A Phase Adjustment Approach for Interference Reduction in OFDM-Based Cognitive Radios
Bibliographic record
Abstract
The problem of cross-band interference in single-antenna and multi-antenna OFDM cognitive transmitters is considered. Cross-band interference, which is caused by large OFDM signal sidelobes, is a major drawback of OFDM, especially in cognitive radio applications where it is crucial to protect primary licensed users from the secondary user's interference. In this paper, we propose a novel low complexity technique, referred to as a phase adjustment technique, to tackle this problem in single-antenna and multi-antenna OFDM cognitive transmitters. In this technique, the phase of each OFDM symbol is adjusted in an attempt to minimize the interference caused by the secondary user to the primary. Unlike prior methods, this technique does not decrease data throughput and has no impact on the bit-error-rate and peak-to-average power ratio of the OFDM symbols. Furthermore, to calculate the adjustment phases, three heuristics, one of which is very low complexity and achieves near optimal performance in numerical simulations, are also proposed. In addition, the performance of the proposed technique is evaluated analytically in some special cases in single and multi-antenna cognitive transmitters, and is verified by numerical simulations.
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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 | 0.001 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| 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".