Baseband Signal Processing Technology Research In Wave And FPGA Implementation

With the rapid development of society, citizens’ demands for cars continue to growing, and the road traffic pressure is heavy. With the problems of increasing prominent traffic safety, intelligent car services will be more favored by communities. It is obvious that Wireless Access in Vehicular Environments(WAVE) can be the development directions of automotive electronics industry. It is the most basic function of WAVE for providing a full range of shared services and real-time traffic conditions message. These services are provided by WAVE system is not only the complex integration of communications, services, terminal hardware, which is also a catalyst automotive business chain.This paper mainly researches some issues of baseband in WAVE system. It is important for the future of the practical application of WAVE system. The main contents are shown as follows:Firstly this paper makes a detailed description of the basic principles and characteristics of WAVE system using OFDM physical layer technology. Depth analysis of the influence of synchronization errors causing for OFDM system, and simulation results are given to verify the error. In addition, as for MAC of WAVE system using anti-collision mechanism, there would be some problems when a large number of nodes request to access this environment, this paper will make the appropriate research and analysis.In addition, based on the classical Schmidl and Cox’s algorithm, this paper makes a focus on studying several synchronization algorithms. Through detailed calculations and derive formulas, we analyze the shortcomings of metric curve exists platform area in Schmidl and Cox’s algorithm and multi-side peaks in Minn’s algorithm. By analyzing the above algorithm shortcomings, this paper presents an improved synchronization algorithm based on training symbols by designing new training symbol. This improved algorithm not only eliminates the influence of the platform area, but also eliminates the interference of multi-side peaks. Finally simulation verified that this improved algorithm can improve the accuracy of the symbol timing.Then, WAVE system has low throughput when a large number of nodes request to access this environment. This paper use OFDMA access technology to solve this problem. By designing receiver module which meets OFDMA-based CSMA / CA mechanism, the throughput of WAVE system would be improved.Finally, the individual modules of WAVE system use FPGA to finish communication. As electronic communication technology now, FPGA with its high efficiency, large data computing and other characteristics is widely used. This paper presents the design of the transmitter and receiver core modules and some optimization algorithms. With the practical application of FPGA simulation, the design presented in this paper is more persuasive.