Voice and Position Simultaneous Communication System Based on Beidou Navigation Constellation

Zhen Ao,Guiqing He,Feng Li,Qiang Ma

doi:10.1051/jnwpu/20203851010

Abstract

Considering China Beidou has unique two-way communication capability for short messages that are not available in other navigation systems such as GPS, a 600bps vocoder adapted to the short message channel of Beidou is developed. The sinusoidal excitation linear prediction algorithm is adopted by the vocoder to achieve voice communication with clear communication quality. Furthermore, a coordinate compression algorithm for processing positioning information is designed to provide more transmission space for speech encoded data. Based on the above-mentioned results, a communication system that only the Beidou navigation system is used to complete two-way secure voice and positioning simultaneous interpretation is realized. The system firstly uses a voice conversion program to convert the voice coded data obtained by the vocoder codec module into the Beidou short message data format; and then the voice code analysis program and the latitude and longitude analysis program is used to parse the voice code and location information; Finally, the experimental results of voice communication and positioning transmission are verified on the Beidou short message transceiver, and the subjective MOS test score indicates that the way is paved for the practical use of Beidou short message voice communication.

Highlights

[6] 李强, 舒勤军, 谢虹恩, 等. 一种基于混合 MELP / CELP 的 4kbit / s 声码器 [ J] . 重庆邮电大学学报, 2017, 29 ( 2) : 143⁃148 LI Qiang, SHU Qinjun, XIE Hongen, et al A 4 kbit / s Vocoder Based on Hybrid MELP / CELP[ J]
Considering China Beidou has unique two⁃way communication capability for short messages that are not available in other navigation systems such as GPS, a 600bps vocoder adapted to the short message channel of Beid⁃ ou is developed
The sinusoidal excitation linear prediction algorithm is adopted by the vocoder to achieve voice communication with clear communication quality

Summary

Introduction

敖振1, 李凤1, 马嫱2, 何贵青1 (1.西北工业大学电子信息学院, 陕西西安 710072; 2.陕西省无线电监测站, 陕西西安 710065) 摘要:针对中国北斗比 GPS 等其他导航系统独有的短报文双向通信功能,研发了适配北斗短报文信道的 600 bit / s 声码器。声码器采用正弦激励线性预测(sinusoidal excitation linear prediction,SELP) 算法,实现了通信质量清晰的语音通信,并进一步设计了一种处理定位信息的坐标压缩算法,为语音编码数据提供了更大的传输空间。基于以上研究,实现了仅用北斗导航系统完成双向保密语音和定位同传的通信系统。该系统首先利用语音转换程序将声码器编解码模块获取的语音编码数据转换为北斗短报文数据格式;然后利用语音编码解析程序与经纬度解析程序从北斗短报文数据中解析出语音编码与位置信息;最后,在北斗短报文收发器上验证了语音通信与定位传输实验效果,主观 MOS 测试评分表明该研究为北斗短报文语音通信实用化铺平了道路。基于开发声码器的正弦激励线性预测算法,自主研发的低码率声码器芯片可以在 600 bit / s 速率下合成较高质量的语音。芯片采用 UART 接口与 MCU 连接通信,UART 波特率为 9 600 bit / s,数据格式为 8N1,用户可以通过 UART 接口实现语音编码数据读写,且该过程是异步、全双工的。并与处理器之间以定长帧进行通信,帧长为 8 字节。每 75 ms, 输出和接收 1 帧数据。帧结构字段定义如下: Header- 1( B1) : 1 byte,帧头,固定为 0x4C Header- 2( B2) : 1 byte,帧头,固定为 0x4E Data( B3⁃B8) : 语音数据 2.2 程序设计 2.2.1 语音编码转换程序设计此程序的设计是本系统至关重要的一部分,用来将语音编码数据转化为北斗短报文数据格式,并将短报文发送给 RDSS 模块。在北斗短报文通信中,发送方是以通信申请语句的形式发送短报文的, 通信申请语句格式如表 1 所示。

Results

Conclusion