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In this paper, we investigate the performance of a generic relay system for small cells. The main features include the selection decode-and-forward (DF) scheme, Rician and Rayleigh fading, single or repeated transmissions in direct link, and maximal-ratio combining at destination. We are able to derive a set of closed-form expressions for the end-to-end performance. Based on these formulas, we define...
This work considers the downlink of a multicell massive MIMO system in which L base stations (BSs) of N antennas each communicate with K single-antenna user equipments randomly positioned in the coverage area. Within this setting, we are interested in evaluating the sum rate of the system when MRT and RZF are employed under the assumption that each intracell link forms a MIMO Rician uncorrelated fading...
In this paper, we analyze the secure performance of satellite communication networks in Shadowed Rician Channel. It is very important to analyze the secure performance of the satellite-terrestrial networks. In this paper, both the Alice, Bob and Eve are equipped with single antenna respectively. Specifically, the exact closed-form expressions for the probability of non-zero secrecy capacity, the secrecy...
Aerial communication platforms have been recently recognized as an effective solution to provide wireless access to terrestrial users, which promise to increase reliability and throughput thanks to their superior coverage capabilities. In this paper, we explore the impact of the height of an Unmanned Aerial Vehicle (UAV) on the area over which it can provide wireless service. We investigate the problem...
In this paper, a novel two-way relaying technique based on network coding is proposed to improve the throughput of dual-hop mixed free-space optics (FSO)/radio-frequency (RF) communication systems. We investigate the performance of the proposed systems over Gamma-Gamma atmospheric turbulence and Rice/Rayleigh channels. The effect of pointing error on FSO link is also considered in our analysis. Closed-form...
In this paper analysis of Digital audio broadcasting on its four different modes have been performed. All the possible four modes have been executed and simulated on SIMULINK platform under different types of modulation schemes and channels. This paper is trying to develop a novel scheme of low cost, complexity wise reduced communication model for open air performance analysis. Thus the paper implements...
This paper analyzes closed-form outage probability of opportunistic amplify-and-forward (AF) for orthogonal frequency division multiplexing (OFDM) relaying over Rician fading environment. The opportunistic relay node is selected by maximizing signal-to-noise ratio (SNR) over all the relay nodes. In this paper, we propose a method by which a closed form outage probability approximation for opportunistic...
In this paper, we investigate the outage behavior of the LTE-A relay system subject to the non- identical Rician fading. For the case of decode- and-forward (DF) relaying without the direct link, a closed-form formulas is derived. Moreover, for the case of DF relaying with the direct link, an exact expression in series is derived. Furthermore, a closed-form formula is derived for the situation where...
This paper analyzes a closed-form outage probability of opportunistic amplify-and-forward (AF) orthogonal frequency division multiple access (OFDMA) relaying in the presence of independent and identically distributed (i.i.d) and independent but non-identically distributed (i.n.d) fading environments. In practice, opportunistic relaying often experiences Rician fading channel, however, there is a very...
Spectrum sensing is a key function of cognitive radio to prevent the harmful interference with licensed users and identify the available spectrum for improving the spectrum utilization. In Spectrum Sensing, function of secondary users (SUs) is to detect the spectrum holes. However, in practice detection performance is often compromised with multipath fading, shadowing and receiver uncertainty issues...
Opportunistic interference alignment (OIA) is a well known precoding technique that uses interference alignment to improve the rate of secondary user (SU) simultaneously nullifying the interference that SU causes to a primary user (PU). In this paper, we analyse the efficacy of OIA technique in multi-user multiple input multiple output (MU-MIMO) underlay cognitive radio network (CRN) for generalized...
In this paper BER (Bit error rate) analysis of wireless cooperative schemes have been done under different fading channels to estimate the error performance of the cooperative schemes. Significance of cooperation is to improve transmission quality. We have simulated two cooperative schemes, Amplify and forward (AF) and Decode and forward (DF) and calculated BER for these schemes for the Rayleigh channel...
Spectrum sensing technique is the most crucial factor that determines the performance of Cognitive Radio (CR) systems. Wideband spectrum sensing using Nyquist and sub Nyquist sampling rates proved to have better performance than other types of spectrum sensing. Multi-rate spectrum sensing technique have advantage over other wideband spectrum sensing technique regarding the probability of detection,...
Maximum ratio combining (MRC) and selection combining (SC) are studied for multi-branch dual-hop amplify-and-forward relaying systems. Expressions for the statistical metrics, such as the probability density function, cumulative distribution function and the moment generating function are obtained for systems operating over independent but non-identically distributed Rician fading links. Such systems...
Wireless channel with the presence of Line of Sight (LOS) is often modeled as Rician distribution. In order to track the channel for mobile users, exponentially weighted Least Squares (LS) Single Input Multiple Output (SIMO) channel estimation is employed. By incorporating the optimum forgetting, the system performance in terms of tracking Mean Square Error (MSE) and Bit Error Rate (BER) is evaluated...
Cognitive radio (CR) technique is useful for to know the uses of radio spectrum. CR is used to sense the spectrum periodically to know the primary user activity in fading environment. Cooperation among multiple CRs helps to enhance the reliability of detection of the primary user (PU), to overcome the unreliable decision by a single CR due to channel uncertainties. Along with the Co-operation of multiple...
A unified performance analysis is presented for dual-hop amplify-and-forward (AF) relaying systems operating over non-identically distributed Rician fading channels. A general, two-parameter AF relaying model is used such as to cover various AF relaying schemes, namely, variable-gain AF relaying, fixed-gain AF relaying, and channel-assisted relaying, as well other unconventional schemes. Although,...
Cooperative spectrum sensing is an efficient scheme to deal with the effects of fading components on detection performance in cognitive radio networks. Energy efficiency is one of the impacting factors of this solution. In this paper, we apply the optimal double threshold ‘n-ratio’ fusion rule over Nakagami and Rician fading channels and examine its performance through numerical simulations. Evaluations...
Cooperative spectrum sensing is an efficient solution to deal with the effects of fading components on detection performance in cognitive radio networks. Data fusion is one of the fundamental elements of this solution. In this paper, we derive the optimal ‘n-ratio’ fusion rule over Nakagami and Rician fading channels and examine its performance through numerical simulations and compare the results...
Cognitive radio (CR) systems need to detect the presence of licensed primary user (PU) reliably. Cooperation among multiple CRs helps to enhance the reliability of detection of the PU in case of unreliable decision by a single CR due to channel uncertainties. In this paper, we consider cooperative spectrum sensing (CSS) based on energy detection in cognitive radio networks (CRN) which uses soft combination...
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