No abstract

The arid climate regions, such as in Riyadh city (Saudi Arabia), are characterized by strong dust storms which can deteriorate the performance of wireless systems. In addition, due to that the accelerated growth in many high buildings in a modern city such as Riyadh creates non-line of sight (NLOS) conditions can be represented by diffraction mechanism causes also attenuation loss affects the received wireless signals. This paper presents a new modelling study on the influence of dust storm and diffraction mechanism on wireless point to point (P-toP) communication links in Riyadh. This unique study uses measured dust storm data and real urban scenarios to simulate the wireless links and investigate the effect on receiver performance based on the receiver sensitivity criterion. Several frequencies allocated for the fifth-generation (5G) wireless systems have been utilized as operation frequencies. The results showed that there is an inverse proportional between the attenuation loss due to diffraction and the distance over which the signal travels between the transmitter and receiver particularly when either the transmitter or the receiver is more close to the diffraction object. This study reveals that higher frequencies lead to higher diffraction loss, higher dust storm loss as well as higher free space loss. Moreover, certain millimeter-wave frequencies, such as 60 GHz, experience very high losses due to atmospheric absorption that can only operate on very short link distances. Besides, there is a need for high-quality receivers, especially for very high operating frequencies.

Abstract-Spectrum sharing between wireless systems becomes a critical issue due to emerging new technologies and spectrum shortage. Recently, IMT-Advanced system has been allocated in the same frequency band (3500 MHz) along with fixed services on co-primary basis, which means that harmful interference probability may be transpired. Channel bandwidths (BW) and natural of deployment areas of wireless systems are of the main effective factors in spectrum sharing. Spectrum Emission Mask (SEM) model will be used to study these factors effects beside the interference to noise ratio (I/N ) as a fundamental criterion for coexistence and sharing between systems. The frequency and distance separation and antenna height effects are essential to be investigated to achieve spectrum sharing.

Coexistence analysis is extremely important in examining the possibility for spectrum sharing between orthogonal frequency‐division multiplexing (OFDM)‐based international mobile telecommunications (IMT)‐Advanced and other wireless services. In this letter, a new closed form method is derived based on power spectral density analysis in order to analyze the coexistence of OFDM‐based IMT‐Advanced systems and broadcasting frequency modulation (FM) systems. The proposed method evaluates more exact interference power of IMT‐Advanced systems in FM broadcasting systems than the advanced minimum coupling loss (A‐MCL) method. Numerical results show that the interference power is 1.3 dB and 3 dB less than that obtained using the A‐MCL method at cochannel and adjacent channel, respectively. This reduces the minimum separation distance between the two systems, which eventually saves spectrum resources.