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In a video streaming application, quality of experience for a user can be affected by various factors. The video quality can be improved if the effective throughput can be increased at an acceptable packet loss rate and low latency. To reduce the packet loss rate over error-prone channels, a cross-layer error control scheme is developed for heterogeneous data transmission over wireless channels in...
In order to meet the explosive traffic demand, the capacity of Long Term Evolution(LTE) system needs to be further expanded, and one choice is to integrate unlicensed carrier into the overall LTE system. However, unlicensed band might be shared by other communication systems like Wi-Fi and radar, so the available bandwidth for each user could not be guaranteed. We propose a carrier aggregation resource...
User satisfaction is a critical design metric of wireless communications systems and networks. In this paper, we consider user satisfaction of wireless communications networks from a human psychological point of view through the prospect theory. Due to the asymmetrical s-shaped value function and the dependence of reference point described by the prospect theory, user satisfaction is degraded significantly...
Automatically recognizing personality based on historical action logs in online social networks is a promising method to infer a person's behaviors, and it has received a lot of attention lately as it might lead to the construction of a better personal recommendation system. However, very few previous works in the literature put their focus on predicting personality from Chinese texts. As Chinese...
Cognitive radio now-a-days has opened a new horizon for researchers to mitigate the up-growing demand for RF spectrum within our limited resources. The threshold plays very important role for sensing process in energy based detectors as it is widely used in CR network due to its fast performance and ability to perform without any prior knowledge or information. Conventional energy detectors has fixed...
New designed power systems of electric and hybrid vehicles influence other systems by generated disturbing electromagnetic field. One of the promising measures to mitigate this negative effect can be found in additional shielding of cables, which can be provided by electrically conductive textile materials. This paper focuses on verification of utilization of specifically designed shielding textile...
In this paper, we introduce an improved relative channel reciprocity calibration method in TDD massive multiple-input multiple-output (MIMO) systems. The improved calibration method divide the massive MIMO system into one Single-Input Single-Output (SISO) system and two Single-Input Multiple-Output (SIMO) systems instead of calibrating the massive MIMO directly. We select the channel with high channel...
In a multichannel system, the transmitter can perform precoding techniques to alleviate the effects of fading and interference. However, the precoding transformation matrix usually results in high peak to average power ratio (PAPR). In order to avoid inefficiently operating the power amplifier, for a precoded multi-input multi-output (MIMO) system, we consider using a PAPR reduction method based on...
Unipolar orthogonal frequency division multiplexing (U-OFDM) is compatible with optical intensity modulation and attract attention recently. Existing synchronization methods cannot be used directly or do not perform well in U-OFDM systems because U-OFDM signals are unipolar. Therefore, a novel synchronization algorithm, i.e., negative mirror image (NMI) algorithm, is proposed, where the training sequence...
The change-point detection of Power Quality (PQ) events has been a critical issue in smart grids because of the wide adoption of delicate power electronic devices. In this work, we design algorithms to achieve two goals. The first one is to detect various PQ events in the quickest sense under the false alarm constraints. The second goal is to mitigate the severe misdetection caused by the malfunctioned...
We numerically examine the influences of the cladding index and the cladding thickness on the transmission bandwidth of the terahertz (THz) pipe waveguide. Numerical results show that, when the refractive index or the thickness of the cladding decreases, the transmission band becomes broader under either condition. However, the transmission band suffers a larger loss when the cladding index decreases...
In this paper, we study the transceiver design problem for amplify-and-forward interference multiple-input multiple-output (MIMO) relay communication systems, where multiple transmitter-receiver pairs communicate simultaneously with the aid of a relay node. We aim at minimizing the mean-squared error (MSE) of the signal waveform estimation at the receivers subjecting to transmission power constraints...
Accurate spectrum sensing is very important for cognitive radio systems. In the cooperative spectrum sensing, the unreliable nodes will result in deterioration of detection performance. This paper focuses on the spectrum sensing in the case of unreliable nodes and proposes a weighted reliability cooperative spectrum sensing algorithm. In the algorithm, the global fusion center only chooses the cognitive...
A low-power and area-efficient 10 GHz LC- voltage controlled oscillator is designed for fiber lasers application in microwave signal generation from a free running mode-locked Er-fiber laser. In the stretched-pulse regime, the Er-fiber laser is designed at close-to-zero dispersion to minimize the phase noise of extracted microwaves. In order to suppress the excess phase noise in the opticalto- electronic...
In this paper, we propose a superimposed channel training algorithm for multiple-input multiple-output (MIMO) relay communication systems with time-varying channels. The time-varying characteristic of the channels is described by the complex-exponential basis expansion model (CE-BEM). The proposed algorithm can estimate the individual first-hop and second-hop time-varying channel matrices of MIMO...
In the mixed-line-rate (MLR) wavelength-division multiplexing (WDM) networks, for each wavelength of fiber, it can provide different bandwidths in 10/40/100 Gbps by using different modulation formats. In this paper, the virtual topology design (VTD) problem is studied for allocating the multi-hour traffic on MLR-WDM networks. The goal is to construct a feasible virtual topology to meet the traffic...
In this paper, a multicast optical Ethernet switch based on SOA (Semiconductor Optical Amplifiers) technology with optical output buffers is proposed. Only the header of optical packets is converted to electronic signals to control entire operations of the optical Ethernet switch and the packet payloads can be transparently destined to their output ports. An optical output buffer is designed to queue...
An iterative digital signal processing (DSP) for reducing signal-to-signal beating interference (SSBI) in a multiband direct-detection optical orthogonal frequency division multiplexing (DDO-OFDM) system is proposed and demonstrated experimentally. Without applying any optical/electrical filter in the receiver, all the OFDM signal bands can be almost uniformly recovered even under severely SSBI contamination...
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