Abstract

Optical correlation techniques have been used to decode a binary cyclic error control code in real time. The code is generated by using a primitive polynomial as the characteristic function of a linear feedback shift register. Each code word generated is a cyclic shift of every other code word, except for the zero code word. It is shown that a set of 15-bit code words is able to correct three errors per word and detect up to seven errors. The cyclic nature of the code lends itself to a correlation approach for decoding. I present results of decoding systems using both twin and single Bragg cell correlators showing that all code words, including the zero code word, can be correctly identified with up to three bit errors per word. With currently available acousto-optic cells chip rates of several hundred megahertz are achievable.

© 1992 Optical Society of America