A broadband self-interference cancellation circuit for simultaneous full-duplex radio applications
Bibliographic record
Abstract
All wireless communication systems so far have employed either time division duplexing (TDD), where the transmitter and receiver share the same frequency band but operate in orthogonal time slots, or frequency division duplexing (FDD), where the time slots are shared but orthogonal frequency bands are used. In order to meet the requirements for the upcoming 5G mobile standards, the concept of simultaneous full-duplex is being actively pursued, where both time slots and frequency bands can be shared between the transmitter and the receiver. The greatest hurdle in achieving full-duplex communication is the self-interference from the transmitter that is several orders of magnitude stronger than the desired signal at the receiver. Realizing such broadband cancellation has been hitherto very challenging, because not only does it demand broadband cancellation in amplitude, phase and group delay of the echo signals, but also require such a cancellation circuit to be linear, low-noise and ultra-compact for a mobile form factor. This work will demonstrate the first self-interference radio-frequency cancellation circuit that achieves an 80 MHz linear time evolution (LTE) cancellation bandwidth in a linear, tunable, compact, and fully monolithic integrated circuit (IC) implementation for such full-duplex radios. A proof-of-concept prototype is realized in 0.13 µm complementary metal oxide semiconductor (CMOS) process that utilizes techniques such as frequency translations and baseband Hilbert transforms to attain a measured 23 dB of self-interference cancellation over an 80MHz signal bandwidth. The entire circuit consumes 34 mW from a 1.2V supply in an active area of just 0.84 mm².
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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 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.001 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.002 | 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".