Study On BPSK Modulator Delay Calibration Technology

As the development of satellite technology, distance measurement plays a key role in aerospace measurement and control, navigation and other fields. In order to improve the accuracy of range measurement, it is necessary to accurately measure the absolute transmission delay of signal in the transmitter and receiving system. BPSK is one of the main modulations of navigation positioning system. Measurement of the BPSK modulator delay in the transmitting device delay measurement is very difficult. Therefore, how to measure delay of the modulator accurately is the key to solve the measuring delay of launch device.The basic idea in this paper is to realize delay measuring for the BPSK modulator in satellites’ navigation system. This paper discusses the definition of transmit system delay. It introduces sampling mode, transforms mode and the principle and process of BPSK signal demodulation by software. From the practice, a delay measuring system of the BPSK modulator based on software radio was established in this paper. In the measuring system, a digital oscilloscope is working as a high speed data collector to capture the modulated signal. By using orthogonal transformation demodulation software and time correlation principle, insert-delay measurement is done under BPSK modulation.