In this paper, we re-examine the decoding problem of a distributedturbo code (DTC) over the three-node one-way relay channel based on the decode-and-forward protocol. In the traditional DTC scheme, the decoder at the...
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In this paper, we re-examine the decoding problem of a distributedturbo code (DTC) over the three-node one-way relay channel based on the decode-and-forward protocol. In the traditional DTC scheme, the decoder at the destination assumes the error-free Viterbi decoding at the relay. However, the error propagation effect resulting from unsuccessful decoding at the relay may cause significant performance loss in some practical scenarios. Improved decoders reported in the literature typically assume a certain memoryless error model, which ignores the fact that relay decoding errors are correlated and bursty. In this paper, we propose a novel trellis error model (TEM) to accurately represent the statistics of relay decoding errors and construct two TEM-based iterative decoders (TEM-IDs) with two and three components, respectively. The TEM-ID with three components has a lower complexity than that of the TEM-ID with two components at the cost of minor performance loss. We also derive a new BER bound for the near maximum likelihood decoding of the DTC using a uniform interleaver. In addition, the extrinsic information transfer chart analysis is applied to estimate the threshold performance of the TEM-ID for large code lengths. Extensive simulation results verify that the new decoders can perform close to the derived BER bound and outperform existing decoders. Finally, we show that the TEM-ID can be extended for general distributed concatenated coding systems.
In this paper, we propose and analyze a new relaying scheme for the three-node cooperative system, named as clustering-based relay selective decode-and-forward (CSDF). The source broadcasts a parallel concatenated rec...
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ISBN:
(纸本)9781509027088
In this paper, we propose and analyze a new relaying scheme for the three-node cooperative system, named as clustering-based relay selective decode-and-forward (CSDF). The source broadcasts a parallel concatenated recursive systematic convolutional (RSC) code to both the relay and the destination. When the decoding error is detected at the relay, a kernel K-Means clustering algorithm is applied to distinguish the reliable bits from the unreliable bits. The relay then forwards the bits that are deemed reliable and discards the bits that are not, resulting in less errors propagating to the destination. The closed-form expression of bit error rate(BER) is derived to demonstrate the relation between error propagation and system performance of our proposed relaying scheme. Simulation results show that the proposed scheme achieves better performance and efficiently reduce error propagation.
A wireless sensor network (WSN) usually consists of a large number of battery-powered low-cost sensors with limited data collection and processing capacity. In order to prolong the lifetime of the WSN with a target er...
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A wireless sensor network (WSN) usually consists of a large number of battery-powered low-cost sensors with limited data collection and processing capacity. In order to prolong the lifetime of the WSN with a target error performance, a novel clustered distributedcoding framework, referred to as distributed multiple-sensor cooperative turbocoding (DMSCTC), is developed for a large-scale WSN with sensor grouped in cooperative cluster. In the proposed DMSCTC scheme, a simple forward error correction is employed at each sensor and a simple multi-sensor joint coding is adopted at the cluster head, while complicated joint iterative decoding is implemented only at the data collector. The proposed DMSCTC scheme achieves extra distributedcoding gain and cooperative spatial diversity without introducing extra complexity burden on the sensors by transferring the complicated joint decoding process to the data collector. With the proposed scheme, the WSN can achieve the target error performance with less power consumption, thus prolonging its lifetime. The error performance and energy efficiency of the proposed DMSCTC scheme are analyzed, and followed by Monte Carlo simulations. Both analytical and simulation results show that the DMSCTC can substantially improve the energy efficiency of the clustered WSN.
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