The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
The transmission of block-coded images over wireless channels results in lost blocks. In this paper, we propose a new error concealment method for covering up the high packet losses of an original image after its transmission through an error-prone channel. In this scheme, Discrete Wavelet Transform (DWT) is applied to each block of the original image in order to produce a lower resolution copy of...
We propose a new framework for MIMO decoding based on a recently developed technique for reliably conveying linear equations over wireless channels. Each transmit antenna sends an independent data stream using the same linear code. As a result, any integer combination of the codewords is itself a codeword. Each receive antenna observes a random complex-valued combination of the codewords according...
In this paper, we evaluate a multilevel coding (MLC) scheme with multi-stage decoding (MSD) designed for satellite broadcasting communications, where services with different quality of service (QoS) are desirable. A simple Land-Mobile-Satellite (LMS) channel model is presented, based on channel states and their transitions. The instantaneous channel capacity for suburban and forest scenarios is calculated...
Cooperative communication has been recently proposed as a way to improve the performance of wireless communication. However, due to the half duplex constraint, most of the relay networks face a fundamental challenge in terms of multiplexing loss. In this paper, we present an adaptive cooperation via relay selection (ACRS) protocol that improves spectral efficiency. This protocol lets the source transmit...
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...
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...
This paper studies the effects of heterogeneity in DO networks and proposes measures for reducing or removing them. In particular, two types of imbalance, i.e., f-Imbalance and OH-Imbalance are identified and methods for compensating them, i.e., RL padding and AT overhead (OH) channel boost, are proposed. The effectiveness of the proposed methods is demonstrated through both, developing an analytic...
In this paper, we investigate the benefit of joint network-channel distributed coding for the multiple-access half-duplex relay channel. In contrast with previous work, the medium access is not orthogonal and the source-to-relay links are not error-free, which render the reality of wireless environments and notably complicate the problem. Indeed, due to the broadcast nature of wireless media, transmitted...
There has been a tremendous growth in the wireless communication networks and their applications around us. Different applications developed over wireless networks can have very different requirements. For some applications, protection from transmission errors might be of primary, whereas for other application the security and privacy of the information in transit might be the primary requirement...
In downlink relay systems, the conventional straightforward relaying scheme named decode-and-forward (DF) protocol is used at relay station (RS) to decode the data received from base station (BS) and forward the decoded data to the mobile station (MS) to improve the spatial diversity gain. However, conventional DF mode is spectral inefficient and not capacity optimal since the wireless channels in...
Adaptive network coded cooperation (ANCC) scheme has been shown to have better performance than the conventional repetition-based schemes and the space-time coded cooperation (STCC) frameworks for data transmissions from a large collection of terminals to a common destination in large wireless networks. However, the random selection strategy for ANCC protocol may generate many short cycles in the...
Underwater acoustic sensor networks (UASN) can enable many potential oceanic applications. For the environment monitoring and event detection services, the sensor networks will record a large amount of data. But due to the harsh sea conditions and node energy constraints, real-time data delivery to the ground data center may not be feasible. Thus in-network data storage becomes a possible alternative...
A problem of state information transmission over a state-dependent discrete memoryless channel (DMC) with independent and identically distributed (i.i.d.) states, known strictly causally at the transmitter is investigated. It is shown that block-Markov encoding coupled with channel state estimation conditioned on treating the decoded message and received channel output as side information at the decoder...
In this paper, we propose a joint source-channel (JSC) decoding scheme for 3D ESCOT-based video coders, such as Vidwav. The embedded bitstream generated by such coders is very sensitive to transmission errors unavoidable on wireless channels. The proposed JSC decoder employs the residual redundancy left in the bitstream by the source coder combined with bit reliability information provided by the...
We address the problem of non-asymmetric Slepian-Wolf (SW) coding of two correlated non-uniform Bernoulli sources. We first show that the problem is not symmetric in the two sources, contrarily to the case of uniform sources, due to the asymmetry induced by two underlying channel models, namely additive and predictive Binary Symmetric Channels (BSC). That asymmetry has to be accounted for during the...
Combining coding, modulation, transmit and receive diversity, and validly increases the anti-noise performance in fading channels, OSTBC (orthogonal space-time block codes) is a new channel coding technology accompanying with the extensive application of wireless communication. Based on typical channel model of the OSTBC in MIMO (multiple-in, multiple-out) wireless communication channels, a general...
The sphere decoding algorithm for signal transmitted on multiple antennas channel is considered. In this paper, the preprocessing stage is analyzed in order to seek a reduced complexity and some improvements are made to enhance the performance. The computer simulation results show that the improved algorithm by applying Pohst Enumeration with selected initial radius is more efficient than that by...
To overcome the problem that the transmission rate of a multicast channel is limited by the user with the worst channel quality, which causes the total system throughput to be low, the use of both multicast and unicast channels for multicast service is considered in this paper. Unicast channels, in addition to a multicast channel, are allocated to users with signal-to-noise ratios (SNRs) lower than...
We study the effect of relay cluster selection on throughout in multi-hop cooperative communications with one source and one destination. We evaluate the effective relay throughput as a function of the source transmission rate and the network outage probability. Assuming channel side information (CSI) only available at the receivers, we formulate the cluster size optimization to maximize throughput...
We study a wireless broadcast network, where a single source reliably communicates independent messages to multiple destinations, with the aid of relays. We propose a scheme that can achieve rates within a constant gap away from the cut-set bound. The proposed scheme operates in two steps: the inner code induces a broadcast channel with sufficient mutual information between the source and the destinations,...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.