Joint source-channel LZ'77 coding
Stefano Lonardi, Wojciech Szpankowski · 2003
Limited memory and bounded communication resources require powerful data compression techniques, but at the same time noisy tetherless channels and/or corrupted file systems need error correction capabilities. Joint source-channel coding has emerged as a viable solution to this problem. The first practical joint source-channel coding algorithm was presented capable of correcting errors in the popular Lempel-Ziv'77 scheme without practically losing any compression power. This is possible since the LZ'77 (as well as gzip) encoder does not completely remove all redundancy. The inherent additional redundancy left by LZ'77 encoder was used succinctly by a channel coder (e.g., Reed Solomon coder) to protect against a limited number of errors. In addition to these, the scheme proposed is perfectly backward-compatible that is, a file compressed with error-resilient LZ'77 can still be decompressed by a common LZ'77 decoder. Algorithms and supporting experimental data were presented to support the system's claims and theoretical justifications.