Title :
LDPC codes for Gaussian broadcast channels
Author :
Berlin, Peter ; Tuninetti, Daniela
Author_Institution :
EPFL, Lausanne, Switzerland
Abstract :
We study coding over a class of two-user broadcast channels with additive white Gaussian noise and fading known at the receivers only. Joint decoding of low-density parity-check codes is analyzed. The message update rule at the mapping node linking the users´ codes is derived and is shown to exhibit an interesting soft interference cancellation property. Good degree distributions are found using the differential evolution optimization technique and extrinsic information transfer analysis. The corresponding codes have rates close to the boundary of the achievable region for binary constrained input channels, both with and without fading. Simulation results for moderate blocklength show that the optimized codes operate within 1 dB of their thresholds.
Keywords :
AWGN channels; Gaussian channels; broadcast channels; interference suppression; optimisation; parity check codes; radiofrequency interference; Gaussian broadcast channels; LDPC codes; additive white Gaussian noise; binary input channels; differential evolution optimization technique; extrinsic information transfer analysis; low-density parity-check codes; message update rule; soft interference cancellation property; Additive white noise; Broadcasting; Degradation; Fading; Interference cancellation; Iterative algorithms; Iterative decoding; Joining processes; Message passing; Parity check codes;
Conference_Titel :
Signal Processing Advances in Wireless Communications, 2004 IEEE 5th Workshop on
Print_ISBN :
0-7803-8337-0
DOI :
10.1109/SPAWC.2004.1439282