US Patent 9454552 Entropy coding and decoding using polar codes

Technologies are described herein for compressing or decompressing data using polar codes. Some example technologies may receive a data string comprising a first set of symbols. The technologies may transform the data string into a generalized message comprising a second set of symbols by mapping the data string to the generalized message via an inverse of a transformation function. The technologies may identify, based on a polar code, fixed symbols of the generalized message. The technologies may generate a compressed data string by extracting the fixed symbols from the generalized message and concatenating the fixed symbols into the compressed data string. As a result, the generalized message may be transformed into the compressed data string.