GoKawiilfec
Forward error correction for SDR, space, and satellite applications.
fec implements two error-correcting codes that show up throughout software-defined radio and spacecraft links:
Convolutional codes with a Viterbi decoder (hard and soft decision), including the common rate-1/2 k=7, rate-1/2 k=9, rate-1/3 k=9, and rate-1/6 k=15 codes. Supports any rate from 1/2 to 1/8 and any order from k=4 to k=16. On nightly Rust, the simd feature enables a Viterbi decoder with acceleration on SSE/AVX2/AVX512.
with a Viterbi decoder (hard and soft decision), including the common rate-1/2 k=7, rate-1/2 k=9, rate-1/3 k=9, and rate-1/6 k=15 codes. Supports any rate from 1/2 to 1/8 and any order from k=4 to k=16. On nightly Rust, the feature enables a Viterbi decoder with acceleration on SSE/AVX2/AVX512. Reed–Solomon codes over GF(2⁸) with error and erasure decoding, including the standard CCSDS (255,223) code in both the conventional and the on-the-wire dual-basis (Berlekamp) representations.
fec started as and draws heavy inspiration from the author's own libcorrect, a C library for forward error correction. This crate also credits Phil Karn's libfec C library for offering an original implementation of these codes, although this crate does not borrow any source or have any relationship with that library, and the name is purely coincidental.
Standard parameters (primitive polynomials, the CCSDS dual-basis transform) are derived from the published CCSDS standard (CCSDS 131.0-B, Annex D for the dual basis).
Quick start
Convolutional (Viterbi)
use fec :: { ConvEncoder , ConvDecoder } ; // Rate-1/2, order-7 NASA code. let polys = [ 0o161 , 0o127 ] ; let mut enc = ConvEncoder :: new ( 2 , 7 , & polys ) ; let mut dec = ConvDecoder :: new ( 2 , 7 , & polys ) ; let msg = b"hello, error correction" ; let mut encoded = vec ! [ 0u8 ; enc . encode_len ( msg . len ( ) ) ] ; let num_bits = enc . encode ( msg , & mut encoded ) . unwrap ( ) ; // ... encoded is corrupted in transit ... let mut recovered = vec ! [ 0u8 ; msg . len ( ) ] ; dec . decode_hard ( & encoded , num_bits , & mut recovered ) . unwrap ( ) ;
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