Differential receiver design for the Offset-QPSK modulation scheme: ISI-free and non-ISI-free receiver algorithms
Bibliographic record
Abstract
Modulation formats for mobile communications need to support non-linear amplifiers and allow for fast acquisition. A communication system using Offset-QPSK (OQPSK) and differential demodulation satisfies these requirements. Thus, in this thesis, we present two classes of differential receivers for OQPSK. The first class of receivers deals with ISI-free transmission and are attractive solutions because of their simple design. However, the ISI-free transmission assumption strictly requires a pulse shape with maximum excess bandwidth. The second class of receivers are able to deal with ISI by using trellis decoding and the Viterbi algorithm and are, thus, more computationally complex. In this case, efficient use of the bandwidth can be achieved, by optimizing the pulse shapes used, while maintaining the decoder's good performance. The pulse shapes derived include the Modified Raised Cosine (MRC), the Truncated Raised Cosine (TRC) and the Raised Cosine 2 (RC2).
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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 | 0.001 | 0.002 |
| Meta-epidemiology (narrow) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.001 | 0.001 |
| Open science | 0.001 | 0.000 |
| Research integrity | 0.001 | 0.001 |
| Insufficient payload (model declined to judge) | 0.003 | 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".