为了提高紫外无线通信中数据传输速率并降低数据误码率,用紫外LED代替传统的气体放电灯光源,采用FPGA设计实现了脉冲位置调制技术,帧同步技术和循环冗余校验信道编码。实验采用波长范围为380～385 nm的紫外LED作为光源,以光电倍增管作为光电探测器件,完成了室内准视距通信。实验结果表明:采用LED作为光源,能够实现通信距离为5 m以内的115.2 kbps的数据传输;与未编码情况相比,采用信道编码的系统能够实现检错功能和单比特的数据位纠错,降低数据误码率。

In order to improve the data-transmission-rate and bit-error-rate in the ultraviolet-wireless communication system, an enhanced short-range UV communication system based on UV LED is proposed instead of the gas discharge lamp. The system takes the pulse position modulation (PPM). The frame synchronization technology and the cyclic redundancy check channel coding are also applied in the signal process. The scheme is realized and simulated with FPGA. In the experiment, the wavelength spectrum of UV LED ranges from 380nm to 385nm, a photomultiplier tube is used to detect the weak optical signal. The experiment results indicate that the application of LED as the system source is capable of achieving 115. 5 kbps data transmission with the distance less than 5 m. Moreover, PPM and CRC coding, which can help realize the function of data error detection and single bit error correction, decrease the bit error rate.