<span lang="EN-US">This paper presents a four-element frequency reconfigurable antenna system that is novel in terms of gathering both underlay and interweave cognitive radio single multiple input, output (MIMO) design. Built on 50×38×0.8 mm3 Rogers RT/Duroid 5880 substrate, this constructed two scanning elements to sense ultra-wide band (UWB) with controllable notching capabilities act a...

This letter newly proposes a new multi-user detection scheme for multiple users using co-channel heterogeneous radio signals in ubiquitous antenna system. The ubiquitous antenna system is composed of multiple radio base stations (RBSs), the central control station (CCS) which performs the multi-user detection, and radio-on-fiber (RoF) link which connects the RBSs to the CCS. Computer simulation...

An emerging trend in mobile communications is the parallel usage of multiple radio technologies in mobile devices, tablets and other communications modules. In order to support this parallel operation, the devices are equipped with multiple radio transceivers, which are located extremely close to each other. When the different radio technologies operate simultaneously these transceivers interfe...

A tactical radio network is a radio network in which a transmitter broadcasts the same information to its receivers. In this paper, dynamic spectrum management is studied for multiple cognitive tactical radio networks coexisting in the same area. First, we consider the problem of common rate maximization subject to a total power constraint for a single tactical radio network having multiple rec...

For the simulation and design of smart antenna transmission principles in mobile radio, precise knowledge of the time-variant directional multipath structure in various radio environments is required. In this paper a new broadband multiple-input-multiple-output (MIMO) vector radio channel sounder is described which uses multiple antennas at the transmitter as well as at the receiver position. T...

Future wireless communication is expected to integrate collocated different radio access technologies together to meet wide expectation (multiple services) from users and to support mobility. The key requirements in this multiple radio access technology are to meet the Quality of Service (QoS) requirement of the user based on the service type, reduce energy consumption for the particular servic...

The evolution of cellular networks from one generation to another has led to the deployment of multiple radio access technologies (such as 2G/2.5G/3G/4G) in the same geographical area. This scenario is termed heterogeneous cellular networks. In heterogeneous cellular networks, radio resources can be jointly or independently managed. When radio resources are jointly managed, joint call admission...

Images of the multiple-component radio source B1422 + 231 at 2.2 pm show the structure of this source to be essentially the same at radio and infrared frquencies. The most natural explanation for this achromatic structure is gravitational lensing.

ABSTRCT This paper focuses some simulation methods and performance analyses of Code division multiple access (CDMA) soft handoff using OPNET that are useful for the research of CDMA system and management modeling. CDMA is an advanced digital wireless transmission technique over radio waves. It uses mathematical codes, instead of frequencies or time slots, to transmit wireless conversations. Top...