A chip-level OOK OCDMA receiver using an acoustooptic deflector

Abstract

An on-off keying (OOK) optical code division multiple access (OCDMA) chip-level receiver that uses acoustooptic deflector (AOD) is presented. This receiver saves the hardware complexity encountered in conventional chip-level receivers, especially for large number of time chips. In OOK OCDMA, larger number of chips is required in order to improve the error performance or increase the number of users. The presented receiver may require no chip synchronization but symbol or frame synchronization is required. The proposed receiver can be used in tunable optical codes with minimum change in the hardware. However, this receiver has more multiple access interference (MAI) which can be reduced using optical pulse shaping or increasing the spatial separation between focused beams in the AOD. Commercially available AODs can decode OOK OCDMA signals with number of chips Yl as large as one thousand or more. The geometry, design, and operation of an AO OOK OCDMA receiver are introduced, error performance is discussed, and interference analysis is presented.