This Demo Unit SDQPSK Satellite Demodulator receives a PSK modulated signal (usually it will be QPSK) in the L Band range of 950-2150 MHz and demodulates the signal providing an MPEG-2 digital output stream. This output stream will be stripped of the Forward Error Correction (FEC) added to the stream before it was uplinked, but will still be “scrambled” if encryption has been utilized on the original MPEG-2 stream. If the original MPEG-2 stream was not scrambled, the output is ready for further processing. The most common operations would be decoding into base band analog video & audio signals or remodulation for cable delivery using a QAM modulator.
Before QAM modulation, the MPEG-2 stream may be scrambled utilizing a scrambling algorithm specifically designed for cable delivered signals. If the demodulated stream is scrambled, descrambling would be required prior to decoding. If the stream is to be QAM modulated onto a cable channel, it could be used directly in it’s scrambled state, be decoded and rescrambled utilizing a different cable oriented scrambling algorithm or be descrambled and applied directly to a QAM modulator for “in the clear” cable delivery.