Bibliographic record
Abstract
Multiple-input-multiple-output (MIMO) capacity of waveguide and cavity channels is investigated using the modal expansion technique. Rectangular and circular waveguides and cavities are studied in details. Approximate expressions for the number of modes and for the capacity are given. A MIMO system architecture is suggested for a waveguide channel, which achieves the full capacity by making use of the mode orthogonally (or near orthogonality) using an eigenmode modulator at the Tx end and a spatial correlation receiver at the Rx end. Various practical limitations (e.g., nonideal waveguides and modulators, using discrete sensors instead of continuous, one-dimensional sensors instead of two-dimensional, etc.) and their impact on the capacity are discussed. It is demonstrated that long cavities are equivalent to waveguides in terms of capacity. The concept of spatial capacity is introduced to characterize the limits on the transmission rates that are due to both electromagnetic and information-theoretic considerations, which can be evaluated in a closed form for ideal waveguides and cavities. It follows that the traditional single-mode transmission is optimum in terms of capacity in the small signal-to-noise ratio region only.
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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 | 0.002 | 0.006 |
| Meta-epidemiology (narrow) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.000 |
| Bibliometrics | 0.002 | 0.001 |
| Science and technology studies | 0.001 | 0.002 |
| Scholarly communication | 0.002 | 0.003 |
| Open science | 0.001 | 0.002 |
| Research integrity | 0.001 | 0.001 |
| Insufficient payload (model declined to judge) | 0.006 | 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".