Apparatus for transmitting streams of information bits and methods for estimating the most likely sequence sent

Claim 2

Apparatus for transmitting a stream of information bits by sending corresponding signals over a channel in a plurality of signalling slots, the apparatus being characterised in comprising: encoding means adapted to encode the information bits that appear during a block of at least two said signalling slots by adding one or more redundant bit, to form a set of signal point selection bits for said block; selection means adapted to select, for each said set of signai point selection bits, a multi-dimensional signal point drawn from a multi-dimensional constellation for said block, said multi-dimensional signal point selected for a particular said block being dependent on the multi-dimensional signal point selected for at least one other said block; said selection means being arranged operatively to establish a correspondence between each possible combination of said signal point selection bits and the coordinates of a multi-dimensional signal point in said multi-dimensional constellation, and, said encoding means and said selection means being arranged operatively to define a partitioning of said multi-dimensional constellation into a plurality of multi-dimensional subsets and to determine the subset from which said multi-dimensional signal point is selected based upon at least one of said signal point selection bits, said multi-dimensional constellation being a concatenation of constituent constellations each of which has fewer dimensions than said multi-dimensional constellation and is partitioned into constituent subsets, and each said multi-dimensional subset being based upon said constituent subsets but being other than a concatenation of constituent subsets of said constituent constellations; and modulation means adapted in operation to modulate at least one carrier for transmission over said channel in accordance with each selected said multi-dimensional signal point.

Claim 3

Apparatus according to Claim 1, further charac-' terised in that said encoding means comprises a convolutional coder adapted to generate a set of convolutionally encoded bits including said redundant bit, and in that said multi-dimensional subset from which said multi-dimensional signal point is drawn is selected based on said convolutionally encoded bits.

Claim 4

Apparatus according to Claim 1 or Claim 2, further characterised in being arranged such that said constituent subsets in each said constituent constellation are grouped to form constituent families such that the minimum distance between constituent points within each said constituent subset is greater than the minimum distance between constituent points within each said constituent family, which is in turn greater than the minimum distance between constituent points within said constituent constellation; such that said multi-dimensional constellation is partitioned into said multi-dimensional subsets based on said distances of said constituent families and subsets; and such that said multi- dimensional subsets are grouped to form multi- dimensional families also based on said distances.

Claim 5

Apparatus according to Claim 3, further characterised in being arranged such that each said constituent family comprises constituent subfamilies each of which comprise a plurality of said constituent subsets chosen such that the minimum distance between constituent points within each said constituent subfamily is greater than the minimum distance between constituent points within each said constituent family and is less than the minimum distance between constituent points within each said constituent subset, and said multi-dimensional constellation is partitioned into said multi- dimensional subsets also based on said distances of said constituent subfamilies.

Claim 6

Apparatus according to any preceding Claim, further characterised in being arranged such that each said multi-dimensional subset comprises multi-dimensional types each of which is a concatenation of said constituent subsets.

Claim 7

. 6. Apparatus according to Claim 3 and Claim 5, further characterised in being arranged such that said constituent subsets that belong to a given said constituent constellation and that are associated with multi-dimensional types of a given said multi- dimensional subset, are different and belong to one said constituent family of said-g-iv6n constituent constellation.

Claim 8

Apparatus according to Claim 4 and Claim 5, further characterised in being arranged such that said constituent subsets that belong to a given said constituent constellation and that are associated with multi-dimensional types of a given said multi- dimensional subset, are different and belong to one said constituent subfamily of said given constituent constellation.

Claim 9

Apparatus for transmitting a stream of information bits by sending corresponding signals over a channel in a plurality of signalling slots, the apparatus being characterised in comprising: encoding means adapted to encode the information bits that appear during a block of at least two said slots by adding one or more redundant bit, to form a set of signal point selection bits for said block; selection means adapted to select, for each said set of signal point selection bits, a multi-dimensional signal point drawn from a multi-dimensional constellation for said block, said multi-dimensional signal point selected for a particular said block being dependent on the multi-dimensional signal point selected for at least one other said block; said selection means being arranged operatively to establish a correspondence between each possible combination of said signal point selection bits and the coordinates of a multi-dimensional signal point in said multi-dimensional constellation, said encoding means and said selection means being arranged operatively to define a partitioning of said multi-dimensional constellation into a plurality of multi-dimensional subsets, said multi-dimensional constellation being a concatenation of a plurality of constituent constellations each of which has fewer dimensions than said multi-dimensional constellation, and said constituent constellations comprising arrangements of signal points which are ambiguous under phase rotations of particular amounts, preferably including 90°, 180° and 270°, and said encoding means and said selection means being further adapted to cause said selected multi-dimensional signal points to be susceptible to being decoded in a manner that avoids the effect of channel-induced phase rotations of any of said amounts; and modulation means adapted in operation to modulate at least one carrier for transmission over said channel in accordance with the coordinates represented by each selected said multi-dimensional signal point. -

Claim 10

Apparatus for transmitting a stream of information bits by sending corresponding signals over a channel in a plurality of signalling slots, the apparatus being characterised in comprising: encoding means adapted to encode the information bits that appear during a block of at least two said slots by adding one or more redundant bit, to form a set of signal point selection bits for said block; selection means adapted to select, for each said set of signal point selection bits, a multi-dimensional signal point drawn from a multi-dimensional constellation for said block, said multi-dimensional signal point selected for a particular said block being dependent on the multi-dimensional signal point selected for at least one other said block; said selection means being arranged operatively to establish a correspondence between each possible combination of said signal point selection bits and the coordinates of a multi-dimensional signal point in said multi-dimensional constellation, said encoding means and said selection means being arranged operatively to define a partitioning of said multi-dimensional constellation into a plurality of multi-dimensional subsets, said multi-dimensional constellation being a concatenation of a plurality of constituent constellations each of which has fewer dimensions than said multi-dimensional constellation, and said constituent constellations comprising arrangements of signal points which are ambiguous under phase rotations of particular amounts, preferably including 90°, 180° and 270°, and said encoding means and said selection means being further adapted to cause said selected multi-dimensional signal points to be susceptible to being decoded in a manner that avoids the effect of channel-induced phase rotations of any of said amounts; and modulation means adapted in operation to modulate at least one carrier for transmission over said channel in accordance with the coordinates represented by each selected said multi-dimensional signal point. -

Claim 11

Apparatus according to Claim 8, further characterised in that said encoding means and said selec- ' tion means are further arranged operatively to define said partitioning into said multi-dimensional subsets so that the coordinates of each said multi- dimensional signal point in a given said multi- dimensional subset will be translated, under a phase rotation of any of said amounts, into the coordinates of another said multi-dimensional signal point in said given multi-dimensional subset.

Claim 12

Apparatus according to Claim 8, further characterised in being arranged such that each said constituent constellation is partitioned into constituent subsets such that a said constituent subset is translated into another said constituent subset under a phase rotation corresponding to one said particular amount; and in that said encoding means and said selection means are arranged operatively to define said partitioning of said multi-dimensional constellation such that each said multi-dimensional subset comprises multi-dimensional types each of which is a concatenation of said constituent subsets and said multi-dimensional subset is invariant under a rotation of said particular amount.

Claim 13

Apparatus according to Claim 5 or Claim 10, further characterised in being arranged such that said types comprise all possible concatenations of said constituent subsets and each said type belongs to at least one said multi-dimensional subset.

Claim 14

Apparatus according to Claim 9, further characterised in that said encoding means comprises a convolutional coder which is adapted operatively to generate from at least one said information bit a plurality of convolutionally-encoded bits that include said redundant bit; in that said selection means is adapted to select the multi-dimensional subset from which said multi-dimensional point is drawn based on said convolutionally-encoded bits, and in that said encoding means further comprises a differential encoder operatively arranged to differentially encode at least one non-convolufionally- encoded said information bit to remove the ambiguity resulting from a rotation of any of said amounts.

Claim 15

Apparatus according to Claim 12, further characterised in that said differential encoder is operatively arranged to differentially encode only non-convolutionally-encoded said information bits.

Claim 16

Apparatus according to Claim 8, further characterised in that said encoding means and said selection means are further arranged operatively to define said partitioning into said multi-dimensional subsets so that the coordinates of each said multi- dimensional signal point in a given said multi- dimensional subset will be translated, under phase rotations of at least one but not all of said amounts, into the coordinates of another said multi-dimensional signal point in said given multi-dimensional subset, and will be translated by another one of said amounts into the coordinates of another said multidimensional signal point in another said multi- dimensional subset; and in that said encoding means and said selection means comprise a convolutional coder whose state transitions are associated with said multi-dimensional subsets so that the ambiguity resulting from said translation by said other amount is removed.

Claim 17

Apparatus according to Claim 14, further characterised in being arranged such that the multi- dimensional subset which results from rotating a first mufti-dimensional subset by said other amount is assigned to a state transition which has a predetermined relationship to the state transition to which the first multi-dimensional subset is assigned.

Claim 18

Apparatus according to Claim 15, further characterised in being arranged such that if said. first multi-dimensional subset is assigned to a transition from a first state to a second state of said convolutional coder, then said resulting multi-dimensional subset is assigned to a transition between two states determined by a predetermined one-to-one function of said first and second states.

Claim 19

Apparatus according to any of Claims 14, 15 or 16, further characterised in that said convojutionai coder is adapted operatively to generate from at least one said information bit a plurality of convolutionally-encoded bits that include said redundant bit; in that said selection means is adapted to select the multi-dimensional subset from which said multi-dimensional point is drawn based on said convolutionally-encoded bits; and in that said encoding means further comprises a differential encoder operatively arranged to differentially encode at least one non-convolutionally-encoded said information bit to remove the ambiguity resulting from rotation by any of said amounts.

Claim 20

Apparatus according to Claim 17, further characterised in that said convolutional coder is operatively arranged to generate said convolutionally-encoded bits from bits which include at least one differentially coded said information bit.

Claim 21

Apparatus according to any preceding claim, further characterised in that constituent constellations are all two-dimensional or are all four-dimensional constellations.

Claim 22

Apparatus for transmitting a stream of information bits by sending corresponding signals over a channel in a plurality of signalling slots, the apparatus being characterised in comprising: encoding means adapted to encode the information bits that appear during a block of at least two said signalling slots by adding one or more redundant bit, to form a set of signal point selection bits for said block; selection means adapted to select, for each said set of signal point selection bits, a multi-dimensional signal point drawn from a multi-dimensional constellation for said block, said multi-dimensional signal point selected for a particular said block being dependent on the multi-dimensional signal point selected for at least one other said block; said selection means being arranged operatively to establish a correspondence between each possible combination of said signal point selection bits and the coordinates of a multi-dimensional signal point in said multi-dimensional constellation, said encoding means and said selection means being arranged operatively to define a partitioning of said multi-dimensional constellation into a plurality of multi-dimensional subsets, said multi-dimensional constellation being a concatenation of constituent constellations each of which has two dimensions and is partitioned into constituent subsets, and each said multi-dimensional subset comprising at least two multi-dimensional subtypes each formed by a concatenation of said constituent subsets, said encoding means comprising a convolutional encoder adapted to generate from at least one said information bit a plurality of convolutionally-encoded bits that include said redundant bit, and said selection means being arranted operatively to select the subtype from which said multi-dimensional signal point is drawn based on said convolutionally-encoded bits and at least one subtype selection bit from among non-convolutionally encoded said information bits; and modulation means adapted in operation to modulate at least one carrier for transmission over said channel in accordance with the coordinates represented by each selected said multi-dimensional signal point.

Claim 23

Apparatus for transmitting a stream of information bits by sending corresponding signals over a channel in a plurality of signalling slots, the apparatus being characterised in comprising: encoding means adapted to encode the information bits that appear during a block of at least two said signalling slots by adding one or more redundant bit, to form a set of signal point selection bits for said block; selection means adapted to select, for each said set of signal point selection bits, a multi-dimensional signal point drawn from a multi-dimensional constellation for said block, said multi-dimensional signal point selected for a particular said block being dependent on the multi-dimensional signal point selected for at least one other said block; said selection means being arranged operatively to establish a correspondence between each possible combination of said signal point selection bits and the coordinates of a multi-dimensional signal point in said multi-dimensional constellation, said encoding means and said selection means being arranged operatively to define a partitioning of said multi-dimensional constellation into a plurality of multi-dimensional subsets, said multi-dimensional constellation being a concatenation of constituent constellations each of which has two dimensions and is partitioned into constituent subsets, and each said multi-dimensional subset comprising at least two multi-dimensional subtypes each formed by a concatenation of said constituent subsets, said encoding means comprising a convolutional encoder adapted to generate from at least one said information bit a plurality of convolutionally-encoded bits that include said redundant bit, and said selection means being arranted operatively to select the subtype from which said multi-dimensional signal point is drawn based on said convolutionally-encoded bits and at least one subtype selection bit from among non-convolutionally encoded said information bits; and modulation means adapted in operation to modulate at least one carrier for transmission over said channel in accordance with the coordinates represented by each selected said multi-dimensional signal point.

Claim 24

Apparatus according to Claim 20, further characterised in that said encoding means comprises a bit converter arranged operatively to translate each bit value combination of said subtype selection bit and said convolutionally-encoded bits into a plurality of groups of constituent subset selection bits; and in that said selection means is further arranged operatively to use said groups respectively to specify the constituent subsets corresponding to the multi-dimensional subtype from which said multi-dimensional signal point is drawn.

Claim 25

The apparatus of Claim 21, further characterised in being arranged such. that the number of said subtype selection bits plus the number of said convolutionally-encoded bits is the same as the aggregate number of said constituent subset selection bits in said groups.

Claim 26

Apparatus according to Claim 20, further characterised in being arranged such that said multi-dimensional signal point belonging to said subtype is selected based on the remaining said information bits.

Claim 27

Apparatus according to Claim 20, further characterised in being arranged such that said constituent constellations comprise arrangements of signal points that are ambiguous under channel-induced phase rotations of at least one particular amount; and in that said encoding means further comprises a differential encoder operatively arranged to differentially encode at least one said subtype selection bit to cause said selected multi- dimensional signal points to be susceptible to being decoded in a manner which avoids the effect of channel-induced phase rotations of any of said mounts.

Claim 28

Apparatus according to Claim 20, further characterised in being arranged such that each said constituent subset is divided into first and second groups, and the groups from which the constituent signal points of each selected multi- dimensional signal point are drawn are based upon combination selection bits from among said remaining information bits such that the group for which one said constituent signal point is drawn depends on the group from which another said constituent signal point is drawn.

Claim 29

Apparatus according to Claim 25, further characterised in that said encoding means further comprises a block encoder arranged operatively to convert said combination selection bits into a plurality of sets of group selection bits used respectively to specify said constituent groups.

Claim 30

Apparatus according to Claim 25 or 26, further characterised in being arranged such that said remaining information bits, other than said combination selection bits, are organized in a plurality of sets each used to select a constituent signal point from one of said selected constituent groups.

Claim 31

Apparatus according to any of Claims 25, 26 or 27, further characterised in being arranged such that said first and second groups of a said constituent subset can be obtained, respectively, from said first and second groups of another said constituent subset through a phase rotation corresponding to a phase ambiguity of said constituent constellation.

Claim 32

Apparatus according to Claim 28, further characterised in being arranged such that the same pattern of said combination selection bits is assigned to combinations of groups that are obtained from each other under a phase rotation corresponding to a phase ambiguity of said mutli-dimensional constellation.

Claim 33

Apparatus according to Claim 26 or any claim appendent thereto, further characterised in being arranged such that the same bit pattern of each said set of group selection bits is associated with constituent groups that are obtained from each other under a phase rotation corresponding to a phase ambiguity of said constituent constellation.

Claim 34

Apparatus according to Claim 27 or 29, further characterised in being arranged such that the same pattern of each said set of constituent signal point selection bits is associated with constituent signal points that are obtained from each other under a phase rotation corresponding to a phase ambiguity of said constituent constellation.

Claim 37

A method according to Claim 32, further characterised in that the distance between said received multidimensional signal and the nearest multi-dimensional signal point in each said multi- dimensional subset is determined on a combination of distances with respect to constituent subsets of each said multi-dimensional type within said multi- dimensional subset.

Claim 38

A method according to Claim 32, further characterised in that each said constituent constellation has more than 2 dimensions and is a concatenation of two-dimensional constellations, each said two-dimensional constellation being partitioned into two-dimensional subsets, the distances between each received two-dimensional signal and the nearest two-dimensional signal points being determined in the corresponding said two-dimensional subsets; and in that the distance between each received constituent signal and the nearest constituent signal points in said constituent subsets is determined on combinations of said distances with respect to said two-dimensional subsets corresponding to said constituent subset.

Claim 39

Apparatus for transmitting a stream of information bits by sending corresponding signals over a channel in a plurality of signalling slots, the apparatus being characterised in comprising: encoding means adapted to encode the information bits that appear during a block of at least two said signalling slots by adding one or more redundant bit, to form a set of signal point selection bits for said block; selection means adapted to select, for each said set of signal point selection bits, a multi-dimensional signal point drawn from a multi-dimensional constellation for said block, said multi-dimensional signal point selected for a particular said block being dependent on the multi-dimensional signal point selected for at least one other said block, said selection means being arranged operatively to establish a correspondence between each possible combination of said signal point selection bits and the coordinates of a multi-dimensional signal point in said multi-dimensional constellation, and said encoding means and said selection means being arranged operatively to define a partitioning of said multi-dimensional constellation into a plurality of multi-dimensional subsets comprising respectively a multi-dimensional lattice and translations of said lattice; and modulation means adapted in operation to modulate at least one carrier for transmission over said channel in accordance with the coordinates represented by each selected said multi- dimensional signal point.

Claim 40

Apparatus for transmitting a stream of information bits by sending corresponding signals over a channel in a plurality of signalling slots, the apparatus being characterised in comprising: encoding means adapted to encode the information bits that appear during a block of at least two said signalling slots by adding one or more redundant bit, to form a set of signal point selection bits for said block; selection means adapted to select, for each said set of signal point selection bits, a multi-dimensional signal point drawn from a multi-dimensional constellation for said block, said multi-dimensional signal point selected for a particular said block being dependent on the multi-dimensional signal point selected for at least one other said block, said selection means being arranged operatively to establish a correspondence between each possible combination of said signal point selection bits and the coordinates of a multi-dimensional signal point in said multi-dimensional constellation, and said encoding means and said selection means being arranged operatively to define a partitioning of said multi-dimensional constellation into a plurality of multi-dimensional subsets comprising respectively a multi-dimensional lattice and translations of said lattice; and modulation means adapted in operation to modulate at least one carrier for transmission over said channel in accordance with the coordinates represented by each selected said multi- dimensional signal point.

Claim 41

Apparatus according to Claim 35, further characterised in being arranged such that said lattice comprises a multi-dimensional constellation of the type used in a block-coded modulation system.

Claim 42

Apparatus for transmitting a stream of information bits by sending corresponding signals over a channel in a plurality of signalling slots, the apparatus being characterised in comprising: encoding means adapted to encode the information bits that appear during a block of at least two said signalling slots by adding one or more redundant bit, to form a set of signal point selection bits for said block; selection means adapted to select, for each said set of signal point selection bits, a multi-dimensional signal point drawn from a multi-dimensional constellation for said block, said multi-dimensional signal point selected for a particular said block being dependent on the multi-dimensional .signal point selected for at least one other said block; said setection means being arranged operatively to establish a correspondence between each possible combination of said signal point selection bits and the coordinates of a multi-dimensional signal point in said multi-dimensional constellation, said encoding means and said selection means being arranged operatively to define a partitioning of said multi-dimensional constellation into a plurality of multi-dimensional subsets, said multi-dimensional constellation being a concatenation of constituent constellations each of which has two dimensions, and being further arranged operatively to define a partitioning of said constituent constellations into . more than four constituent subsets; and modulation means adapted in operation to modulate at least one carrier for transmission over said channel in accordance with the coordinates represented by each selected said multi-dimensional signal point.

Claim 43

Apparatus for transmitting a stream of information bits by sending corresponding signals over a channel in a plurality of signalling slots, the apparatus being characterised in comprising: encoding means adapted to encode the information bits that appear during a block of at least two said signalling slots by adding one or more redundant bit, to form a set of signal point selection bits for said block; selection means adapted to select, for each said set of signal point selection bits, a multi-dimensional signal point drawn from a multi-dimensional constellation for said block, said multi-dimensional signal point selected for a particular said block being dependent on the multi-dimensional .signal point selected for at least one other said block; said setection means being arranged operatively to establish a correspondence between each possible combination of said signal point selection bits and the coordinates of a multi-dimensional signal point in said multi-dimensional constellation, said encoding means and said selection means being arranged operatively to define a partitioning of said multi-dimensional constellation into a plurality of multi-dimensional subsets, said multi-dimensional constellation being a concatenation of constituent constellations each of which has two dimensions, and being further arranged operatively to define a partitioning of said constituent constellations into . more than four constituent subsets; and modulation means adapted in operation to modulate at least one carrier for transmission over said channel in accordance with the coordinates represented by each selected said multi-dimensional signal point.

Claim 44

Apparatus according to any of Claims 1, 8, 20 or 37, further characterised in being arranged such that each said constituent constellation is divided into two groups.

Claim 45

Apparatus according to Claim 38, further characterised in that said encoding means and said selection means are arranged operatively to exclude from said multi-dimensional constellation some multi-dimensional signal points which are concatenations of signal points belonging to constituent constellations, said multi-dimensional signal points which are excluded being based on the groups to which said constituent signal points belong.

Claim 46

Apparatus according to Claim 39, further characterised in being arranged such that there are N said constituent constellations and the groups in each constituent constellation include a first group that has N times as many signal points as the second group.

Claim 47

Apparatus according to Claim 40, further characterised in being arranged such that said excluded multi-dimensional signal points comprise multi-dimensional signal points which correspond to more than one constituent signal point in said second groups.

Claim 48

Apparatus according to Claim 38, further characterised in being arranged such that said constituent constel lations include arrangements of signal points that are ambiguous under a channel-induced phase rotation of a particular amount, and such that each said group is invariant under a phase rotation of said particular amount.

Claim 49

Apparatus according to any of Claims 1, 8, 20, or 37, further characterised in being arranged such that each said constituent constellation is divided into two groups, and such that all of said constituent subsets for each said constituent constellation have the same numbers of constituent signal points in each said group.

Claim 50

Apparatus according to any of Claims 1, 8, 20, 35, or 37, further characterised in being arranged such that each said block spans N said signalling slots, N being a power of two, and preferably being 2, 4, or 8.

Claim 51

Apparatus according to any of Claims 1, 8, 20, or 37, further characterised in being such that said multi-dimensional constellation is a concatenation of constituent constellations including a 2N-dimensional constellation, N being a power of two.

Claim 52

Apparatus according to any of Claims 1, 8, 20, or 35, further characterised in being arranged such that the number of said multi-dimensional subsets is fewer than 4111 where 2N is the number of dimensions of said multi-dimensional constellation.

Claim 53

Apparatus according to Claim 46, further characterised in that N is 2 and there are 8 said multi-dimensional subsets.

Claim 54

Apparatus according to Claim 46, further characterised in that N is 4 and there are 16 said multi-dimensional subsets.

Claim 55

Apparatus according to Claim 46, further characterised in that N is 8 and there are 32 said multi-dimensional subsets.

Claim 56

Apparatus according to any of Claims 1, 8, 20, 35, or 37, further characterised in being arranged such that the number of said multi-dimensional subsets is fewer than 8111 where 2N is the number of dimensions of said multi-dimensional constellation.

Claim 57

Apparatus according to Claim 50, further characterised in that N is 2 and there are 32 said multi-dimensional subsets.

Claim 58

Apparatus according to any of Claims 1, 8, 20, 35, or 37, further characterised in being arranged such that the minimum distance within said multi- dimensional constellation is smaller than the minimum distance within each said multi-dimensional subset.

Claim 59

Apparatus according to any of Claims 1, 9, 20, or 37, further characterised in being arranged such that the minimum distance within each said constituent constellation is smaller than the minimum distance within each said constituent subset.

Claim 60

Apparatus according to Claim 37, further characterised in that there are 8 said constituent subsets.

Claim 61

Apparatus according to Claim 17, further characterised in that said multi-dimensional constellation has 4 dimensions and said convolutional coder has 16 states.

Claim 62

Apparatus according to Claim 12, further characterised in that said multi-dimensional constellation has 8 dimensions and said convolutional coder has 64 states.

Claim 63

Apparatus according to Claim 38, further characterised in being arranged such that one said group is divided into subgroups that are rotationally invariant under phase rotations for which said constituent constellation is invariant.

Claim 64

Apparatus according to Claim 57, further characterised in being arranged such that all of said constituent subsets for each said constituent constellation have the same numbers of constituent signal points in each said subgroup.

Claim 65

Apparatus according to any of Claims 1, 8, 20, 35, or 37, further characterised in being arranged such that said multi-dimensional subsets comprise multi-dimensional families such that the minimum distance within each said family is greater than the minimum distance within said multi-dimensional constellation, said encoding means being arranged operatively to encode said information bits on the basis of said families.

Claim 66

Apparatus according to Claim 59, further characterised in being arranged such that said multi-dimensional families comprise muIfi-dimensional subfamilies such that the minimum distance within each said subfamily is greater than the minimum distance within each said family.

Claim 67

Apparatus according to any of Claims 1, 8, 20, 35, or 37, further characterised in being arranged such that Q said information bits appear in each said signalling slot, Q being an integer, preferably 7.

Claim 68

Apparatus according to any of Claims 1, 8, 20, 35 or 37, further characterised in being arranged such that Q said information bits appear in each said signalling slot, Q being non-integral, and preferably 6⅛, 5t or 4%.

Claim 69

Apparatus according to Claims 25 or 38, further characterised in that said two groups comprise inner and outer groups operatively requiring different average powers respectively.

Claim 70

Apparatus according to any preceding claim, further characterised in that said signalling slots correspond to successive signalling intervals.

Claim 71

Apparatus according to any of Claims 1, 8, 20, or 35, further characterised in that said information bits are arranged operatively to -appear at the rate of seven per slot; in that each said block spans two said signalling slots; in that said multi-dimensional constellation has four dimensions; in that said multi-dimensional constellation is partitioned into eight multi-dimensional subsets; in that said encoding means comprises a finite-state device having 16 states; and in that said constituent constellations are two identical two-dimensional constellation each having 192 two-dimensional signal points.

Claim 72

Apparatus according to any of Claims 1, 8, 20, or 35, further characterised in that said information bits appear at the rate of seven per slot; in that each said block spans four said signalling slots; in that said multi-dimensional constellation has eight dimensions; in that said multi-dimensional constellation is partitioned into sixteen multi-dimensional subsets; in that said encoding means comprises a finite-state device having 64 states; and in that said constituent constellations are four identical two-dimensional constellations each having 160 two-dimensional signal points.

Claim 73

Apparatus according to any of Claims 1, 8, 20, 35, or 37, further characterised in that said information bits appear at the rate of seven per slot; in that each said block spans two said signalling slots; in that said multi-dimensional constellation has four dimensions; in that said multi-dimensional constellation is partitioned into 32 multi-dimensional subsets; in that said encoding means comprises a finite-state device having 64 states; and in that said constituent constellations are two identical two-dimensional constellations each having 192 two-dimensional signal points partitioned into eight subsets.

Claim 74

Apparatus according to Claims 12 and 17, further characterised in that said phase ambiguity amounts include 90°, 180°, 270°; and in that said convention coder is a linear convolutional coder.

Claim 75

Apparatus according to any of Claims 1, 8, 20, 35, or 37, further characterised in being arranged such that said constituent constellations are portions of rectangular lattices.