Repository landing page
unknown
Low-density graph codes for coded cooperation on slow fading relay channels
Abstract
We study Low-Density Parity-Check (LDPC) codes with iterative decoding on block-fading (BF) Relay Channels. We consider two users that employ coded cooperation, a variant of decode-and-forward with a smaller outage probability than the latter. An outage probability analysis for discrete constellations shows that full diversity can be achieved only when the coding rate does not exceed a maximum value that depends on the level of cooperation. We derive a new code structure by extending the previously published full-diversity root-LDPC code, designed for the BF point-to-point channel, to exhibit a rate-compatibility property which is necessary for coded cooperation. We estimate the asymptotic performance through a new density evolution analysis and the word error rate performance is determined for finite length codes. We show that our code construction exhibits near-outage limit performance for all block lengths and for a range of coding rates up to 0.5, which is the highest possible coding rate for two cooperating users- journalArticle
- info:eu-repo/semantics/article
- info:eu-repo/semantics/publishedVersion
- Technology and Engineering
- low-density parity-check code
- mutual information
- density evolution
- Block fading channels
- relay channels
- PARITY-CHECK CODES
- CONVOLUTIONAL-CODES
- WIRELESS NETWORKS
- DIVERSITY
- PERFORMANCE
- CAPACITY
- THEOREMS
- DESIGN