| US 7,616,618 B2 | ||
| Code cycle modulation in optical code division multiple access systems | ||
| P. Vijay Kumar, Rolling Hills Estates, Calif. (US); Reza Omrani, Los Angeles, Calif. (US); Joseph D. Touch, Manhattan Beach, Calif. (US); Alan E. Willner, Los Angeles, Calif. (US); and Poorya Saghari, Los Angeles, Calif. (US) | ||
| Assigned to University of Southern California, Los Angeles, Calif. (US) | ||
| Filed on Nov. 29, 2005, as Appl. No. 11/289,259. | ||
| Claims priority of provisional application 60/631685, filed on Nov. 30, 2004. | ||
| Prior Publication US 2006/0209739 A1, Sep. 21, 2006 | ||
| Int. Cl. H04B 7/216 (2006.01) | ||
| U.S. Cl. 370—342 [385/2; 385/3; 359/10; 359/11] | 21 Claims |
| 1. An optical code division multiple access (OCDMA) system, comprising:
an optical transmitter system configured to transmit data from a plurality of users through a shared optical channel by encoding
the data from each user with a spreading code assigned to that user, each spreading code including a unique sequence of T
time chips along a time axis, the data from each user representable by T symbols; and
an optical receiver system configured to demodulate the data from each user by correlating signals received from the transmitter
system with the spreading code assigned to that user;
wherein when transmitting a data symbol for each user, the transmitter system is configured to select one out of T distinct
cyclic shifts of the spreading code assigned to that user, and to transmit the selected cyclic shift of the assigned spreading
code along the time axis.
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