Direct- or Fast-Access Decoding Schemes for VF Codes

In this paper, we propose two schemes, which enable any VF code to realize director fast-access decoding for any long source sequence. Direct-access decoding means that any source symbol of any position can be directly decoded within constant time, not depending on the length of source sequence N , without decoding the whole codeword sequence. We also evaluate the memory size necessary to realize directaccess decoding or fast-access decoding with decoding delayO(log log N ), O(log N ), and so on, in the proposed schemes. key words: VF code, direct-access decoding, rank function, select function