两径衰落短波信道下的改进型双向判决反馈均衡器 - 应用科学学报.pdf

30 5 Vol. 30 No. 5 20129 JOURNAL OF APPLIED SCIENCES — Electronics and Information Engineering Sept. 2012 DOI: 10.3969/j.issn.0255-8297.2012.05.002 210016 (bidirectional decision-feedback equalizer, BiDFE) BiDFE . BiDFE DFE DFE . BiDFE DFE DFE . BiDFE DFE DFE (bidirectional arbitrated DFE, BAD) BAD. TN911.5 0255-8297(2012)05-0448-07 Modified Bidirectional Decision-Feedback Equalizer for Two-Ray Fading HF Channels SHAO Han-qin, XU Da-zhuan, WANG Lei College of Electronic and Information Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing 210016, China Abstract: In this paper, we consider the use of a bidirectional decision-feedback equalizer (BiDFE) in two-ray fading HF channels. A low-complexity modified BiDFE using the properties of these channels is proposed. Coefficients of the equalizer are optimized, and the outputs of forward DFE and time-reversal DFE are combined using maximal ratio combining (MRC) rules. Theoretical analysis and computer simulations show that the proposed scheme completely cancels inter-symbol interference (ISI) between the two streams so that signal-to- noise ratio (SNR) is the sum of SNRs of the two streams. The performance of modified BiDFE is superior to conventional DFE and bidirectional arbitrated DFE (BAD), while the computation complexity is lower than BAD. Keywords: bidirectional decision-feedback equalizer (BiDFE), two-ray fading channels, high frequency (HF) channel, inter-symbol interference (ISI), maximal ratio combining (MRC) MLSE