Research on GNSS-like indoor navigation signal system

This paper proposes a GNSS-like indoor navigation signal system method, including signal characteristics, including carrier frequency, signal modulation, signal spreading code and signal working bandwidth, and the message information is broadcast by the indoor communication link; The signal ranging code was generated with a ranging code rate of 20.46MHz, a code length of 1023 and a period of 50μs. Signal modulation, using BPSK mode to generate the required signal; The signal message, including message content, message frame header, message structure and verification mode, is broadcast through the base station. The signal design in this paper adopts a larger bandwidth design, which provides better anti-multipath ability and improves the stable acquisition probability of the signal. The short period pulse design is adopted to reduce the mutual interference between signals. A message protocol suitable for indoor environment is defined. It changed the transmission mode of indoor navigation messages, improved the information acquisition time and shortened the parsing time.