convolutional turbo code (CTC) has been adopted as an optional channel coding scheme for wireless metropolitan area networks (WMAN) and digital video broadcasting (DVB) owing to its powerful error correction capabilit...
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convolutional turbo code (CTC) has been adopted as an optional channel coding scheme for wireless metropolitan area networks (WMAN) and digital video broadcasting (DVB) owing to its powerful error correction capability and flexibility. In spite of the fact that the internal interleaver of CTC mainly affects the characteristics of the code, interleaving parameters, especially for small and moderate block sizes, have not been fully optimized in terms of performance. In this paper, we investigate structural behavior of interleaving parameters and suggest several optimization methodologies for the CTC interleaver of 802.16 systems. Simulation shows that power gains up to 0.7 dB can be acquired at a target frame error rate of 10(-5) by only substituting the newly optimized parameters for the current ones.
WiBro (Wireless Broadband), the standard of highspeed portable internet (HPI) based on OFDMA/TDD and IP network in Korea, is the subset of consolidated version of IEEE802.16e Wireless MAN standard. In this paper, the ...
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ISBN:
(纸本)9781424402656
WiBro (Wireless Broadband), the standard of highspeed portable internet (HPI) based on OFDMA/TDD and IP network in Korea, is the subset of consolidated version of IEEE802.16e Wireless MAN standard. In this paper, the architecture and key physical layer technologies of WiBro are briefly introduced, whereas the convolutional turbo code (CTC) with high-order modulation is presented in detail. The performance of convolutional turbo coded WiBro system with QPSK, 16QAM and 64QAM over ITU-R channel models is simulated, where pilot tones aided channel estimation and 1-tap equalization are applied. Simulation results show that the good BER performances of CTC with short code block size in WiBro systems, which facilitates the flexibility of channel resource allocation. Given the same code block size, CTC outperforms TC (turbocodes) and CC (convolutionalcodes).
A new scheme of concatenating the block turbocode (BTC) with the space-time block code (STBC) for an OFDM system in dispersive fading channels is investigated in this paper. The good error correcting capability of BT...
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A new scheme of concatenating the block turbocode (BTC) with the space-time block code (STBC) for an OFDM system in dispersive fading channels is investigated in this paper. The good error correcting capability of BTC and the large diversity gain characteristics of STBC can be achieved simultaneously. The resulting receiver outperforms the iterative convolutionalturbo receiver with maximum a posteriori probability expectation-maximization (MAP-EM) algorithm. Because of its ability to perform the encoding and decoding processes in parallel, the proposed system is easy to implement in real time.
Blind coherent detection of convolutional turbo codes is a hard problem in the presence of strong phase noise. Since the operating signal-to-noise ratio is usually very low, phase synchronisation algorithms suffer fro...
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Blind coherent detection of convolutional turbo codes is a hard problem in the presence of strong phase noise. Since the operating signal-to-noise ratio is usually very low, phase synchronisation algorithms suffer from phase ambiguities and cycle slips. A possible remedy is to perform joint phase estimation and decoding on a combined state-space model for the time-varying phase and the component convolutionalcodes. We demonstrate that joint phase estimation and decoding is in fact mandatory only for one component code, while ordinary BCJR decoding can be used for the second component code. Monte Carlo simulations for the turbocode used in the DVB-RCS standard show that the performances of the proposed scheme are close to decoding with perfect knowledge of the phase.
WiBro (Wireless Broadband), the standard of high-speed portable internet (HPI) based on OFDMA/TDD and IP network in Korea, is the subset of consolidated version of IEEE802.16e Wireless MAN standard. In this paper, the...
详细信息
WiBro (Wireless Broadband), the standard of high-speed portable internet (HPI) based on OFDMA/TDD and IP network in Korea, is the subset of consolidated version of IEEE802.16e Wireless MAN standard. In this paper, the architecture and key physical layer technologies of WiBro are briefly introduced, whereas the convolutional turbo code (CTC) with high-order modulation is presented in detail. The performance of convolutional turbo coded WiBro system with QPSK, 16QAM and 64QAM over ITU-R channel models is simulated, where pilot tones aided channel estimation and 1-tap equalization are applied. Simulation results show that the good BER performances of CTC with short code block size in WiBro systems, which facilitates the flexibility of channel resource allocation. Given the same code block size, CTC outperforms TC (turbocodes) and CC (convolutionalcodes).
This paper proposes a soft-detector with near-maximum likelihood (ML) performance in multiple-input multiple-output (MIMO) systems. The proposed detector performs an initial detection for candidate vectors by applying...
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ISBN:
(纸本)9781467348232;9781467348225
This paper proposes a soft-detector with near-maximum likelihood (ML) performance in multiple-input multiple-output (MIMO) systems. The proposed detector performs an initial detection for candidate vectors by applying a low complexity channel matrix ordering. The detection order then is diversified to extend the list of candidates, from which high-quality soft-output can be generated. In addition, a method for reducing overhead from the diversification of the detection order is presented. Simulation results on a 4 x 4 system with a convolutional turbo code of 5/6 rate show that the proposed detector can approximate the performance of the soft-ML detector but its complexity is approximately 46% of a reference detector [5].
A stream-oriented parallel concatenated convolutional (turbo) code (PCCC) is examined. The stream encoder uses continuous encoding with an interleaver constructed with using a tapped delayline. Stream decoding is envi...
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ISBN:
(纸本)0780344081
A stream-oriented parallel concatenated convolutional (turbo) code (PCCC) is examined. The stream encoder uses continuous encoding with an interleaver constructed with using a tapped delayline. Stream decoding is envisioned using a pipeline of continuous decoding modules. Performance of the stream PCCC is examined and compared to a block-oriented scheme. Block interleaver design is addressed for continuous encoding and a class of non-block interleavers termed convolutional interleavers are considered.
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