The Personal Access Satellite System (PASS) strawman design, as described in the PASS Concept Study Report, (hereafter referred to as the Strawman Design) utilizes a hybrid Time Division Multiple Access (TDMA)/ Frequency Division Multiple Access (FDMA) implementation. TDMA is used for the forward direction (from Suppliers to Users), and FDMA for the return direction (from Users to Suppliers). I...

The exponential rise in wireless communication demands and allied applications have revitalized academia-industries to develop more efficient routing protocols. Wireless Sensor Network (WSN) being battery operated network, it often undergoes node death-causing pre-ma...

a wireless sensor network (wsn) is a wireless decentralized structure network consists of many nodes. nodes can be fixed or mobile. wsn applications typically observe some physical phenomenon through sampling of the environment so determine the location of events is an important issue in wsn. wireless localization used to determine the position of nodes. the precise localization in wsns is a co...

In this paper, we study WSN design, as a multi-objective optimization problem using GA technique. We study the effects of GA parameters including population size, selection and crossover method and mutation probability on the design. Choosing suitable parameters is a trade-off between different network criteria and characteristics. Type of deployment, effect of network size, radio communication...

One of the most important challenges with respect to wireless access is the limited capacity of the air interface which is due to the fact that the available transmission bandwidth is finite. Since the number of wireless subscribers is still growing rapidly and the desire for higher data rates is rising – partially due to an ever growing popularity of the Internet – a more efficient use of freq...

This paper proposes a multi-cluster wireless powered Internet of Things (WP-IoT) network assisted by multiple intelligent reflecting surfaces (multi-IRS). In this network, power station (PS) first broadcasts energy to the distributed IoT devices grouped into clusters. The then use harvested convey their information an access point (AP), based on hybrid time- and frequency-division (TDMA-FDMA) p...

In this paper, a companding technique is proposed to effectively reduce the peak-to-average power ratio (PAPR) in single-carrier frequency division multiple access (SC-FDMA) systems. By companding the samples with large amplitudes, while enhancing those with small amplitudes, a significant reduction in the PAPR can be achieved. The performance of the proposed SC-FDMA with companding system is s...

wireless ad hoc networks are composed of independent nodes managing the network without any infrastructure. the connection between nodes is provided by sending packages and by trusting to each other. therefore, using efficient and certain protocols is the essential requirement of these networks. due to special characteristics of wireless ad hoc networks such as lack of a fixed infrastructure, t...

A new problem encoding is devised for the minimum span frequency assignment problem in wireless communications networks which is compact and general. Using the new encoding, which reduces search space dramatically over previous problem encodings, an optimization algorithm is developed which combines a genetic algorithm global search with a computationally efficient local search method from the ...