用于地铁的OFDM测距雷达的FPGA实现

The FPGA implementation of OFDM ranging radar in subway

随着城市中地铁的普及,其安全性受到广泛关注。提出了一种用于地铁的OFDM雷达测距系统以提高地铁的安全性。设计以Xilinx公司的Virtex5系列XC5VLX50T为核心,以ML505为FPGA硬件开发平台,以ISE13.4和Modelsim为软件平台,以AD9280为A/D转换芯片,以AD9708为D/A转换芯片。在硬件实现中运用了FFT算法以及Cordic算法。该系统基于应答式雷达原理,雷达波形采用OFDM信号,通过相位测距法计算列车间距离。系统基带部分的测试结果显示系统误差为2m,具有较高的实用价值。

With the popularity of subway in cities,people begin to focus on its safety.This paper proposes an OFDM radar ranging system for subway in order to improve its safety.The design uses Xilinx Virtex5 XC5VLX50T as the core chip,uses ML505 as the FPGA hardware development platform,uses ISE13.4 and Modelsim as the software platform,uses AD9280 as the ADC chip and AD9708 as the DAC chip.Based on the principle of secondary radar,the radar waveform is designed as OFDM signal and phase measurement is adopted to calculate the distance between two trains.FFT and Cordic algorithms are implemented in hardware design.The testing process of baseband is described in detail,results show that the system error is 2 meters,which possesses high practical value.