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Proceedings Paper

Design and evaluation of a virtual quadrant receiver for 4-ary pulse position modulation/optical code division multiple access (4-ary PPM/O-CDMA)
Author(s): A. J. Mendez; V. J. Hernandez; R. M. Gagliardi; C. V. Bennett
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Paper Abstract

M-ary pulse position modulation (M-ary PPM) is an alternative to on-off-keying (OOK) that transmits multiple bits as a single symbol occupying a frame of M slots. PPM does not require thresholding as in OOK signaling, instead performing a comparison test among all slots in a frame to make the slot decision. Combining PPM with optical code division multiple access (PPM/O-CDMA) adds the benefit of supporting multiple concurrent, asynchronous bursty PPM users. While the advantages of PPM/O-CDMA are well known, implementing a receiver that performs the comparison test can be difficult. This paper describes the design of a novel array receiver for M-ary PPM/O-CDMA (M = 4) where the received signal is mapped onto an xy-plane whose quadrants define the PPM slot decision by means of an associated control law. The receiver does not require buffering or nonlinear operations. In this paper we describe a planar lightwave circuit (PLCs) implementation of the receiver. We give detailed numerical simulations that test the concept and investigate the effects of multi-access interference (MAI) and optical beat interference (OBI) on the slot decisions. These simulations provide guidelines for subsequent experimental measurements that will be described.

Paper Details

Date Published: 13 February 2007
PDF: 6 pages
Proc. SPIE 6457, Free-Space Laser Communication Technologies XIX and Atmospheric Propagation of Electromagnetic Waves, 64570H (13 February 2007); doi: 10.1117/12.725384
Show Author Affiliations
A. J. Mendez, Mendez R&D Associates (United States)
V. J. Hernandez, Univ. of California/Davis (United States)
Lawrence Livermore National Lab. (United States)
R. M. Gagliardi, Univ. of Southern California/Los Angeles (United States)
C. V. Bennett, Lawrence Livermore National Lab. (United States)

Published in SPIE Proceedings Vol. 6457:
Free-Space Laser Communication Technologies XIX and Atmospheric Propagation of Electromagnetic Waves
Steve Mecherle; Olga Korotkova, Editor(s)

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