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In this paper, we develop Prioritized Adaptive Code-Enhanced (PACE) link-layer protocol to achieve preferred data recovery order across connections, while maintaining stable and reliable data flow over a wireless network. We classify link-layer traffic arrivals into different priorities based on delay constraint and distortion associated with that traffic. We formulate the link-layer buffer as a multiclass...
One method for reducing the decoding complexity of network coding in wireless broadcast systems is to generate sparse encoding vectors. The problem of finding the minimal Hamming weight of innovative encoding vectors over large finite field is formulated. By reducing the problem of hitting set to it, we show that the problem is NP-hard. However when the number of users is fixed, the problem can then...
We consider the design of an efficient streaming system for live video over peer-to-peer networks. Such a system must accommodate for large populations of heterogeneous users, behave robustly irrespective of user dynamics and ensure prescribed levels of quality of experience. Seeking a solution capable of addressing also the lack of incentives for peer-to-peer collaboration and the scarcity of certain...
When a live streaming video is delivered over a peer-to-peer (P2P) network, the chunk delay is always a problem of great concern. A serious chunk delay can produce obvious discontinuity of the streaming video, resulting in low satisfaction of the service. Video on P2P is divided into several chunks and distributed to the peers. Each chunk has its own playback time deadline. The playback time of a...
A phase-based delta-sigma analog-to-digital converter (ADC) architecture with a combination voltage-controlled and digitally-controlled delay lines (VCDL-DCDL) is presented. The architecture uses this VCDL-DCDL combination as the phase-domain counterparts of an ADC-DAC in a traditional delta-sigma modulator. Simulation results of the new modulator achieve a 60.1 dB SNR, or a 9.7 bit over a 10 MHz...
In order to address the long runtimes required to fully simulate hybrid automatic repeat-request (ARQ) systems, such as high-speed downlink packet access (HSDPA), we propose an information-theoretic approach to accelerate the simulation while still maintaining its fidelity. The approach is based on the concept of information-outage probability, and involves the computation of the mutual information...
Malicious packet dropping attack is a major security threat to the data traffic in the sensor network, since it reduces the legal network throughput and may hinder the propagation of sensitive data. Dealing with this attack is challenging since the unreliable wireless communication feature and resource constraints of the sensor network may cause communication failure and mislead to the incorrect decision...
In this paper, Advanced Adaptive Image Coding (AAIC) is proposed to increase compression performance for frame delay memory applications. The AAIC contains two techniques to improve the quality of decompressed images. The first is a Mean Adaptive Image Coding (MAIC) to reduce the impact of noise on image compression. The second is a Content-based Bit Exchange Technique (CBBET) to provide an adaptive...
A new coding concept called credit-based variable-to-variable length (cbv2v) coding is proposed in this paper. A binary cbv2v code is constructed, and analysis of its performance shows that cbv2v coding can achieve much better trade-off among the coding delay, redundancy, and space complexity than does variable-to-variable length (v2v) coding. Specifically, let L be the total number of source words...
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...
A sender and receiver are connected by two links, which both pass through a burst erasure channel. The channel induces an erasure burst of length B onto both links, but the bursts are separated by d time units. Source packets arrive at the sender, and are encoded with a streaming code such that the receiver can decode with a delay T. If source packet s[t] arrives at the sender at time t, then the...
The paper describes the transmission of BPSK signals in an OFDM system with 64-point IFFT at transmitter and FFT at receiver. The channel over which transmission will take place is ISI Rayleigh fading channel given by 2 tap channel model with path delay [0, 0.5] μs. The sampling frequency of OFDM is to be kept at 20MHz. Cyclic prefix for OFDM is calculated for improving bandwidth efficiency of the...
This paper presents a CMOS 1.1–2.8 GHz 10 bits digitally controlled oscillator (DCO) for high speed clocking of SoCs. The DCO includes only 269 tuning cells, which is possible thanks to an original algorithm based on weighted combined thermometer code, used for the DCO frequency control. The control circuit of the DCO includes only binary-to-thermometer decoders: that was possible with the proposed...
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...
Short-range wireless audio transmission with high quality on the one hand often encounters error-prone channels, while on the other hand decoding delay plays a critical role in the application. A lot of prior art in audio error concealment is either only intuitively motivated or adds too much delay to the transmission. In this paper we propose a framework for transmitted audio error concealment without...
We propose two new protocols based on physical layer network coding for collision resolution in multiple access networks.When a collision occurs the receiver decodes the sum of the collided packets and after a number of transmissions, equal to or slightly higher than the number of original packets, it can recover all of them. One of the proposed protocols based on fountain codes can resolve collisions...
An improved algebraic decoding algorithm (ADA) is presented to decode up to five possible errors in a binary systematic (47, 24, 11) quadratic residue (QR) code. The main idea of the improved ADA is to find out the new conditions in four-error and five-error cases and the smallest degree of the unknown syndrome polynomial in five-error case. Thus, the computational complexity in the finite field can...
This paper proposes a method to optimize the performance of tandem source-channel coding with respect to the mean-squared error by exploiting the unequal error protection coding. More specifically, we formulate a combination of linear programming and grid search to optimize degree distributions for unequal error protected rateless channel codes. An asymptotic upper bound for the mean-squared error...
This paper evaluates the performance of FASTAR code in Multimedia Broadcast Multicast Service (MBMS) System. It is demonstrated that FASTAR code, which is optimised for erasure channel through its overhead minimising degree distribution, can improve the system performance compared to the conventional systematic Raptor code. The system is simulated under the Evolved UMTS Terrestrial Radio Access (E-UTRA)...
Coordination between two or more multiple access channel (MAC) receivers can enlarge the achievable rate region of the whole system. This paper focuses on coordination by sharing the codebooks of the users between the receivers of MACs. We first define the achievable rate region of the time invariant multiple coordinated MAC (MCMAC) and subsequently derive its achievable rate region. We later express...
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