Evolution of PAPR Reduction Techniques: A Wavelet Based OFDM Approach

Wireless Personal Communications - Orthogonal frequency division multiplexing (OFDM) is considered among the most suitable multiplexing technique for realizing high speed wireless communication in...     

Request combining in multiprocessors with arbitrary interconnectionnetworks

Several techniques have been proposed to allow parallel access to a shared memory location by combining requests. They have one or more of the following attributes: requirements for a priori knowledge of the request to combine, restrictions on the routing of messages in the network, or the use of sophisticated interconnection network nodes. We present a new method of combining requests that does not have the above requirements. We obtain this new method for request combining by developing a classification scheme for the existing methods of request combining. This classification scheme is facilitated by separating the request combining process into a two part operation: determining the combining set, which is the set of requests that participate in a combined access; and distributing the results of the combined access to the members of the combining set. The classification of combining strategies is based upon which system component, processor elements, or interconnection network performs each of these tasks. Our approach, which uses the interconnection network to establish the combining set and the processor elements to distribute the results, lies in an unexplored area of the design space. We also present simulation results to assess the benefits of the proposed approach     

Recent Advances in MAC Protocols for the Energy Harvesting Based WSN: A Comprehensive Review

Wireless Personal Communications - Wireless sensor networks are catching the attention of the researchers in various fields like structural, healthcare monitoring, but the real world adoption is...     

An Adaptive Weighted Min-Mid-Max Value Based Filter for Eliminating High Density Impulsive Noise

In this study, non-orthogonal multiple access (NOMA) together with cognitive radio (CR) benefit to the vehicle-to-everything (V2X) as promising application with high spectrum efficiency. We have higher priority to evaluate system performance of the secondary network in such CR-NOMA system operating in the context of V2X. We first arrange vehicles belonging to serving group in this CR-NOMA assisted V2X, and it is beneficial to serve massive connections for vehicles. There are two scenarios studied in this paper, with and without the support of CR scheme. In our proposed system, two system metrics need be investigated to evaluate performance of vehicles that need higher quality of service (QoS). Our results indicate that the outage performance gap among two vehicles exists since different transmit power allocation factors were assigned to them. In particular, the outage probability is first derived in exact forms and then the bit error rate (BER) can be further achieved. In specific situations, the optimal outage probability can be obtained by numerical simulations. Simulation results are also provided to verify the correctness of the derived expressions and it exhibits advantages of the proposed CR-NOMA assisted V2X system in terms of two main metrics such as outage probability and BER.

     

BER performance of MQAM with L‐branch MRC diversity reception over correlated Nakagami‐m fading channels

Exact and closed form generalized expressions for bit error rate (BER) of M‐ary quadrature amplitude modulation (MQAM) with L‐branch maximal ratio combining (MRC) space diversity reception in fading channels are derived and analyzed. The fading channels are modeled as identical but correlated frequency‐nonselective slow Nakagami‐m fading channels corrupted by additive white Gaussian noise (AWGN). Analytical results obtained are in terms of few finite range integrals with an integrand composed of elementary functions. Because of their simple form, these analytical results readily allow numerical evaluation in cases of practical interest. The results are also general enough to include Nakagami‐m fading channels with and without correlation, no diversity system, Rayleigh fading channels with and without correlation, and AWGN as special cases. The numerical results for the case of 16QAM are shown graphically and also in tabular form in order to examine the effects of fading severity, order of diversity, and branch correlation on the BER performance. The two correlation models considered are constant correlation model and exponential correlation model. One may be interested to know how the BER of MQAM is related to symbol error rate (SER) of MQAM. Therefore, the BER results obtained in this paper are also compared with that obtained directly from the SER. It is expected that the analytical results presented in this paper will provide a convenient tool for design and analysis of a radio communication system with space diversity reception in uncorrelated and correlated fading environment. Copyright © 2002 John Wiley & Sons, Ltd.     

An enhanced architecture for route discovery and load balancing in WSN

The Journal of Supercomputing - The sensor network comprises various sensor nodes in which packet transfer requires detection of the route. The discovery of the path in such a network becomes...     

Yield strength of twin-belt cast Al–Mg–Sc–Zr alloy after annealing

AA5xxx aluminium alloys are used in the automotive and packaging industries owing to their high strength and ductility. The addition of Sc and Zr to these alloys has shown promise for improving high temperature stability and therefore broadening the range of applications. This high temperature stability is due to the formation of fine Al₃(Sc, Zr) precipitates during aging. In this work, two twin-belt cast Al–3%Mg alloys, one with 0·4% Sc and the other without Sc, were annealed at 300 and 400°C. Hardness, tensile yield stress and electrical resistivity measurements were used to examine the evolution of microstructure and strength of the alloys. These results were then utilised to develop a yield stress–precipitation model to describe simultaneous precipitation hardening and recovery.