In this paper we consider the time-division multiple-access relay channel (MARC). We propose a low-complexity compress-and-forward-based transmission scheme that consists of a scalar quantization of log-likelihood rat...
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ISBN:
(纸本)9781457720529
In this paper we consider the time-division multiple-access relay channel (MARC). We propose a low-complexity compress-and-forward-based transmission scheme that consists of a scalar quantization of log-likelihood ratios (LLRs), followed by a suitably defined network code. This scheme is well suited also for asymmetric source-relay channel conditions. We use the information bottleneck method (IBM) for designing the LLR quantizers and we propose a modified IBM algorithm with more favorable numerical properties. Finally, we assess the performance of the proposed scheme in AWGN and fading channels using numerical simulations, including a comparison with existing transmission schemes.
This paper extends the well-known sourcecoding problem of multiple descriptions, in its general and basic setting, to analog source-channelcoding scenarios. Encoding-decoding functions that optimally map between the...
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ISBN:
(纸本)9781479999897
This paper extends the well-known sourcecoding problem of multiple descriptions, in its general and basic setting, to analog source-channelcoding scenarios. Encoding-decoding functions that optimally map between the (possibly continuous valued) source and the channel spaces are numerically derived. The main technical tool is a non-convex optimization method, namely, deterministic annealing, which has recently been successfully used in other mapping optimization problems. The obtained functions exhibit several interesting structural properties, map multiple source intervals to the same interval in the channel space, and consistently outperform the known competing mapping techniques.
In this paper, we propose a new joint source-channel decoding technique for transmitting binary Markov sources over AWGN channels. Our approach is based on serially concatenated coding and code doping for inner code. ...
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ISBN:
(纸本)9781467318808
In this paper, we propose a new joint source-channel decoding technique for transmitting binary Markov sources over AWGN channels. Our approach is based on serially concatenated coding and code doping for inner code. By combining the Markov source and the outer code trellis diagrams, a super trellis is constructed to exploit the time-domain correlation of the source. A modified version of BCJR algorithm is derived based on this super trellis, that can achieve considerable gain in terms of mutual information. The standard BCJR algorithm is used for decoding of inner code where code doping is adopted for better matching of extrinsic information transfer (EXIT) characteristics. EXIT chart analysis is performed to investigate convergence property of the proposed technique and to optimize the code parameters. Simulation results for bit error rate (BER) evaluation and EXIT chart analysis indicate that the proposed technique can achieve significant gains over the system in which source redundancy are not exploited, and thereby the BER performance of the proposed system is very close to the Shannon limit.
Sufficient and necessary conditions for reliable lossless communication of two correlated sources over classes of phase asynchronous cognitive interference channels are derived. Namely, we consider interference channe...
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ISBN:
(纸本)9781467309202
Sufficient and necessary conditions for reliable lossless communication of two correlated sources over classes of phase asynchronous cognitive interference channels are derived. Namely, we consider interference channels in which one of the encoders, i.e., the secondary or cognitive user, is causally or non-causally aware of the other's message. Moreover, as a practical constraint, we assume the transmitters are not aware of the phase shifts introduced by channels. We show that, for both classes of causal and noncausal cooperation, under strong interference conditions, separate source and channelcoding is optimal for reliable communication of both users. Also, we derive necessary and sufficient conditions for reliable communication of the cognitive radio transmission while the primary is able to maintain the same information rate it could reliably send in the absence of the secondary. To the best of our knowledge, this is the first work to find fundamental limits of lossless reliable communication for cognitive interference channels.
We consider the joint source-channelcoding problem of a 3D video transmitted over an AWGN channel. The goal is to minimize the total number of bits, which is the sum of the number of source bits and the number of for...
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ISBN:
(纸本)9781479903573
We consider the joint source-channelcoding problem of a 3D video transmitted over an AWGN channel. The goal is to minimize the total number of bits, which is the sum of the number of source bits and the number of forward error correction bits, under two constraints: the quality of the primary view and the quality of the secondary view must be greater than or equal to a predetermined threshold at the receiver. The quality is measured in terms of the expected PSNR of an entire decoded group of pictures. A MVC (multiview coding) encoder is used as the source encoder, and rate compatible punctured turbo codes are utilized for protection of the encoded 3D video over the noisy channel. Equal error protection and unequal error protection are compared for various 3D video sequences and noise levels.
This paper considers the Softcast joint source-channel video coding scheme for data transmission over parallel channels with different power constraints and noise characteristics, typical in DSL or PLT channels. To mi...
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ISBN:
(纸本)9781467399623
This paper considers the Softcast joint source-channel video coding scheme for data transmission over parallel channels with different power constraints and noise characteristics, typical in DSL or PLT channels. To minimize the mean square error at receiver, an optimal precoding matrix design problem has to be solved, which requires the solution of an inverse eigenvalue problem. Such solution is taken from the MIMO channel precoder design literature. Alternative suboptimal precoding matrices are also proposed and analyzed, showing the efficiency of the optimal precoding matrix within Softcast, which provides gains increasing with the encoded video quality.
Recently, the joint source-channelcoding schemes based on analog mappings have gained prominence. Their simplicity and low delay compared to other coding strategies make them more suitable for real-time applications....
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ISBN:
(纸本)9781467310680
Recently, the joint source-channelcoding schemes based on analog mappings have gained prominence. Their simplicity and low delay compared to other coding strategies make them more suitable for real-time applications. In this work, we propose a novel joint source-channelcoding scheme, based also on analog mappings, for a point-to-point communication channel with side information at the receiver (also known as Wyner-Ziv scenario).
To enable robust multiview video streaming over current wireless broadcast infrastructures, this paper proposes a joint source and channelcoding optimization framework for video streaming based upon multiview video c...
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ISBN:
(纸本)9781467399623
To enable robust multiview video streaming over current wireless broadcast infrastructures, this paper proposes a joint source and channelcoding optimization framework for video streaming based upon multiview video coding technique. It utilizes random linear coding (RLC) with ladder-shaped global coding coefficient matrix (GCM) for unequal erasure protection. An accurate expression of the decoding probability for RLC with ladder-shaped GCM is derived. A fast two-layer local search algorithm is developed to solve the source and channelcoding rate allocation problem, where the source and channel rate of each layer can be adjusted independently for the overall video quality. Simulation results demonstrate significant video quality improvement to existing rate allocation schemes.
A communication system based on the joint source-channelcoding principle is proposed where a fixed-rate source encoder using neither a codebook nor an entropy encoder is exploited to avoid the error propagation effec...
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ISBN:
(纸本)9781467318808
A communication system based on the joint source-channelcoding principle is proposed where a fixed-rate source encoder using neither a codebook nor an entropy encoder is exploited to avoid the error propagation effect and thus gain in system robustness. An explicit expression of the mean square error (MSE) distortion of the system for a uniform source is derived. Based on the MSE distortion, the optimal design of the communication system under the total transmission rate constraint is formulated as a mixed integer nonlinear optimization problem. We provide an algorithm to achieve the optimal solution via a convex optimization solver. The numerical result shows that the overall performance of the proposed system is close to the performance of the entropy coding scalar quantizer (ECSQ) system established by A. Gyorgy and T. Linder [1] for almost all rate regions.
In this work, a new robust and efficient airborne synthetic aperture radar (SAR) image coding transmission scheme based on compressive sensing (CS) against lossy channels is proposed. The robustness is achieved using ...
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ISBN:
(纸本)9781479957521
In this work, a new robust and efficient airborne synthetic aperture radar (SAR) image coding transmission scheme based on compressive sensing (CS) against lossy channels is proposed. The robustness is achieved using the democracy of CS. Considering the poor R-D performance of the traditional CS due to SAR image's weak sparsity, we use directional lifting wavelet transform (DLWT) as sparse representation and sparse-filtering to eliminate the interference of small coefficients. By exploiting the inter-scale dependency of DLWT coefficients, an efficient Bayesian reconstruction algorithm is adopted. Furthermore, optimal tradeoff between bit-depth and measurement rate is used. Experimental results show that the proposed scheme is more robust against packet loss compared with the traditional joint source-channelcoding (JSCC) scheme. When the packet loss rate (PLR) is excessive, the JSCC scheme easily leads to cliff effect, however, the R-D performance of the proposed scheme decreases more gracefully while achieving a comparative R-D performance.
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