| This dissertation is mainly concerned with construction of structured low-density parity-check (LDPC) codes, especially in quasi-cyclic (QC) form, for three different types of channels, namely the additive white Gaussian noise (AWGN), the binary random erasure, and the binary burst erasure channels. Several new algebraic methods for systematic construction QC-LDPC codes are presented. Also presented is a simple iterative algorithm for correcting erasure bursts. Codes constructed perform very well over all three types of channels and can be encoded using simple shift-registers with linear complexity. This encoding advantage is not shared by other types of LDPC codes and is important in practice. In addition, codes constructed by these methods also show very encouraging performance with high spectral efficiency transmission over fading channels. |
