Weak Signal GPS Synchronization for Locating in-Building Cellular Telephones
Bibliographic record
Abstract
This paper investigates the application of a parallel noncoherent matched filter that can allow GPS signal acquisition even for the very low SNR signals found within large buildings. Recent government regulations require technology that can supply emergency "9-1-1" dispatchers with cellular telephone location to within 50 meters and this is very difficult with current technology. With surroundings at room temperature, our simulation results show codephase acquisition at GPS signal strengths as low as -175 dBW (29 dBHz). Segmentation of the matched filter and non-coherent summation allows Doppler and carrier frequency offsets as large a 5 kHz. The matched filter operates at half-chip intervals and provides a correlation output for each of the 2046 codephases in the 1023 chip code sequence. These outputs are individually accumulated (or averaged) over many code cycles to improve the probability of correct codephase detection. At -175 dBW signal strength, simulations indicate a mean acquisition time of 1.2 seconds. After accumulating for 10,000 cycles (10 seconds), the probability of correct detection exceeds 99%
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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".