THROUGHPUT AND BIT ERROR RATE ANALYSIS OF LUBY TRANSFORM CODES WITH LOW AND MEDIUM NODAL DEGREE DISTRIBUTIONS

Abstract

This study presents two degree distributions namely low and medium nodal degree distributions aiming to build a low overhead Luby Transform (LT) codes. The motivation is to design a fast encoder/decoder especially for real-time multimedia streaming and multicasting applications using LT codes. The key idea of this study is to restrict the average degree of the transmitted encoded symbols as minimal. The impacts of low and medium degree encoded symbols on the performance of LT codes over an Additive White Gaussian Noise channel (AWGN) have been analyzed by the means of Bit Error Rate (BER), encoder/decoder delay, ripple size, throughput, overhead and bandwidth utilization as the performance metrics. Simulation results show that the proposed nodal degree distributions for LT codes achieve better throughput and BER performance at low overhead and delay with minimal decoding iterations by having a constantly decreasing ripple in comparison with conventional Robust Soliton Distribution (RSD) based LT codes.