高速伪随机码调制激光测距雷达电子学系统设计

Electronics system design for laser ranging radar based on high speed pseudorandom modulation technique

针对采用光子计数的高速伪随机码激光测距,开发了基于高性能FPGA的电子学系统。该系统将伪随机码调制信号发送、码元数据接收、累加运算、互相关运算、距离信息提取及网络通信等功能集成在单个Altera公司的Stratix IV系列FPGA芯片中。系统中采用10阶M序列伪随机码,伪随机码发送和接收速率为1 GHz,周期为10 k Hz。接收的码元经过10次累加和阈值比较后,利用1 024个并行的同或逻辑实现互相关运算。互相关运算和距离信息提取的重复频率为1 k Hz。理想条件下的测试结果表明,系统达到了设计要求。

In the paper an electronics system for laser ranging radar based on high speed pseudorandom modulation and photon counting techniques is presented. All functions, such as pseudorandom code transmission, code reception,accumulation, correlation, distance calculation and network communication, were integrated into one high-performance FPGA chip of Altera Stratix IV. Ten order M sequence pseudorandom code was used in the design. The transmitting and receiving repeat frequency was 10 k Hz with 1GHz code rate. The received codes were accumulated by 10 times and changed to 1 bit binary codes by compared with a settled threshold. The correlation was done in 1ms by using 1024 parallel Exclusive-or operations. The test results under ideal conditions showed the affectivity of the developed system.