Detection of shortened OOC codewords in optical CDMA systems with double hard-limiters

The effect of double hard-limiters in direct-detection optical asynchronous code division multiple access (CDMA) systems using shortened optical orthogonal codes (OOC) is investigated in this work. The performance improvement in case of shortened OOCs is shown by simulating the detector operation for the single and double hard-limiter cases and the two cases are compared to each other. In addition to previous stated results, it is shown that the double hard-limiters improve the receiver performance not only when the desired user sends bit '0', but also when the user sends the bit '1'. (C) 2000 Published by Elsevier Science B.V. All rights reserved.