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The performance of Beamforming has been significantly improved in antenna array signal processing during recent years. To suppress high sidelobe levels of output beampattern and signal direction mismatches, some notable optimization techniques have been developed. In this paper, an improved convex optimization problem is introduced, which minimizes beamformer output power via using a modified objective...
In this paper, we propose a FBMC (filter bank multicarrier) duplexing scheme, where downlink and uplink use FBMC for their transmission. Downlink and uplink transmit at the same time and in the same frequency band but with different subcarriers. We then analyze the advantages and problems of the scheme. We show that it is impossible to achieve full synchronization in time and frequency with both downlink...
Time-frequency (TF) based cognitive radio (CR) sensing schemes have to operate in different environments. In case of completely known distributions of observations under both primary user (PU) present and PU absent hypotheses, sensing can be based on a conventional likelihood ratio testing approach. However, if the observations contain unknown interference signals the conventional approach has to...
SOFC is a electrochemical reaction system with strong nonlinearity. Due to this nonlinear, the pressure of reaction gas fluctuates largely and battery output voltage is difficult to control. To solve these difficult problems, the sliding mode control strategy is proposed, which can ensure pressure of the SOFC system remains constant and then the battery output voltage will keep stable. Firstly, the...
Visual object tracking is one of many important applications for surveillance systems. The issues for visual object tracking are robustness from background interference, scaling and occlusion detection. In this paper, visual object tracking using improved Mean Shift algorithm is proposed. Mean Shift algorithm is used to obtain center object target for tracking. Corrected Background Weighted Histogram...
In the present paper, we have proposed a high-performance 3D recognition method based on the reference point ensemble, which is a natural extension of the generalized Hough transform. The reference point ensemble consists of several reference points, each of which is color-coded by green or red, where the red reference points are used to verify the hypothesis, and the green reference points are used...
Detecting network anomalies means a lot to network security. In respect of detection precision and range, network-wide anomaly detection approaches on the basis of traffic flows have distinctive advantages over the methods of the traditional host computer, single link and single path. However, these approaches face actual problems of performance reduction or being unavailable when noise interference...
We study the robust security-aware beamforming optimization for cognitive interference channel with confidential messages under the imperfect channel state information (CSI) at each cognitive transmitter. The considered problem is formulated as minimizing the total secondary transmitter power under the subject of the each secondary transmitter constraint while guaranteeing the security communication...
Coordinated transmission is an effective way to deal with the inter-cell interference (ICI) problem in a multi-cell distributed antenna system (DAS). However, in a practical scenario, the inter-cell channel state information (CSI) is usually imperfect, consequently causing a significant performance degradation of coordinated transmission. In this paper, to tackle this difficulty, we propose a coordinated...
This paper is written to treat interference combating techniques in a general way to clear terms, present applications and emphasize that combining cooperative and non-cooperative techniques to improve system-performance. The investigations are done under the restriction to minimize resources and to keep the system-complexity low to enhance the efficiency. The figure of merit is the conversion-gain...
We propose a robust 2×2 3 dB waveguide beam splitter designed by shortcuts to adiabaticity. The beam splitter design is achieved by combining shortcuts to adiabaticity and perturbation theory. The error sensitivity of the coupler is minimized by optimizing the system evolution with respect to coupling coefficient variations.
Spread spectrum (SS) modulation is one of the most commonly used methods for data hiding. However, the capacity of SS-based methods is rather limited. To improve the hiding efficiency, this paper presents a method that employs the parallel combinatory spread spectrum (PCSS), in which the hidden data can be transmitted in parallel with a combination of a few pseudo noise sequences. An informed embedding...
The proposed method realizes adaptive reduced-dimension processing based on joint optimization of both reduced-dimension matrix and beam-forming weight vector. Meanwhile, the spatial spectrum reconstruction technology is used to update the covariance matrix of array data online. The simulation results show that the proposed method is robust to the dimension of the reduced-dimension matrix and significantly...
Adaptive beamforming algorithm performance decreases sharply with the increase of array errors. Beamforming algorithm based on diagonal loading is a simple and effective method for improving robustness. But it is difficult to determine the optimal diagonal loading factor, and the fixed load value does not change with the array error, reduce the loading effect. To solve the above problems, this paper...
As the positioning accuracy of GNSS systems will degrade in the presence of electromagnetic interference, jamming detection becomes pivotal part in high-precision wireless communication systems which is conventionally accomplished by energy statistics or time-frequency transformation. In this paper, we present the spatial-frequency adaptive processing (SFAP) method which will achieve highly detecting...
Sparse Code Multiple Access (SCMA), a non-orthogonal multiple access scheme, has been introduced as a key 5G technology to improve spectral efficiency. In this work, we propose SCMA to enable open-loop coordinated multipoint (CoMP) joint transmission (JT). The scheme combines CoMP techniques with multi-user SCMA (MU-SCMA) in downlink. This scheme provides open-loop user multiplexing and JT in power...
We address a new robust optimization problem in a multiuser multiple-input single-output broadcasting system with simultaneous wireless information and power transmission. Assuming that perfect channel- state information (CSI) for all channels is not available at the BS, the uncertainty of the CSI is modeled by an norm-bounded uncertainty set. To optimally design transmit beamforming weights and receive...
Dynamic inter-cell interference coordination (ICIC) is a multi-point cooperation technology that has attracted significant interest for inter-cell interference mitigation in wireless communication systems due to its potential performance gain, robustness and relatively low complexity. This paper describes mechanisms for implementation of dynamic ICIC as well as the standardized support that exists...
The use of Long Term Evolution (LTE) in the unlicensed 5 GHz band, referred to as LTE-U, is a promising enhancement to increase the capacity of LTE networks and meet the requirements of future systems. This paper considers a Q-learning based Channel Selection strategy to decide the most appropriate channel to use for downlink traffic offloading in the unlicensed band as a mechanism to greatly facilitate...
Frequency diverse array (FDA) is a new antenna array concept. Different from phased-array which offers range-independent beampattern, FDA employs a small frequency increment across the antenna elements and yields a range-dependent beampattern. This enables the array beam to scan without the need of phase shifters or mechanical steering and provides potentials to suppress/detect range-dependent interferences/targets...
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