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This paper presents a capacity analysis of a decode-and-forward (DF) cooperative network with adaptive source transmission. Three different adaptive techniques are considered: (i) optimal simultaneous power and rate adaptation (OPRA); (ii) constant power with optimal rate adaptation (ORA); (iii) truncated channel inversion with fixed rate (TIFR). Closed form capacity expressions are derived for non-identical...
BitTorrent and practical network coding are efficient methods for sharing files in a peer-to-peer network. Both face the problem to distribute a given file using peers with different and dynamic bandwidth and only temporal availability. For this, BitTorrent partitions the files and uses the upload and download of each peer. In addition to this, practical network coding uses a random linear combination...
The output distribution, when rate is above capacity, is investigated. It is shown that there is an asymptotic equipartition property (AEP) of the typical output sequences, independently of the specific codebook used, as long as the codebook is typical according to the standard random codebook generation. This equipartition of the typical output sequences is caused by the mixup of input sequences...
In this paper a fast version of the parallel weighted bit flipping LDPC decoding algorithm (PWBF) is presented. The idea, which allowed decreasing the computational complexity of the PWBF method, is based on the observation that in dependency on signal to noise ratio, many of the received bits in the codeword of LDPC code could be without error. The augmented algorithm makes tests based on syndromes...
We study analog decoders in an abstract level and show that their dynamic equations can change with message representation domain. This result, which is in contrast with the behavior of conventional discrete-time iterative decoders, is derived based on continuity requirement for messages that are passed between processing nodes in analog decoders. In this paper, this requirement is met by assigning...
Flash memories are the most widely used type of non-volatile electronic memories. Every flash memory cell has q discrete levels for storing information. A prominent property of flash memories is that although it is easy to increase a cell level, to decrease any cell level, a whole block of cells have to be erased and reprogrammed. To minimize the number of expensive block erasure operations and to...
An adaptive, invariant to user performance fluctuation or noisy input signal, gesture recognition scheme is presented based on Self Organizing Maps, Markov Models and Levenshtein sequence distance. Multiple modalities, all based on the hand position during gesturing, train different classifiers which are then fused in a weak classifier boosting-like setup by weight assignment to each stream. The adaptability...
Evolutionary algorithms have employed the SAW (stepwise adaptation of weights) method in order to solve CSPs (constraint satisfaction problems). This method originated in hill-climbing algorithms used to solve instances of 3-SAT by adapting a weight for each clause. Originally, adaptation of weights for solving CSPs was done by assigning a weight for each variable or each constraint. Here we investigate...
A new modulation coding method for signal waveform modulation multilevel disc is presented. The proposed code uses run-length and signal level to satisfy the channel constraints. The density ratio and information bits per 400 nm are 1.67 and 2.08 respectively.
In this paper, three new multiple-input multiple-output (MIMO) channel capacity achieving, full and partial diversity, space-time block codes with reduced decoder complexities are proposed for MIMO systems having two, three and four transmit antennas. It is shown that the proposed codes have the same transmission rates as those of spatial multiplexing schemes while, moreover, offer second order transmit...
In this study, phoneme-based isolated Turkish word recognition with Common Vector Approach (CVA) has been performed. CVA has been used to classify phonemes. The phoneme sequence obtained from the classification is decoded into the word using redundant hash addressing (RHA). The phoneme-based speech recognition is more suitable than the word-based speech recognition for implementing applications that...
A novel cooperative transmission scheme utilizing superposition modulation and incremental relaying together is proposed. Incremental relaying is provided by a hybrid automatic repeat request (H-ARQ) type feedback channel. Decode-and-forward method with superposition modulation is performed under the control of feedback data. The outage probability analysis is effectuated, and it is shown that the...
This paper presents two different repetition based joint network-channel coding schemes for a three-terminal communication system where two-users want to exchange information via a relay. The transmission is divided into three slots in time where the first and second slots are allocated to the RA (Repeat Accumulate) encoded data of the users. In the first scheme we propose, the relay decodes the received...
In this paper, a simple low complexity iterative receiver for space-time coded (STC) transmission is proposed and the performance over frequency-selective fast and quasistatic fading channels is investigated. Simulation results show that the performance of the proposed structure improves with each iteration. Considering the practically prohibitive complexity of optimal equalizers, the proposed iterative...
In this paper, the performance of cooperative networks introduced in the literature is analyzed for asynchronous direct sequence code-division-multiple-access (DS-CDMA) systems in frequency-selective slow fading environment. We show that the full benefits of cooperative diversity cannot be achieved if no multiuser interference suppression is employed at the cooperative end. We consider two scenarios;...
In this paper, we focus on single-selection opportunistic relaying with the decode-and-forward protocol over Rayleigh fading channels. The end-to-end average signal-to-noise ratios (SNR) and ergodic capacities of both proactive and reactive opportunistic relaying are analyzed as a closed form in a high source-to-relay SNR regime where all link qualities satisfy the required SNR. The derived results...
Under limited channel state information at the transmitter the communication suffers from the outage events produced by a data rate selection not supported by the current channel realization. Automatic repeat request (ARQ) protocols are a useful tool to deal with those outage events in delay-tolerant services. This work looks into how automatic repeat request (ARQ) protocols are applied to the half-duplex...
Automatic Repeat re-Quest (AQR) is implemented to ensure reliable transmission when channel state information (CSI) is not available to the source and the selected transmission rate is not supported by the current channel realization. We consider a relay system with hybrid relay scheme, where the relay switches between decode-and-forward (DF) and compress-and-forward (CF) adapting to the decoding...
Irregular Variable Length Coding Design for serial concatenated and iteratively decoded Time-Hopping (TH) Pulse Position Modulation (PPM) UltraWideBand (UWB) Spread-Spectrum (SS) Impulse radio system is considered. The proposed design is capable of low Signal-to-Noise Ratio (SNR) operation in Nakagami-m fading channel amalgamated with joint source and channel coding schemes. A number of component...
Current models in Wyner-Ziv video coding consider the temporal correlation noise to be side-information independent (SII). This paper goes beyond this assumption and proposes a novel model, of which the parameters are side-information dependent (SID). The proposed model is experimentally validated showing remarkable accuracy improvement over the conventional SII model. Moreover, a novel SID technique...
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