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This paper uses a nested lattice chain to perform lattice coding and decoding for a Gaussian wiretap channel, in which we derive the achievable rates and the equivocation rate. We also show that it is possible to achieve the equivocation rate of the classical Gaussian wiretap channel, and meet the reliability and security criteria using the nested lattice construction.
We consider the joint source-channel coding problem of sending a Gaussian source over a single input-single output (SISO) fading channel when the decoder has additional correlated side information whose quality is also time-varying. We assume a block fading model for both the channel and side information qualities, and assume perfect state information at the receiver, while the transmitter has only...
A reliability-based iterative majority-logic decoding algorithm for regular low-density parity-check (LDPC) codes was recently proposed by Huang et al. In this paper we present an improved version of that algorithm by introducing a different reliability measure for each check-sum of the parity-check matrix, and taking it into account in the computation of the extrinsic information that is used to...
We consider the problem of bandwidth expansion for lossy joint source-channel coding over a memoryless Gaussian channel. A low delay 1:3 bandwidth expansion hybrid digital-analog coding system, which combines a scalar quantizer and a 1:2 nonlinear analog coder, is proposed. It is shown that our proposed system outperforms the 1:3 generalized hybrid scalar quantizer linear coder in terms of signal-to-distortion...
Causal video coding is a coding paradigm where video source frames are encoded in a frame by frame manner, the encoder for each frame can use all previous frames and all previous encoded frames, and the corresponding decoder can use only all previous encoded frames. In this paper, the design of causal video coding is considered from an information theoretic perspective by modeling each frame as a...
In this paper, a quantization scheme based on hard-decision partition and adaptive reconstruction levels is proposed for High Efficiency Video Coding (HEVC), the video coding standard currently under development, which has demonstrated approximately 40% bit saving compared to H.264/AVC. For each video frame, the residual signal after motion estimation is transformed and then quantized by a hard-decision...
For decoding non-binary low-density parity-check (LDPC) codes, logarithm-domain sum-product (Log-SP) algorithms were proposed for reducing quantization effects of SP algorithm in conjunction with FFT. Since FFT is not applicable in the logarithm domain, the computations required at check nodes in the Log-SP algorithms are computationally intensive. What is worse, check nodes usually have higher degree...
Layered structure is widely used in the design of Low-Density Parity-Check (LDPC) code decoders due to its fast convergence speed. However, correct checking process is difficult to implement in layered decoder, which results in unnecessary iterations. In this paper, an early termination strategy is presented for layered LDPC decoder to avoid redundant number of iterations. This approach makes use...
Although great achievements have been obtained in the past, recent developments towards ultra high definition video have been asking for further compression efficiency gains regarding the H.264/AVC state-of-the-art. As an answer to these needs, ITU-T and MPEG started a new standardization project called High Efficiency Video Coding. This paper extends and integrates a perceptual visual model in the...
Practical codes are developed for quadratic Gaussian lossy compression when side information may be absent by hybridizing successively refinable trellis coded quantization (SR-TCQ) and low-density parity-check (LDPC) codes. A 2-refinement level SR-TCQ is used to generate a common description for both decoders and an individual description for the decoder with side information. Then, the common description...
In applications to secured diffusion of digital images, several watermarking solutions have been studied in the field of Data Hiding. For this aim, the main idea consists in embedding an information in the digital media with good properties in terms of robustness, capacity and invisibility (perceptual transparency and statistical undetectability). Recent studies has highlighted the importance of statistical...
Recent work for single-relay channels shows that quantize-forward (QF) with long-message encoding achieves the same reliable rates as compress-forward (CF) with short-message encoding. It is shown that short-message QF with backward or pipelined (sliding-window) decoding also achieves the same rates. Similarly, for many relays and sources, short-message QF with backward decoding achieves the same...
Canonical distributed quantization schemes do not scale to large sensor networks due to the exponential decoder storage complexity that they entail. Prior efforts to tackle this issue have largely been limited to the suboptimal schemes of source grouping and decoding, thus failing to use all available information at the decoder. We propose a new decoding paradigm where all received bits are used in...
In this work Weber's law is followed for designing a perceptually-shaped side-informed data hiding scheme. The resulting method is a generalized version of a logarithmic quantization algorithm previously proposed by the authors. Closed formulas for analyzing the embedding power and decoding error probability of this new method are provided, and experimental results showing its good behavior against...
We present techniques for processing MPEG-audio encoded signals during the decoding process, using efficient fixed-point arithmetic operations. A large signal-to-quantization-noise-ratio is achieved over a large range of input levels. By taking advantage of MPEG-audio built-in properties, quantization distortion at the outputs of our systems is kept largely inaudible, even though only low-resolution...
This paper presents a network-adaptive multiple description coding (MDC) method for enhanced video streaming over multipath channels. The novel feature of the proposed MDC network adaptation scheme is the generation of a controlled amount of side information to compensate for drift distortion due to packet loss. This yields higher robustness of multiple description (MD) H.264/AVC streams than single...
We analyze the fundamental limits of key generation and describe an implementation based on error correcting codes. We show that key extraction based on channel coefficients significantly outperforms key extraction based on received signal strength indicators (RSSI). The development in this paper is based on an IEEE 802.11a orthogonal frequency-division multiplexing (OFDM) model and We demonstrate...
This paper introduces an adaptive scanning order for bitplane image coding engines, which is devised from a rate-distortion optimization perspective that uses recent advances in coefficient modeling and distortion estimation. The main idea is to always select the next coefficient to be coded so that image distortion and code stream length are minimized. The sequence of visited coefficients is adapted...
A new semantic steganographic algorithm for hiding data in the motion trajectories of Video Objects (VOs) is presented. First, a set of primitives (objects bounding-box coordinates and its centroid) are used to dene a VO. The centroid of VO is tracked in each frame and its coordinate is stored in a trajectory vector. The proposed algorithm embeds data in the VO object trajectory by presenting a relationship...
Compressive sensing (CS) is recently and enthusiastically promoted as a joint sampling and compression approach. The advantages of CS over conventional signal compression techniques are architectural: the CS encoder is made signal independent and computationally inexpensive by shifting the bulk of system complexity to the decoder. While these properties of CS allow signal acquisition and communication...
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