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Record W2015250236 · doi:10.1117/12.473977

Optical Code-Division Multiple Access: Challenges and Solutions

2003· article· en· W2015250236 on OpenAlexaff
Lawrence R. Chen

Bibliographic record

VenueProceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE · 2003
Typearticle
Languageen
FieldEngineering
Topicgraph theory and CDMA systems
Canadian institutionsMcGill University
Fundersnot available
KeywordsComputer scienceTurbo codeCoding (social sciences)Code division multiple accessForward error correctionFocus (optics)Electronic engineeringCode (set theory)Computer engineeringComputer networkDecoding methodsTelecommunicationsOptics

Abstract

fetched live from OpenAlex

Optical code-division multiple-access (OCDMA) is a technique well-suited for providing the required photonic connectivity in local access networks. Although the principles of OCDMA have been known for many years, it has never delivered on its potential. In this paper, we will describe the key challenges and impediments that have prevented OCDMA from delivering on its potential, as well as discuss possible solutions. We focus on the limitations of one-dimensional codes and the benefit of exploiting the additional degrees of freedom in using multiple dimensions for defining the codes. We discuss the advantages of using differential detection in order to implement bipolar communications. We then show how two-dimensional wavelength-time codes can be appropriately combined with differential detection in order to achieve high performance OCDMA systems with a large number of users operating with good BER performance for a large aggregate capacity. We also discuss the impact of channel coding techniques, for example forward error correction or turbo coding, on BER performance.

Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.

How this classification was reachedexpand

Full frame machine prediction

Teacher imitation

Not calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.

metaresearch head score (Codex)0.003
metaresearch head score (Gemma)0.005
Version: metacan-v3-hybrid-931329e0061cValidation status: machine_predicted_unvalidated
Candidate categoriesnone
Consensus categoriesnone
DomainCandidate signal: none · Consensus signal: none
Study designCandidate signal: Not applicable · Consensus signal: none
GenreCandidate signal: Empirical · Consensus signal: none
Teacher disagreement score0.007
Threshold uncertainty score0.017

Distilled classifier scores by category (both heads)

CategoryCodexGemma
Metaresearch0.0030.005
Meta-epidemiology (narrow)0.0010.000
Meta-epidemiology (broad)0.0010.000
Bibliometrics0.0010.001
Science and technology studies0.0020.003
Scholarly communication0.0040.008
Open science0.0020.003
Research integrity0.0070.005
Insufficient payload (model declined to judge)0.0040.002

Machine scores (provisional)

The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.

Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.

Opus teacher head0.023
GPT teacher head0.233
Teacher spread0.210 · how far apart the two teachers sit on this one work
Validation statusscore_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from it

Classification

machine, unvalidated

Machine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.

The models applied no category: nothing in the taxonomy fit this work.
Study designNot applicable
Domainnot available
GenreEmpirical

How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".

Quick stats

Citations2
Published2003
Admission routes1
Has abstractyes

Explore more

Same venueProceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIESame topicgraph theory and CDMA systemsFrench-language works237,207