Toward a Network Coding Constellation for Two-Way Relay Node Channels
Bibliographic record
Abstract
In Physical-Layer Network Coding (PNC), the symbol detected at the relay node in two-way relay channels (TWRC) is the superposition of the symbols transmitted by the sinks. We refer to these symbols as pnc-symbols. In traditional modulation constellations such as Quadrature Amplitude Modulation (QAM) and Phase Shift Keying (PSK), the demodulator may fail to optimally identify pnc- symbols formed from pairs of central symmetrical symbols (CSS) because their superposition may yield to the same output point (i.e., to the same decision region) due to the presence of a central symmetry point. In order to avoid such ambiguity, we propose a non central symmetry constellation (CSC), called 4-TRAQAM, which is used by the sinks such that the decision regions of the output points are pair-wise disjoint.We show that the sinks in the PNC-based TWRC can be considered as a single transmitter using the same modulation as the real sinks with a higher order.We further derive the average energy of pnc- symbols and the error probability of the derived PNC-based TWRC modulation, and we show that the 4- TRAQAM provides the best trade-off between the average energy and the disjointness of the decision regions, compared to other used QAM.
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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 | 0.003 |
| Meta-epidemiology (narrow) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.001 |
| Science and technology studies | 0.000 | 0.001 |
| Scholarly communication | 0.001 | 0.001 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.001 | 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".