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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...
Benefits of intra-superchannel spectral-equalization are demonstrated in a production 8Tbps system. ~1.2dB OSNR improvement and ~4.5dB reduction in power-spread is measured relative to inter-superchannel equalization. Tradeoff between OSNR and nonlinearity dictates the net reach improvement.
GPS satellites transmission consists of two pseudorandom noise codes, modulated on two carriers. For position determination of a GPS receiver on the earth two parameters, satellite position and pseudo ranges of each Satellite Vehicle are to be estimated by decoding the Navigation message from each satellite which depends on the Carrier to Noise Ratio (C/N0) at the receiver. GPS employs spread spectrum...
In last few years there has been significant growth in the area of wireless communication. Quality of Service (QoS) has become an important consideration for supporting variety of applications that utilize the network resources. IEEE 802.16/WiMAX is a new network which is designed with quality of service in mind. This paper focuses on the comparison of quality of service parameters between different...
This paper presents a self organized spectrum chunk selection algorithm in order to minimize the mutual inter-cell interference among Home Node Bs (HeNBs), aiming to improve the system throughput performance compared to the existing frequency reuse one scheme. The proposed algorithm is useful in Local Area (LA) deployment of the Long Term Evolution-Advanced (LTE-A) systems, where the HeNBs are expected...
This paper study the performance of an orthogonal frequency division multiple access (OFDMA) system under fractional load based in long term evolution (LTE) downlink. Fractional load is defined by a situation where only a fraction of the bandwidth is used for transmission due to lack of traffic. This type of situation should result in a global increase of signal to interference and noise ratio (SINR)...
Currently International Telecommunications Union (ITU) is working on specifying the system requirements towards the next generation mobile communication systems called International Mobile Telecommunications-Advanced (IMT-A). This paper presents an overview on the technological requirements and current enhancements leading towards IMT-A. The relay nodes, support for higher bandwidth, local area indoor...
LTE-advanced systems, which aim to provide high data rate wireless services, have received world-wide researching interests nowadays. In this paper, the performance of fixed frequency reuse with different reuse factors is studied in LTE-advanced systems. Performance is measured in terms of both average cell throughput and cell edge user throughput. It is found that a properly chosen reuse factor with...
In this paper, voice signal compression (VSC) is a technique that is used to convert the voice signal into encoded form and when compression is required, it can be decoded at the closest approximation value of the original signal. This work present a new algorithm to compress voice signals by using an ldquoadaptive wavelet packet decomposition and psychoacoustic modelrdquo. The main goals of this...
The main source of interference in OFDMA system in downlink is inter-cell interference, which can severely limit the throughput of users near the cell edge. The inter-cell interference coordination (ICIC) is one method to improve the performance. In this paper autonomous inter-cell interference avoidance schemes under fractional load (FL) conditions in the downlink for 3rd generation partnership project...
In this paper, voice signal compression and spectrum analysis (VSCSA) is a technique that is used to compress transparent high quality voice signals upto 45% - 60% of the source file at low bit rate 45 kbps with same extension (i.e. .wav to .wav), then voice spectrum analysis (VSA) is started. Voice signal compression (VSC) is done by using adaptive wavelet packet a tool of MatLab for decomposition...
We propose an in vivo retinal imaging platform for quantifying gliosis in response to neurotoxicity of certain compounds. Gliosis, in the form of retinal GFAP-GFP expression, was non-invasively and longitudinally imaged using a confocal scanning laser ophthalmoscope (SLO) and its progression was monitored over a period of two weeks. However, the retinal images have very poor signal-to-noise ratio...
In this paper we propose a non-contention based mechanism for allocation of the spectral resources by several interfering Home e-NodeBs (HeNBs) deployed by the same or different operators, potentially in random manner in a given geographical area. The proposed mechanism facilitates allocation of spectral resources from a common pool based on the individual traffic requirements of the HeNBs, thereby...
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