Performances of trigonometric chirp spread spectrum modulation in AWGN & rayleigh channels
Bibliographic record
Abstract
A linear CSS (Chirp Spread Spectrum) system generally requires its time-bandwidth product to be 60 or more in order to achieve satisfactory orthogonality between different chirp signals. Thus, a linear CSS system occupies very wide bandwidth (e.g. 60MHz or higher) for 1μs chirp duration. To improve the orthogonality and to reduce the bandwidth requirements, this paper explores two kinds of non-linear chirps: power function chirp and trigonometric chirp. It is concluded that a pair of trigonometric chirp can be made orthogonal under some mild conditions, and the orthogonality shows periodic characteristic. In other words, the CSS system based on trigonometric chirp could result in significant reduction in required bandwidth as compared to that of linear chirps for the same channel performance. Further, extensive simulations have been carried out to illustrate the BER vs. Eb/No performance in Gaussian and Rayleigh channels. The results show that the performance of the CSS system based on trigonometric chirp outperforms that of linear chirp based systems, especially when the time-bandwidth product of chirp is small (e.g. 30sHz or less).
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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 | 0.001 | 0.003 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.001 |
| Open science | 0.001 | 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".