Coding for higher-level modulation
AssigneeTelefonaktiebolaget LM Ericsson
InventorPeter Schramm
Life of this patent
Estimating the term…
Abstract
Source symbols are encoded for use in a higher level modulator by partitioning the source symbols into a number of classes. This principle is applied in a number of alternative transmitter and receiver embodiments. In one embodiment, a corresponding encoder is provided for each of the classes, and for each class, each of the source symbols is supplied to the corresponding encoder. For each encoder, coded symbols are supplied at an encoder output and the coded symbols are partitioned into a number of levels associated with the corresponding class, wherein at least one of the classes has at least two levels assigned to it. The partitioned coded symbols are then supplied to a mapper that generates amplitude coefficient signals. Corresponding receivers perform inverse operations to those performed by the transmitters.
Claims42
A method of encoding a plurality of source symbols for use in a higher level modulator, the method comprising the steps of:
- partitioning the source symbols into a number of classes;
- providing a corresponding encoder for each of the classes, and for each class, supplying each of the source symbols to the corresponding encoder;
- for each encoder, supplying coded symbols at an encoder output and partitioning the coded symbols into a number of levels associated with the corresponding class, wherein at least one of the classes has at least two levels associated with it;
- and
- supplying the partitioned coded symbols to a mapper that generates amplitude coefficient signals.
A method of decoding a plurality of source symbols that have been modulated in a higher level modulator, the method comprising the steps of:
- receiving demodulator output samples;
- providing a number of metric computation units in correspondence with a number of levels;
- assigning each level to one of a number of classes;
- supplying the demodulator output samples to each of the metric computation units and generating computed metric signals at an output of each metric computation unit;
- providing a corresponding decoder for each class;
- and
- supplying the computed metric signals from each of the metric computation units to the corresponding decoder, and generating decoded source symbols.
A method of decoding a plurality of source symbols that have been modulated in a higher level modulator, the method comprising the steps of:
- receiving demodulator output samples;
- providing a number of metric computation units in correspondence with a number of levels;
- assigning each level to one of a number of classes, wherein at least one of the classes has at least two levels assigned to it;
- for a first class, supplying the demodulator output samples to each of the corresponding metric computation units and generating computed metric signals at an output of each corresponding metric computation unit;
- providing a corresponding decoder for each class;
- for the first class, supplying the computed metric signals from each of the corresponding metric computation units to the corresponding decoder, and generating a first set of decoded source symbols;
- for a second class, supplying delayed demodulator output samples and the first set of decoded source symbols to each of the corresponding metric computation units and generating computed metric signals at an output of each corresponding metric computation unit;
- for the second class, supplying the computed metric signals from each of the corresponding metric computation units to the corresponding decoder, and generating a second set of decoded source symbols.
A method of encoding a plurality of source symbols for use in a higher level modulator, the method comprising the steps of:
- supplying the source symbols to an encoder;
- partitioning the encoded symbols into a number of classes;
- providing a corresponding puncturing unit for each of the classes, and for each class, supplying each of the source symbols to the corresponding puncturing unit, wherein puncturing is different in at least two of the puncturing units;
- for each puncturing unit, supplying punctured coded symbols at a puncturing unit output and partitioning the punctured coded symbols into a number of levels associated with the corresponding class;
- and
- supplying the partitioned punctured coded symbols to a mapper that generates amplitude coefficient signals.
A method of decoding a plurality of source symbols that have been modulated in a higher level modulator, the method comprising the steps of:
- receiving demodulator output samples;
- providing a number of metric computation units in correspondence with a number of levels;
- assigning each level to one of a number of classes;
- supplying the demodulator output samples to each of the metric computation units and generating computed metric signals at an output of each metric computation unit;
- and
- providing a corresponding inverse puncturing unit for each class, wherein puncturing is different in at least two of the inverse puncturing units;
- supplying the computed metric signals from each of the metric computation units to the corresponding inverse puncturing unit, and generating inverse punctured metric signals;
- and
- supplying the inverse punctured metric signals from each of the inverse puncturing units to a single decoder.
An apparatus for encoding a plurality of source symbols for use in a higher level modulator, the apparatus comprising:
- means for partitioning the source symbols into a number of classes;
- a plurality of encoders in correspondence with the number of classes, wherein:
- each encoder is coupled to receive each of the source symbols for the corresponding class;
- and
- each encoder supplies coded symbols at an encoder output;
- for each encoder, means for partitioning the coded symbols into a number of levels associated with the corresponding class, wherein at least one of the classes has at least two levels associated with it;
- and
- a mapper, coupled to receive the partitioned coded symbols, for generating amplitude coefficient signals.
An apparatus for decoding a plurality of source symbols that have been modulated in a higher level modulator, the apparatus comprising:
- means for receiving demodulator output samples;
- a plurality of metric computation units in correspondence with a number of levels, wherein each level is assigned to one of a number of classes and wherein each of the metric computation units receives the demodulator output samples and generates computed metric signals at an output of the metric computation unit;
- and
- a plurality of decoders in correspondence with the number of classes, wherein each decoder receives the computed metric signals from the corresponding metric computation unit and generates therefrom decoded source symbols.
An apparatus for decoding a plurality of source symbols that have been modulated in a higher level modulator, the apparatus comprising:
- means for receiving demodulator output samples;
- a number of metric computation units in correspondence with a number of levels, wherein each level is assigned to one of a number of classes, and wherein at least one of the classes has at least two levels assigned to it;
- a plurality of decoders, each in correspondence with one of the classes;
- and
- delaying means, coupled to receive the demodulator output samples, for generating delayed demodulator output samples,
- wherein:
- for a first class, the demodulator output samples are supplied to each of the corresponding metric computation units that generate computed metric signals at an output of each corresponding metric computation unit;
- for the first class, the computed metric signals are supplied from each of the corresponding metric computation units to the corresponding decoder, and generating a first set of decoded source symbols;
- for a second class, the delayed demodulator output samples and the first set of decoded source symbols are supplied to each of the corresponding metric computation units that generate computed metric signals at an output of each corresponding metric computation unit;
- and
- for the second class, the computed metric signals are supplied from each of the corresponding metric computation units to the corresponding decoder that generates a second set of decoded source symbols.
An apparatus for encoding a plurality of source symbols for use in a higher level modulator, the apparatus comprising:
- an encoder, coupled to receive the source symbols, wherein the encoder generates encoded symbols;
- means for partitioning the encoded symbols into a number of classes;
- a plurality of puncturing units, each in correspondence with one of the classes, wherein for each class, each of the source symbols is supplied to the corresponding puncturing unit, wherein for each puncturing unit:
- punctured coded symbols are supplied at a puncturing unit output;
- puncturing is different in at least two of the puncturing units;
- and
- the punctured coded symbols are partitioned into a number of levels associated with the corresponding class;
- and
- a mapper, coupled to receive the partitioned punctured coded symbols, for generating amplitude coefficient signals.
An apparatus for decoding a plurality of source symbols that have been modulated in a higher level modulator, the apparatus comprising:
- means for receiving demodulator output samples;
- a number of metric computation units in correspondence with a number of levels, wherein:
- each level is assigned to one of a number of classes;
- the demodulator output samples are supplied to each of the metric computation units;
- and
- computed metric signals are generated at an output of each metric computation unit;
- a plurality of inverse puncturing units in correspondence with the number of classes, wherein:
- the computed metric signals from each of the metric computation units are supplied to the corresponding inverse puncturing unit;
- puncturing is different in at least two of the inverse puncturing units;
- and
- the inverse puncturing units generate inverse punctured metric signals;
- and
- a single decoder, coupled to receive the inverse punctured metric signals from each of the inverse puncturing units.
Dependencies are inferred from the claim text.