A competent decoding algorithm for Trellis Code in Digital Mobile Radio

摘要

A competent and fast decoding method for a Rate 3/4 Trellis Coded Modulation (TCM) used in Digital Mobile Radio systems, is proposed in this paper. Digital Mobile Radio (DMR) is a standard for digital radio. European Telecommunication Standard Institute (ETSI) developed the specification for the Professional Mobile Radio (PMR) users. TCM is a bandwidth efficient modulation. In TCM, doubling of constellation points helps the bandwidth conservation. TCM incorporates the best of plethoric non-binary modulation and finite state encoder. In this paper, we present an implementation of Trellis coding in DMR systems. The algorithm utilizes the Finite State Table of the coder and also the constellation mapper. BER analysis shows a coding gain of 2dB roughly. The simulations are performed by using MATLAB and the channel used for simulation is Additive White Gaussian Noise.