FSK and IQ modulation

1. What is IQ modulation?
2. What modulation is performed in FSK?
3. What is IQ signal processing?
4. Why is FSK more immune to noise?

What is IQ modulation?

What's an IQ Modulator? An IQ modulator is a device that converts baseband information into RF signals. Internally, two double-balanced mixers are combined as shown below. By modulating with both in-phase (I) and quadrature (Q) inputs, any arbitrary output amplitude and phase can be selected.

What modulation is performed in FSK?

Frequency Shift Keying FSK is the digital modulation technique in which the frequency of the carrier signal varies according to the digital signal changes. FSK is a scheme of frequency modulation.

What is IQ signal processing?

I/Q signaling refers to the use of two sinusoids that have the same frequency and a relative phase shift of 90°. Amplitude, phase, and frequency modulation can be performed by summing amplitude-modulated I/Q signals. Quadrature modulation refers to modulation that involves I/Q signals.

Why is FSK more immune to noise?

Since FSK relies on frequency change and not amplitude change to indicate data states, an FSK receiver is inherently immune to amplitude noise.