Dynamic Quadrant Swapping Scheme Implemented in a Post Conversion Block for I, Q Mismatch Reduction in a DQPSK Receiver
Bibliographic record
Abstract
This paper presents a new dynamic quadrant swapping scheme that reduces crosstalk due to I/Q path mismatch for DQPSK receiver. The scheme reduces crosstalk by selectively transforming/swapping the I, Q components of the received symbols. The scheme's effectiveness is demonstrated by applying it to the IF digitizer part of the receiver. In the IF digitizer the incoming IF (first IF) signal is mixed and then converted to two digital signals, the I and Q signals, both at a second IF. These digital signals are then fed into a post conversion block. In this block dynamic quadrant swapping is applied, which reduces the crosstalk. Using an IF digitizer that includes two separate mixers with two separate low pass sigma-delta modulators for I and Q paths, the scheme's effectiveness is tested. Both simulation results and measured results show a significant improvement in image rejection ratio and BER, when the scheme is applied. With a SNR of 10.8 dB, at a 160.16 MHz incoming IF, and with a data rate of 36 kbps, the scheme improves the measured BER from 4.2 × 10 to 1.4 × 10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">- 3</sup> . At a 10 MHz incoming IF, and with a data rate of 2 kbps, the scheme improves the measured image rejection ratio from 41 dB to 65 dB and the measured BER from 1.3 × 10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-3</sup> to 0.7 × 10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-3</sup> . The post conversion block is layout in 0.09 ¿m CMOS technology. It occupies an area of 0.00092 mm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> , and is simpler than previous reported schemes. The IF digitizer is fabricated in 0.35 ¿m CMOS technology.
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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 | 0.001 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.000 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.001 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.001 |
| 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".