Applied Mechanics and Materials Vols. 263-266

Abstract: The performance of atmospheric communication system is limited by the atmospheric turbulence. In this paper, we present a practical 10Gbps DPSK transmission system for free space optical (FSO) communication with low error probability and wide-opening eye diagram. Compared to OOK modulation, DPSK format is a more effective way to resist the atmospheric turbulence. In addition, we designed parameters of this modulation system to be varied as the channel situation changed to achieve an optimized performance. The experiment results show that such a DPSK system could greatly overcome the atmospheric turbulence.

Abstract: Event-B is a formal language for system modeling, which allows early-stage comparison of design alternatives and identifies potential sources of defects. Stop-and-Wait ARQ is the basis of data link layer protocols in TCP. Our work aims to model the protocol in Event-B to reduce development risks. The paper is presented in two parts: modeling of the error-free transmission in the protocol without time constraints, and then adding of time constraints to model the overtime retransmission.

Abstract: We study the performance of the three-node relay network. Three combining methods for the Amplify-and-Forward (AF) protocol and the Decode-and-Forward (DF) protocol are compared. Simulations indicate that the AF protocol is better than DF under all these three combining methods. To combine the incoming signals the channel quality should be estimated as accuracy as possible, more estimation accuracy requires more resource. A very simple combining method can obtain the performance comparative with optimal combining methods approximately. At the same time, all three combining methods for both diversity protocols can achieve the maximum diversity order.

Abstract: Rate-matching is to ensure the transmission channel multiplexed total bit rate to match the physical channel carrying capacity in TD-SCDMA system. It directly affects the quality of sending data. This paper is focused on the researches of rate-matching, the three important parameters is calculated, the rate-matching processing is presented, the computation flow chart is given, and the computation results is listed to demonstrate the influence of semi-static performance on data rate-matching. It provides some basis for the further research of TDD communication.

Abstract: The first interleaving is an effective measure to eliminate long time continuous error during channel coding and multiplexing of TD-SCDMA. In this paper, a circulated cross-connection method is proposed for the first interleaving , and the implemation schedule is designed. The results verified that the method could meet the performance requirement for the first interleaving and is accurate and reliable.

Abstract: A new dynamic form component applicable to be integrated with GIS (Geographic information system) was developed to meet the needs of the geographic information industry and the demands of GIS customers. The general framework of the dynamic form component and adopted key technologies such as dynamic compilation and reflection are studied. Practical applications in GIS projects show that the dynamic form component can effectively improve the development speed and quality of GIS applications, and can provide appropriate user interactive abilities.

Abstract: Underwater acoustic networks (UWAN) play a crucial role in the development of modern marine military defense and civilian marine. In many cases, the simulation of routing and MAC protocols in underwater acoustic network has ignored the impact of some critical features of complex underwater acoustic channel upon UWAN performances. This paper establishes a channel model for the Rayleigh fading channel in shallow-water medium-range communication in OPNET network simulation software. It simulates the time-varying and multi-path effects of underwater acoustic channel, which are reflected in the received power and bit error rate. Finally the validity of this channel model is verified by simulations.

Abstract: To achieve survivable communications, it is important to build trusted and stable routes in routing algorithm for mobile ad-hoc networks (MANETs). This paper proposes a multipath routing protocol, the security- and stability-aware multipath routing protocol (S²AMR), locating and preserving the trusted and stable routes in MANETs. In S²AMR, we combine a dynamic trust mechanism with a stability model to satisfy the security requirements and stability requirements, respectively. S²AMR is extended by the AODV protocol, in which a node makes a routing decision based on the trust value on its neighboring nodes and its stability degree, and finally a set of survivable routes are established through the trust value and the stability degree of nodes along these routes. The effectiveness of our approach is validated through extensive simulations.

Abstract: In order to solve tower cranes interference and collision problems in the construction site, wireless communication mode among tower cranes is analyzed. Comparing of different network mode for the ratio station, rotating point-to-multipoint wireless network mode is put forward. Wireless token ring network solutions are put forward for half-duplex radio communication. Token-ring network communication protocols are draw up and workflow of wireless network is analyzed in detail. Distributed control algorithm for the group tower cranes anti-collision is put forward based on wireless communication algorithm

Abstract: An efficient Integrated Bandwidth Allocation Scheme (IBAS) is proposed to serve the lower priority requests can be early assigned the bandwidth without waiting too long. These will speed up the channel capture by priority data to support the multimedia traffic over DOCSIS-compliant cable networks. The efficiency of IBAS is investigated by simulations. The results show that by adopting IBAS can not only shorten the collision period but also minimize the average request delay of lower priority requests. Performance has been improved in throughput and delay compares to the current DOCSIS specifications.