OCDMA System

Code-division multiple-access (CDMA) is a spread spectrum technique, and it has been well researched and implemented in mobile radio communications which employ electrical signal processing. In this approach, a unique address sequence that is approximately orthogonal to the sequences assigned to all other receivers is assigned to each receiver in the network. Data bits that are to be transmitted are first modulated by the assigned sequence of the targeted receiver before being sent. The incoming data is then detected by targeted receiver by correlating it to its own address sequence. As long as the total sum of the cross-correlations of the approximately orthogonal sequences to the targeted receiver is not excessive, it is possible for number of users to simultaneously access the network.