Esquema de sincronismo para sistemas OCDMA basado en códigos ópticos aleatorios

Abstract

In this paper, a technique for code acquisition in optical code-division multiple-access (OCDMA) systems using the recently introduced Random Optical Codes (ROCs) is presented. The acquisition scheme, which is based on the transmission of a synchronization preamble, is described. This scheme is a modification of another one previously presented [1], where the phenomenon which we have called “auto-collision” is now resolved. The equations that allow us to establish an upper bound for the acquisition performance are indicated and several results which prove the reliability of these expressions are presented. These results show that the acquisition scheme is practically infallible when the synchronization preamble is constituted by three or four bits, irrespective of the multi-user interference, then making it very appropriate for optical communications over very saturated scenarios (with a large number of users).