On the benefits of non-uniform signaling in chip-asynchronous CDMA
Bibliographic record
Abstract
This paper explores chip-asynchronous CDMA transmission when single-user demodulation and decoding are used at the receiver. First, a chip-level channel model is presented to account for chip-asynchronism between different users. Using the model, the symmetric capacity of chip-asynchronous CDMA is investigated. Numerical results indicate that a sum rate of 2 bits per channel use is achievable when chip symbols {-1, 1} are utilized in appropriate non-equiprobable fashion. This represents over a 2.5 times capacity gain over traditional uniform chip signaling in chip-synchronous CDMA. Consequently, the symmetric sum capacity is further investigated when the zero chip symbol is also utilized for CDMA transmission. The obtained capacity results indicate that nonuniform signaling with {-1,0,+1} chip symbols can lead to an energy efficient CDMA transmission scheme which could achieve energy savings of up to 3 dB over the traditional CDMA with equiprobable {-1, +1} chip symbols.
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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 | 0.004 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.001 |
| Scholarly communication | 0.001 | 0.002 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.000 | 0.001 |
| 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".