Implementation and verification of BDS signal generator

Chinese satellite navigation system Beidou is growing rapidly. Consequently, development of Beidou navigation system (BDS) receiver is necessary. BDS signal generator is fundamental equipment for research and verification of Beidou receiver, which can provide stable and reliable experimental environment. On the basis of mathematical model of BDS IF(Intermediate Frequency) signal, this paper analyzes the key technology in the process of BDS signal generation, and shows the structure of BDS signal generator. An algorithm based on three order polynomial is proposed to calculate dynamic carrier doppler. Mathematical model of accurate signal transmission delay is also illustrated. Signal transmission delay of random sampling time can be calculated by using this method. According to verification of BDS software receiver and hardware GNSS receiver, positioning result is in accord with preset value, which meets the expected requirements.