Performance of non-binary LDPC-based space-time coded OFDM systems over multiple fading channels

By concatenating a space-time block coded orthogonal frequency-division multiplexing (STC-OFDM) scheme with powerful channel codes, the performance of STC-OFDM system can be further enhanced. In this paper, LDPC codes based on binary extension fields GF(q = 2b, b > 1) is used to a STC-OFDM system (called the new system), the performance of new system is evaluated and the comparisons are carried out between binary LDPC-based STC-OFDM system(old system) and the new system by simulation under the Addition White Gaussian Noise(AWGN) channels and multiple Raleigh fading channels. Result shows that with the aid of non binary LDPC codes the new system is superior to the old one under AWGN and multi-path Rayleigh fading channels, the performance gets better as the field order increases, but the computational complexity is increased also.

[1]  David J. C. MacKay,et al.  Low-density parity check codes over GF(q) , 1998, IEEE Communications Letters.

[2]  Lajos Hanzo,et al.  Turbo Coding, Turbo Equalisation and Space-Time Coding for Transmission over Fading Channels , 2002 .

[3]  Lajos Hanzo,et al.  Single- and Multi-carrier Quadrature Amplitude Modulation : Principles and Applications for Personal Communications, WLANs and Broadcasting , 2000 .

[4]  Evangelos Eleftheriou,et al.  Regular and irregular progressive edge-growth tanner graphs , 2005, IEEE Transactions on Information Theory.

[5]  Robert Michael Tanner,et al.  A recursive approach to low complexity codes , 1981, IEEE Trans. Inf. Theory.

[6]  Radford M. Neal,et al.  Near Shannon limit performance of low density parity check codes , 1996 .

[7]  Guosen Yue,et al.  Performance analysis and design optimization of LDPC-coded MIMO OFDM systems , 2004, IEEE Trans. Signal Process..

[8]  Siavash M. Alamouti,et al.  A simple transmit diversity technique for wireless communications , 1998, IEEE J. Sel. Areas Commun..

[9]  Vahid Tarokh,et al.  Space-time coded OFDM for high data-rate wireless communication over wideband channels , 1998, VTC '98. 48th IEEE Vehicular Technology Conference. Pathway to Global Wireless Revolution (Cat. No.98CH36151).

[10]  Henk Wymeersch,et al.  Log-domain decoding of LDPC codes over GF(q) , 2004, 2004 IEEE International Conference on Communications (IEEE Cat. No.04CH37577).

[11]  Hanjong Kim.  Turbo coded orthogonal frequency division multiplexing for digital audio broadcasting , 2000, 2000 IEEE International Conference on Communications. ICC 2000. Global Convergence Through Communications. Conference Record.

[12]  D. Declercq,et al.  Fast Decoding Algorithm for LDPC over GF(2q) , 2003 .