Powerful error correction combining inner and outer codes. Outer code (e.g., Reed-Solomon) protects against burst errors, inner code (e.g., convolutional) handles random errors. Achieves near-capacity performance with polynomial decoding complexity.
| Property | Value |
|---|---|
| Category | Error Correction |
| Sub-category | Concatenated Code |
| Security status | 🎓 Educational Only |
| Complexity | Expert |
| Inventor | Dave Forney |
| Year | 1966 |
| Origin | 🇺🇸 United States |
| Source | algorithms/ecc/concatenated.js |
Status: 🎓 Educational Only
| Issue | Description | Mitigation |
|---|---|---|
| Decoding Delay | Two-stage decoding introduces latency. Outer decoder must wait for all inner codewords. | — |
| Error Propagation | Uncorrected errors from inner decoder appear as symbol erasures to outer decoder. | — |
2 vectors ship with this algorithm and run in the test suite. Byte values are hexadecimal.
Vector 1 — Concatenated code simple test
| Field | Value |
|---|---|
innerType |
hamming |
outerType |
repetition |
input |
01000101 |
expected |
000101000001010001010000010100010100000101 |
Vector 2 — Concatenated all zeros
| Field | Value |
|---|---|
innerType |
hamming |
outerType |
repetition |
input |
00000000 |
expected |
000000000000000000000000000000000000000000 |