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.
Necessity of common data format for curves of Instrumented Indentation Testing (IIT) and review of independent analysis program tangentGo
