Rate compatible ldpc codes for wireless applications

Low-density parity-check codes have been shown to perform very close to capacity over many channels with a constant signal-to-noise ratio. In wireless communications, the channel conditions vary with time at a reasonably fast rate. Adaptive coding methods such as ARQ schemes are very effective in varying channel conditions. ARQ schemes use a set of codes with varying rate and performance in a rate compatible manner. In this review, we investigate ARQ schemes that use rate compatible low-density parity-check codes. Recent research has shown that performance within 0.5dB of capacity is possible over a wide range of channel conditions using such ARQ schemes. © 2004 Taylor & Francis Group, LLC.