Design of Trellis Coding Algorithm for a Robust Data Transmission over AWGN Channel

Abstract

For a fixed link margin, a wireless communication system's performance can be considered as dissatisfactory when the received power is lower as compared to noise power, which is called as deep fade. To overcome this, multiple links are utilized for transmission, which is called as diversity. During the deep fades, Shannon’s capacity is achievable by adapting appropriate data rate as well as modulation scheme and power relative to the fade level, which can play an important role for successful data exchange between the receiver and the transmitter. The Trellis Coded Modulation (TCM) is considered as a bandwidth-efficient modulation. In the current paper, complete encoder and decoder design that transmits data with a code rate 3/2 (Trellis Code) is discussed. A trellis encoder performs as a Finite State Machine (FSM) that uses convolution coding and moreover, the decoder uses Maximum Likelihood (ML) detection with the help of state table and trellis diagram. Both the algorithms are simulated using MATLAB.