Energy-efficient decoding of low-density parity-check codes
Bibliographic record
Abstract
For my family, whose unconditional love and support made this work possible.2-2 A communication system showing LDPC encoding and decoding. . . .2-3 Tanner graph representation of the (16, 8) LDPC code whose parity check matrix is shown in Figure 2-1. . . . . . . . . . . . . . . . . .2-4 Example of an H matrix for a quasi-cyclic (QC)-LDPC code, showing its construction from blocks of circularly shifted identity matrices. .2-5 Basic architecture for a partially parallel decoder of QC-LDPC codes.3-1 Canonical LDPC decoder architecture. . . . . . . . . . . . . . . . . .3-2 LDPC decoder architecture with a bidirectional interleaver. . . . . . .3-3 A circular shift network composed of transmission gates performs both the forward and reverse circular shift, depending on which direction the signal is driven. . . . . . . . . . . . . . . . . . . . . .3-4 Schematic of a check node with n bits. . . . . . . . . . . . . . . . . .3-5 Top level block diagram of our bidirectional system, in VN-to-CN (forward) operation with the data flow highlighted. . . . . . . . . .3-6 Top level block diagram of our bidirectional system, in CN-to-VN (reverse) operation with the data flow highlighted. . . . . . . . . .3-7 Schematic view of the transmission gate cell, showing transistor sizes.3-8 Layout of the transmission gate cell, with rulers showing the cell's overall dimensions (1.12m 3.92m). . . . . . . . . . . . . . . . .3-9 SPICE circuit used to determine timing. . . . . . . . . . . . . . . . .vii 3-10 Interconnect model used to estimate energy consumption. . . . . . . .4-1 Some examples of pulse width encoded messages.The message y is the check node result produced from the inputs a, b, and c. . . . . .4-2 The average number of transitions per edge per decoded codeword, for the (660, 484) LDPC code used in this work. . . . . . . . . . . .4-3 PWM-MS check node of degree d c = 4. . . . . . . . . . . . . . . . . .4-4 PWM-MS variable node of degree d v = 3. . . . . . . . . . . . . . . . .4-5 Special architecture for PWM-MS variable node with degree d v = 2. .4-6 Sign-checking circuit for PWM-MS variable nodes. . . . . . . . . . . .4-7 Block diagram of the designed decoder. . . . . . . . . . . . . . . . . .4-8 Detailed block diagram of the PWM-MS decoders showing the critical paths of the unpipelined decoders (in red) and the pipelined decoder (in blue). . . . . . . . . . . . . . . . . . . .
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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 | 0.002 | 0.001 |
| Meta-epidemiology (narrow) | 0.001 | 0.001 |
| Meta-epidemiology (broad) | 0.001 | 0.001 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.001 | 0.000 |
| Scholarly communication | 0.000 | 0.001 |
| Open science | 0.003 | 0.001 |
| Research integrity | 0.001 | 0.002 |
| 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".