Method of and system for power line carrier communications

Claim 1

A system for wideband transmission of data on an electricity distribution network, comprising: at least one transmitter including means for generating encoded signals corresponding respectively to logical-one bits and logical-zero bits, each encoded signal corresponding to a logical-one bit consisting of a first predetermined, unrelated sequence of frequencies and each encoded signal corresponding to a logical-zero bit consisting of a second, different predetermined and unrelated sequence of frequencies; means for coupling said encoded signals on said electricity distribution network; and at least one receiver having means for receiving from said at least one transmitter, input encoded signals on said electricity distribution network, and a homodyne, non-coherent demodulator including (a) first demodulator means having first and second channels for demodulating said logical-one bit signals, said first demodulator means comprising, (i) in said first channel, a first local signal generator means for providing a first reference signal that is a replica of said encoded logical-one bit signal, first multiplier means for forming a product of said input encoded signal and said first reference signal, first filter means coupled to an output of said first multiplier means for passing substantially only a first dc component therefrom, and first squaring means for squaring said first dc component, and (ii) in said second channel, a second local signal generator means for providing a second reference signal that is, in quadrature, a replica of said encoded logical-one bit signal, second multiplier means for forming a product of said input encoded signal and said second reference signal, second filter means coupled to an output of said second multiplier means for passing substantially only a second dc component therefrom, second squaring means for squaring said second dc component; first summer means for summing outputs of said first and second squaring means and first integrator means for accumulating from said first summer means first output signals corresponding to said first sequence of frequencies, (b) second demodulator means having third and fourth channels for demodulating said logical-zero bit signals, said third demodulator means comprising, (i) in said third channel, a third local signal generator means for providing a third reference signal that is a replica of said encoded logical-zero bit signal, third multiplier means for forming a product of said input encoded signal and said third reference signal, third filter means coupled to an output of said third multiplier means for passing substantially only a third dc component therefrom, and third squaring means for squaring said third dc component, and (ii) in said fourth channel, a fourth local signal generator means for providing a fourth reference signal that is, in quadrature, a replica of said encoded logical-zero bit signal, fourth multiplier means for forming a product of said input encoded signal and said fourth reference signal, fourth filter means coupled to an output of said fourth multiplier means for passing substantially only a fourth dc component therefrom; fourth squaring means for squaring said fourth dc component; second summer means for summing outputs of said third and fourth squaring means and second integrator means for accumulating from said second summer means second output signals corresponding to said second sequence of frequencies, and (c) comparator means for comparing output signals from said first and second integrator means for indicating a logical-one or logical-zero bit.

Claim 2

A system for wideband transmission of data on an electricity distribution network, comprising: at least one transmitter including means for generating encoded signals corresponding respectively to logical-one bits and logical-zero bits, each encoded signal corresponding to a logical-one bit consisting of a first predetermined, unrelated sequence of frequencies and each encoded signal corresponding to a logical-zero bit consisting of a second, different predetermined and unrelated sequence of frequencies; means for coupling said encoded signals on said electricity distribution network; and at least one receiver having means for receiving from said at least one transmitter, input encoded signals on said electricity distribution network, and a homodyne, non-coherent demodulator including (a) first demodulator means having first and second channels for demodulating said logical-one bit signals, said first demodulator means comprising, (i) in said first channel, a first local signal generator means for providing a first reference signal that is a replica of said encoded logical-one bit signal, first multiplier means for forming a product of said input encoded signal and said first reference signal, first filter means coupled to an output of said first multiplier means for passing substantially only a first dc component therefrom, and first squaring means for squaring said first dc component, and (ii) in said second channel, a second local signal generator means for providing a second reference signal that is, in quadrature, a replica of said encoded logical-one bit signal, second multiplier means for forming a product of said input encoded signal and said second reference signal, second filter means coupled to an output of said second multiplier means for passing substantially only a second dc component therefrom, second squaring means for squaring said second dc component; first summer means for summing outputs of said first and second squaring means and first integrator means for accumulating from said first summer means first output signals corresponding to said first sequence of frequencies, (b) second demodulator means having third and fourth channels for demodulating said logical-zero bit signals, said third demodulator means comprising, (i) in said third channel, a third local signal generator means for providing a third reference signal that is a replica of said encoded logical-zero bit signal, third multiplier means for forming a product of said input encoded signal and said third reference signal, third filter means coupled to an output of said third multiplier means for passing substantially only a third dc component therefrom, and third squaring means for squaring said third dc component, and (ii) in said fourth channel, a fourth local signal generator means for providing a fourth reference signal that is, in quadrature, a replica of said encoded logical-zero bit signal, fourth multiplier means for forming a product of said input encoded signal and said fourth reference signal, fourth filter means coupled to an output of said fourth multiplier means for passing substantially only a fourth dc component therefrom; fourth squaring means for squaring said fourth dc component; second summer means for summing outputs of said third and fourth squaring means and second integrator means for accumulating from said second summer means second output signals corresponding to said second sequence of frequencies, and (c) comparator means for comparing output signals from said first and second integrator means for indicating a logical-one or logical-zero bit.

Claim 14

A method of wideband transmission of data on an electricity distribution network, comprising the steps of: generating encoded signals corresponding respectively to logical-one bits and logical-zero bits, each encoded signal corresponding to a logical-one bit consisting of a first predetermined, unrelated sequence of frequencies and each encoded signal corresponding to a logical-zero bit consisting of a second, different predetermined, unrelated sequence of frequencies; coupling said encoded signals on said electricity distribution network; and receiving input encoded signals on said electricity distribution network, said step of receiving including the steps of (a) establishing first and second frequency channels for demodulating said logical-one bit signals and third and fourth channels for demodulating said logical-zero bit signals; (b) in said first channel, providing a first reference signal that is a replica of said encoded logical-one bit signal, forming a first product signal that is a product of said input encoded signal and said first reference signal, filtering said first product signal for passing substantially only a first dc component thereof and squaring said first dc component to obtain a first output signal; (c) in said second channel, providing a second local signal that is, in quadrature, a replica of said encoded logical-one bit signal, forming a second product signal that is a product of said input encoded signal and said second reference signal, filtering said second product signal for passing substantially only a second dc component thereof and squaring said second dc component to obtain a second output signal; (d) in said third channel, providing a third reference signal that is a replica of said encoded logical-zero bit signal, forming a third product of said input encoded signal and said third reference signal, filtering said third product signal for passing substantially only a third dc component thereof and squaring said third dc component to obtain a third output signal; and (e) in said fourth channel, providing a fourth reference signal that is, in quadrature, a replica of said encoded logical-zero bit signal, forming a fourth product of said input encoded signal and said fourth reference signal, filtering said fourth product signal for passing substantially only a fourth dc component thereof and squaring said fourth dc component to obtain a fourth output signal; (f) summing said first and second output signals to obtain a first summed output signal corresponding to said first sequence of frequencies; (g) summing said third and fourth output signals to obtain a second summed output signal corresponding to said second sequence of frequencies; (h) integrating said first summed signal to obtain a first integrated output signal; (i) integrating said second summed signal to obtain a second integrated output signal; and (j) comparing said first and second integrated output signals for indicating a logical-one or logical-zero bit.

Claim 15

A method of wideband transmission of data on an electricity distribution network, comprising the steps of: generating encoded signals corresponding respectively to logical-one bits and logical-zero bits, each encoded signal corresponding to a logical-one bit consisting of a first predetermined, unrelated sequence of frequencies and each encoded signal corresponding to a logical-zero bit consisting of a second, different predetermined, unrelated sequence of frequencies; coupling said encoded signals on said electricity distribution network; and receiving input encoded signals on said electricity distribution network, said step of receiving including the steps of (a) establishing first and second frequency channels for demodulating said logical-one bit signals and third and fourth channels for demodulating said logical-zero bit signals; (b) in said first channel, providing a first reference signal that is a replica of said encoded logical-one bit signal, forming a first product signal that is a product of said input encoded signal and said first reference signal, filtering said first product signal for passing substantially only a first dc component thereof and squaring said first dc component to obtain a first output signal; (c) in said second channel, providing a second local signal that is, in quadrature, a replica of said encoded logical-one bit signal, forming a second product signal that is a product of said input encoded signal and said second reference signal, filtering said second product signal for passing substantially only a second dc component thereof and squaring said second dc component to obtain a second output signal; (d) in said third channel, providing a third reference signal that is a replica of said encoded logical-zero bit signal, forming a third product of said input encoded signal and said third reference signal, filtering said third product signal for passing substantially only a third dc component thereof and squaring said third dc component to obtain a third output signal; and (e) in said fourth channel, providing a fourth reference signal that is, in quadrature, a replica of said encoded logical-zero bit signal, forming a fourth product of said input encoded signal and said fourth reference signal, filtering said fourth product signal for passing substantially only a fourth dc component thereof and squaring said fourth dc component to obtain a fourth output signal; (f) summing said first and second output signals to obtain a first summed output signal corresponding to said first sequence of frequencies; (g) summing said third and fourth output signals to obtain a second summed output signal corresponding to said second sequence of frequencies; (h) integrating said first summed signal to obtain a first integrated output signal; (i) integrating said second summed signal to obtain a second integrated output signal; and (j) comparing said first and second integrated output signals for indicating a logical-one or logical-zero bit.

Claim 25

A system for wideband transmission of data on an electricity distribution network, comprising: at least one transmitter including means for generating encoded signals corresponding respectively to logical-one bits and logical-zero bits, each encoded signal corresponding to a logical-one bit consisting of a first predetermined, unrelated sequence of frequencies and each encoded signal corresponding to a logical-zero bit consisting of a second, different predetermined, unrelated sequence of frequencies; means for coupling said encoded signals on said electricity distribution network; at least one receiver having means for receiving from said at least one transmitter, input encoded signals on said electricity distribution network, and a homodyne demodulator including first demodulator means in a first frequency channel means for converting said logical-one bit signals into corresponding first dc signals, second demodulator means in a second frequency channel means for converting said logical-zero signals into corresponding second dc signals; offset compensation means coupled to said receiver for compensating any error voltage developed by said receiver as a result of offset voltage produced by components of said receiver; and comparator means for comparing output signals from said first and second channel means for indicating a logical-one or logical-zero bit.

Claim 26

A system for wideband transmission of data on an electricity distribution network, comprising: at least one transmitter including means for generating encoded signals corresponding respectively to logical-one bits and logical-zero bits, each encoded signal corresponding to a logical-one bit consisting of a first predetermined, unrelated sequence of frequencies and each encoded signal corresponding to a logical-zero bit consisting of a second, different predetermined, unrelated sequence of frequencies; means for coupling said encoded signals on said electricity distribution network; at least one receiver having means for receiving from said at least one transmitter, input encoded signals on said electricity distribution network, and a homodyne demodulator including first demodulator means in a first frequency channel means for converting said logical-one bit signals into corresponding first dc signals, second demodulator means in a second frequency channel means for converting said logical-zero signals into corresponding second dc signals; offset compensation means coupled to said receiver for compensating any error voltage developed by said receiver as a result of offset voltage produced by components of said receiver; and comparator means for comparing output signals from said first and second channel means for indicating a logical-one or logical-zero bit.