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In the wireless sensor networks, deploying a small amount of heterogeneous nodes which directly communicate with the Sink node, can form shortcuts. The shortcuts can make the network to have small-world properties, which can save energy and improve network performance. In the large-scale networks, the optimal deployment of heterogeneous nodes is a NP-hard problem. Considering the total energy consumption of the network and the uniformity of each node energy consumption, this paper presents a clustering heterogeneous network routing algorithm which based on mixed integer programming (CHNMIP). Firstly, the algorithm supposes that the heterogeneous nodes can only be placed in the position of the common nodes and converts the optimal deployment of heterogeneous nodes into a mixed integer programming problem, and finds out the approximate optimal solution using Lagrangian relaxation and Benders decomposition algorithm. Then, it dynamically divides common nodes into clusters, and sets the appropriate transmission. Finally, it theoretically analyzes the performance of CHNMIP routing algorithm, and the simulation results also show that CHNMIP routing algorithm can better improve the network performance in different simulation environment.

In this paper, a joint revisit and dwell time management (JRDTM) strategy for single target tracking based on the predicted Bayesian Cramer-Rao lower bound (BCRLB) in phased array radar system is addressed. We achieve the time resources management by formulating and solving an optimization problem, which is to minimize the resource amount used for tracking with the tracking accuracy of the target meeting a predesigned threshold. As the BCRLB provides a lower bound on the estimated mean square error (MSE) of target state, the predicted BCRLB model with time resources is derived and employed as the metric for the tracking performance. We put forward a converted algorithm to settle the optimization problem subsequently. Simulation results demonstrate that the proposed joint management strategy can help to achieve the tracking performance with less resource consumed.

In this paper, we will investigate a joint beam and dwell time allocation strategy for multiple targets tracking based on the phased array radar system. We achieve the resources allocation by formulating and solving an optimization problem, which is to minimize the total dwell time on all targets with the tracking accuracy of each target satisfying a pre-designed requirement. Since the Bayesian Cramer-Rao lower bound (BCRLB) provides a lower bound on the error of any unbiased estimator, it is employed as the metric for the tracking performance. The optimization problem is proved nonconvex and we solve it through a two-step decomposition algorithm. Simulation results show that the optimization strategy we propose is effective in resource saving and favourable for achieving a better tracking performance of worse targets compared to the operating mode with uniform resources allocation.

In order to improve the denoising effect of the pulsar signal, a new denoising method is proposed in the no-subsampling wavelet packet domain based on the local Laplace prior model. First, we count the true noise-free pulsar signal's wavelet packet coefficient distribution characteristics and construct the true signal wavelet packet coefficients' Laplace probability density function model. Then, we estimate the denosied wavelet packet coefficients by using the noisy pulsar wavelet coefficients based on maximum a posteriori criteria. Finally, we obtain the denoisied pulsar signal through no-subsampling wavelet packet reconstruction of the estimated coefficients. The experimental results show that the proposed method performs better when calculating the pulsar time of arrival than the translation-invariant wavelet denoising method.

Routing problem is one of the most important issues to a wireless sensor network (WSN), and multicast communication has become necessary to support some new applications. In the paper, we propose an energy-aware multicast routing algorithm for WSNs. The algorithm is based on geographic routing, and defines the multicast region as rectangle that has smallest area but covers all destination nodes, where an access point is selected as a gateway. The whole routing process includes two phases. The first phase is to seek a minimal energy path from the sink to the access point based on the idea of dynamic programming. The second phase is to search for a broadcast tree between the access point and the destination nodes in the multicast region. Experiments indicate that our algorithm has better performance on energy expends and success rate of tree setup.

The paper proposes a distributed bandwidth reservation protocol (DBRP) for QoS routing in ad hoc networks. The protocol adopts a TDMA-based model, derives from AODV, refers to the idea of three slot states (I.Jawhar et al., 2004), and adopts two-time reservation and controlling-flooding scheme. The protocol takes both the hidden-terminal and exposed-terminal problems into account. And it can solve the simultaneous reservation of several paths. In addition, controlling-flooding method can effectively control routing overhead, and two-time reservation can improve request success rate. Simulation results show the new protocol has better performance in denser networks and heavier traffic conditions.

This paper presents a digital solution to restrain the impact of the unwanted low-frequency signal on the practical driving signal, i.e. carrier signal, in a MEMS gyroscope with automatic gain control (AGC) mechanism. For this purpose, an ASIC has been designed and fabricated. With digital signal processing (DSP) techniques, the digital demodulated angular rate signal is adjusted by using a self-multiplied practical carrier signal after LPF in a digital divider. The simulation gives an SNR of better than 70 dB, which indicates that good device performance can be possibly achieved with this principle even though the driving is not ideal.