Applied Mechanics and Materials Vols. 556-562

Abstract: This paper links the parameter estimation problem of polarization diversity bistatic multiple-input multiple-output (MIMO) radar to propagator method (PM), and proposes an algorithm for joint estimation of direction-of-departure (DOD), direction-of-arrival (DOA) and polarization information for bistatic MIMO radars. PM algorithm is a low complexity algorithm since it requires no eigen-value decomposition (EVD) of the covariance matrix of the received data. The proposed algorithm can estimate the multiple parameter accurately, while achieve paired parameters estimation automatically. Through obtaining polarization information, MIMO radars can further increase the target location and identification accuracy. Simulation results verify the feasibility and effectiveness of the proposed algorithm.

Abstract: Starting from constitution of design symbols, this article analyzes the constitution forms before sending and receiving messages, the decomposed information carriers of senders and receivers, the coding rules of sending messages formulated by senders and decoding rules of receiving messages by receivers, thus concludes three basic rules, namely, regular、irregular and mixed type of understanding. And the design symbol reveals the distribution and enjoyment of culture. Without social relationships and communication of individuals, there will be no symbols and transmission、the systematic integration of various human design symbols as well as the approaches of the accumulation of collective experience and the pass of behaviors of individuals.

Abstract: The article proposed one-pass authenticated key establishment protocol from optimal eta pairings in random oracle for Wireless Sensor Networks. Security of the protocol relies on Computational Diffie-Hellman Problem on Optimal Eta Pairings. In one-pass key establishment protocol, the initiator computes a session key and a re1ated message. The key token is to be sent to the intended receiver using receiver's public key and sender secret key. From the received key token the receiver compute the session key, which is the same as the one computed by the sender,using sender public key and receiver's secret key. Because of low communication overhead, the scheme is better suited for Wireless Sensor Networks (WSNs) than the traditional key establishment protocol to establish the session key between two adjacent nodes.

Abstract: Recently, two-way relay network has been taken attention. In this paper, the two-way relayprotocols of ultra-wideband (UWB) network based on code-multiplexed transmitted-reference (CMTR)impulse radio have been studied. Based on code-multiplexed scheme, a new two-way relayingstrategy for two-slots protocol is designed. The corresponding bit error rate (BER) performance isevaluated via simulations and compared with three-slots scheme which can get path diversity gainfrom direct link between terminals. Simulation results reveal that the performance of the two-slotsrelaying scheme is almost same with that of the three-slots scheme. Meanwhile the throughput ispromoted about 33% over three-slots scheme.

Abstract: Boiler combustion system is a multiple input multiple output complex controlled process, which with large time delay and model uncertainty features. In order to improve the control quality of industrial boiler system and find the appropriate control algorithm to realize the optimal control of boiler combustion system, the article has carried on the model identification for boiler combustion system by the method of neural network. It could make the adjustment of controller parameter more effective, make industrial process simulation more convenient; and play a big role for online control and forecast to the industrial object. The results show that the modified ELMAN neural network can identify the mathematical model of combustion system quickly and accurately.

Abstract: The clutter distribution of an airborne multiple input and multiple output (MIMO) radar in non-homogeneous environment varies with ranges and samples in different range gates are not independent identically distributed vectors, so that the statistical space time adaptive processing (STAP) methods degrade heavily. A clutter suppression method for airborne MIMO radar in non-homogeneous environments is studied in this paper. Firstly, Space time autoaggressive (STAR) method is introduced to airborne MIMO radar for clutter suppression and then an AR model parameters estimation method for STAR is proposed to decrease the complexity of traditional method. Simulation results show the proposed method can estimate parameters exactly and rapidly with only few training samples and be fit for clutter suppression in non-homogeneous environments.

Abstract: This paper investigates the implementation of cooperative communication in small-cells network. Cooperative communication is some cells that in a network can work together, ex. joint transmit power and exchange resource allocation among them. Therefore, cooperative small-cells can be possible to add more multiple input multiple output (MIMO) antennas. But, channel state information (CSI) is required. In practice, perfect channel state information may not be perfect due to the real condition of the real environment such as delay, error, and etc. This paper illustrates cooperative small-cells under error model on the channel estimation. Our propose system is combined by implementing block diagonalization pre-coding and power allocation based on water-filling algorithm. As investigated by simulation results, our proposed coordinated small-cells showed good performances compare to previous algorithm either with perfect channel or with the error channel estimation.

Abstract: This paper analyzes the radiation characteristics of fishbone antenna arrays and concludes its optimum set of array formation. In order to study the feasibility of apply fishbone antenna into pashed array, the common fishbone antenna array is analyzed and simulated by the method of moments. It mainly calculated the radiation properties of two-element array, four-element array and six-element array under the linear array, rectangular array and sector array respectively. Comparing characteristics of different number of array element under the same array type and the different array types under the same number of array element, it suggests that two-element array is the most appropriate array type when sector arrayed, and the array types of 3 x 2, 2 x 2 and 1 x 2 have relatively good effect of beam scanning in low frequency with phase shift.

Abstract: Multiple-input multiple-output (MIMO) radar with frequency diversity (f-MIMO) is applied to HF radar. An array processing model of f-MIMO HF radar is developed. To eliminate the grating lobe of f-MIMO radar beamforming, two approaches are proposed. One is to apply particle swarm optimization (PSO) algorithm to select the optimal carrier frequency combination. Another is to extract array elements from the virtual receive array to get the optimal sparse array structure, and the simplified physical receive array structure is proposed. Simulation results demonstrate the effectiveness of the method proposed.

Abstract: Spatial and temporal chirp will effects a pulse both in space and in time domains. So effectively controlling and utilizing the spatial and temporal chirp has great significance. In this manuscript, firstly the dispersion properties of the prism pair is theoretical analyzed, and the phase delay second derivative expression of the thin prism is obtained. Then a setup is demonstrated to experimentally investigate the spatial and temporal properties of the femtosecond pulse beam. The spatial chirp and temporal chirp effects on the femtosecond pulse beam are experimentally obtained. Both theoretical analysis and experimental results indicate that the group delay dispersion due to prisms is always negative, and the pulse beam can be compressed or broadened by the prism pair based on changing the prisms referring parameters.