Análisis de las codificaciones de canal: LDPC y Turbo código, utilizando modulaciones no uniformes sobre canales AWGN con desvanecimiento.

Abstract

This research it presents an analysis of LDPC and Turbo channel codes, using digital modulations with non-uniform NUC-QAM constellations of order M=64, 256, 1024 and 4096, in channels with additive white Gaussian noise (AWGN) with flat fading. Two metrics were used to estimate the bitstream behavior during channel coding: the signal to noise ratio (SNR), and the bit error rate (BER). Three possible scenarios are considered for the Communications Channel. The first case corresponds to a communication channel that’s applied without channel coding, the second case applies LDPC channel coding, and the third case it applied Turbo channel coding. The channel simulation is performed based on the Rayleigh probability distribution statistical model. The results for each case are obtained through functions programmed in Matlab software. The performance results of LDPC and Turbo channel coding are compared with the results obtained without applying channel coding, and it is determined which of them performs better with a wide range of SNR values. Finally, it is obtained that the best coding is LDPC as the BER stabilizes in the order of (10^(-6)) much lower compared to Turbo coding.