Marine GMDSS/DSC VHF Decoder_b


In previous posts I looked at various aspects of GMDSS/DSC using Scicos (Ref.2/7). In the last post I built a BFSK Random Data Generator on GNU Radio and in this post I use the random data produced to test a BFSK BPF decoder on GNU Radio.

BFSK BPF Decoder Schematic

Fig.1 BFSK BPF Decoder Schematic
Fig.2 BFSK BPF Decoder Opt Random Data & BPF Pulses
Fig.3 BPSK Input Random Data

Figure 1 shows the BFSK BPF Bandpass Filter Non-Coherent Decoder schematic. BPF1 is tuned to the mark frequency of 2100Hz and BPF2 is tuned to the space frequency of 1300Hz. Envelope detection is done with squaring and a LPF Low Pass Filter. Figure 2 shows the BPF pulses and the decoder output. Figure 3 shows the original random data input.

GNU Radio Basics Course

Fig.4 YouTube Video Marine GMDSS/DSC CH70 Decoder_b

Please send your comments, questions and suggestions to:

YouTube Channel
YouTube Channel


#1. – “BFSK Generator on GNU Radio”

#2. – “Marine GMDSS/DSC VHF Decoder_a”

#3. – “RTL-SDR for HF Marine GMDSS/DSC on SDRangel”

#4. – “VHF Marine GMDSS/DSC Decode & Scicos Simulation”

#5. – “RTL-SDR for HF Marine GMDSS/DSC”

#6. – “RTL-SDR for Marine GMDSS/DSC on RaspberryPi4”

#7. – “RTL-SDR for Marine GMDSS/DSC on Multipsk”

By Jeremy Clark

Jeremy Clark is a Senior Telecommunications Engineer and Advanced Amateur Radio Operator VE3PKC. He is the author of E-Books on Telecommunications, Navigation & Electronics.