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The multiple-access relay channel (MARC) and its Gaussian version are important models in cellular, ad hoc communication systems, and sensor networks and also, this channel is a comprehensive model which consist of two important channels: Relay Channel (RC) and Multiple Access Channel (MAC). In this paper, we study and analyse the two-user state-dependent discrete and memoryless MARC in which the...
One of the promising architectures for the next generation of content distribution networks is the “cache network”, where each node has cache or local storage.We consider the index coding problem, where a central content server disseminates compressed multiple content data to each client that recovers the target content using the cached content, as side information. The coding scheme discussed in...
This paper proposes a novel nonbinary concatenated coding system with nonbinary Reed-Solomon (RS) inner codes and a nonbinary convolutional outer code for Narrowband Power Line Channel (NB-PLC). This channel is modeled with a “Middleton A” impulsive noise and an AWGN noise. With this structure, the inner decoder will correct random and short burst errors while the outer decoder will correct much longer...
This paper addresses a practical aspect of coded on-off keying free-space optical communication systems: quantization of demodulator outputs in receiver. Receivers with and without knowledge of channel state information (CSI) are considered. Proposed quantization schemes for soft decision decoding with CSI are uniform with quantization intervals proportional to channel gains. The schemes are studied...
This paper considers the problem of reducing the broadcast delay of wireless networks using instantly decodable network coding (IDNC) based device-to-device (D2D) communications. In D2D-enabled networks, devices help hasten the recovery of the lost packets of devices in their transmission range by sending network coded packets. To solve the problem, the different events occurring at each device are...
In this paper, we tackle the compressive phase retrieval problem in the presence of noise. The noisy compressive phase retrieval problem is to recover a K-sparse complex signal s ∈ ℂn, from a set of m noisy quadratic measurements: yi = |aiHs|2 + wi; where aiH ∈ ℂn is the ith row of the measurement matrix A ∈ ℂm×n, and wi is the additive noise to the ith measurement. We consider the regime where K...
We introduce the “blind index coding” (BIC) problem, which generalizes the classic index coding problem by considering a sender that has some uncertainty about the side information that is available at each receiver. This problem naturally arises in wireless networks in which users obtain their side information through wireless channels with errors that may be unknown to the sender. For the proposed...
In this paper, we propose algorithms for computing Walsh-Hadamard transform with arbitrary K-sparse support. When K is sublinear in the dimension N of the time-domain signal, the algorithms achieve vanishing error probability as K increases without bound and involve sublinear computational complexity. Specifically, under the noiseless setting, an algorithm based on random hashing and successive cancellation...
We study sequential transmission of Gauss-Markov sources over erasure channels under a zero decoding delay constraint. A two-stage coding scheme which can be described as a hybrid between predictive coding with limited past and quantization & binning is proposed. This scheme can achieve significant performance gains over baseline schemes in simulations involving i.i.d. erasure channels, and in...
A four-receiver degraded broadcast channel with secrecy outside a bounded range is studied, over which a transmitter sends four messages to four receivers. In the model considered, the channel quality gradually degrades from receiver 4 to receiver 1, and receiver k is required to decode the first k messages for k = 1, …, 4. Furthermore, message 3 is required to be secured from receiver 1, and message...
We analyze a class of high performance, low decoding data-flow codes suitable for high bit-rate optical-fiber communication systems. A spatially-coupled split-component ensemble is defined, encompassing the most representative codes in this class, staircase codes and braided block codes. Our definition preserves two important properties of this class of codes: deterministic partitioning of component-code...
It is well known that cooperation between users in a communication network can lead to significant performance gains relative to the same network without cooperation. One common model which has been studied recently is the two users degraded broadcast channel (BC) with cooperating decoders. It can be viewed as a special case of the relay-broadcast channel (RBC), where the link from the relay to the...
The objective of low-delay codes is to protect communication streams from erasure bursts by minimizing the time between the packet erasure and its reconstruction. Previous work has concentrated on the constant-delay scenario, where all erased packets need to exhibit the same decoding delay. We consider the case of heterogeneous delay, where the objective is to minimize the average delay across the...
The problem of constructing error correcting codes for defective memories, where some of the cells are defected and unable to switch their states, is considered. This is a classical problem in coding theory which has recently received renewed attention due to application to new technologies for non-volatile memories such as phase change memories. We show how the state of the art capacity achieving...
We study a multihop “virtual” full-duplex relay channel as a special case of a general multiple multicast relay network. For such channel, quantize-map-and-forward (QMF) (or noisy network coding (NNC)) achieves the cut-set upper bound within a constant gap where the gap grows linearly with the number of relay stages K. However, this gap may not be negligible for the systems with multihop transmissions...
The connection between index coding and matroid theory have been well studied in the recent past. El Rouayheb et al. established a connection between multi linear representation of matroids and wireless index coding. Muralidharan and Rajan showed that a vector linear solution to an index coding problem exists if and only if there exists a representable discrete polymatroid satisfying certain conditions...
In Index coding there is a single sender with multiple messages and multiple receivers each wanting a different set of messages and knowing a different set of messages a priori. The Index Coding problem is to identify the minimum number of transmissions (optimal length) to be made so that all receivers can decode their wanted messages using the transmitted symbols and their respective prior information...
The connection between index coding and matroid theory have been well studied in the recent past. El Rouayheb et al. established a connection between multi linear representation of matroids and wireless index coding. Muralidharan and Rajan showed that a vector linear solution to an index coding problem exists if and only if there exists a representable discrete polymatroid satisfying certain conditions...
The problem of simultaneously generating two keys for a cellular model is investigated, in which each of four terminals, X0, X1, X2, and X3 observes one component of correlated sources. The terminal X0 wishes to generate secret keys K1 and K2 respectively, with terminals X1 and X2 under the help of terminal X3. They are allowed to communicate over a public channel. Both K1 and K2 are required to be...
Polar codes are the first error-correcting codes to provably achieve the channel capacity but with infinite code-lengths. For finite codelengths the existing decoder architectures are limited in working frequency by the partial sums computation unit. We explain in this paper how the partial sums computation can be seen as a matrix multiplication. Then, an efficient hardware implementation of this...
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