The MSS Hub station receives C-band signal from the MSS reporting terminals through INSAT and converts it to an IF to 73.930 MHz ±60KHz. A 120 KHz band is allotted for MSS Type C Reporting service. An IF Down Converter is interfaced between RF Down Converter and Burst Demodulator. The IF Down-converter is a NCO based tunable down-converter used to convert the IF signal to 9.0 KHz signal. This 9.0 KHz signal is fed to the DSP based burst demodulator for further processing.
The Burst Demodulator accepts modulated (BPSK) signal at 9 KHz ±5 KHz from the IF Down Converter and the output demodulated data at 300 bits/sec along with clock signal is input to the baseband processing sub system (network manager). This BPSK Burst Demodulator is realized using DSP processor.