SDPSK-Specific Demodulation Method for the Nanortu Field-Programmable Gate Array / SDPSK-Specifiska Demodulācijas Metode Nanortutm Programmētajām Loģiskajām Integrācijas Shēmām

The software-defined radio (SDR) solutions inpart flexibility to the satellite applications when the devices are physically inaccessible after the launch. The nanoRTU FPGA-based controller (AAC Microtec) may be programmed to serve as a software-defined differential phase shift keying (SDPSK) modem backend to be used in satellites for communication with the Earth. The modem consists of two units - a modulator and a demodulator. A fully functional symmetric SDPSK modulator for nanoRTU FPGA has already been implemented. The next step of the modem implementation is the development of demodulator. In order to implement such facilities, the existing demodulation techniques should be reviewed in order to propose the appropriate method in which the demodulator would be capable of demodulating a signal, and, at the same time, would be resource-efficient. The author describes a valid method of specific SDPSK signal demodulation for the nanoRTU FPGA.