A Unified Perspective of Different Multicarrier CDMA Schemes
Bibliographic record
Abstract
In the conventional multicarrier CDMA schemes, different users utilize different spreading codes to realize the multiple accessing (which is the CDMA technique) and the bits from the same user are transmitted on different frequency subcarriers to realize the multiplexing (which is the OFDM technique). However, the function of the set of subcarriers and the function of the set of spreading codes can be switched. That is, the bits from the same user are spread with different accessing codes but they are transmitted on the same subcarrier. Based on this idea, we introduce a new multicarrier scheme which is named as CDM-OFDMA. We put the MC-DS-CDMA and CDM-OFDMA schemes into one unified formula format. Their performances are evaluated and compared. Under equal deterministic channel characteristic condition, it is found that the CDM-OFDMA scheme has a better performance than the MC-DS-CDMA scheme. The main reason is that the MAI from the same subcarrier is much bigger than the MAI from other subcarriers and in the CDM-OFDMA scheme the MAI from the same subcarrier is avoided by employing the orthogonal spreading codes
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot 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.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.001 | 0.002 |
| Meta-epidemiology (narrow) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.001 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.001 | 0.001 |
| Scholarly communication | 0.003 | 0.004 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.002 | 0.002 |
| Insufficient payload (model declined to judge) | 0.001 | 0.000 |
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.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
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".