Error detection in arithmetic coding with artificial markers

Error detection in arithmetic code is usually achieved by inserting markers in the source sequence during encoding. Transmission errors can then be detected in the decoding process if the inserted markers do not appear at the expected positions. Unlike the existing approaches in which the marker symbol is selected from the set of source symbols, we propose that the marker be created artificially so as not to affect the original distribution of the source symbols. Our scheme is proved to possess a better compression ratio than existing marker approaches at the same error misdetection probability. The relationship between codeword length expansion and error misdetection probability within a coded block is well formulated, which makes it easy to adapt to channels with different bit error rates. Simulation results show that, for adaptive arithmetic coding implemented using finite-precision computation, the distribution of error detection delay has a peak at a value slightly larger than the length of the decoding register. With a sufficiently long register, our approach can detect most error patterns in long source sequences at a high probability.