Performance of pi /4-QDPSK in a Rayleigh/lognormal/delay spread/AWGN-cochannel interference environment
Bibliographic record
Abstract
The performance of pi /4-QDPSK system is presented in a fast Rayleigh fading/slow lognormal shadowing/delay spread/AWGN channel in the presence of cochannel interference. The performance of the system is measured in terms of symbol error rate (SER). The system was simulated using two-ray model for normalized value of Doppler shift (0.001), degree of shadowing ( sigma =6), and several values of time delays and carrier-to-interference ratios. It is seen that the system performance is limited by the presence of cochannel interference. When cochannel interference is negligible, the system performance is dominated by the ratio between the main path signal and the delayed path signal, and the differential time delay between them. It is observed that the shadowing degrades the system performance at low CNR but not at high CNR (i.e., CNR>50 dB). The irreducible symbol error rate (ISER) does not vary significantly as the differential time delay between the two path varies.>
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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) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.001 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.001 | 0.000 |
| 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".