4,598 research outputs found
A quantum analog of Huffman coding
We analyze a generalization of Huffman coding to the quantum case. In
particular, we notice various difficulties in using instantaneous codes for
quantum communication. Nevertheless, for the storage of quantum information, we
have succeeded in constructing a Huffman-coding inspired quantum scheme. The
number of computational steps in the encoding and decoding processes of N
quantum signals can be made to be of polylogarithmic depth by a massively
parallel implementation of a quantum gate array. This is to be compared with
the O (N^3) computational steps required in the sequential implementation by
Cleve and DiVincenzo of the well-known quantum noiseless block coding scheme of
Schumacher. We also show that O(N^2(log N)^a) computational steps are needed
for the communication of quantum information using another Huffman-coding
inspired scheme where the sender must disentangle her encoding device before
the receiver can perform any measurements on his signals.Comment: Revised version, 7 pages, two-column, RevTex. Presented at 1998 IEEE
International Symposium on Information Theor
Real-time data compression of broadcast video signals
A non-adaptive predictor, a nonuniform quantizer, and a multi-level Huffman coder are incorporated into a differential pulse code modulation system for coding and decoding broadcast video signals in real time
Recommended from our members
Parallel data compression
Data compression schemes remove data redundancy in communicated and stored data and increase the effective capacities of communication and storage devices. Parallel algorithms and implementations for textual data compression are surveyed. Related concepts from parallel computation and information theory are briefly discussed. Static and dynamic methods for codeword construction and transmission on various models of parallel computation are described. Included are parallel methods which boost system speed by coding data concurrently, and approaches which employ multiple compression techniques to improve compression ratios. Theoretical and empirical comparisons are reported and areas for future research are suggested
- …