Applied Mechanics and Materials Vol. 443

Abstract: With the rapid development of electronic information science and network transmission technology, the signal processing technology has been widely applied to various fields, which is the most important component of signal detection and transmission, and the key signal processing technology for processing sensor crude signals. Based on this, the experimental system of sensor coarse signal processing model is established, and in the experimental system, the transformer can carry out signal recognition for voltage and current, the use of PC microcontroller and embedded AD converter carries out analog / digital conversion for sensor crude signal. For the amplification process of sensor coarse signal, the use of adaptive genetic algorithm carries out mathematical modeling, the realization of the signal identification, acquisition and processing functions through software programming control. Finally, the intelligent processing of sensor coarse signal is successfully completed by the experiment system, and the signal processing effect is given as well.

Abstract: With the continuous development of the 3rd generation telecommunication, the requirement of fluent switching is taken more consideration. The paper presents the relevant parameters and the implication of 2G/3G mode switching in CS domain. Proposes the optimization analysis of the basic principle of 2G/3G mode switching in CS domain, suggests a method using neighboring CIO to refine the origin switching methods, with the analysis of typical case by using the specific implementation process of neighboring CIO, the refined method proved to be of actual value and high efficient

Abstract: It uses Windows low-level audio API to record and broadcast voice packets, encodes and decodes through G.729A, and groups by TCP/IP protocol, transmits data packets by UDP on the SOCK_DGRAM SOCKET between the client and the server, So as to achieve the function of Internet voice communication. To ensure user friendly interface, the premise here using multi-threaded programming. In addition, the system also in application-layer protocol adds the text chat function which based on TCP transmission. The essence of the design is to realize software to communicate by voice or text which based Windows operating system. The successful debugging of this software will have a positive effect on the PC to PC kind of VoIP communications system.

Abstract: With the technology development, wireless network has been the important combination of current high and new technology. In order to confirm communication performance and different high-efficiency satisfaction of various users, relay question research of wireless network communication is the hot spot. Take the advantage of cooperation diversity technique can diverse each node in the network system. Moreover, optimize the relationship among each node is the important method of communication technology. This article evaluates relay questions in the wireless network communication. It analyzes relay and protocol, explains three transmission methods in network communication, discuss selection algorithm of multi-relay, and combines genetic algorithm and selection algorithm of multi-relay. In the end, this article provides part of the core codes.

Abstract: To protect the primary user and improve the credibility of spectrum sensing, a spectrum sensing optimization algorithm based on antenna selection is proposed in this paper. In the case where the channel coefficient and signal-to-noise ratio are not known, one antenna weighting and selection algorithm based on auto-correlation is proposed. This algorithm can also be used to distinguish whether it is necessary for antennas selection so as to optimize spectrum sensing performance. Based on auto-correlation ratio, selecting parts of the antennas to cooperatively sense spectrum can maximize the detection probability. Simulations are used to verify the method. The results indicate that the proposed antenna weighting and selection algorithm can be able to optimize network performance.

Abstract: The multi-access interference and quality of communication system can be greatly improved by beam forming technology when the smart antenna is adopted. This paper investigates the performance improvement given by a multi-antenna receiver on a mobile terminal , and a link level simulation scheme is presented based on TD-SCDMA system. The performance of dual smart antenna under different circumstance is analyzed, and three different adaptive algorithms are compared under the specifically modeled multipath fading channel. The simulation results show that a dual-antenna arrangement on a mobile terminal can achieve better performance than a conventional single antenna.

Abstract: The article introduces the constitution and message format of Memo bus RTU Communication Protocol, and provides a method for data transfer optimization through by the analysis of the communication protocol format. This method is fit on the inverter and controller which is based on the Memo bus RTU communication protocol and utilized theRS-485 port while the data being transported. By Considering this kind of inverter's distribution, this paper puts forward a method which is based on dividing by functional data block, able to sequence rankly criterion of the function data block, and able to transport date block divided by the function, thereby, this method decreases the redundancy enormously, elevates the system response speed, and solves the technical problem of controller PID output port's real time remote control to multiple inverters.

Abstract: To meet the needs of ZigBee protocol on voice communication in wireless sensor network and realize low-cost and low-consumption wireless voice communication in short distance, multi-hop voice communication nodes software based on multimedia voice node plate of wireless RF chip is designed. Thus, multi-node network communication, real-time voice sampling and multi-hop relay transmission are implemented. Also, it features high-quality voice, low fault system, and high reliability. All these make it applied widely in a larger range.

Abstract: Many kinds of control instrumentation have USB interface as standard interface supplying more convenient, faster data transmission methods nowadays. However, due to the complexity of the USB protocol, developing applications using USB protocol is not very easy. We propose a smart method using the USB-to-UART chip CP2101 and design the software with LabWindows/CVI in this paper. A USB to UART hardware circuit design and the LabWindows / CVI environment USB CP2101 communication program design methods.

Abstract: With the rapid development of science and technology, the current spectrum resources cannot simply cope with the high-load wireless networks cross-layer transmission. This thesis is based on the in-depth analysis of cognitive radio technology to understand the routing protocol in wireless cross-layer data transmission, and then discuss the relevant characteristics of the AODV routing protocol, and base on the AODV, the routing protocol uses in the analysis of the radio network organization based on the proposed to the possibility of cross-layer cognitive radio.