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Record W1617922428 · doi:10.1109/ccece.2002.1012923

Augmenting the capacity of CDMA systems

2003· article· en· W1617922428 on OpenAlexaff
Tianlong Song, E. Shwedyk

Bibliographic record

Venuenot available
Typearticle
Languageen
FieldEngineering
TopicAdvanced Wireless Communication Techniques
Canadian institutionsUniversity of WinnipegUniversity of Manitoba
Fundersnot available
KeywordsCode division multiple accessHadamard codeAlgorithmHadamard transformComputer scienceCode (set theory)Sequence (biology)Interference (communication)Channel capacityBlock codeGold codeMathematicsNoise (video)Channel (broadcasting)Set (abstract data type)Spread spectrumTelecommunicationsDecoding methodsArtificial intelligence

Abstract

fetched live from OpenAlex

Improvement of the capacity of the CDMA (code division multiple access) system is a major objective. The capacity of the system is mainly limited by the signal to noise ratio, where the noise comes from the channel background and from MAI (multiple access interference). Usually, the way to improve the capacity is to decrease the MAI; this is why orthogonal codes are adopted by the IS-95 standard. One problem is that the number of orthogonal codes is constrained by the dimensionality of the signal space. So in IS-95, there are only 64 orthogonal codes available when the number chips for each sequence is 64. To solve this problem, a non-orthogonal code called WBE (Welch bound equality) sequences (Massey and Mittelholzer 1991) is used in this paper The criterion to construct the code is to minimize the MAI. Two methods are used to construct the WBE sequences: from a linear cyclic code or from a Hadamard matrix. In order to improve the performance of the WBE sequence set, an iteration receiver (Sari et al. 1999) is applied. The conclusion obtained is that when the number of users is slightly greater than the signal space dimensionality, after the first iteration, the performance is only marginally worse than the orthogonal CDMA system.

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)0.001
metaresearch head score (Gemma)0.009
Version: metacan-v3-hybrid-931329e0061cValidation status: machine_predicted_unvalidated
Candidate categoriesnone
Consensus categoriesnone
DomainCandidate signal: none · Consensus signal: none
Study designCandidate signal: Simulation or modeling · Consensus signal: Simulation or modeling
GenreCandidate signal: Methods · Consensus signal: Methods
Teacher disagreement score0.008
Threshold uncertainty score0.027

Distilled classifier scores by category (both heads)

CategoryCodexGemma
Metaresearch0.0010.009
Meta-epidemiology (narrow)0.0010.000
Meta-epidemiology (broad)0.0010.000
Bibliometrics0.0010.001
Science and technology studies0.0010.001
Scholarly communication0.0020.003
Open science0.0010.003
Research integrity0.0010.001
Insufficient payload (model declined to judge)0.0080.002

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 head0.021
GPT teacher head0.218
Teacher spread0.198 · 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 designSimulation or modeling
Domainnot available
GenreMethods

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

Citations0
Published2003
Admission routes1
Has abstractyes

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