synchronization algorithm can accurately output bit synchronization information at only 5 times the sampling rate, and the demodulation algorithm has only 0.6dB of demodulation loss compared with the theoretical value, which has excellent demodulation performance.