LDPC based time-frequency double differential space-time coding for multi-antenna OFDM systems

• Published in: Journal of Zhejiang University. A. Science Vol. 7; no. 2; pp. 141 - 148
• Main Author: 田继锋 姜海宁 宋文涛 罗汉文
• Format: Journal Article
• Language: English
• Published: Department of Electronic Engineering, Shanghai Jiao Tong University, Shanghai 200030, China 01.02.2006
• Subjects: OFDM系统; 时变信道; 时频双微分空时译码; 正交频分复用; 频率选择性衰落; Time-varying channels; LDPC; Differential space-time coding; OFDM; Frequency-selective fading
• DOI: 10.1631/jzus.2006.A0141
• ISSN: 1673-565X

Differential space-time coding was proposed recently in the literature for multi-antenna systems, where neither the transmitter nor the receiver knows the fading coefficients. Among existing schemes, double differential space-time （DDST） coding is of special interest because it is applicable to continuous fast time-varying channels. However, it is less effective in frequency-selective fading channels. This paper＇s authors derived a novel time-frequency double differential space-time （TF-DDST） coding scheme for multi-antenna orthogonal frequency division multiplexing （OFDM） systems in a time-varying frequency-selective fading environment, where double differential space-time coding is introduced into both time domain and frequency domain. Our proposed TF-DDST-OFDM system has a low-complexity non-coherent decoding scheme and is robust for time- and frequency-selective Rayleigh fading. In this paper, we also propose the use of state-of-the-art low-density parity-check （LDPC） code in serial concatenation with our TF-DDST scheme as a channel code. Simulations revealed that the LDPC based TF-DDST OFDM system has low decoding complexity and relatively better performance.