A Systematic LT Coded Arrangement for Transmission Over Correlated Shadow Fading Channels in 802.11 Ad-hoc Wireless Networks

摘要

Systematic Luby Transform (SLT) codes constitute rateless codes, which are capable of adaptively adjusting their code rate depending on the channel quality without any explicit channel state information (CSI) at the transmitters. In this paper, we investigate the performance of an SLT coded wireless system communicating over a correlated fading channel within an 802.11b network. The simulation results show that the SLT coded system can achieve a 3 dB gain in term of fading deviation when fading correlation changes from 1 Hz to 5 Hz. Moreover, it is found that a system employing an SLT code can provide similar performance to other rateless codes, namely the Luby Transform (LT) code and the Random Linear Fountain Code (RLFC). However, this level of performance is achieved with a reduced number of decoding operations. A 20% reduction is achieved when the standard deviation of the fading amplitude is 10 dB and the communication distance is 7 m. Greater reductions are observed under more benign propagation conditions.