🔶 5G NR LDPC · Fixed Test Vectors
TS 38.212 · Deterministic Encoding · Same input → Same output
✅ Fixed Input: Clicking "Encode" repeatedly produces the same output because the input bits are fixed.
This allows you to verify the encoding correctness against 3GPP test vectors.
Base Graph
BG1 (large TB)
BG2 (small TB)
TB size (A) bits
Lifting factor (Zc)
2 4 8
16 32
64
128 256 384
RV Index
0 (start)
1
2
3
E (rate matched bits)
▶ Encode (Deterministic)
A=120 · BG=BG2 · Zc=64 · E=256 · RV=0
🔒 Fixed Input
✓ ready
Input seed: 0x5A3C
Kb: 10
N: 3200
K: 640
P: 2560
CBs: 1
① Fixed Input TB + TB‑CRC
The input bits are fixed (generated from a seed). Clicking "Encode" repeatedly produces the same bits.
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② CB Segmentation + CB‑CRC
Segmented into code blocks. Each CB gets 24‑bit CRC. CRC bits highlighted .
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③ LDPC Encoding BG=BG2 · Zc=64
Systematic bits (info + CRC + filler) + deterministic parity computed using the BG matrix.
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██ info ██ CRC
██ filler ██ parity
④ Rate Matching (Circular Buffer + RV)
Select E bits from circular buffer starting at RV offset.
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██ selected bits
⑤ Concatenation → Final Codeword
All rate‑matched CBs concatenated for transmission.
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