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In this report, we consider an outage probability for full-duplex single-input single-output (SISO) system. In the presence of self-interference, we derive a closed-form expression of outage probability. We consider Rayleigh and Rician fading channels for the channel between two nodes and for the self-interference channel, respectively. We evaluate the outage probability based on different K factor...
PCM (phase-coded modulation) signal is a kind of radar signal that is widely used in many circumstances, such as PD processing, communication, etc. In wild electromagnetic environment, the identification of PCM signals is important in passive location system. STFT is an efficient method in time-frequency analysis, which can exactly identify PCM signals with wave-entropy analysis. Theory verification...
A unified capacity analysis under weak and composite turbulences of a free-space optical (FSO) link that accounts for pointing errors and both types of detection techniques (i.e. intensity modulation/direct detection as well as heterodyne detection) is addressed in this work. More specifically, a unified exact closed-form expression for the moments of the end-to-end signal-to-noise ratio (SNR) of...
As spectrum sensing detects the presence of primary user (PU) signal, an efficient and reliable spectrum sensing scheme plays a critical role in cognitive radio (CR). In this paper, a novel spectrum sensing method via stochastic resonance (SR) under low signal-to-noise ratio (SNR) is presented. It is shown that the introducing of suitable additional noise can enhance sequential energy detector (SED)...
Recently, cognitive radio (CR) has gained a lot of attention with its spectrum sensing feature, because it provides better spectrum utilization in wireless communication. The spectrum sensing plays a major role in CR. In this paper, a new technique of spectrum sensing is proposed in which optimal Bayesian detector is used to detect the presence of M-ary quadrature amplitude modulated primary signal...
The performance analysis of Alamouti space time block code (STBC) based orthogonal frequency division multiplexing (OFDM) is often analyzed on the assumption that the channel is constant over Alamouti code period (two consecutive OFDM symbol block). But when the channel is fast fading, this assumption does not hold good and causes co-channel interference (CCI) and inter-carrier interference (ICI)...
Cell range extension (CRE) has been used as a method to extend the coverage of small cells and help offload macro cell users to small cells by adding a cell specific offset (CSO) to small cells in heterogeneous network deployment. However, previous literatures only considered CSO setting in sparse small cell networks (SCN) deployment where the number of small cells is relatively small. In this paper,...
In heterogeneous network where picocells are overlaid onto macrocells, combined usage of cell range expansion (CRE) and enhanced inter-cell interference coordination (eICIC) is very effective in improving the system capacity. Two parameters of the CRE bias value and the ratio of ABS (almost blank subframe) affect each other. Thus, the comprehensive control of both parameters is very important to improve...
In this paper, the user cooperation behaviors under eavesdropping attack are analyzed through game theory. Considering the physical layer security, we prove that the conventional cooperation scheme actually deteriorates the secrecy performance compared to the direct transmission, given that the eavesdropper has a better channel condition to the users than the destination. In this case, the necessary...
This paper considers spectrum utilization in cognitive radio (CR) based on both simultaneously adaptive spectrum sensing and transmission at Tx and bit error rate (BER) variation checking at Rx. A novel detecting model is proposed to consider the full-duplex second-user (SU)'s simultaneous sensing and transmitting whether the primary user (PU) is active or not. The probability of detection is provided,...
The energy efficiency of OFDM systems is known to be low due to the high peak-to-average power ratio problem. The linear-amplification-with-nonlinear-component (LINC) technique can solve the problem by decomposing the input signal into two constant-envelop component signals and applying high-efficient nonlinear amplifiers. However, the power combiner, a key component used to combine the amplified...
In this paper, we propose a two-stage interference alignment (IA) scheme for the downlink of partially connected heterogeneity networks (HetNets), where the partial connectivity is induced by the path loss and the low transmission power of small cells. Particularly, in the first stage, the macro cell carries out conventional IA with a set of fully connected small cells. We derive the maximum number...
In underlay cognitive networks, the unlicensed (secondary) user is allowed to share the spectrum with the licensed (primary) user under the constraint that the interference at the primary user should be below a specific threshold. This constraint forces the cognitive network to apply power control techniques, which typically result in limited transmission power and hence limited coverage area. As...
Quadrature Amplitude Modulation (M-QAM) was developed to rapidly and automatically identify the modulation levels of digitally modulated signals at low signal-to-noise ratios (SNR). The method uses wavelet transforms with the optimal scale combining with manifold learning method to identify the modulation levels of the M-QAM signals. Simulation results show that when the SNR is not lower than − 22...
Silicon photonic components are key enablers for low-cost, compact, and reduced power-consumption coherent transceivers. This paper discusses models used to analyze the performance of silicon photonic ring modulators in coherent links, and presents simulation results for 32- and 16-Gbaud PM-QPSK back-to-back transceivers incorporating these modulators in comparison with designs using LiNbO3 MZMs....
In order to analyze the performance of mean level CFAR detector in various environments overall, the basic principles of the conventional cell-averaging (CA), greatest-of (GO) and smallest-of (SO) constant false rate (CFAR) detectors are analyzed firstly. Then the analytical results of performance are presented for these mean level CFAR detectors in multiple targets background with one or more interfering...
This paper presents an improved ISI shaping technique for multi-bit ΔΣ DACs. Compared to the prior ISI shaping method (Lars Risbo et al, JSSC, 2011) that monitors only the up (0 → 1) transitions, the proposed technique makes use of both the up and down (1 → 0) transitions with negligible hardware cost. It provides a finer control of the transition activity, thereby improving the ISI shaping effect...
The new releases of Long Term Evolution (LTE) systems are attracting most of the mobile users by proposing of their capabilities in network satisfaction. Quality of service (QoS) and network capacity are being insisted as two dominant factors for the utmost network satisfaction within any mobile network contracts. On the other hand, the heterogeneous network (HetNet), which is constructed based on...
In this paper, we propose clustered multi-hop relaying to guarantee fairness among relays and reduce transmission failure probability. For cluster-to-cluster communication, cooperative diversity is adopted and cumulative distribution function (CDF) based relay selection for cooperative diversity is used. The cooperative ARQ in each cluster is adopted to reduce the possibility of the transmission failure...
In this paper, we study the effective small-cell deployment scenarios to improve the system performance. We consider three deployment strategies — the random deployment, the deployment for the worst-performance user, and the cell-edge deployment [1]. From the system level simulation results, we suggest the effective small-cell deployment strategy in terms of the signal-to-interference plus noise ratio...
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