Optimum digital modulation for nonlinear FDMA uplink and a regenerative satellite on-board processor
Bibliographic record
Abstract
A number of linear, digital modulation techniques are evaluated for FDMA access to a regenerative, satellite repeater. The new aspect of the research is in considering a regenerative rather than an amplifying satellite transponder. QPSK, OQPSK, both with Nyquist pulse shaping, and MSK are the modulation techniques considered. A nonlinear, high power amplifier (HPA) is included in the user terminal for the FDMA uplink access to the regenerative satellite repeater. The multi-carrier demodulation algorithm on-board the satellite is based on the transmultiplexer algorithm as all uplink signals are assumed to have a fixed data rate. The performance criteria used in the study are power efficiency, bandwidth efficiency, and the complexity of the transmultiplexer algorithm for on-board processing, all of which vary relative to the modulation technique considered. If the HPA is linear we find that QPSK is the best modulation. When the HPA is nonlinear, however, it is the worst technique and OQPSK is best. The performance analysis is based on a full computer simulation of 8 uplink carriers being processed by the transmultiplexer algorithm. The downlink would be based on TDM access but is not considered in the paper.
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How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| 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 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.000 | 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 teacher head, 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".