Demodulation

The downconverted signal undergoes a demodulation process. This step is the opposite of modulation and refers to the process required to extract the original information signal from the modulated signal.

The process of digital demodulation involves matched filtering, symbol timing extraction, and symbol synchronization followed by frequency offset correction. The frequency-offset-corrected signal is decimated down to symbol-spaced data, which is then mapped back to a recovered bit stream.

The following VIs are used in analog demodulation:

• MT Demodulate AM
• MT Demodulate FM
• MT Demodulate PM

Digital demodulation returns the time-aligned demodulated waveform, the demodulated information bit stream, and measurement results obtained during demodulation. The following VIs are used in digital demodulation:

• MT Demodulate ASK
• MT Demodulate FSK
• MT Demodulate MSK
• MT Demodulate PAM
• MT Demodulate PSK
• MT Demodulate QAM
• MT Demodulate CPM

Note  Use the following VIs if your application requires only the demodulated bit stream.

• MT Detect ASK
• MT Detect FSK
• MT Detect MSK
• MT Detect PAM
• MT Detect PSK
• MT Detect QAM
• MT Detect CPM