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Universal QAM demodulator

Product code: CMS0006

Our universal QAM Demodulator core is aimed at broadband point-to-point and point-to-multipoint applications and supports QAM orders from 2 (BPSK) to 256.
Integrates with Commsonics QAM Modulator(CMS0004), Reed-Solomon(CMS0013) and Viterbi(CMS0002) cores to form a complete broadband Modem.

Block diagram

Universal QAM demodulator block diagram (click to enlarge)
Click on diagram to enlarge


  • Low demodulator implementation loss
    <0.2dB (16QAM), <0.4dB (256QAM).
  • IF sub-sampling or I/Q baseband input.
  • Wide carrier acquisition range.
  • Programmable symbol rate.
  • Large QAM support : BPSK .. QAM-256.
  • Variable ADC sampling frequency.


  • Cable downstream
    (e.g. DOCSIS, DVB-C).
  • Point-to-point terrestrial microwave
    (e.g. ETSI, FCC channels up to 56MHz).
  • Satellite up/downlink
    (e.g. DVB-S, DVB-DSNG).


  • Single external clock source.
  • Single external analogue AGC loop.
  • All-digital timing and carrier recovery.
  • Digital channel filtering.
  • Optimised for ASIC, Xilinx and Altera.
  • Evaluation boards available.