Perfect difference codes for synchronous fiber-optic CDMA communication systems

In this paper, we introduce the perfect difference sets and propose a synch ronous fiber-optic code-division multiple-access system (CDMA) using these sets to generate the signature codes. Two interesting properties of these c odes are discussed: 1) any two different codes are cyclic-shifted with each other and 2) the cross correlation between any two different codes is exac tly one, Thus, we may treat these codes as quasi-orthogonal codes. Using th e first property of these codes, we can simplify design of the transmitter. In the receiver, we can use the second property to effectively eliminate t he multiple-user interference (MUI) without reducing the number of usable c odes. Based on the proposed transmitter and receiver the system performance is derived, The numerical examples reveal that the proposed system can pro vide reliable communication even under heavy load, We believe that the prop osed system using perfect difference codes outperforms any other synchronou s fiber-optic CDMA systems.