Iterative decoding of GMSK modulated convolutional code

An iterative decoding scheme for the serial concatenation of a convolutional code and a GMSK modulator is presented. The maximum a posteriori probability (MAP) algorithm accepting a priori information and providing a soft-output is applied to a GMSK differential phase detector (DPD). An iteration scheme is devised to act between the demodulation and the subsequent convolutional decoder. Compared with the traditional decoding method, simulation results of the new scheme show an evident improvement in overcoming the severe intersymbol interference of GMSK signals