Development Of SW OFDM System Simulation Platform Based On SOPC Technology

In the new century, wireless communication technology developed rapidly by various real-time multimedia services and Internet technologies. Especially in the last decade, as the extensive use of digital signal processing, RF circuit manufacturing technology and semiconductor technology, wireless communication devices became smaller, cheaper and more convenient. The FPGA chips in the field of wireless communications, made the real-time signal processing possible.This paper made a detailed analysis of the shortwave channel and set up a simulation platform of shortwave OFDM system with Matlab. The simulation system combined different channel models and used different modulation and coding methods to acquire the parameters of short-wave OFDM system performance.The paper realized based multi-speed convolutional coding module, Vierbi decoder modules, interleaving module, deinterleaving module, QPSK modulation / demodulation module, Pilot plug-in module, IFFT / FFT module, the cyclic prefix modules, scrambling / descrambling module, training sequence generating module and NIOSⅡcontrol system of OFDM system on the FPGA chip.The system adopted a new model of software radio architecture, used SOPC technology to achieve the key modules of the OFDM system in the form of hardware, in order to improve the operation rate OFDM system. The system used the bus width can flexibly configure core processor (NIOSⅡ) as the system's main controller, making the controller separate from OFDM processing module, thereby reducing the burden of the processor to achieve the dynamic configuration and reconstruction of each module under different work rate and different modulation methods. The system used C language to realize protocol processing function which was hard to be realized by hardware.The paper proved reliability and feasibility of the design after the system debugging of the circuit, and it had some practical value.