Quasi-cyclic low-density parity-check coded multi-band-OFDM UWB systems

Multi-band orthogonal frequency division multiplexing (MB-OFDM) has been considered as a prominent solution for ultra wideband (UWB) technology supporting high speed, short range and point-to-point wireless communications. In this paper, we design quasi-cyclic (QC) low-density parity-check (LDPC) codes that are modified from implementation-oriented (IO) LDPC codes and examine their capability and suitability for MB-OFDM systems in terms of performance and implementation complexity. We evaluate the performance of QC-LDPC codes over MB-OFDM systems for four different data rates. By simulations, it is shown that the transmission distance of QC-LDPC coded MB-OFDM systems can increase by 29%-73% compared with that of convolutional codes. In addition, it is shown that QC-LDPC codes can be realized by a rate-configurable encoder and decoder.