A robust high speed indoor wireless communications system using chirp spread spectrum
Bibliographic record
Abstract
This paper considers the implications of using chirp spread spectrum (CSS) as an antimultipath modulation technique for the transmission of high speed (>10 Mb/s) data in the indoor wireless channel. Three elements are required for a CSS system to perform optimally in the multipath environment-a chirp spreader/correlator for resolution of the channel multipath, a phase-differential modulation scheme to co-phase the multipath components and a RAKE for recombination of the symbol energy. The advantage of CSS is that all three of these elements can be implemented with simple analog hardware. A prototype CSS system is presented along with simulated and measured performance plots in the indoor channel. Test results indicate that a CSS system using DQPSK can perform within 2 dB of Gaussian DQPSK in 10 m non-line of sight (NLOS) indoor channels with excess delay >200 ns, down to bit error rates of 10/sup -7/ with single omni antennas in transmitter and receiver and no coding, at data rates of 20 Mb/s and higher.
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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 | 0.000 | 0.001 |
| 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) | 0.002 | 0.001 |
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".