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To protect digital subscriber loop (DSL) systems against impulse noise (IN), interleaving combined with Reed-Solomon (RS) coding has been used. Nevertheless, interleaving introduces a long delay. This paper considers retransmission instead of interleaving to reduce such delay and proposes an approach using the available RS decoding failure status to trigger retransmission request. Retransmission probability,...
There is currently an ongoing debate surrounding what would be the best choice for smart grid communication technology. One of the promising communication technologies for smart grid realization is Powerline Communication (PLC). However, because of its noisy environment and the low capacity of Narrowband Powerline Communication, its viability for smart grid realization is being questioned. To investigate...
Wireless sensor networks (WSN) are one of most interesting emerging technologies. WSN can be used to perform monitoring, surveillance, sensing and measuring operations. In order to further increase these applications, minimizing energy consumption is one of the most critical issues. Therefore, accurate energy model is required for the evaluation of wireless sensor networks performance. In this paper,...
Wavelet transform is used in signal processing to represent a statistical random signal in to various frequency components. The transform converts the signal into approximation coefficient and detail coefficients; the mean of each coefficient for a noiseless signal is ideally zero but the mean of the coefficients for a noisy signal is shifted from zero. The noise of a wireless channel can be reduced...
With ever increasing demands on spectral efficiency, complex modulation schemes are being introduced in fiber communication. However, these schemes are challenging to implement as they drastically increase the computational burden at the fiber receiver's end. We perform a feasibility study of implementing a 16-QAM112-Gbit/s decision directed equalizer on a state-of-the-art FPGA platform. An FPGA offers...
MANET are characterized by their limited bandwidth and high packet error rate. In mobility, multi-path and shared bandwidth contexts, routing protocols play a major role. On-demand routing approaches lead to high delay while, in linkstate protocols, controls messages broadcasting consumes much bandwidth. Hybrid protocols such as Zone Routing Protocol (ZRP) attempt to exploit the advantages of both...
In this paper we introduce an efficient decoding method which is based on the dimensionality reduction of the search tree in the sphere decoder for the golden code in a low SNR regime. A codeword of the golden code has four independent m-QAM data symbols, hence, the required complexity of the exhaustive-search decoder is m4. An efficient implementation of the maximum-likelihood decoder for the golden...
The overlay approach to dynamic spectrum access recently proposed in information theory allows both primary users (PUs) and secondary users (SUs) to simultaneously access the same spectrum with comparable power levels while ensuring no degradation to the performance of PUs. However, this approach is based on a number of idealized assumptions that are difficult to satisfy in practice, and existing...
The practical deployment of widely favoured transparent optical networks is prohibitive as transmission reach of optical signals in such networks is limited by accumulation of physical layer impairments (PLIs). Translucent optical networks have thus become a viable solution and are seen as technically feasible in the near future. In translucent networks, the optical-electrical-optical (OEO) conversion...
The fourth generation mobile communication system is expected to be implemented on a frequency band higher than the bands already assigned for IMT-2000. Therefore, to compensate propagation loss, relay schemes have been investigated. Amplify-and-Forward (AF) relay has advantages on complexity and time slot usage. However, the coupling effect between transmit and receive antennas in the relay station...
This paper presents an orthogonal look up tables (LUTs) based predistorter (PD) whose coefficients are generated adaptively to minimize the out-band distortion power. It has low complexity and high robustness to impairments from the feedback circuit, with the drawback of slow convergence meanwhile. To counteract the performance degradation in the case of fast transmission power control (TPC) due to...
In this paper, we propose an adaptive single-carrier (SC) transmission suitable for near maximum likelihood (ML) block signal detection using QR decomposition and M-algorithm (QRM-MLBD). QRM-MLBD can significantly improve the bit error rate (BER) performance of SC block transmission. However, in order to achieve a close-to-ML performance, the use of a fairly large number M of surviving paths in the...
We study a dynamic WDM network with nonideal components in the physical layer which uses an impairment-aware routing and wavelength (RWA) algorithm for connection provisioning. We investigate the reduction in blocking probability (BP) by utilizing service Level Agreement (SLA) metric i.e. setup delay tolerance during connection provisioning. Furthermore, we explore the improvement in the network performance...
Single-carrier (SC) waveform has a lower peak-to-average power ratio than multi-carrier waveform. Furthermore, it can exploit the channel frequency-selectivity through frequency-domain equalization (FDE) to improve the transmission performance. SC-FDE is a block transmission. The cyclic prefix (CP) is inserted in front of each data block. Instead of CP insertion, the known training sequence (TS) insertion...
In this paper, a 60-GHz channel model that incorporates the presence of human activity, and which is an extension of the standard channel model proposed by the IEEE 802.15.3c group, is presented. In the presence of human activity, various measurement results show that the attenuation due to human blockage can be 20 dB or more, and thus is non-negligible. Various measurement results in the literature...
We investigate the use of the minimum mean-squared- error decision-feedback-equalizer (MMSE-DFE) as a preprocessor to reduce the computational complexity of symbol detection in frequency-selective multiple- input multiple-output (MIMO) channels. The preprocessor delays and focuses the received signal energy which reduces the effects of inter-symbol- interference and multiple-access-interference. This...
In this paper, the performance of adaptive modulation for multiuser amplify-and-forward relay networks over Nakagami-$m$ fading is studied. Specifically, adaptive discrete rate five-mode $M$-ary quadrature amplitude modulation is employed with fixed switching thresholds. In particular, the detrimental effect of feedback delays in multiuser scheduling is quantified. To this end, an upper bound of the...
Incremental relaying (IR) is known to improve the spectral efficiency of cooperative communication by using the destination feedback. In IR, the relay nodes are employed to assist the source transmission only if it is failed. When the relay nodes perform demodulate-and-forward (DmF), all of them are eligible to forward the source information. This is different from decode-and-forward (DF), where only...
In this paper, we propose a new routing protocol for home networks, called dependable routing protocol (DRP) that adapts to the changes in local topology within home networks nvironments. DRP is based on an effective selection of paths through which a packet must pass to reach the home unit. The selection, in such dynamic home networks, is made using dependable routing, i.e, in a way that maximizes...
Orthogonal Frequency Division Multiplexing (OFDM) is a robust multi-carrier modulation technique for high data rata wired/wireless transmission systems due to its good performance in multi-path channels. In this paper, a chaos-evolutionary programming (CEP) hybrid approach is proposed to achieve a minimum degradation of OFDM transmission over multi-path channels, taking into account, the Doppler effect...
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