We consider the coding problem for lossy source coding with side information at the decoder, which is known as the Wyner-Ziv source coding problem. The goal of the coding problem is to find the minimum rate such that the probability of exceeding a given distortion threshold is less than the desired level. We give an equivalent expression of the minimum rate by using the chromatic number and notions of covering of a set. This allows us to analyze the coding problem in terms of graph coloring and covering.

Green cognitive radio (CR) plays an important role in offering secondary users (SUs) with more spectrum with smaller energy expenditure. However, the energy efficiency (EE) issues associated with green CR for fading channels have not been fully studied. In this paper, we investigate the average EE maximization problem for spectrum-sharing CR in fading channels. Unlike previous studies that considered either the peak or the average transmission power constraints, herein, we considered both of these constraints. Our aim is to maximize the average EE of SU by optimizing the transmission power under the joint peak and average transmit power constraints, the rate constraint of SU and the quality of service (QoS) constraint of primary user (PU). Specifically, the QoS for PU is guaranteed based on either the average interference power constraint or the PU outage constraint. To address the non-convex optimization problem, an iterative optimal power allocation algorithm that can tackle the problem efficiently is proposed. The optimal transmission powers are identified under both of perfect and imperfect channel side information (CSI). Simulations show that our proposed scheme can achieve higher EE over the existing scheme and the EE achieved under perfect CSI is better than that under imperfect CSI.

In this paper, we consider a source coding with side information partially used at the decoder through a codeword. We assume that there exists a relative delay (or gap) of the correlation between the source sequence and side information. We also assume that the delay is unknown but the maximum of possible delays is known to two encoders and the decoder, where we allow the maximum of delays to change by the block length. In this source coding, we give an inner bound and an outer bound on the achievable rate region, where the achievable rate region is the set of rate pairs of encoders such that the decoding error probability vanishes as the block length tends to infinity. Furthermore, we clarify that the inner bound coincides with the outer bound when the maximum of delays for the block length converges to a constant.

We analyze the error performance of coding for ordered random variables with side information at the decoder, where encoder input as well as side information are deliberately extracted from the output of correlated sources. A tight upper bound on error probability is derived for linear encoding, and minimum distance decoding for a binary source and Gaussian distributed side information. Some features caused by the signal extraction are discussed.

In this paper, we consider the lossy source coding problem with delayed side information at the decoder. We assume that delay is unknown but the maximum of delay is known to the encoder and the decoder, where we allow the maximum of delay to change with the block length. In this coding problem, we show an upper bound and a lower bound of the rate-distortion (RD) function, where the RD function is the infimum of rates of codes in which the distortion between the source sequence and the reproduction sequence satisfies a certain distortion level. We also clarify that the upper bound coincides with the lower bound when maximums of delay per block length converge to a constant. Then, we give a necessary and sufficient condition in which the RD function is equal to that for the case without delay. Furthermore, we give an example of a source which does not satisfy this necessary and sufficient condition.

Single view distributed video coding (DVC) is a coding method that allows for the computational complexity of the system to be shifted from the encoder to the decoder. This property promotes the use of DVC in systems where processing power or energy use at the encoder is constrained. Examples include wireless devices and surveillance. This paper proposes a multi-hypothesis transform domain single-view DVC system that performs symbol level coding with a non-binary low-density parity-check code. The main contributions of the system relate to the methods used for combining multiple side information hypotheses at the decoder. The system also combines interpolation and extrapolation in the side information creation process to improve the performance of the system over larger group-of-picture sizes.

In the letter, we propose an improved histogram shifting (HS) based reversible data hiding scheme for small payload embedding. Conventional HS based schemes are not suitable for low capacity embedding with relatively large distortion due to the inflexible side information selection. From an analysis of the whole HS process, we develop a rate-distortion model and provide an optimal adaptive searching approach for side information selection according to the given payload. Experiments demonstrate the superior performance of the proposed scheme in terms of performance curve for low payload embedding.

The overflow probability is one of criteria that evaluate the performance of fixed-to-variable length (FV) codes. In the single source coding problem, there were many researches on the overflow probability. Recently, the source coding problem for correlated sources, such as Slepian-Wolf coding problem or source coding problem with side information, is one of main topics in information theory. In this paper, we consider the source coding problem with side information. In particular, we consider the FV code in the case that the encoder and the decoder can see side information. In this case, several codes were proposed and their mean code lengths were analyzed. However, there was no research about the overflow probability. We shall show two lemmas about the overflow probability. Then we obtain the condition that there exists a FV code under the condition that the overflow probability is smaller than or equal to some constant.

In this paper, side information refinement methods for Wyner-Ziv video codec are presented. In the proposed method, each block of a Wyner-Ziv frame is separated into a predefined number of groups, and these groups are interleaved to be coded. The side information for the first group is generated by the motion compensated temporal interpolation using adjacent key frames only. Then, the side information for remaining groups is gradually refined using the knowledge of the already decoded signal of the current Wyner-Ziv frame. Based on this basic concept, two progressive side information refinement methods are proposed. One is the band-wise side information refinement (BW-SIR) method which is based on transform domain interleaving, while the other is the field-wise side information refinement (FW-SIR) method which is based on pixel domain interleaving. Simulation results show that the proposed methods improve the quality of the side information and rate-distortion performance compared to the conventional side information refinement methods.

This paper presents a paraunitary filter bank (PUFB) based on a direct lifting structure of a building block and its inverse transform for lossless-to-lossy image coding. Although the conventional lifting-based filter banks (LBFBs), which are constructed by lifting structures with integer coefficients and rounding operations, suffer from degradation of coding performance due to much rounding error generated by cascading lifting structures, our proposals can be applied to any PUFB without losing many ones because building blocks can be applied to every lifting block as it is. It is constructed with very simple structures and many rounding operations are eliminated. Additionally, the number of rounding operations is reduced more by using two-dimensional block transform (2DBT) of separated transform to each building block. As result, even though the proposed PUFBs require a little side information block (SIB), they show better coding performance in lossless-to-lossy image coding than the conventional ones.

This paper proposes a joint source-channel coding technology to transmit periodic vital information such as an electrocardiogram. There is an urgent need for a ubiquitous medical treatment space in which personalized medical treatment is automatically provided based on measured vital information. To realize such treatment and reduce the constraints on the patient, wireless transmission of vital information from a sensor device to a data aggregator is essential. However, the vital information has to be correctly conveyed through wireless channels. In addition, sensor devices are constrained by their battery power. Thus, a coding technique that provides robustness to noise, channel efficiency and low power consumption at encoding is essential. This paper presents a coding method that uses correlation of periodic vital information in the time domain, and provides a decoding scheme that uses the correlation as side information in a maximum a posteriori probability algorithm. Our results show that the proposed method provides better performance in terms of mean squared error after decoding in comparison to differential pulse-code modulation, and the uncoded case.

This letter proposes a method to retrieve the original image X out of multiple sets of SI (Side Information) in distributed video coding (DVC). Using Turbo decoding methods, the most reliable segments from the decoded Yi's were selected for the composition of Y∞, whose conditional entropy H(X| Y∞) became much lower than any individual conditional entropy H(X| Yi). This proposal has improved the peak signal-to-noise ratio (PSNR) by 1.1 to 1.8 dB, compared to the conventional single SI-based approach.

In order to reduce the peak-to-average power ratio (PAPR) of orthogonal frequency division multiplexing (OFDM) signals over fading channels, the selected mapping (SLM) scheme and channel estimation technique can be used. Because of the side information of SLM, however, the data rate decreases in the conventional transmission method. In this letter, to overcome this impairment, we propose a technique which transmits side information by using pilot tones. Numerical analysis and computer simulations show that this method can maintain the PAPR reduction ability of SLM while improving error performance.

This paper clarifies the adequacy of the linear channel coding approach for the source coding with partial side information at the decoder. A sufficient condition for an ensemble of linear codes which achieves the Wyner's bound is given. Our result reveals that, by combining a good lossy code, an LDPC code ensemble gives a good code for source coding with partial side information at the decoder.

We consider the blind recovery problem such that images embedded with side information are given, and we want to obtain the side information under some prescribed constraints. In this case, the system equation becomes y=Ax+b where in addition to the unknown A and x, b also is an unknown quantity and but clearly not a noise component. We assume that several images with the same embedding side information are given, and the image processing to b is described as the perturbation of A. We formulate the optimization function to obtain A, b and x, under the constraint of some finite brightness levels i.e. finite alphabets.

List decoding is a process by which a list of decoded words is output instead of one. This works for a larger noise threshold than the traditional algorithms. Under some circumstances it becomes useful to be able to find out the actual message from the list. List decoding is assumed to be successful, meaning, the sent message features in the decoded list. This problem has been considered by Guruswami. In Guruswami's work, this disambiguation is done by sending supplementary information through a costly, error-free channel. The model is meaningful only if the number of bits of side information required is much less than the message size. But using deterministic schemes one has to essentially send the entire message through the error free channel. Randomized strategies for both sender and receiver reduces the required number of bits of side information drastically. In Guruswami's work, a Reed-Solomon code based hash family is used to construct such randomized schemes. The scheme with probability utmost ε reports failure and returns the whole list. The scheme doesn't output a wrong message. Also, in Guruswami's work some theoretical bounds have been proved which lower bound the bits of side information required. Here we examine whether the gap between the theoretical bounds and existing schemes may be narrowed. Particularly, we use the same scheme as in Guruswami's work, but use hash families based on Hermitian curve and function fields of Garcia-Stichtenoth tower and analyze the number of bits of side information required for the scheme.

In this letter, we study the capacity of fading channels with perfect channel side information (CSI) at the receiver and quantized CSI at the transmitter. We present a general algorithm for the joint design of optimal quantization and power control for maximizing the forward link capacity over flat fading channels. Numerical results for Rayleigh fading are given.

We propose source coding algorithms that use the randomness of a past sequence. The proposed algorithms solve the problems of multi-terminal source coding, rate-distortion source coding, and source coding with partial side information at the decoder. We analyze the encoding rate and the decoding error rate in terms of almost-sure convergence.

Orthogonal frequency division multiplexing (OFDM) is a possible candidate for the modulation used in mobile multimedia communications because of its robustness to fading and flexibility of transmission rate. Partial transmit sequence (PTS) is an effective technique for reducing the peak power of OFDM signals by means of phase rotation. In PTS, side information (SI) is transmitted to correct the effects of the phase rotation. We propose a new method based on rotationally invariant trellis coded modulation for coded OFDM with PTS. In this method, no SI is required and the few information bits affected by the phase rotation are not used as data. (They are regarded as dummy bits). It is shown that the proposed method yields better bit error rate (BER) performance than other methods using side information under the condition of almost the same transmission rate.

This letter evaluates the peak-to-average power ratio (PAR) performance in a space-time block coded (STBC) multicode CDMA (MC-CDMA) system using a selected mapping (SLM) approach. The ordinary method is to apply the SLM scheme for each transmit antenna individually, while the investigated SLM-based STBC MC-CDMA system selects the transmitted sequence with the lowest average PAR over all transmit antennas concurrently. SLM-based STBC MC-CDMA system retrieves the side information very accurately at the expense of a slight degradation of the PAR performance, which can improve the overall detection performance of the STBC MC-CDMA system in the presence of erroneous side information compared to the ordinary SLM approach.