California Institute of Technology

Other

Fabrizio Pollara

Dariush Divsalar

Samuel J Dolinar

Robert J McEliece

Hui Jin

Sam Dolinar

Serial concatenated trellis coded modulation (SCTCM) includes an outer coder, an interleaver, a recursive inner coder and a mapping element. The outer coder receives data to be coded and produces outer coded data. The interleaver permutes the outer coded data to produce interleaved data. The recursive inner coder codes the interleaved data to produce inner coded data. The mapping element maps the inner coded data to a symbol. The recursive inner coder has a structure which facilitates iterative decoding of the symbols at a decoder system. The recursive inner coder and the mapping element are selected to maximize the effective free Euclidean distance of a trellis coded modulator formed from the recursive inner coder and the mapping element. The decoder system includes a demodulation unit, an inner SISO (soft-input soft-output) decoder, a deinterleaver, an outer SISO decoder, and an interleaver.

Serial turbo trellis coded modulation using a serially concatenated coder

A turbo-like code is formed by repeating the signal, coding it, and interleaving it. A serial concatenated coder is formed of an inner coder and an outer coder separated by an interleaver. The outer coder is a coder which has rate greater than one e.g. a repetition coder. The interleaver rearranges the bits. An outer coder is a rate one coder.

Interleaved serial concatenation forming turbo-like codes

A coding system uses a serially concatenated coder driving an interleaver, which drives a trellis coder. This combination, while similar to a turbo coder, produces certain different characteristics.

Several improved turbo code apparatuses and methods. The invention encompasses several classes: (1) A data source is applied to two or more encoders with an interleaver between the source and each of the second and subsequent encoders. Each encoder outputs a code element which may be transmitted or stored. A parallel decoder provides the ability to decode the code elements to derive the original source information d without use of a received data signal corresponding to d. The output may be coupled to a multilevel trellis-coded modulator (TCM). (2) A data source d is applied to two or more encoders with an interleaver between the source and each of the second and subsequent encoders. Each of the encoders outputs a code element. In addition, the original data source d is output from the encoder. All of the output elements are coupled to a TCM. (3) At least two data sources are applied to two or more encoders with an interleaver between each source and each of the second and subsequent encoders. The output may be coupled to a TCM. (4) At least two data sources are applied to two or more encoders with at least two interleavers between each source and each of the second and subsequent encoders. (5) At least one data source is applied to one or more serially linked encoders through at least one interleaver. The output may be coupled to a TCM. The invention includes a novel way of terminating a turbo coder.

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La Canada, CA, United States of America

Fabrizio Pollara