Terminology » RF Basics » Coherence Bandwidth and Coherence Time Explained

Coherence Bandwidth and Coherence Time Explained

coherence bandwidth coherence time channel delay spread wireless communication

This page describes the difference between Coherence Bandwidth and Coherence Time.

Coherence Bandwidth

The bandwidth (range of frequencies) over which a channel remains constant is called the Coherence Bandwidth.

Coherence Bandwidth ≈ (1 / Maximum Delay Spread)

A more accurate way to calculate coherence bandwidth is by using the RMS Delay Spread. This is because different channels will experience varying signal intensities over different delay spans, even with the same delay spread.

Coherence Bandwidth

Coherence Time

The time over which a channel remains constant is called the Coherence Time.

Coherence Time