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LSB steganography and Vigenere chiper methods are integrated in used for data security validation in this study. This approach used Arithmetic Coding method for data compression and data decompression. To maintain the authenticity of the data file, a hash function (SHA 256) technique was added. This paper presents a prototype called Ste-Chy as a proof of concept of the combination of these techniques...
The second-order coding rate for source-channel codes with m levels of unequal message protection (UMP) is derived. The second-order coding rate takes the form of an optimization problem which reduces to separate source-channel coding rate for m = 2. A procedure for solving the given optimization problem is proposed. The proposed procedure exploits the structure of the problem to reduce the optimization...
We show how to replace some of the randomized decisions in the encoding and decoding of polar codes by deterministic decisions. Specifically, we prove that random decisions on low-entropy bits may be replaced by an argmax decision without any loss of performance. We illustrate the usefulness of this result in the case of polar coding for the Wyner-Ziv problem and for channel coding.
Spatially coupled LDPC codes have attracted much attention due to the promising performance. Recursive encoding with low delay and low complexity has been proposed in the literature for selected node degrees. To realize the recursive encoding of spatially coupled LDPC codes with arbitrary rates, we propose in this paper a modified structure of the parity-check matrix and implement the encoding using...
The method of typical sequences is a fundamental tool in asymptotic analyses of information theory. The conditional typicality lemma is one of the most commonly used lemmas in the method of typical sequences. Recent works have generalised the definition of typicality to general alphabets or general probability distributions. However, there is still a lack of the conditional typicality lemma based...
The rate regions of independent distributed source coding (IDSC) problems, a sub-class of the broader family of multi-source multi-sink networks, are investigated. An IDSC problem consists of multiple sources, multiple encoders, and multiple decoders, where each encoder has access to all sources, and each decoder has access to a certain subset of the encoders and demands a certain subset of the sources...
This paper presents a high-throughput structured low density parity check (LDPC) code and an optimal parallel decoder architecture with advanced Ping-Pong RAMs for the HINOC 2.0 systems. An additional iteration scheme is proposed to further improve decoding performance by taking full use of time intervals of the discontinuous streams, an important feature in HINOC 2.0 systems. The proposed LDPC code...
We study the optimization of analog joint source-channel coding schemes based on non-linear mappings for the transmission of independent Gaussian messages over the two user Gaussian Broadcast Channel (GBC). We focus on a low complexity, low delay, analog joint source channel coding communication system based on extensions of existing Nested Quantization techniques. A procedure to optimize the decoding...
This paper addresses a practical aspect of coded on-off keying free-space optical communication systems: quantization of demodulator outputs in receiver. Receivers with and without knowledge of channel state information (CSI) are considered. Proposed quantization schemes for soft decision decoding with CSI are uniform with quantization intervals proportional to channel gains. The schemes are studied...
This paper proposes an improved Logarithmic Maximum A Posteriori (Log-MAP) algorithm for Turbo decoding in the Third Generation Partnership Project Long Term Evolution (3GPP LTE). In the proposed algorithm, we exploit the understanding of polynomial regression function to approximately compute the logarithm term (also called correction function) in the Jacobian logarithmic function. The goal is to...
For digital terrestrial television broadcasting (DT-TB) systems, orthogonal frequency division multiplexing (OFDM) technique is considered to be an effective method to combat the frequency selective channel cause by multi-path effect. In the single frequency network (SFN) scenario, Alamouti space frequency block coding (SFBC) is introduced to provide spatial diversity gain and improve the link stability...
We study classical source coding with quantum side-information where the quantum side-information is observed by a helper and sent to the decoder via a classical channel. We derive a single-letter characterization of the achievable rate region for this problem. The direct part of our result is proved via the measurement compression theory by Winter. Our result reveals that a helper's scheme that separately...
An achievable scheme for zero-delay transmission of an i.i.d. Gaussian source over an additive white Gaussian noise channel with no bandwidth limitation is introduced, and its energy-distortion performance is analyzed. By the nature of the problem, one must transmit each source sample separately but can use the channel infinitely many times. The proposed scheme builds on separation of source and channel...
When transmitting information over a noisy channel, two approaches are common: assuming the channel errors are independent of the transmitted content and devising an error-correcting code, or assuming the errors are data dependent and devising a constrained-coding scheme that eliminates all offending data patterns. In this paper we analyze a middle road, which we call a semiconstrained system. In...
Codes with local permutation constraints are described. Belief propagation decoding is shown to require the computation of permanents, and trellis-based methods for computing the permanents are introduced. New insights into the asymptotic performance of such codes are presented. A universal encoder for codes with local constraints is introduced, and simulation results for two code structures, SUDOKU...
The problem of channel coding with the erasure option is revisited for discrete memoryless channels. The interplay between the code rate, the undetected and total error probabilities is characterized. Using the information spectrum method, a sequence of codes of increasing blocklengths n is designed to illustrate this tradeoff. Furthermore, for additive discrete memoryless channels, the ensemble performance...
This paper studies likelihood decoding for channel coding over discrete memoryless channels. It is shown that the likelihood decoder recovers the same random-coding error exponents as the maximum-likelihood decoder for i.i.d. and constant-composition random codes. The role of mismatch in likelihood decoding is studied, and the notion of the mismatched likelihood decoder capacity is introduced. It...
This paper provides a universal framework for establishing one-shot achievability results for coordination and secrecy problems. The framework is built on our previous framework [Yassaee et al. 13] for proving one-shot achievability results in the context of source and channel coding problems. In the coordination and secrecy problems, one needs to compare an induced distribution by encoding/decoding...
We analyze the optimal trade-off between the error exponent and the excess-rate exponent for variable-rate Slepian-Wolf codes. We first derive upper (converse) bounds on the optimal error and excess-rate exponents, and then lower (achievable) bounds, via a simple class of variable-rate codes which assign the same rate to all source blocks of the same type class. The resulting Slepian-Wolf codes bridge...
We consider the model of random binning and finite-temperature (FT) decoding for Slepian-Wolf (SW) codes, from a statistical-mechanical perspective. While ordinary random channel coding is intimately related to the random energy model (REM) in statistical mechanics, it turns out that random binning (for SW coding) is analogous to another, related statistical mechanical model, which we call the random...
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