检索结果-内蒙古大学图书馆

hybrid digital-analog coding with Bandwidth Compression for Gaussian Source-Channel Pairs

IEEE TRANSACTIONS ON COMMUNICATIONS 2009年第4期57卷 997-1012页

作者： Wang, Yadong Alajaji, Fady Linder, Tamas Bank Montreal Toronto ON Canada Queens Univ Dept Math & Stat Kingston ON K7L 3N6 Canada

Three hybrid digital-analog (HDA) systems, denoted by HDA-I, HDA* and HDA-II, for the coding of a memoryless discrete-time Gaussian source over a discrete-time additive memoryless Gaussian channel under bandwidth compression are studied. The systems employ simple linear coding in their analog component and superimpose their analog and digital signals before channel transmission. Information-theoretic upper bounds on the asymptotically optimal mean squared error distortion of the systems are obtained under both matched and mismatched channel conditions. Allocation schemes for distributing the channel input power between the analog and the digital signals are also examined. It is shown that systems HDA* and HDA-II can asymptotically achieve the optimal Shannon-limit performance under matched channel conditions. Low-complexity and low-delay versions of systems HDA-I and HDA-II are next designed and implemented without the use of error correcting codes. The parameters of these HDA systems, which employ vector quantization in conjunction with binary phase-shift keying modulation in their digital part, are optimized via an iterative algorithm similar to the design algorithm for channel-optimized vector quantizers. Both systems have low complexity and low delay, and guarantee graceful performance improvements for high CSNRs. For memoryless Gaussian sources the designed HDA-II system is shown to be superior to the HIDA-I designed system. When applied to a Gauss-Markov source under Karhunen-Loeve processing, the HDA-I system is shown to provide considerably better performance.

关键词： Broadcasting hybrid digital-analog coding joint source-channel coding linear analog coding robustness vector quantization

来源：评论

学校读者我要写书评

暂无评论

hybrid digital-analog coding with bandwidth expansion for correlated Gaussian sources under Rayleigh fading

引用

EURASIP JOURNAL ON ADVANCES IN SIGNAL PROCESSING 2017年第1期2017卷 1页

作者： Yahampath, Pradeepa Univ Manitoba Dept Elect & Comp Engn Winnipeg MB R3T 5V6 Canada

Consider communicating a correlated Gaussian source over a Rayleigh fading channel with no knowledge of the channel signal-to-noise ratio (CSNR) at the transmitter. In this case, a digital system cannot be optimal for a range of CSNRs. analog transmission however is optimal at all CSNRs, if the source and channel are memoryless and bandwidth matched. This paper presents new hybrid digital-analog (HDA) systems for sources with memory and channels with bandwidth expansion, which outperform both digital-only and analog-only systems over a wide range of CSNRs. The digital part is either a predictive quantizer or a transform code, used to achieve a coding gain. analog part uses linear encoding to transmit the quantization error which improves the performance under CSNR variations. The hybrid encoder is optimized to achieve the minimum AMMSE (average minimum mean square error) over the CSNR distribution. To this end, analytical expressions are derived for the AMMSE of asymptotically optimal systems. It is shown that the outage CSNR of the channel code and the analog-digital power allocation must be jointly optimized to achieve the minimum AMMSE. In the case of HDA predictive quantization, a simple algorithm is presented to solve the optimization problem. Experimental results are presented for both Gauss-Markov sources and speech signals.

关键词： hybrid digital-analog coding Predictive quantization Transform coding Fading channels Speech coding

来源：评论

学校读者我要写书评

暂无评论

hybrid digital-analog coding of memoryless Gaussian sources over AWGN channels with bandwidth compression

Hybrid digital-analog coding of memoryless Gaussian sources ...

引用

23rd Biennial Symposium on Communications

作者： Wang, Yadong Alajaji, Fady Linder, Tamas Queens Univ Dept Math & Stat Kingston ON K7L 3N6 Canada

ISBN: (纸本)9780780395275

We present a low-complexity and low-delay joint source-channel coding method for bandwidth compression using a hybrid digital-analog (HDA) coding/modulation system based on the recent work in [3]. Analytical optimal distortion expressions (under both matched and mismatched channel conditions) are obtained for the proposed RDA system with a linear analog part for a memoryless Gaussian source and additive white Gaussian noise (AWGN) channel under the mean squared error distortion measure. We consider two HDA coding schemes, both of which employ a vector quantizer cascaded with binary phase-shift keying (BPSK) modulation in the digital part, but differ in that they use linear (resp. non-linear) coding with pulse amplitude modulation (PAM) in the analog part. We derive an optimal power allocation scheme for the system with linear analog coding and present performance comparisons with purely analog and purely digital systems, as well as the scheme in [3]. Simulation results show that, under linear analog coding, the proposed scheme outperforms the scheme of [3] for medium to high channel signal-to-noise ratios (CSNRs). Furthermore, the performance of the HDA scheme with the linear analog part is within 1 dB of the optimal distortion bound for the mismatched HDA system for high CSNRs;for the scheme with non-linear analog coding, the performance can be improved at high CSNRs.

关键词： hybrid digital-analog coding joint source-channel coding vector quantization broadcasting robustness

来源：评论

学校读者我要写书评

暂无评论

Zero-Delay hybrid digital-analog coding Under Energy Constraints

引用

IEEE COMMUNICATIONS LETTERS 2024年第2期28卷 263-267页

作者： Xu, Lu Chen, Xuechen Deng, Xiaoheng Cent South Univ Sch Comp Sci & Engn Changsha 410075 Peoples R China

This letter proposes a coding scheme for transmitting a Gaussian source with energy constraints in zero source delay scenario. While previous studies focused on the achievable minimum distortion with an infinite number of channel symbols, we also consider the robustness to finite symbols. The constructed scheme is based on the hybrid digital-analog (HDA) coding method, which encodes the quantized value of the source and the quantization error using a large number of channel symbols in total. Theoretical analysis reveals that our scheme achieves the optimal exponent and the same polynomial decay as in the existing work. Experimental results validate the performance gains of our scheme over the cutting-edge ones.

关键词： hybrid digital-analog coding zero-delay energy-distortion tradeoff joint source-channel coding Gaussian channel

来源：评论

学校读者我要写书评

暂无评论

hybrid digital-analog source-channel coding for bandwidth Compression/Expansion

引用

IEEE TRANSACTIONS ON INFORMATION THEORY 2006年第8期52卷 3757-3763页

作者： Skoglund, Mikael Phamdo, Nam Alajaji, Fady Royal Inst Technol Sch Elect Engn SE-10044 Stockholm Sweden Johns Hopkins Univ Appl Phys Lab Laurel MD 20723 USA Queens Univ Dept Elect & Comp Engn Kingston ON K7L 3N6 Canada Queens Univ Dept Math & Stat Kingston ON K7L 3N6 Canada

An approach to hybrid digital-analog (HDA) source-channel coding for the communication of analog sources over memoryless Gaussian channels is introduced. The HDA system, which exploits the advantages of both digital and analog systems, generalizes a scheme previously presented by the authors, and can operate for any bandwidth ratio (bandwidth compression and expansion). It is based on vector quantization and features turbo coding in its digital component and linear/nonlinear processing in its analog part. Simulations illustrate that, under both bandwidth compression and expansion modes of operation, the HDA system provides a robust and graceful performance with good reproduction fidelity for a wide range of channel conditions.

关键词： additive white Gaussian noise (AWGN) channels broadcasting Gaussian sources hybrid digital-analog coding robust coding source-channel coding turbo codes vector quantization

来源：评论

学校读者我要写书评

暂无评论

Zero-Delay Joint Source-Channel coding Using hybrid digital-analog Schemes in the Wyner-Ziv Setting

引用

IEEE TRANSACTIONS ON COMMUNICATIONS 2014年第2期62卷 726-735页

作者： Chen, Xuechen Tuncel, Ertem Univ Calif Riverside Dept Elect Engn Riverside CA 92521 USA

This paper studies zero-delay joint source-channel coding (JSCC) of Gaussian sources over additive white Gaussian noise (AWGN) channels in the Wyner-Ziv scenario, that is, when there is side information about the source available only to the receiver. The proposed encoding scheme is based on hybrid digital-analog (HDA) transmission in a zero-delay fashion. Specifically, to achieve zero-delay, after applying scalar quantization to the source, the properly scaled analog information (quantization error) is superimposed on the scaled digital information (quantized source), and then transmitted. At the receiver side, several reconstruction schemes are analyzed. It is shown that all the schemes, when optimized, are superior to existing uncoded, digital, or hybrid transmission methods. It is also shown that the proposed HDA transmission may result in increased robustness to channel and/or side information mismatch compared to uncoded transmission. Observing that the bandwidth-matched Wyner-Ziv problem is intimately related to the coding scenario without side information but with bandwidth expansion factor 2, the proposed scheme is applied to the latter problem. It is shown that this application results in a better performance than the well-known inverse spiral mapping.

关键词： hybrid digital-analog coding joint source-channel coding zero-delay Wyner-Ziv coding

来源：评论

学校读者我要写书评

暂无评论

Source-Channel coding for Fading Channels With Correlated Interference

引用

IEEE TRANSACTIONS ON COMMUNICATIONS 2014年第11期62卷 3997-4011页

作者： Abou Saleh, Ahmad Chan, Wai-Yip Alajaji, Fady Queens Univ Dept Elect & Comp Engn Kingston ON K7L 3N6 Canada Queens Univ Dept Math & Stat Kingston ON K7L 3N6 Canada

We consider the problem of sending a Gaussian source over a fading channel with Gaussian interference known to the transmitter. We study joint source-channel coding schemes for the case of unequal bandwidth between the source and the channel and when the source and the interference are correlated. An outer bound on the system's distortion is first derived by assuming additional information at the decoder side. We then propose layered coding schemes based on proper combination of power splitting, bandwidth splitting, Wyner-Ziv and hybrid coding. More precisely, a hybrid layer, that uses the source and the interference, is concatenated (superimposed) with a purely digital layer to achieve bandwidth expansion (reduction). The achievable (square error) distortion region of these schemes under matched and mismatched noise levels is then analyzed. Numerical results show that the proposed schemes perform close to the best derived bound and to be resilient to channel noise mismatch. As an application of the proposed schemes, we derive both inner and outer bounds on the source-channel-state distortion region for the fading channel with correlated interference;the receiver, in this case, aims to jointly estimate both the source signal as well as the channel-state (interference).

关键词： Joint source-channel coding distortion region correlated interference dirty paper coding hybrid digital-analog coding fading channels

来源：评论

学校读者我要写书评

暂无评论

Sequential Channel Synthesis

引用

IEEE TRANSACTIONS ON INFORMATION THEORY 2023年第5期69卷 2779-2795页

作者： Yu, Lei Anantharam, Venkat Nankai Univ Sch Stat & Data Sci LPMC KLMDASR Tianjin 300071 Peoples R China Nankai Univ LEBPS Tianjin 300071 Peoples R China Univ Calif Berkeley Dept Elect Engn & Comp Sci Berkeley CA 94720 USA

The channel synthesis problem has been widely investigated over the last decade. In this paper, we consider the sequential version in which the encoder and the decoder work in a sequential way. Under a mild assumption on the target joint distribution we provide a complete (single-letter) characterization of the solution for the point-to-point case, which shows that the canonical symbol-by-symbol mapping is not optimal in general, but is indeed optimal if we make some additional assumptions on the encoder and decoder. We also extend this result to the broadcast scenario and the interactive communication scenario. We provide bounds in the broadcast setting and a complete characterization of the solution under a mild condition on the target joint distribution in the interactive communication case. Our proofs are based on a Renyi entropy method.

关键词： Symbols Encoding Random variables Decoding Entropy Delays Receivers Channel synthesis sequential coding Renyi entropy hybrid digital-analog coding symbol-by-symbol mapping

来源：评论

学校读者我要写书评

暂无评论

Design and performance of VQ-based hybrid digital-analog joint source-channel codes

引用

IEEE TRANSACTIONS ON INFORMATION THEORY 2002年第3期48卷 708-720页

作者： Skoglund, M Phamdo, N Alajaji, F Royal Inst Technol Dept Signals Sensors & Syst SE-10044 Stockholm Sweden SUNY Stony Brook Dept Elect & Comp Engn Stony Brook NY 11794 USA Queens Univ Dept Math & Stat Kingston ON K7L 3N6 Canada Queens Univ Dept Elect & Comp Engn Kingston ON K7L 3N6 Canada

A joint source-channel hybrid digital-analog (HDA) vector quantization (VQ) system is presented. The main advantage of the new VQ-based HDA system is that it achieves excellent rate-distortion-capacity performance at the design signal-to-noise ratio (SNR) while maintaining a "graceful improvement" characteristic at higher SNRs. It is demonstrated that, within the HDA framework, the parameters of the system can be optimized using an iterative procedure similar to that of channel-optimized vector quantizer design. Comparisons are made with three purely digital systems and one purely analog system. It is found that, at high SNRs, the VQ-based HDA system is superior to the other investigated systems. At low SNRs, the performance of the new scheme can be improved using the optimization procedure and using soft decoding in the digital part of the system. These results demonstrate that the introduced scheme provides an attractive method for terrestrial broadcasting applications.

关键词： broadcasting hybrid digital-analog coding joint source-channel coding robust transmission source coding vector quantization (VQ)

来源：评论

学校读者我要写书评

暂无评论

HoloCast plus : hybrid digital-analog Transmission for Graceful Point Cloud Delivery With Graph Fourier Transform

引用

IEEE TRANSACTIONS ON MULTIMEDIA 2022年 24卷 2179-2191页

作者： Fujihashi, Takuya Koike-Akino, Toshiaki Watanabe, Takashi Orlik, Philip V. Osaka Univ Grad Sch Informat Sci & Technol Suita Osaka 5650871 Japan Mitsubishi Elect Res Labs MERL Cambridge MA 02139 USA

Point cloud is an emerging data format useful for various applications such has holographic display, autonomous vehicle, and augmented reality. Conventionally, communications of point cloud data have relied on digital compression and digital modulation for three-dimensional (3D) data streaming. However, such digital-based delivery schemes have fundamental issues called cliff and leveling effects, where the 3D reconstruction quality is a step function in terms of wireless channel quality. We propose a novel scheme of point cloud delivery, called HoloCast+, to overcome cliff and leveling effects. Specifically, our method utilizes hybrid digital-analog coding, integrating digital compression and analog coding based on graph Fourier transform (GFT), to gracefully improve 3D reconstruction quality with the improvement of channel quality. We demonstrate that HoloCast+ offers better 3D reconstruction quality in terms of the symmetric mean square error (sMSE) by up to 183 dB and 10.5 dB, respectively, compared to conventional digital-based and analog-based delivery methods in wireless fading environments.

关键词： Point Cloud hybrid digital-analog coding Graph Signal Processing Wireless Transmission

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：