Data communication arrangement having variable length coding and method therefor
AssigneeNetergy Networks, Inc.
InventorBernd Girod
Life of this patent
Estimating the term…
Abstract
A variable length coding system encodes and decodes symbols as uniquely decodable code words using an assignment scheme having a maximum code word length. According to one embodiment, a first bitstream is combined with a second bitstream to provide a resultant bitstream to be sent over a communications channel. The first bitstream represents the code words in a forward direction, and the second bitstream contains the same code words reversed and bit delayed by at least the maximum code word length. A resultant bitstream can be decoded in forward or reverse direction. The scheme is highly efficient for long blocks of data and the reversible aspect of the coding scheme improves the tolerance for errors caused by channel interference.
Claims21
For use in electronic communication arrangements, a method of representing symbols by a concatenation of variable length code words, comprising:
- using a resultant bitstream to represent the symbols;
- the resultant bitstream provided by combining a first bitstream and a second bitstream, when using a common decoding device for decoding the first and second bitstreams the first bitstream being decodable in a forward direction and the second bitstream being decodable in a reverse direction and when bit-delayed at least by a selected bit length.
For use in electronic communication arrangements, a method of representing symbols by a uniquely decodable concatenation of variable length code words having a maximum code word length, comprising:
- combining a first bitstream and a second bitstream to provide a resultant bitstream, when using a common decoding device for decoding the first and second bitstreams the first bitstream being decodable in a forward direction and the second bitstream being decodable in a reverse direction and bit-delayed at least by code word length;
- transmitting the resultant bitstream over a communications channel;
- receiving the resultant bitstream;
- and
- decoding the resultant bitstream including combining the resultant bitstream with a third bitstream, when using a common decoding device for decoding the third and resultant bitstreams the third bitstream being decodable in a reverse direction relative to the resultant bitstream and bit-delayed at least by code word length.
An arrangement for communicating symbols represented as a concatenation of uniquely decodable code words having a maximum code word length, comprising:
- means for providing a resultant bitstream by combining a first bitstream and a second bitstream, when using a common decoding device for decoding the first and second bitstreams the first bitstream being decodable in a forward direction and the second bitstream being decodable in a reverse direction and bit-delayed at least by the maximum code word length;
- and
- means for transmitting the resultant bitstream over a communications channel to communicate the symbols.
An arrangement for communicating data representing symbols as a concatenation of uniquely decodable code words having a maximum code word length, comprising:
- a programmable data processor, including a program configured and arranged to cause the data processor to provide a resultant bitstream by combining a first bitstream and a second bitstream, when using a common decoding device for decoding the first and second bitstreams the first bitstream being decodable in a forward direction and the second bitstream being decodable in a reverse direction and bit-delayed at least by the maximum code word length;
- and
- communication means for communicating the resultant bitstream over a communications channel to communicate the symbols.
A videoconferencing arrangement for communicating at least video data, with symbols represented as uniquely decodable code words having a maximum code word length, comprising:
- a video camera for generating video data representing captured images;
- a programmable data processor responsive to the video camera and including a program configured and arranged to cause the data processor to provide a resultant bitstream by combining a first bitstream and a second bitstream, each bitstream corresponding to a sequence of the generated video data, when using a common decoding device for decoding the first and second bitstreams the first bitstream being decodable in a forward direction and the second bitstream being decodable in a reverse direction and bit-delayed at least by the maximum code word length;
- communication means for communicating the resultant bitstream over a communications channel to communicate the symbols;
- and
- means for decoding the resultant bitstream.
For use in electronic communication arrangements, a method of decoding symbols represented by a concatenation of variable length code words, comprising:
- providing a resultant bitstream to represent the symbols;
- the resultant bitstream provided by combining a first bitstream and a second bitstream, when using a common decoding device for decoding the first and second bitstreams the first bitstream being decodable in a forward direction and the second bitstream being decodable in a reverse direction and bit-delayed at least by a selected bit length;
- and
- combining the resultant bitstream with a third bitstream, when using a common decoding device for decoding the third and resultant bitstreams the third bitstream being decodable in a reverse direction relative to the resultant bitstream and bit-delayed at least by a selected bit length.
An arrangement for communicating data representing symbols as a concatenation of uniquely decodable code words having a maximum code word length, comprising:
- a programmable data processing circuit configured and arranged to provide a resultant bitstream by combining a first bitstream and a second bitstream, the first and second bitstreams characterized in that, using a common decoding device the first bitstream is decodable in a forward direction and the second bitstream is decodable in a reverse direction and bit-delayed at least by the maximum code word length;
- and
- a data coupler adapted to communicate the resultant bitstream over a communications channel to communicate the symbols.
Dependencies are inferred from the claim text.