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14
Rate-adaptive distributed source coding using Low-Density Parity-Check codes
- In: Proc. Asilomar Conf. on Signals, Syst., Comput
, 2005
"... Source coding with correlated decoder side information is considered. We impose the practical constraint that the encoder be unaware of even the statistical dependencies between source and side information. Two classes of rate-adaptive distributed source codes, both based on Low-Density Parity-Check ..."
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Cited by 30 (10 self)
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Source coding with correlated decoder side information is considered. We impose the practical constraint that the encoder be unaware of even the statistical dependencies between source and side information. Two classes of rate-adaptive distributed source codes, both based on Low-Density Parity-Check (LDPC) codes, are developed and their design is studied. Specific realizations are shown to be better than alternatives of linear encoding and decoding complexity. The proposed rateadaptive LDPC Accumulate (LDPCA) codes and Sum LDPC Accumulate (SLDPCA) codes (of length 6336 bits) perform within 10 % and 5 % of the Slepian-Wolf bound in the moderate and high rate regimes, respectively.
Hybrid concatenated codes with asymptotically good distance growth
- IN PROC. 5TH INT. SYMP. TURBO CODES & REL. TOPICS
, 2008
"... Turbo Codes and multiple parallel concatenated codes (MPCCs) yield performance very close to the Shannon limit. However, they are not asymptotically good, in the sense of having the minimum distance grow linearly with the length of the code. At the other extreme, multiple serially concatenated code ..."
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Cited by 6 (4 self)
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Turbo Codes and multiple parallel concatenated codes (MPCCs) yield performance very close to the Shannon limit. However, they are not asymptotically good, in the sense of having the minimum distance grow linearly with the length of the code. At the other extreme, multiple serially concatenated codes (MSCCs), for example very simple repeat-accumulateaccumulate codes, have proven to be asymptotically good, but they suffer from a convergence threshold far from capacity. In this paper, we investigate hybrid concatenated coding structures consisting of an outer multiple parallel concatenated code with very simple memory-1 component encoders serially concatenated with an inner accumulator. We show that such structures exhibit linear distance growth with block length and that they have better thresholds than MSCCs. The results again indicate the fundamental tradeoff between linear distance growth and convergence threshold.
Chen ‘Syndrome-based lightweight video coding for mobile wireless application
- Proc. Int. Conf. on Multimedia and Expo
, 2006
"... In conventional video coding, the complexity of an encoder is generally much higher than that of a decoder because of operations such as motion estimation consume significant computational resources. Such codec architecture is suitable for downlink transmission model of broadcast. However, in the co ..."
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Cited by 5 (0 self)
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In conventional video coding, the complexity of an encoder is generally much higher than that of a decoder because of operations such as motion estimation consume significant computational resources. Such codec architecture is suitable for downlink transmission model of broadcast. However, in the contemporary applications of mobile wireless video uplink transmission, it is desirable to have low complexity video encoder to meet the resource limitations on the mobile devices. Recent advances in distributed video source coding provide potential reverse in computational complexity for encoder and decoder [1, 2]. In the same spirit, we proposed in this paper a syndrome-based light-weight video encoding scheme for mobile wireless applications. This scheme is based on two innovations: (1) adoption of low resolution low quality reference frames for motion estimation at the decoder; (2) introduction of more powerful product accumulate code. Extensive experimental results have confirmed that this syndrome based encoding can reduce computational complexity at the encoder while maintaining good reconstruction quality at the decoder. Therefore, this light weight video coding scheme is suitable for mobile wireless applications. 1.
Accumulate codes based on 1+D convolutional outer codes
- Communications, IEEE Transactions on
, 2009
"... Abstract—A new construction of good, easily encodable, and soft-decodable codes is proposed in this paper. The construction is based on serially concatenating several simple 1+D convolutional codes as the outer code, and a rate-1 1/(1+D) accumulate code as the inner code. These codes have very low e ..."
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Cited by 1 (1 self)
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Abstract—A new construction of good, easily encodable, and soft-decodable codes is proposed in this paper. The construction is based on serially concatenating several simple 1+D convolutional codes as the outer code, and a rate-1 1/(1+D) accumulate code as the inner code. These codes have very low encoding complexity and require only one shift-forward register for each encoding branch. The input-output weight enumerators of these codes are also derived. Divsalar’s simple bound technique is applied to analyze the bit error rate performance, and to assess the minimal required signal-to-noise ratio (SNR) for these codes to achieve reliable communication under AWGN channel. Simulation results show that the proposed codes can provide good performance under iterative decoding. Index Terms—Low-density parity-check (LDPC) codes, accu-mulate codes, convolutional codes. I.
CODE OPTIMIZATION AND ANALYSIS FOR MULTIPLE-INPUT AND MULTIPLE-OUTPUT COMMUNICATION SYSTEMS
, 2004
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Using Serially-Concatenated-Accumulate Codes
, 2004
"... We describe a practical method for distributed compression of q-ary sources using multi-level serially-concatenated-accumulate codes. Our approach works well at high compression rates, and allows for graceful and incremental rate-adaptivity. Simulations show that the compression efficiency is near t ..."
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We describe a practical method for distributed compression of q-ary sources using multi-level serially-concatenated-accumulate codes. Our approach works well at high compression rates, and allows for graceful and incremental rate-adaptivity. Simulations show that the compression efficiency is near the information-theoretic limits for correlations between sources that obey a Gaussian or Laplacian distribution.
Research Article Differentially Encoded LDPC Codes—Part I: Special Case of Product Accumulate Codes
, 2008
"... Part I of a two-part series investigates product accumulate codes, a special class of differentially-encoded low density parity check (DE-LDPC) codes with high performance and low complexity, on flat Rayleigh fading channels. In the coherent detection case, Divsalar’s simple bounds and iterative thr ..."
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Part I of a two-part series investigates product accumulate codes, a special class of differentially-encoded low density parity check (DE-LDPC) codes with high performance and low complexity, on flat Rayleigh fading channels. In the coherent detection case, Divsalar’s simple bounds and iterative thresholds using density evolution are computed to quantify the code performance at finite and infinite lengths, respectively. In the noncoherent detection case, a simple iterative differential detection and decoding (IDDD) receiver is proposed and shown to be robust for different Doppler shifts. Extrinsic information transfer (EXIT) charts reveal that, with pilot symbol assisted differential detection, the widespread practice of inserting pilot symbols to terminate the trellis actually incurs a loss in capacity, and a more efficient way is to separate pilots from the trellis. Through analysis and simulations, it is shown that PA codes perform very well with both coherent and noncoherent detections. The more general case of DE-LDPC codes, where the LDPC part may take arbitrary degree profiles, is studied in Part II Li 2008. Copyright © 2008 Jing Li (Tiffany). This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. 1.
DIFFERENTIALLY-ENCODED DI-SYMBOL TIME-DIVISION MULTIUSER IMPULSE RADIO IN UWB CHANNEL
, 2007
"... to my parents ..."
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High-Rate Short-Block LDPC Codes for Iterative Decoding with Applications to High-Density Magnetic Recording Channels
"... ar ..."
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