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The transceiver beamforming design problem is studied in this paper for a multi-pair two-way distributed relay network, where multi-antenna users in one user group communicate with their partners in the other user group via distributed single-antenna relay nodes. An iterative algorithm is proposed where transmit and receive beamformings are performed at user nodes, and relay nodes have their own simple...
A method is proposed for reducing the effect of white noise in wideband sparse arrays via a combination of a judiciously designed transformation followed by highpass filters. The reduced noise level leads to a higher signal to noise ratio for the system, which can have a significant effect on the performance of various beamforming methods. As a representative example, the reference signal based (RSB)...
An effective method is proposed to estimate the desired-signal (S) subspace by the intersection between the signal-plus-interference (SI) subspace and a reference space covering the angular region where the desired signal is located. The estimated S subspace is robust to steering vector mismatch and overestimation of the SI subspace, capable of detecting the relative strength of the desired signal...
Estimating the amplitude spectral of noise signal is a very important part in many noise reduction systems. The conventional voice activity detection (VAD)-based method updates the amplitude spectral estimate only in speech absence areas and fails to deal with non-stationary noise. To overcome this problem, this paper proposes two methods to estimate the noise amplitude spectral for non-stationary...
First, the paper analyzes the basic principle of the uplink MU-MIMO and gives the user matching conditions and application suggestion. Then, an estimation method of uplink MU-MIMO gain is presented based on the tests analysis. At last, the performance of uplink MU-MIMO in the current user condition is also given.
The a priori signal-noise-ratio (SNR) estimator plays a very crucial role in the performance of a noise reduction system. The decision-directed (DD) approach, which is the most widely used technique for estimating the a priori SNR, suffers from one-frame delay bias when following the a posteriori SNR. Many modifications of the DD approach in the literature focus on accelerating the tracking speed...
In this paper the transceiver beamforming design problem for multipair two-way distributed relay networks is studied, where each multi-antenna user in one user group communicate with its partner in the other user group via distributed single-antenna relay nodes. To achieve a satisfactory performance while relieving relay nodes of the usual computation task, two iteration-based transceiver beamforming...
In traditional adaptive beamforming, the number of degrees of freedom is limited by the number of sensors in the array. In this paper, a new adaptive beamforming scheme is developed based on the nonuniform linear array structure, whose degrees of freedom can be much greater than the number of physical sensors in the array. In the proposed method, the original covariance matrix of the received array...
Partial discharge (PD) site in high voltage power equipment can be located by solving the time difference equations. Estimating the time difference between PD signals with high accuracy is of great importance for accurate locating. This paper presents a time difference determining algorithm using cumulative energy function and differential energy method. The differential energy characterize the increase...
Distributed algorithms have been proposed to address the problem of detection and estimation over wireless sensor networks. For diffusion algorithms, the combination weights play an important role. The estimates collected from some neighbors are less reliable than the others due to low signal-to-noise ratio (SNR) conditions. Thus, smaller weights can be given to the noisy estimates, with larger weights...
In this paper, the problem of distributed beamforming for cognitive radio systems with frequency-selective channel is studied. Our proposed scheme is based on the filter-and-forward (FF) relay beamforming approach and aims to maximize the received signal to interference plus noise ratio (SINR) at the secondary destination, while suppressing the interference introduced to the primary user. This scheme...
A closed-form solution for direction of arrival (DOA) estimation is presented for the spatially stretched tripole (SST) by adopting a quasi-vector-cross-product (QVCP) based scheme to deal with the mutual coupling problem. After deriving the sufficient condition for the proposed method, we design and study four specific types of SSTs in particular. Simulation results show that the proposed scheme...
Power minimization is a traditional method for interference suppression in satellite navigation systems. It works when the interferences are much stronger than the desired signals and noise, and its main advantage is that the direction of arrival (DOA) information of the desired signals is not required. In this paper, a new method for suppressing strong interferences for satellite navigation based...
In order to solve the transfer function modelling and controller parameter optimization of control systems, a novel design scheme is presented based on prony and particle swarm optimization (PSO) method. In this scheme, an impulse signal is applied to the input of controlled member firstly, and then output signal is estimated by prony analysis to get the transfer function. Finally, controller parameter...
We address the transceiver design problem for amplify-and-forward (AF) MIMO two-way relay systems with imperfect channel estimation. Since only estimated channel state information (CSI) is available, the self-interference (SI) cannot be completely canceled at destination nodes. With both channel estimation errors and residual self-interference considered, we propose two robust schemes to minimize...
Implementation of coincidence detection in PET systems usually involve energy discrimination and time discrimination. Depending on which is performed at first, the coincidence detection can be divided into two ways: energy discrimination before time discrimination (ETD) and time discrimination before energy discrimination (TED). The major difference of them is that, certain doubles from multiples...
We develop a K-SVD algorithm based radar HRRP target recognition method, which can adaptively select the sparse decomposition coefficient based on test noise environment. Experimental results on measured data show our method obtains a better performance than PCA based method.
In non-cooperative communication system, symbol rate is a crucial part of parameter estimation. The symbol rate estimation is deeply researched by the use of Continuous Wavelet transform(CWT). And a new multi-synchronous reference(MSR)approach is proposed to extract precise symbol rate of M-ary Phase Shift Keying (MPSK) signal. The value of MSR algorithm is focused on lower signal-to-noise rate (SNR)...
Vector perturbation (VP) is a prominent precoding technique attracted a lot of attention in recent years. Until now, however, various extended VP techniques proposed to apply in multiuser precoding are almost restricted to one antenna configuration of each user. The restriction does not meet the development of next generation wireless systems. So, the well-known block diagonal (BD) algorithm and VP...
Spectrum sensing is an essential functionality of cognitive radio networks (CRN). Among existing spectrum sensing methods, cooperative spectrum sensing is the best one which can achieve superior sensing performance by introducing spatial diversity of sensing data sources. Such cooperation also introduces additional information exchanging which leads to extra power consumption and reporting delay....
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