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A channel coding Perspective of Collaborative Filtering

IEEE TRANSACTIONS ON INFORMATION THEORY 2011年第4期57卷 2327-2341页

作者： Aditya, S. T. Dabeer, Onkar Dey, Bikash Kumar Stanford Univ Informat Syst Lab Stanford CA 94305 USA Tata Inst Fundamental Res Sch Technol & Comp Sci Bombay 400005 Maharashtra India Indian Inst Technol Dept Elect Engn Bombay Maharashtra India

We consider the problem of collaborative filtering from a channel coding perspective. We model the underlying rating matrix as a finite alphabet matrix with block constant structure. The observations are obtained from this underlying matrix through a discrete memoryless channel with a noisy part representing noisy user behavior and an erasure part representing missing data. Moreover, the clusters over which the underlying matrix is constant are unknown. We establish a threshold result for this model: if the largest cluster size is smaller than C-1 log(mn) (where the rating matrix is of size m x n), then the underlying matrix cannot be recovered with any estimator, but if the smallest cluster size is larger than C-2 log(mn), then we show a polynomial time estimator with asymptotically vanishing probability of error. In the case of uniform cluster size, not only the order of the threshold, but also the constant is identified.

关键词： channel coding clustering collaborative filtering matrix completion recommendation systems

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Random Access channel coding in the Finite Blocklength Regime

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IEEE TRANSACTIONS ON INFORMATION THEORY 2021年第4期67卷 2115-2140页

作者： Yavas, Recep Can Kostina, Victoria Effros, Michelle CALTECH Dept Elect Engn Pasadena CA 91125 USA

Consider a random access communication scenario over a channel whose operation is defined for any number of possible transmitters. As in the model recently introduced by Polyanskiy for the Multiple Access channel (MAC) with a fixed, known number of transmitters, the channel is assumed to be invariant to permutations on its inputs, and all active transmitters employ identical encoders. Unlike the Polyanskiy model, in the proposed scenario, neither the transmitters nor the receiver knows which transmitters are active. We refer to this agnostic communication setup as the Random Access channel (RAC). Scheduled feedback of a finite number of bits is used to synchronize the transmitters. The decoder is tasked with determining from the channel output the number of active transmitters, k, and their messages but not which transmitter sent which message. The decoding procedure occurs at a time nt depending on the decoder's estimate, t, of the number of active transmitters, k, thereby achieving a rate that varies with the number of active transmitters. Single-bit feedback at each time ni, i <= t, enables all transmitters to determine the end of one coding epoch and the start of the next. The central result of this work demonstrates the achievability on a RAC of performance that is first-order optimal for the MAC in operation during each coding epoch. While prior multiple access schemes for a fixed number of transmitters require 2(k) - 1 simultaneous threshold rules, the proposed scheme uses a single threshold rule and achieves the same dispersion.

关键词： channel coding random access channel finite blocklength regime achievability second-order asymptotics rateless codes

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Capacity and channel coding for Wireless Point-to-Point Z² channel

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WIRELESS PERSONAL COMMUNICATIONS 2018年第2期98卷 1785-1798页

作者： Tavakoli, Hassan Univ Guilan Dept Elect Engn Fac Engn Rasht Iran

In this paper, we derive the capacity of the asymmetric Z(2)-channel, which has been presented for the first time as an optimization problem. Similar to the Z-channel, the proposed Z(2)-channel can be modelled as a practical interference wireless channel. In addition, the capacity behavior of Z(2)-channel is discussed and some examples and simulation results for the capacity is presented. Also a code plan has been applied for Z(2)-channel, based on repetition code to simulate its performance and compare it with the original Z-channel. In conclusion, simulation results show that the Z(2)-channel can be used widely for different operating points.

关键词： Capacity channel Z-channel Z(2)-channel channel coding

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MINIMAX NONREDUNDANT channel coding

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IEEE TRANSACTIONS ON COMMUNICATIONS 1995年第2-4期43卷 804-811页

作者： POTTER, LC CHIANG, DM Department of Electrical Engineering Ohio State Uinversity Columbus OH USA

The distortion of a message due to channel noise can be alleviated significantly without redundant error control bits by judicious assignment of binary indices to message symbols. The nonredundant coding gain relies only on a notion of distance between symbols. In this paper, we consider the index assignment problem and adopt a minimax design criterion instead of the usual mean squared error (MSE) measure. The problem is found to be NP-hard, and an effective, heuristic, polynomial-time algorithm is presented for computing approximate solutions. The minimax criterion yields greatly improved worst case performance while maintaining good average performance. In addition, the familiar MSE criterion is shown likewise to yield an NP-hard index assignment task. The MSE problem is a special case of the classical Quadratic Assignment Problem, for which computationally and theoretically useful results are available from the discrete mathematics literature.

关键词： Minimax techniques channel coding Error correction Polynomials Heuristic algorithms Mathematics

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Noisy channel coding via Privacy Amplification and Information Reconciliation

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IEEE TRANSACTIONS ON INFORMATION THEORY 2011年第11期57卷 7377-7385页

作者： Renes, Joseph M. Renner, Renato ETH Inst Theoret Phys CH-8093 Zurich Switzerland

We show that optimal protocols for noisy channel coding of public or private information over either classical or quantum channels can be directly constructed from two more primitive information-theoretic protocols: privacy amplification and information reconciliation, also known as data compression with side information. We do this in the one-shot scenario of structureless resources, and formulate our results in terms of the smooth min- and max-entropy. In the context of classical information theory, this shows that essentially all two-terminal protocols can be reduced to these two primitives, which are in turn governed by the smooth min- and max-entropies, respectively. In the context of quantum information theory, the recently-established duality of these two protocols means essentially all two-terminal protocols can be constructed using just a single primitive. As an illustration, we show how optimal noisy channel coding protocols can be constructed solely from privacy amplification.

关键词： channel coding information reconciliation privacy amplification quantum information Slepian-Wolf coding smooth entropies

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Frequency estimation for complex field image channel coding

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IEE PROCEEDINGS-COMMUNICATIONS 2000年第2期147卷 75-80页

作者： Begusic, D Rozic, N Univ Split Fac Elect Engn Mech Engn & Naval Architecture Split Croatia

BCH (Bose-Chaudhuri-Hocquenghem) codes over complex fields in the frequency domain have been proposed for image coding applications as robust channel coding methods. The embedded problem of estimation of complex sinusoids corrupted by white additive noise may be solved in different ways. A standard approach for modelling such signals employs low-order nearly nonstationary autoregressive (AR) models with complex parameters. In the paper linear prediction/least squares based methods are used for parameter estimation including forward linear prediction (FLP) and forward-backward linear prediction (FBLP). The two parameter estimation methods have been applied to the first- and the second-order AR models with minimal number of samples to obtain efficient frequency estimators for decoding of BCH codes. Computer simulation has been carried out to compare different frequency estimation algorithms with regards to three significant criteria: frequency resolution, computing complexity and coding redundancy. The results show that different algorithms exhibit optimal combinations of characteristics for different constraints and Importance of criteria.

关键词： Frequency estimation BCH codes Parameter estimation Random number sampling complex parameter image coding DEcoding Additive noise Frequency-domain analysis linear prediction Computer Simulation channel coding

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A Generalized channel coding Theory for Distributed Communication

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IEEE TRANSACTIONS ON COMMUNICATIONS 2015年第4期63卷 1043-1056页

作者： Luo, Jie Colorado State Univ Elect & Comp Engn Dept Ft Collins CO 80523 USA

This paper presents generalized channel coding theorems for a time-slotted distributed communication system where a transmitter-receiver pair is communicating in parallel with other transmitters. Assume that the channel code of each transmitter is chosen arbitrarily in each time slot. The coding choice of a transmitter is denoted by a code index parameter, which is known neither to other transmitters nor to the receiver. Fundamental performance limitation of the system is characterized using an achievable region defined in the space of the code index vectors. As the codeword length is taken to infinity, for all code index vectors inside the region, the receiver will decode the message reliably, while for all code index vectors outside the region, the receiver will report a collision reliably. A generalized system error performance measure is defined as the weighted sum of probabilities of different types of communication error events. Assume that the receiver chooses an "operation region" and intends to decode the message if the code index vector is inside the operation region. Achievable bounds on the tradeoff between the operation region and the generalized error performance measure are obtained under the assumption of a finite codeword length.

关键词： channel coding distributed communication error performance

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Investigating the Effect of Different channel coding on the Performance of Sparse Code Multiple Access over AWGN channel

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WIRELESS PERSONAL COMMUNICATIONS 2023年 1-21页

作者： Muhammed, Younus A. Yousif, Raghad Z. Soran Univ Coll Sci Dept Comp Sci Soran KRG Iraq Salahaddin Univ Erbil Coll Sci Dept Phys Erbil KRG Iraq Catholic Univ Erbil Coll Informat Technol Dept IT Erbil KRG Iraq

The next generation of wireless communication systems requires simultaneous and reliable connectivity on a huge scale. Selecting the proper channel coding for sparse code multiple access (SCMA) as code domain non-orthogonal multiple access techniques is crucial for meeting the needs of the internet of things (IoT), which is the foundational technology in fifth generation wireless networks (5G). SCMA is a multiplexing technology that maximizes spectrum efficiency while increasing accessibility. In this research, the bit error rate (BER) of three joint systems has been compared: Joint Turbo code and SCMA (JTCSCMA), Joint low density parity check (LDPC) code and SCAM (JLC-SCMA), and Joint Polar code and SCMA (JPC-SCMA) for downlink sites supporting the IoT. Thus, the channel coder parameters of the proposed systems have been examined in an effort to enhance the overall performance of the combined systems. The simulation results demonstrated that the JPC-SCMA system outperformed other suggested systems over an AWGN channel while requiring less computational complexity. At BER 10(-4), the JPC-SCMA system exhibited an SNR improvement of 1 dB over JLC-SCMA and 2.8 dB over JTC. Additionally, at BER 10(-2), it was observed that JPC-SCMA produced a gain of 4.5 dB at iteration 5 with interleaved case.

关键词： SCMA channel coding MPA Decoding algorithm

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Nonlinear Transform Source-channel coding for Semantic Communications

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IEEE JOURNAL ON SELECTED AREAS IN COMMUNICATIONS 2022年第8期40卷 2300-2316页

作者： Dai, Jincheng Wang, Sixian Tan, Kailin Si, Zhongwei Qin, Xiaoqi Niu, Kai Zhang, Ping Beijing Univ Posts & Telecommun Minist Educ Key Lab Universal Wireless Commun Beijing 100876 Peoples R China Beijing Univ Posts & Telecommun State Key Lab Networking & Switching Technol Beijing 100876 Peoples R China Peng Cheng Lab Shenzhen 518066 Peoples R China

In this paper, we propose a class of high-efficiency deep joint source-channel coding methods that can closely adapt to the source distribution under the nonlinear transform, it can be collected under the name nonlinear transform source-channel coding (NTSCC). In the considered model, the transmitter first learns a nonlinear analysis transform to map the source data into latent space, then transmits the latent representation to the receiver via deep joint source-channel coding. Our model incorporates the nonlinear transform as a strong prior to effectively extract the source semantic features and provide side information for source-channel coding. Unlike existing conventional deep joint source-channel coding methods, the proposed NTSCC essentially learns both the source latent representation and an entropy model as the prior on the latent representation. Accordingly, novel adaptive rate transmission and hyperprior-aided codec refinement mechanisms are developed to upgrade deep joint source-channel coding. The whole system design is formulated as an optimization problem whose goal is to minimize the end-to-end transmission rate-distortion performance under established perceptual quality metrics. Across test image sources with various resolutions, we find that the proposed NTSCC transmission method generally outperforms both the analog transmission using the standard deep joint source-channel coding and the classical separation-based digital transmission. Notably, the proposed NTSCC method can potentially support future semantic communications due to its content-aware ability and perceptual optimization goal.

关键词： Encoding Transforms channel coding Entropy Image coding Semantics Standards Semantic communications nonlinear transform joint source-channel coding rate-distortion perceptual loss

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Combined source-channel coding using turbo-codes

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ELECTRONICS LETTERS 1997年第19期33卷 1613-1614页

作者： Bakus, J Khandani, AK Univ Waterloo Dept Elect & Comp Engn Waterloo ON N2L 3G1 Canada

The authors present a new approach to combined source-channel coding based on using the reliability information available from the Turbo-code channel decoder. Numerical results are presented for the transmission of the DCT coefficients of still images showing a noticeable improvement with respect to an ordinary, as well as a channel optimised quantiser.

关键词： source coding channel coding turbo codes

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