Power- and Bandwidth-Efficient Communications Using LDPC Codes
Piraporn Limpaphayom, Kim A. Winick · IEEE Transactions on Communications · 2004
We apply low-density parity-check (LDPC) codes to a bandwidth-efficient modulation scheme using multilevel coding, multistage decoding, and trellis-based signal shaping. Performance results based on density evolution and simulations are presented. Using irregular LDPC component codes of block length 10/sup 5/ and a 64-quadrature amplitude modulation signal constellation operating at 2 bits/dimension, a bit-error rate of 10/sup -5/ is achieved at an E/sub b//N/sub 0/ of 6.55 dB. At this value of E/sub b//N/sub 0/, the Shannon channel capacity, computed assuming equally likely signaling, is below 2 bits/dimension.