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Motion estimation as well as the corresponding motion compensation is a core part of modern video coding standards, which highly improves the compression efficiency. On the other hand, motion information takes considerable portion of compressed bit stream, especially in low bit rate situation. In this paper, an efficient motion vector prediction algorithm is proposed to minimize the bits used for...
Multi-class classifier is usually constructed by means of combining the outputs of several binary ones, according to an error correcting output code (ECOC) scheme. In the paper, within the framework of ECOC, we analyse of the ECOC of kernel machines originally proposed before. Then we present the generalization bounds of the ECOC of kernel machines according to the results of stability and generalization...
In this paper, we propose a new Distributed Video Coding (DVC) architecture where motion estimation is performed both at the encoder and decoder, effectively combining global and local motion models. We show that the proposed approach improves significantly the quality of Side Information (SI), especially for sequences with complex motion patterns. In turn, it leads to rate-distortion gains of up...
Distributed Video Coding (DVC) provides a new coding paradigm based on lower complex encoders than decoders. On the decoder side some missed frames have to be estimated by means of available frames and a correlation noise model. In addition, parity bit chunks can be requested to the encoder across the feedback channel to correct the mismatches of these frames. This is an iterative procedure which...
Side information construction in Wyner-Ziv video coding is a sensible task which strongly influences the final ratedistortion performance of the scheme. This side information is usually generated through an interpolation of the previous and next images. Some of the zones of a scene however, such as the occlusions, cannot be estimated with other frames. In this paper we propose to avoid this problem...
Multiple description coding is a framework adapted to noisy transmission environments. In this work, we use H.264 to create two descriptions of a video sequence, each of them assuring a minimum quality level. If both of them are received, a suitable algorithm is used to produce an improved quality sequence. The key technique is a temporal image interpolation using motion compensation, inspired to...
This paper investigates a communication system where three terminals exchange their information with each other with the help of a relay. One joint network and channel coding (JNCC) scheme (based on iterative soft information exchange between channel and network decoder) and one separate network and channel coding scheme based on turbo codes are proposed. The outage behavior of the presented systems...
In this paper, we assess the random coding error exponents (EEs) corresponding to decode-and-forward (DF), compress-and-forward (CF) and quantize-and-forward (QF) relaying strategies for a parallel relay network (PRN), consisting of a single source and two relays. Moreover, through numerical analysis we show that the EEs achieved by using QF relaying along with non-Gaussian signaling (coded modulation,...
In this paper, we present a novel rateless code which outperforms LT-code, since it is adapted for network coding. To reduce the delay incurred at the intermediate nodes because of decoding and re-encoding, we design and analyze a novel degree distribution which we call Switched Distribution. This distribution increases the delivery ratio at the decoder even when few encoded symbols are received....
Video streaming over wireless connections remains a challenge today: even when data link and transport layer protocols are tuned to avoid retransmissions and thus reduce the delay and the used bandwidth, the impact on the perceived video quality of imperfect and band-limited radio channels is not negligible. This phenomenon is even more pronounced in multi-hop ad-hoc networks, where the received video...
Dynamic spectrum access (DSA) supporting opportunistic transmission without extra spectrum bandwidth is attractive for future wireless communication. To facilitate such DSA system, a power-efficient (green) communication processor is needed to support extremely high speed operation on a power-limited mobile device. Traditional general-purpose and digital signal processors are unable to simultaneously...
In this paper, we present a low-complexity list sphere search algorithm for achieving near-optimal a posteriori (APP) detection in iterative detection and decoding (IDD). Motivated by the fact that the list sphere decoding searching fixed number of lattice points is inefficient in many scenarios, we design a criterion to search lattice points with non-vanishing likelihood and derive the optimal sphere...
A two-stage coding scheme incorporated with a square M-quadrature amplitude modulation (QAM) scheme is proposed to realize multiple non-discrete data rates while reducing the packet error rate (PER) at small packet sizes. Subject to the intended code rate, Turbo-coded parity packets are generated through bit-wise XOR combinations of the source packets to provide additional soft information which can...
Low Density Parity Check (LDPC) codes have been adopted in a number of wired and wireless communication standards due to their improved error correcting ability and relatively simple decoder structure. However, for very high throughput systems operating in the multi-Gb/s range conventional decoding methods based on message passing are limited, due largely to the sheer volume of messages being exchanged...
This paper addresses mobile terminal (MT) relaying in order to improve the performance of mobile satellite broadcasting. It considers selective decode-and-forward (SDF) relaying with BICM-OFDM air interface. The BER upper bound was derived for the threshold-based SDF relaying in Rician fading channels. The suboptimal SNR threshold was then obtained by minimising this analytical upper bound. This scheme...
Air bandwidth is a precious resource for wireless communication. Multiple-antenna (MIMO) systems enable an increase in channel capacity without increasing the air bandwidth. An iterative demapping and decoding at the receiver improves the communications performance remarkably. However, MIMO demapping and channel decoding have a high computational complexity. Energy consumption, latency and throughput...
The exact expressions for symbol error probability and outage probability of randomized distributed space-time codes (RDSTC) under Rayleigh fading are derived. The diversity gain derived in the literature uses the Chernoff bound which may not be achievable in general. Utilizing the exact expression, the achievable diversity gain of RDSTCs is validated. The analytical expressions are verified by Monte-Carlo...
This paper mostly concerned with the various packet size effect on performance of erasure correctable codes for cognitive radio. Among these types of codes we tried to simulate Raptor code to discover its suitability for assumed erasure channel in cognitive radio. The main target after supporting the functionality of coding-based cognitive radio would be finding the appropriate packet length that...
In densely deployed wireless sensor networks, observations of the sensor nodes are spatially correlated. In this paper, we study a joint channel decoding scheme utilizing bit correlation of the sensor observations according to bit levels of analog-digital converter (ADC). If sensor ADC output is interpreted as natural binary numeral, carry propagation may occur between adjacent ADC output values....
Wyner's work on wiretap channels and the recent works on information theoretic security are based on random codes. Achieving information theoretical security with practical coding schemes is of definite interest. In this note, the attempt is to overcome this elusive task by employing the polar coding technique of Arikan. It is shown that polar codes achieve nontrivial perfect secrecy rates for binary-input...
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