Design and Implementation of FPGA-Based Universal Receiver for BeiDou Short Message

The BeiDou-3 system is an independently developed and autonomously operated global navigation system in China, offering three fundamental services through its short message communication capabilities: location reporting, emergency search and rescue, and message communication. The undistorted reception of BeiDou short message information by a BeiDou short message receiver plays a crucial role in the implementation of BeiDou short message services. BeiDou short messages are divided into global short messages and region short messages, with significant differences in their spreading spectrum method. Hence, the research on a universal BeiDou short message receiver holds significant importance. In response to the distinct spreading spectrum method employed for global short messages and region short messages, this paper designs a universal Beidou short message receiver based on FPGA. By introducing a short message data caching module that controls the acquisition timing, it achieves rapid and effective acquisition of both global and region short messages. Furthermore, the functionality provided by the tracking loop and pseudocode switching controller module ensures continuous and stable tracking of both global and region short messages. Xilinx's xc7z100ffg900-2 chip was used for simulation and actual testing, which verified that the designed Beidou short message universal receiver can receive global short messages and region short messages without distortion.