Matlab Examples – Amplitude Demodulation using Coherent Detection

My previous post talked about modulating the amplitude of the carrier to embed a message signal. The demo uses Simulink found in Matlab.

Here, I will show how we can recover our transmitted message using synchronous detection (coherent or homodyne detection). Synchronous detection does not waste any energy in the carrier when there is no message and is used for Double Sideband Suppressed Carrier AM (DSB-SC AM).

However, this detection scheme uses more complicated circuitry called phased-locked loops. At the receiver end, the local oscillator must track the phase drift of the transmitted carrier in order for this detection scheme to work.

A simpler detection scheme is called envelope detection. Envelope detection is suited only for Double Sideband Large Carrier AM (DSB-LC). However, this scheme uses up carrier energy when there is no message embedded in the carrier. Envelope detection consists of a simple diode, resistor and capacitor and is discussed in a later video.

Related posts:

1. Matlab Examples: Amplitude Modulation using Simulink Here is an example of using Matlab to demonstrate Amplitude...