Block coded modulation system

A modulation system for sending digital data over a band-limited channel in accordance with a code word corresponding to a plurality of modulation signal points drawn from a constellation of available signals, said code word being selected from an available set of said code words on the basis of a block of said digital data, the code words belonging to said available set for said block being independent of said signal points corresponding to the code word selected for any other said block, said system comprising

• an encoder for selecting said code word,
• said constellation comprising groups having equal numbers of said signals,
• said encoder being arranged so that the group from which at least one said signal point for said block is drawn depends on the group from which at least one other said signal point for said block is drawn, and
• a modulator for sending said signal points over said channel,
• said signal points being two-dimensional, said code words being 2m-dimensional, m being the number of said signal points corresponding to each said code word, each said block of said digital data comprising mN bits, N being an integer representing the number of bits of said digital data per signaling interval, m being an even integer no smaller than 2, said constellation comprising 1.5.times.2.sup.N signals.

A modulation system for sending digital data over a band-limited channel in accordance with a code word corresponding to a plurality of modulation signal points drawn from a constellation of available signals, said code word being selected from an available set of said code words on the basis of a block of said digital data, the code words belonging to said available set for said block being independent of said signal points corresponding to the code word selected for any other said block, said system comprising

• an encoder for selecting said code word,
• said constellation comprising groups having equal numbers of said signals,
• said encoder being arranged so that the group from which at least one said signal point for said block is drawn depends on the group from which at least one other said signal point for said block is drawn, and
• a modulator for sending said signal points over said channel,
• said signal points being two-dimensional, said code words being 2m-dimensional, m being the number of said signal points corresponding to each said code word, and
• wherein said encoder is further arranged so that m-1 said signal points for each said block may be drawn from amount all said signals in said constellation, and the one remaining said signal point for said block is drawn from a group that depends on the groups from which said m-1 signal points are drawn, and
• wherein said group from which said one remaining signal point is drawn depends on a single-parity-check code based on at least one of said bits.

A modulation system for sending digital data over a band-limited channel in accordance with a code word corresponding to a plurality of modulation signal points drawn from a constellation of available signals, said code word being selected from an available set of said code words on the basis of a block of said digital data, the code words belonging to said available set for said block being indepedent of said signal points corresponding to the code word selected for any other said block, said system comprising

• an encoder for selecting said code word,
• said constellation comprising groups having equal numbers of said signals,
• said encoder being arranged so that the group from which at least one said signal point for said block is drawn depends on the group from which at least one other said signal point for said block is drawn, and
• a modulator for sending said signal points over said channel,
• said signal points being two-dimensional, said code words being 2m-dimensional, m being the number of said signal points corresponding to each said code word, and
• wherein said encoder is further arranged so that m-1 said signal points for each said block may be drawn from among all said signals in said constellation, and the one remaining said signal point for said block is drawn from a group that depends on the groups from which said m-1 signal points are drawn, and
• wherein said group from which said one remaining signal point is drawn is determined by said encoder based on a state-transition trellis for said block.

A modulation system for sending digital data over a band-limited channel in accordance with a code word corresponding to a plurality of modulation signal points drawn from a constellation of available signals, said code word being selected from an available set of said code words on the basis of a block of said digital data, the code words belonging to said available set for said block being independent of said signal points corresponding to the code word selected for any other said block, said system comprising

• an encoder for selecting said code word,
• said constellation comprising groups having equal numbers of said signals, said groups each comprising subsets having equal numbers of said signals,
• said encoder being arranged so that the group and subset from which at least one said signal point for said block is drawn depends on the group and subset from which at least one other said signal point for said block is drawn, and
• a modulator for sending said signal points over said channel.

A modulation system for sending a block of digital data bits over a band-limited channel using a plurality of modulation signal points drawn from a two-dimensional constellation of available signals, said system comprising

• an encoder for selecting said signal points based on said bits,
• said constellation comprising a plurality of inner signals, and a plurality of outer signals located farther from the origin than said inner signals,
• one bit of said digital data determining whether any of said plurality of signal points will be drawn from said outer signals,
• if an outer signal will be drawn, at least one other bit of said digital data determining which of said plurality of signals points will be an outer signal point and
• a modulator for sending said signal points over said channel.