Applied Mechanics and Materials Vols. 719-720

Abstract: G3-PLC, an orthogonal frequency division multiplexing (OFDM) power line communication solution, has recently gained a lot of attention. It supports the application of four types of baseband mapping modes in different environments. These modes typically require a hard-decision demodulation, which will lead to nearly 3dB preference loss. In this paper, we propose an improvement scheme for the baseband mapping modes by changing the constellation encoding method. The optimal soft decision algorithm which makes use of log likelihood ratio (LLR) of the probabilities is used in the demodulators. Simulation results show that the proposed scheme can outperformer previous algorithm.

Abstract: In order to solve the problems revealed in loom devices deployed in textile enterprises, such as excessive varieties, differences caused by different produced times, technical inconsistence and over-complicated equipments, the paper puts forward the system structure and control strategy in the loom management system which solves the information networking problems for different structured loom equipments, achieves real-time data collection and detection on-site through which clients could get the latest updated weaving information, the system can be used as a reference for similar applications.

Abstract: According to the traditional AES algorithm, we present an optimized scheme, which offers an implementation of AES key expansion algorithm. The key expansion algorithm is shown by matrix in this scheme, then it is converted to look-up table, we use FPGA which has rich look-up table and storage resources to implement algorithm in parallel. The scheme reduces the complexity of the algorithm. As can be seen from experimental results, according to the needs of the encryption system, the system data processing speed and data throughput can be changed in real-time by changing the system clock.

Abstract: Low power data radio transceiver was designed based on ATMEGA88PA microcontroller and A7102C RF chip. The design principle was described. The hardware circuit diagram and the software flow chart were given. Experimental results showed that in the 433MHz band the standby current was less than 2uA, the transmitting power was 14.9dbm, the receiving sensitivity was-110dbm and the communication distance was 1.2KM in open space.

Abstract: “Authorized Shared Access” (ASA) is a spectrum management policy which enables the secondary system to opportunistically utilize the licensed spectrum of the primary systems. In the coexistence of LTE-A system with primary systems, one of the constituent cells of the CoMP cooperating set may be affected because it has to vacate the ASA frequency for it overlaps with the protected area of the primary system. As a result, the CoMP cooperating set will be changed, and the operation of the CoMP can’t be continued execution. In this case, the UE’s QoS can’t be guaranteed and even the UE experiences call drop when using the traditional method. In this paper, by utilizing a central controller, we propose an efficient method for managing CoMP cooperating set on the ASA spectrum. The change information about the affected cell is sent to the serving cell of the CoMP through the central controller in advance. Then, the serving cell may reselect a new CoMP cooperating set or determine CoMP information indicating whether the CoMP cooperating set will be continued based on this change information, which effectively ensures continued execution of CoMP and the UE’s QoS. Simulation results show that the proposed method can provide better performance compared with the traditional method.

Abstract: An energy-aware and congestion-avoidance routing protocol for mobile Ad Hoc network is proposed in this paper. The protocol modifies RREQ of AODV by adding some fields including energy and load information. When nodes forward RREQ they also rewrite these fields with their own situation. So the destination node can find a shortest route without low-power nodes and high-load nodes to avoid instable route most probably. On the other hand, the protocol can protect low-level energy nodes and avoid congestion.

Abstract: This paper describes the current status of power communication systems, problems and solutions, proposed to build an integrated platform system for communications management and control.The integrated platform system is divided into four parts: Comprehensive Monitoring Subsystem, Resource Management Subsystem, Operation and Maintenance Management Subsystem, Security Management and Control Subsystem, which can monitor the resource, operation and maintenance, and security controls etc.This system can implement communication professional management, process management, user management, daily operation, maintenance work management standardization, process and automation; promote systematic and integrated for communication network, improve service management level and efficiency of operation and maintenance; and provide better support and protection for developing the grid and the smart grid.

Abstract: Aiming at the weight degeneracy phenomena in particle filter algorithm, a resampling method improving the diversity based on GA-aided particle filter was presented. Taking the advantage of genetic algorithm ( GA ) in selection ,crossover and inheritance to make up for the shortcoming of resampling. Genetic operation on particles in real number domain is adapted to reduce the complex of the genetic algorithm. And the evolutionary idea of genetic algorithm was combined with particle filter, by using selection, and mutation to improve the weight degeneracy and diversity of particle filter. This GA-aided particle filter was applied in the established GPS system nonlinear dynamic state space model. The experimental results based on the collected real GPS data is compared with the tradition particle filter, and compared with the effective number of particles and particle distribution. The experimental results indicated that the GA-aided particle filter can increase the number of particle, and effectively solve the particle degradation phenomena, the estimation accuracy of GA-aided particle filter is better than that of particle filter (PF).

Abstract: Ad-hoc communications is a mobile communication networks and computer networks combine with no infrastructure support, and network survivability and flexibility is strong, especially suitable for emergency communication. As the existing mobile ad hoc network routing protocols lack of network load balancing capabilities, this paper proposed a routing protocol based on load balancing LBBR (Load Balancing Based Routing). Simulation results shows that, LBBR can improve the success rate of packet transmission, reducing the average end to end delay, thus effectively improving network performance.

Abstract: For high data rate transmission, the parallel turbo decoding can guarantee high communication reliability as well as reduce the decoding latency greatly. A challenge in the design of parallel turbo decoder is the design of collision-free interleavers in order to avoid the memory access collision in the decoding process. In this letter, a novel algorithm for the generation of collision free S-random interleavers of turbo codes is proposed. The proposed algorithm can obtain larger spreading factor, S, and better average code distance than the existing collision free row column S-random interleavers.