Digital Modulations Unit

The Digital Modulations Unit, is a complete digital communications Unit designed to explain the basic concepts of digital modulation.

ATENG 10954 — Digital Modulations Unit

All elements are mounted in a metallic box, with power supply and block diagram.

• Functional blocks:
• Line coding:
  Non return to zero level line coding circuit (NRZL).
  Non return to zero mark line coding circuit (NRZM).
  Biphase manchester line coding circuit.
  Biphase mark circuit line coding circuit.
  Return to zero line coding circuit (RZ).
  Return to bias line coding circuit (RB).
  Alternate mark Inversion line coding circuit (AMI).
• Modulators and demodulators:
• Amplitude-shift keying (ASK):
  Mixer.
  Filter.
• Frequency-shift keying (FSK):
  Phase-locked loop detector (PLL).
• Phase-shift keying (PSK):
  Unipolar to bipolar converter.
  Mixers.
• Carrier recovery circuit:
  Multiplier and divider circuits.
  Squarer circuit.
  Voltage controlled oscillator (VCO).
  Sampler.
  Filter.
  Level-crossing detector.
• Quadrature phase-shift keying (QPSK):
  Dbit encoder circuit.
  Unipolar to bipolar converters.
  Mixers.
• Carrier recovery circuit:
  Multiplier and divider circuits.
  Squarer circuit.
  Voltage controlled oscillator (VCO).
  Samplers circuits.
  Filter.
  Level-crossing detectors.
  Dbit decoder circuit.
• Analog generators:
  Carrier signal.
• Digital generators:
  A byte (8 bits, serial).
  Six analog Inputs.
  Eigth analog outputs.
  Twenty eight test points.
  Two controls.
  Cables and accessories, for normal operation.