Scalability techniques in electronically processed CDMA for low cost and flexible optical access networks

J. B. Rosas-Fernandez, J. D. Ingham, R. V. Penty, I. H. White

Research output: Chapter in Book/Report/Conference proceedingConference contribution

1 Citation (Scopus)


Recently, the coding and decoding of code-division multiple-access (CDMA) signals using electronic transversal filters at a chip rate of 18 Gchips/s for use in passive optical access networks (PONs) was demonstrated. The system used 7-chip transversal filters giving a potential for 7 users, where each user had a data rate of 1.25 Gb/s. In this paper, we show two techniques to scale up the electronically processed CDMA (ECDMA) system, namely by increasing the number of chips in the code and doubling the capacity using I and Q modulation of two in-quadrature channels. For increasing the number of chips, we demonstrate an electronically processed Walsh Code with 16 chips at 18 Gchip/s. An auto-cross correlation ratio of 18.1 dB is achieved between two orthogonal codes after transmission over 10km of SMF. In addition, I-Q modulation of two electronic CDMA channels using the same electronic transversal filters is demonstrated. Here, two in-quadrature channels with chip rates of 18 Gchip/s show the potential of current technology for future 40 Gb/s throughput ECDMA PONs.

Original languageEnglish
Title of host publicationICTON 2009
Subtitle of host publication11th International Conference on Transparent Optical Networks
Publication statusPublished - 18 Nov 2009
EventICTON 2009: 11th International Conference on Transparent Optical Networks - Ponta Delgada, Portugal
Duration: 28 Jun 20092 Jul 2009


ConferenceICTON 2009: 11th International Conference on Transparent Optical Networks
CityPonta Delgada


  • CDMA
  • Electronic processing
  • Optical access networks
  • Passive optical networks

ASJC Scopus subject areas

  • Computer Networks and Communications
  • Electrical and Electronic Engineering
  • Electronic, Optical and Magnetic Materials

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