Novel Rotated Quasi-Orthogonal Space-Time Block Codes With the Fixed Nearest Neighbor Number
Bibliographic record
Abstract
In this letter, we consider a coherent communication system equipped with multiple transmitter antennas and a single receiver antenna, i.e., a MISO system. For such a system, quasi-orthogonal STBC designs with fast maximum likelihood (ML) decoding have been proposed. However, full diversity cannot be achieved by such codes. The rotated quasi-orthogonal STBC overcomes such shortcomings and enables full diversity and optimal coding gain. However, for large constellations, the performance of such codes deteriorates due to the increase of the number of the nearest neighbor per symbol. In this letter, we propose to add the number of nearest neighbor as a design criterion. We show that for the rotated quasi-orthogonal code proposed in, the number of nearest neighbor tends to infinity when the size of constellation becomes infinite. Furthermore, we propose to have a particular value of rotation and show that this value not only achieves full diversity and maximum coding gain, but also has only a small number of nearest neighbors even for very large constellations.
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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 | 0.002 |
| Meta-epidemiology (narrow) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.000 |
| Bibliometrics | 0.000 | 0.001 |
| Science and technology studies | 0.000 | 0.001 |
| Scholarly communication | 0.001 | 0.001 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.001 | 0.001 |
| 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".