Global Patent Index - EP 1101309 A1

EP 1101309 A1 2001-05-23 - METHOD AND APPARATUS FOR REDUCED INTERFERENCE IN OPTICAL CDMA

Title (en)

METHOD AND APPARATUS FOR REDUCED INTERFERENCE IN OPTICAL CDMA

Title (de)

VERFAHREN UND VORRICHTUNG FÜR VERRINGERTE INTERFERENZEN IN OPTISCHEM CDMA

Title (fr)

PROCEDE ET DISPOSITIF DE REDUCTION D'INTERFERENCE EN AMCR OPTIQUE

Publication

EP 1101309 A1 (EN)

Application

EP 99938889 A

Priority

  • US 9917258 W
  • US 12734398 A

Abstract (en)

[origin: WO0007317A1] A multi-user optical fiber communications system uses spread spectrum code division multiple access techniques to achieve better bandwidth utilization. Each channel of the system is provided with light source that is temporally and spectrally modulated by an encoder. Modulation is accomplished by first passing the data through a pulse modifier to obtain a stream of shortened pulses with a reduced duty cycle. The modulated light is coupled to a fiber and data are recovered by the decoder. The source includes a superluminescent fiber source that is split multiple times and amplified in a hierarchical manner to produce a plurality of like sources. The like sources are decorrelated by adding delays to the different sources. Each of the encoders includes an encoding mask having a first code that encodes the optical signal. Light, spatially encoded by the mask and temporally modulated with data, is transmitted over a fiber link with the signals of other users and received by a decoder. Within each decoder, a polarization insensitive separator splits the received light into two equal power components which are provided to two decoding masks used to decode the signal. One of the masks has a second code identical to the first code and the other mask has a third code complementary to the first code. The output light beams filtered by the masks are differentially detected to generate an output signal, which is further processed for data recovery. The electrical signal is low pass filtered and electrically square law detected. The first codes are selected from a set of unipolar codes derived from a set of balanced bipolar orthogonal codes. The codes may be either binary or analog.

IPC 1-7 (main, further and additional classification)

H04J 11/00; H04B 10/155

IPC 8 full level (invention and additional information)

H04J 14/00 (2006.01); H04B 10/50 (2013.01); H04B 10/516 (2013.01); H04J 11/00 (2006.01); H04J 13/00 (2006.01); H04J 14/04 (2006.01); H04J 14/06 (2006.01)

CPC (invention and additional information)

H04J 11/0023 (2013.01); H04B 10/503 (2013.01); H04B 10/516 (2013.01); H04J 14/007 (2013.01)

Citation (search report)

See references of WO 0007317A1

Designated contracting state (EPC)

AT BE CH CY DE DK ES FI FR GB GR IE IT LI LU MC NL PT SE

EPO simple patent family

WO 0007317 A1 20000210; AU 5327899 A 20000221; BR 9912598 A 20020102; CA 2339113 A1 20000210; EP 1101309 A1 20010523; JP 2002521957 A 20020716; RU 2001105929 A 20030127

INPADOC legal status


2002-08-28 [18D] APPLICATION DEEMED TO BE WITHDRAWN

- Effective date: 20020201

2001-05-23 [17P] REQUEST FOR EXAMINATION FILED

- Effective date: 20010219

2001-05-23 [AK] DESIGNATED CONTRACTING STATES:

- Kind Code of Ref Document: A1

- Designated State(s): AT BE CH CY DE DK ES FI FR GB GR IE IT LI LU MC NL PT SE

2001-05-23 [AX] REQUEST FOR EXTENSION OF THE EUROPEAN PATENT TO:

- Free text: AL;LT;LV;MK;RO;SI