Orthogonality of FSK modulation for non-coherent detection

1. What is non-coherent detection of FSK?
2. What is orthogonal FSK?
3. What is coherent and non-coherent detection in ASK FSK?
4. What is the condition of orthogonality of the binary FSK signals?

What is non-coherent detection of FSK?

As an example, the performance of a noncoherent frequency shift-keyed (FSK) system is analyzed exactly under the influence of an additive Gaussian noise in the presence of multipath fading. These performances are compared to those of the approximately analyzed cases where the sampling representation technique was used.

What is orthogonal FSK?

Noncoherent orthogonal M-ary frequency-shift-keying (M-FSK) is a simple and robust form of digital communication when the transmission channel is such that fast reliable carrier recovery is difficult or impractical to achieve and the bandwidth requirements are not overly stringent.

What is coherent and non-coherent detection in ASK FSK?

The main methods of FSK detection are asynchronous detector and synchronous detector. The synchronous detector is a coherent one, while asynchronous detector is a non-coherent one.

What is the condition of orthogonality of the binary FSK signals?

For an FSK modulation with coherent detection, in order to ensure orthogonality, the frequency separation between symbols is Δf=f2−f1=1/2T.