Performance analysis of LDPC codes for time-selective complex fading channels
نویسندگان
چکیده
Abstract— Low-density parity-check (LDPC) codes are analyzed using density evolution techniques for a frequency-nonselective, time-selective fading channel where the fading affects both the amplitude and the phase of the transmitted signal. To aid the channel estimation process, pilot symbols are transmitted periodically. The performance of several message-passing estimation/decoding algorithms is investigated, and the optimal energy allocation between the pilot and coded symbols is evaluated. The results show that optimal power allocation can improve the performance by more than 1 dB for moderate channel dynamics. Finally, necessary and sufficient conditions for the convergence to error-free transmission are derived that take into account the channel coherence time.
منابع مشابه
Space-Time Coded OFDM for High Data rate Wireless Communication over Wideband Channels
Assume a STC (space-time codes) OFDM (orthogonal frequency-division multiplexing) scheme the receiver antennas and multiple transmitters on compared time-chosen fading channels and frequency. It has been displayed that the time-selectivity product array is the input parameter to describe the associated fading channel outage capacity. It is considered that space-time codes with huge efficient ex...
متن کاملLDPC-based space-time coded OFDM systems over correlated fading channels: Performance analysis and receiver design
We consider a space–time coded (STC) orthogonal frequency-division multiplexing (OFDM) system with multiple transmitter and receiver antennas over correlated frequencyand time-selective fading channels. It is shown that the product of the time-selectivity order and the frequency-selectivity order is a key parameter to characterize the outage capacity of the correlated fading channel. It is also...
متن کاملRepeat Accumulate Based Designs for LDPC Codes on Fading Channels
Irregular repeat-accumulate Root-Check LDPC codes based on Progressive Edge Growth (PEG) techniques for block-fading channels are proposed. The proposed Root-Check LDPC codes are both suitable for channels under F = 2, 3 independent fadings per codeword and for fast fading channels. An IRA(A) Root-Check structure is devised for F = 2, 3 independent fadings. The performance of the new codes is i...
متن کاملPerformance of Spatially-Coupled LDPC Codes and Threshold Saturation over BICM Channels
We study the performance of binary spatiallycoupled low-density parity-check codes (SC-LDPC) when used with bit-interleaved coded-modulation (BICM) schemes. This paper considers the cases when transmission takes place over additive white Gaussian noise (AWGN) channels and Rayleigh fast-fading channels. The technique of upper bounding the maximum-a-posteriori (MAP) decoding performance of LDPC c...
متن کاملStudy of Structured Root-LDPC Codes and PEG Techniques for Block-Fading Channels
In this work, we propose structured Root-LowDensity Parity-Check (LDPC) codes and design techniques for block-fading channels. In particular, Quasi-Cyclic Root-LDPC codes, Irregular repeat-accumulate Root-LDPC codes and Controlled Doping Root-LDPC codes based on Progressive Edge Growth (PEG) techniques for block-fading channels are proposed. The proposed Root-LDPC codes are both suitable for ch...
متن کامل