Design and implementation of an open-source BDS-3 B1C/B2a SDR receiver

GNSS software-defined radio (SDR) receiver has been and will continue to be a tremendous research enabler given its flexibility and GNSS modernization as well as improvements to complimentary technologies. An open-source suite of GNSS SDRs capable of post-processing all open-service GNSS signals has been developed by the GNSS Lab at the University of Colorado, Boulder. As the latest expansion, processing capabilities for the B1C/B2a signals of the third-generation BeiDou navigation satellite system (BDS-3) are incorporated into this SDR package. To provide a basic implementation framework for GNSS community, separate or joint processing of the data and pilot channels are realized in the B1C/B2a SDR; and both narrowband and wideband tracking modes are implemented specifically for B1C pilot channel. Soon after the launch of the first two BDS-3 satellites, the B1C/B2a signals have been captured and the initial tracking results have been obtained. We describe the design strategy and implementation of the BDS-3 B1C/B2a SDR and report the processing results. The emphasis is placed on the B1C processing due to the novelty and complexity of the quadrature multiplexed binary offset carrier modulation employed by B1C.