Coded modulation for mobile radio

Claim 1

Apparatus comprising means for receiving a succession of blocks of input data, and means for defining an alphabet of codewords each associated with a unique one of the possible values of said input data blocks and for generating, in response to said blocks of input data, the associated ones of said codewords, each of the codewords of said alphabet being comprised of a combination of at least two modulated signal points taken from a predetermined constellation of modulated signal points, said alphabet of codewords having built-in X-fold diversity so that each of the codewords of said alphabet differs from each other codeword of said alphabet at at least X particular signal points positions, where X is an integer greater than unity, and the minimum squared Euclidean distance between said codewords being greater than the absolute minimum squared Euclidean distance associated with said alphabet.

Claim 14

A method for decoding a plurality of sequences of received signal points received over respective fading channels, each of said sequences representing a particular transmitted 2N-dimensional codeword of a predetermined block code, said code being of a type comprised of an alphabet of codewords each of which is, in turn, comprised of a combination of at least two modulated signal points of a constituent constellation, said alphabet being an alphabet which can be formed by (a) selecting particular concatenations of the signal points of the constituent constellation to be a first set of elements, (b) grouping the last-defined set of elements into subsets, (c) selecting at least ones of the elements of particular selected concatenations of the subsets of step (b), and (d) repeating steps (b), (c) and (d) until 2N-dimensional elements are formed, whereby those elements are said 2N-dimensional codewords, said method comprising the steps of measuring, for each particular sequence, the squared Euclidean distance between each received signal point of that particular sequence and all possible transmitted signal points to provide an ensemble of preliminary signal point metrics associated with said each received signal point of said particular sequence, combining the resulting ensembles of preliminary signal point metrics to generate an ensemble of final signal point metrics, finding, for each of a plurality of elements made up of concatenations of received signal points, the closest element from each of the subsets of possible transmitted elements by adding the final signal point metrics corresponding to each element of that particular subset and selecting as said closest element the element corresponding to a subset metric equal to the smallest such sum, finding, for each of a plurality of higher-dimensional elements made up of concatenations of the previously selected closest elements, the closest element from each of the higher-dimensional subsets of possible transmitted elements by adding the subset metrics corresponding to each possible concatenation of subsets of that particular higher-dimensional subset and selecting, as said closest element, the element corresponding to a higher-dimensional subset metric equal to the smallest such sum, and iterating the second of said finding steps until a single 2N-dimensional element is selected, said 2N-dimensional element being the decoded codeword.

Claim 15

A method for decoding a plurality of sequences of received signal points received over respective fading channels, each of said sequences representing a particular transmitted 2N-dimensional codeword of a predetermined block code, said code being of a type comprised of an alphabet of codewords each of which is, in turn, comprised of a combination of at least two modulated signal points of a constituent constellation, said alphabet being an alphabet which can be formed by (a) selecting particular concatenations of the signal points of the constituent constellation to be a first set of elements, (b) grouping the last-defined set of elements into subsets, (c) selecting at least ones of the elements of particular selected concatenations of the subsets of step (b), and (d) repeating steps (b), (c) and (d) until 2N-dimensional elements are formed, whereby those elements are said 2N-dimensional codewords, said method comprising the steps of measuring, for each particular sequence, the squared Euclidean distance between each received signal point of that particular sequence and all possible transmitted signal points to provide an ensemble of preliminary signal point metrics associated with said each received signal point of said particular sequence, combining the resulting ensembles of preliminary signal point metrics to generate an ensemble of final signal point metrics, finding, for each of a plurality of elements made up of concatenations of received signal points, the closest element from each of the subsets of possible transmitted elements by adding the final signal point metrics corresponding to each element of that particular subset and selecting as said closest element the element corresponding to a subset metric equal to the smallest such sum, finding, for each of a plurality of higher-dimensional elements made up of concatenations of the previously selected closest elements, the closest element from each of the higher-dimensional subsets of possible transmitted elements by adding the subset metrics corresponding to each possible concatenation of subsets of that particular higher-dimensional subset and selecting, as said closest element, the element corresponding to a higher-dimensional subset metric equal to the smallest such sum, and iterating the second of said finding steps until a single 2N-dimensional element is selected, said 2N-dimensional element being the decoded codeword.

Claim 25

A method comprising the steps of receiving a succession of blocks of input data, and generating, in response to said blocks of input data, associated codewords of an alphabet of codewords each associated with a unique one of the possible values of said input data blocks, each of the codewords of said alphabet being comprised of a combination of at least two modulated signal points taken from a predetermined constellation of modulated signal points, said alphabet of codewords having built-in X-fold diversity, where X is an integer greater than unity, and the minimum squared Euclidean distance between said codewords being greater than the absolute minimum squared Euclidean distance associated with said alphabet.

Claim 26

A method comprising the steps of receiving a succession of blocks of input data, and generating, in response to said blocks of input data, associated codewords of an alphabet of codewords each associated with a unique one of the possible values of said input data blocks, each of the codewords of said alphabet being comprised of a combination of at least two modulated signal points taken from a predetermined constellation of modulated signal points, said alphabet of codewords having built-in X-fold diversity, where X is an integer greater than unity, and the minimum squared Euclidean distance between said codewords being greater than the absolute minimum squared Euclidean distance associated with said alphabet.

Claim 39

A method comprising the steps of receiving a succession of blocks of input data at a rate of m bits every T seconds, where T is a predetermined signalling interval m>0, generating, in response to said blocks of input data, associated codewords of an alphabet of codewords each associated with a unique one of the possible values of said input data blocks, each of the codewords of said alphabet being comprised of a combination of at least two modulated signal points taken from a predetermined constellation of modulated signal points, said constellation including more than 2 m modulated signal points and said alphabet of codewords having built-in diversity.

Claim 40

A method comprising the steps of receiving a succession of blocks of input data at a rate of m bits every T seconds, where T is a predetermined signalling interval m>0, generating, in response to said blocks of input data, associated codewords of an alphabet of codewords each associated with a unique one of the possible values of said input data blocks, each of the codewords of said alphabet being comprised of a combination of at least two modulated signal points taken from a predetermined constellation of modulated signal points, said constellation including more than 2 m modulated signal points and said alphabet of codewords having built-in diversity.

Claim 48

A method comprising the steps of receiving a succession of blocks of input data, and defining an alphabet of 2N-dimensional codewords each associated with a unique one of the possible values of said input data blocks and generating, in response to each of said blocks of input data, the associated one of said codewords, each of the codewords of said alphabet being comprised of a combination of at least two modulated signal points of a constituent constellation, said alphabet of codewords having built-in diversity, and said alphabet being an alphabet which can be formed by (a) selecting particular concatenations of the signal points of the constituent constellation to be a first set of elements, (b) grouping the last-defined set of elements into subsets, (c) selecting at least ones of the elements of particular selected concatenations of the subsets of step (b), and (d) repeating steps (b), (c) and (d) until 2N-dimensional elements are formed, whereby those elements are said 2N-dimensional codewords.

Claim 49

A method comprising the steps of receiving a succession of blocks of input data, and defining an alphabet of 2N-dimensional codewords each associated with a unique one of the possible values of said input data blocks and generating, in response to each of said blocks of input data, the associated one of said codewords, each of the codewords of said alphabet being comprised of a combination of at least two modulated signal points of a constituent constellation, said alphabet of codewords having built-in diversity, and said alphabet being an alphabet which can be formed by (a) selecting particular concatenations of the signal points of the constituent constellation to be a first set of elements, (b) grouping the last-defined set of elements into subsets, (c) selecting at least ones of the elements of particular selected concatenations of the subsets of step (b), and (d) repeating steps (b), (c) and (d) until 2N-dimensional elements are formed, whereby those elements are said 2N-dimensional codewords.

Claim 50

A method for decoding a sequence of received signal points representing a transmitted 2N-dimensional codeword of a predetermined block code, said code being of a type comprised of an alphabet of codewords each of which is, in turn, comprised of a combination of at least two modulated signal points of a constituent constellation, said alphabet being an alphabet which can be formed by (a) selecting particular concatenations of the signal points of the constituent constellation to be a first set of elements, (b) grouping the last-defined set of elements into subsets, (c) selecting at least ones of the elements of particular selected concatenations of the subsets of step (b), and (d) repeating steps (b), (c) and (d) until 2N-dimensional elements are formed, whereby those elements are said 2N-dimensional codewords, said method comprising the steps of measuring the squared Euclidean distance between each received signal point and all possible transmitted signal points to provide an ensemble of signal point metrics associated with said each received signal point, finding, for each of a plurality of elements made up of concatenations of received signal points, the closest element from each of the subsets of possible transmitted elements by adding the signal point metrics corresponding to each element of that particular subset and selecting as said closest element the element corresponding to a subset metric equal to the smallest such sum, finding, for each of a plurality of higher-dimensional elements made up of concatenations of the previously selected closest elements, the closest element from each of the higher-dimensional subsets of possible transmitted elements by adding the subset metrics corresponding to each possible concatenation of subsets of that particular higher-dimensional subset and selecting, as said closest element, the element corresponding to a higher-dimensional subset metric equal to the smallest such sum, and iterating the second of said finding steps until a single 2N-dimensional element is selected, said 2N-dimensional element being the decoded codeword.

Claim 51

A method for decoding a sequence of received signal points representing a transmitted 2N-dimensional codeword of a predetermined block code, said code being of a type comprised of an alphabet of codewords each of which is, in turn, comprised of a combination of at least two modulated signal points of a constituent constellation, said alphabet being an alphabet which can be formed by (a) selecting particular concatenations of the signal points of the constituent constellation to be a first set of elements, (b) grouping the last-defined set of elements into subsets, (c) selecting at least ones of the elements of particular selected concatenations of the subsets of step (b), and (d) repeating steps (b), (c) and (d) until 2N-dimensional elements are formed, whereby those elements are said 2N-dimensional codewords, said method comprising the steps of measuring the squared Euclidean distance between each received signal point and all possible transmitted signal points to provide an ensemble of signal point metrics associated with said each received signal point, finding, for each of a plurality of elements made up of concatenations of received signal points, the closest element from each of the subsets of possible transmitted elements by adding the signal point metrics corresponding to each element of that particular subset and selecting as said closest element the element corresponding to a subset metric equal to the smallest such sum, finding, for each of a plurality of higher-dimensional elements made up of concatenations of the previously selected closest elements, the closest element from each of the higher-dimensional subsets of possible transmitted elements by adding the subset metrics corresponding to each possible concatenation of subsets of that particular higher-dimensional subset and selecting, as said closest element, the element corresponding to a higher-dimensional subset metric equal to the smallest such sum, and iterating the second of said finding steps until a single 2N-dimensional element is selected, said 2N-dimensional element being the decoded codeword.