Simultaneous amplitude and phase modulation

Introduction

In this example we present a DSPsandbox-Cavas project that performs simultaneous amplitude and phase modulation.

NOTE: This document assumes that the user has some prior experience in using DSPsandbox-Canvas. If this is not the case, please have a look at My first DSP design.

Building the ampl & phase modulation design

A documentation of all the available DPS modules is available here. The modules used in this design are:

• ADC[32]
• DAC[32]
• IN[1]
• DDS[32]
• mult[32]
• const[32]

Operation of the ampl & phase modulation design

• ADC1 provides the phase modulation (ADC1=[-1V,+1V] ---> phase=[-PI rad, +PI rad])
• ADC2 provides the amplitude modulation (ADC2=[-1V,+1V] ---> ampl=[-1V, 1V])
• IN0 is an external (active high) phase reset for the DDS core. We additionally use it to clear the multipliers of the designs.
• DAC1/DAC2 are the modulated SIN/COS output waveforms.
• The carrier frequency is adjusted through the 32 bit constant pInc. The relation between pInc and the DDS frequency is explained in the DDS[32] documentation.