'''Orthogonal variable spreading factor''' ('''OVSF''') is an implementation of [[Code division multiple access]] (CDMA) where before each signal is transmitted, the [[Spread spectrum|spectrum is spread]] through the use of a user's code. User's codes are carefully chosen to be mutually [[orthogonal]] to each other.
These codes are derived from an OVSF code tree, and each user is given a different, unique code. An OVSF code tree is a complete [[binary tree]] that reflects the construction of [[Hadamard matrix|Hadamard matrices]].
