Space diversity is one of the important techniques of overcoming the influence of atmospheric turbulence on laser communication. Having analyzed the theory of diversity technique, the paper has focused on researching the space diversity technique and established the joint probability density function of the threshold value. Outage probability is studied in laser communication and get the variat...

System capacity is considered for a group of interfering users employing single user detection and multiple transmit and receive antennas for at Rayleigh fading channels with independent fading coeecients for each path. The focus is on the case where there is no channel state information at the transmitter, but channel state information is assumed at the receiver. It is shown that the optimum s...

For hostile communication environments, noncentralized mobile communication network with directive/adaptive antennas and Global Positioning System (GPS) has been proposed for the purpose of minimizing the radio exposure and making it difficult for an interceptor to detect the signals. This paper investigates the interceptor’s search for the direction-of-arrival (DOA) of the transmitting signal ...

The use of directional antenna in wireless ad hoc networks potentially increases simultaneous communication by directing the transmitting and receiving beams towards the receiver and transmitter node as compared to omni-directional antenna, where nodes in the vicinity of a communication are kept silent. However, in order to implement effective directional MAC protocol using directional antenna,...

Large-scale MIMO systems have been considered as one of the possible candidates for the next-generation wireless communication technique, due to their potential to provide significant higher throughput than conventional wireless systems. For such systems, Zero-Forcing (ZF) and Conjugate Beamforming (CB) precoding have been considered as two possible practical spatial multiplexing techniques, an...

Abstract—This paper presents the effect of the orbit inclination on the pointing error of the satellite antenna and consequently on its footprint on earth for a typical Kuband payload system. The performance assessment is examined using both analytical simulations and practical measurements, taking into account all the additional sources of the pointing errors, such as East-West station keeping...

This paper compares measurement with prediction of ITU-R Recommendation P.1546. This recommendation mainly depends on propagation curves which are based on the measurement result. The basic field strength is derived from the curve corresponding to transmitting antenna height, frequency and required distance and then correction factor is added to this. There are two important correction values i...

This paper focuses on assessing the limitations in the direction-finding process of radio sources with directional antennas in an urbanized environment, demonstrating how signal source antenna parameters, such as beamwidth and maximum radiation direction affect bearing accuracy in non-line-of-sight (NLOS) conditions. These evaluations are based on simulation studies, which use measurement-teste...

The develpoment of smart antennas for mobile phones has recently recevied much interest due to compact size of multimode phones and requirements to keep the amount of RF power absorbed by a user below a certain level. In this paper a new Yagi Uda shaped frequency reconfigurable antenna for multimode mobile applications has been presented. The proposed fabricated antenna have return loss better ...

The wireless channel of High-Speed Railway communication system is rapidly time-varying. The orthogonal frequency division multiplexing transmitting over this channel will be exposed to the intercarrier interference caused by large Doppler spread. The sectorised antenna can be employed for Doppler mitigation and obtaining Doppler diversity gain. In this paper the performance of this directional...