In order to improve the transmission performance of chaotic signals, a Multi-User Orthogonal Correlation Delay Shift Keying (MU-OCDSK) scheme was proposed based on Correlation Delay Shift Keying (CDSK) scheme and Multi-Carrier Correlation Delay Shift Keying (MC-CDSK) scheme. The multi-carrier was used to modulate chaotic signals. Compared with CDSK, the proposed scheme not only has higher spectral efficiency, but also improves bit error rate. Theoretical simulation and Monte Carlo simulation show that compared with MC-CDSK, the proposed scheme not only doubles the transmission rate, but also improves the bit error rate. The results of theoretical simulation and Monte Carlo simulation are consistent.

Under the background of strong noise, it is difficult to detect and extract weak signals. To solve the above problems, a new combination model of power and exponential function in tri-stable system was proposed based on the classic bistable system model and the Gaussian Potential model. First of all, the tri-stable system model was constructed by combining power function and exponential function, then the stochastic resonance was generated by adjusting related parameters, which was validated by numerical simulations. Secondly, using the average Signal-to-Noise Ratio (SNR) of output as a measure index, the artificial fish swarm intelligence algorithm was used to optimize the corresponding parameters, which makes the tri-stable system combining the power function and the exponential function achieve the maximum output SNR, and the phenomenon stochastic resonance was generated. Finally, it was applied to the diagnosis of bearing faults. At the same condition that the output SNR is -25.8 dB, the output SNR of the bistable system and tri-stable system combining the power function and the exponential function is -13.1 dB and -8.59 dB respectively. Simulation results demonstrate that the performance of the proposed system is better than the bistable system, and it is effective in weak signal detection and extraction.

For the problem of cross subframe interference caused by the use of dynamic subframe configuration in Long Term Evolution in Unlicensed band (LTE-U) system, a hybrid dynamic clustering algorithm which considered large-scale loss and cell traffic volume was proposed. Firstly, the information of large-scale loss and cell traffic volume was periodically measured by base station, then the corresponding relevance metric value was calculated. Secondly, according to the relevance metric value, the cells were clustered by polling to realize periodic update of clustering result. Finally, the dynamic subframe configuration was performed according to the updated cell clustering result. Simulation results showed that compared with the traditional static clustering algorithm in the medium traffic arrival rate conditions, the uplink-downlink user average throughput of hybrid dynamic clustering algorithm was increased by about 16.92% and 34.33%, the uplink-downlink user average delay was decreased by about 14.18% and 36.32%. Simulation results demonstrate that the hybrid dynamic clustering algorithm can effectively reduce the impact of cross subframe interference, and improve system throughput, which has better performance compared to the traditional static clustering algorithm.

Concerning to the problem of preserving users' identity privacy during the process of authentication in Vehicular Ad Hoc NETwork (VANET), a novel anonymous authentication scheme without cryptography based on the theory of linear equation was proposed. The scheme constructed an anonymous authentication model based on the basic theory of solving linear equations without employing any symmetric or asymmetric cryptosystem, which avoided disclosure of the identity information during the process of anonymous authentication. Besides, the proposed scheme not only satisfied the requirement of anonymous authentication between On Board Unit (OBU) and Road Side Unit (RSU), but also ensured the anonymous authentication among OBU. The results of the security and complexity analysis show that the proposed scheme is secure and efficient, and it needs low costs of computation and communication.

It is difficult for users to find the needed items from a large-scale project resource repository because the project resources in it are disordered, so a parallel fuzzy partition algorithm based on MapReduce was proposed. The algorithm firstly abstracted and standardized characteristic attributes of original project resource. Then a similarity matrix was established based on the standardized characteristic attributes of the project, and it was segmented by using block matrix. MapReduce was used to process the block matrix and merge the results. Finally, the algorithm obtained the partition results according to the threshold. The contrast experiment among the proposed algorithm, K-means algorithm and genetic algorithm shows that the proposed algorithm has higher accuracy and recall, it can achieve better speedup in large-scale data calculation and divide project resources effectively and accurately.

In the Wireless Sensor Network (WSN) routing, if the node does not fully consider the path node residual energy and link status of the route, some nodes will be dead early, hence the lifetime of the network will be shorten seriously. To resolve this problem, a uneven clustering routing algorithm for wireless sensor network was proposed based on ant colony optimization algorithm. Firstly, the method clustered nodes using uneven clustering algorithm which considered the node energy. Then considering the node need to transmit data as source node, the sink node as destination node, ant colony optimization algorithm was used to do multipath searching, and the searching process fully considered the factors such as transmission energy consumption, path minimum residual energy, transmission distance and transmission hops, time delay and bandwidth of selected link. Several optimal paths that met the conditions were given to complete the information transmission between source and the destination nodes at last. The experimental results show that the lifetime of WSN can be effectively prolonged while fully considering the path transmission energy consumption, path minimum residual energy and transmission hops.