Transmitting and receiving system for digital communication on electric power-lines

• US 6,674,806 B1
• Filed: 09/19/2000
• Issued: 01/06/2004
• Est. Priority Date: 09/19/2000
• Status: Expired due to Fees

• Current Assignee: Kohji Toda
• Original Assignee: Kohji Toda
• Inventors: Toda, Kohji
• Primary Examiner(s): Vo, Don N.
• Application Number:
  US09/666,004
• Time in Patent Office: 1,204 Days
• Field of Search: 375/259, 375/257, 375/258, 340/310.01, 340/310.03, 340/310.06, 340/310.07
• US Class Current: 375/259
• CPC Class Codes: H04B 2203/5412 by modofying wave form of the power source
• CPC Class Codes: H04B 2203/5483 using coupling circuits
• CPC Class Codes: H04B 3/54 Systems for transmission via power distribution lines

Abstract

A transmitting and receiving system for digital communication on electric power-lines comprises a transmitting device and a receiving device. The transmitting device consists of an input terminal, a bipolar-pulse generator, a first piezoelectric substrate, first- and second coded IDTs, a first intermediary IDT, an electrode group, a synchronizing device, an envelope detecting device, a monopolar-pulse generator, and a mixer connected with electric power-lines. The receiving device consists of a receiving connector connected with the electric power-lines, a tuning coil, a second piezoelectric substrate, a second intermediary IDT, third- and fourth coded IDTs, a detecting device, and a detecting terminal. If a message digital-signal is applied to the bipolar-pulse generator via the input terminal, high-frequency bipolar-pulses (−1 and 1) are generated, and after all, are transduced to first- and second coded digital-signals at the monopolar-pulse generator. The first- and second coded digital-signals are delivered into the electric power-lines via the mixer. On the other hand, if the first coded digital-signal is received at the receiving connector, the first coded digital-signal is applied to the second intermediary IDT via the tuning coil. The first coded digital-signal is, after all, transduced to a first decoded pulse at the third coded IDT. In the same way, the second coded digital-signal is transduced to a second decoded pulse at the fourth coded IDT. As a result, an output digital-signal, which is composed of the first- and second decoded pulses and is equivalent to the message digital-signal, is detected at the detecting terminal via the detecting device.

Claims

1. A transmitting and receiving system for digital communication on electric power-lines comprising:

a transmitting device consisting of

an input terminal,

a bipolar-pulse generator,

a first piezoelectric substrate,

a first coded IDT consisting of at least three interdigital electrode pairs, and having a first coded pattern,

a second coded IDT consisting of at least three interdigital electrode pairs, and having a second coded pattern,

a first intermediary IDT,

an electrode group consisting of two sideward IDTs and a central IDT between said sideward IDTs,

a synchronizing device connected between said first intermediary IDT and one of said sideward IDTs,

an envelope detecting device connected with said central IDT,

a monopolar-pulse generator, and

a mixer connected with electric power-lines; and

a receiving device consisting of

a receiving connector connected with said electric power-lines,

a tuning coil,

a second piezoelectric substrate,

a second intermediary IDT,

a third coded IDT having a third coded pattern in reverse to said first coded pattern,

a fourth coded IDT having a fourth coded pattern in reverse to said second coded pattern,

a detecting device, and

a detecting terminal,

said bipolar-pulse generator receiving monopolar pulses of a message digital-signal via said input terminal, and transducing said monopolar pulses to bipolar pulses (−

1 and

     1),

said first- and second coded IDTs exciting first- and second SAWs, respectively, on said first piezoelectric substrate when receiving said bipolar pulses (−

1 and

     1), respectively,

said first intermediary IDT detecting a coded burst-signal corresponding to said first- and second coded patterns, respectively,

said synchronizing device generating a synchronizing pulse-signal,

said one of said sideward IDTs receiving said coded burst-signal and said synchronizing pulse-signal, and exciting a third SAW on said first piezoelectric substrate,

the other of said sideward IDTs receiving said coded burst-signal at the same time that said one of said sideward IDTs receives said coded burst-signal, and exciting a fourth SAW on said first piezoelectric substrate,

said central IDT receiving said third- and fourth SAWs simultaneously,

said monopolar-pulse generator causing a coded digital-signal via said envelope detecting device, and then, delivering said coded digital-signal into said electric power-lines via said mixer,

said receiving connector receiving said coded digital-signal from said electric power-lines,

said second intermediary IDT exciting a fifth SAW on said second piezoelectric substrate, when receiving said coded digital signal via said tuning coil,

said third- and fourth coded IDTs detecting two decoded pulses, respectively, if said fifth SAW corresponds to said third- and fourth coded patterns, respectively,

said detecting device delivering an output digital-signal, which is based on said two decoded pulses and is equivalent to said message digital-signal, via said detecting terminal.

2. A transmitting and receiving system for digital communication on electric power-lines as defined in claim 1, wherein said first-, second-, third-, and fourth coded patterns are changed in accordance with a designated time region, respectively.

3. A transmitting and receiving system for digital communication on electric power-lines as defined in claim 1, wherein the propagation direction of said first- and second SAWs is orthogonal to that of said third- and fourth SAWs.

4. A transmitting and receiving system for digital communication on electric power-lines as defined in claim 1, wherein said first- and second piezoelectric substrates are made of a piezoelectric ceramic plate, respectively, the polarization axis thereof being parallel to the thickness direction thereof.

5. A transmitting and receiving system for digital communication on electric power-lines as defined in claim 1 further comprising a subdevice, which is located between said tuning coil and said second intermediary IDT and consists of a third piezoelectric substrate, an input IDT, an output IDT located in parallel with said input IDT, an envelope detecting device, and a bipolar-pulse generator,

said input IDT receiving said coded digital-signal via said tuning coil, and exciting a SAW on said third piezoelectric substrate,

said output IDT detecting a coded row of bursts,

said envelope detecting device of said subdevice causing a coded row of digital-pulses,

said bipolar-pulse generator of said subdevice generating a coded row of high-frequency bipolar-pulses, and

said second intermediary IDT receiving said coded row of high-frequency bipolar-pulses.

6. A transmitting and receiving system for digital communication on electric power-lines as defined in claim 1 further comprising a bipolar-pulse generator in place of said monopolar-pulse generator.

7. A transmitting and receiving system for digital communication on electric power-lines comprising:

a transmitting device consisting of

an input terminal,

a first bipolar-pulse generator,

a first piezoelectric substrate,

a first coded IDT consisting of at least three interdigital electrode pairs Pi (i=1, 2, . . . , n), of which two neighbors are at a distance L from each other, and having a first coded pattern,

a second coded IDT consisting of at least three interdigital electrode pairs Pi (i=1, 2, . . . , n), of which two neighbors are at a distance L from each other, and having a second coded pattern,

a first electrode-group consisting of an interdigital electrode A₀ and an interdigital electrode A_i (i=1) at a distance iL (i=1) from said interdigital electrode A₀,

an envelope detecting device connected with said first electrode-group,

a monopolar-pulse generator, and

a mixer connected with electric power-lines; and

a receiving device consisting of

a receiving connector connected with said electric power-lines,

a tuning coil,

a second piezoelectric substrate,

a second electrode-group consisting of a central interdigital electrode B₀, a left interdigital electrode B<sub>−

1</sub> at a distance L₀ from said central interdigital electrode B₀, and an interdigital electrode B_i (i=1) at a distance L₀+iL (i=1) from said central interdigital electrode B₀,

a second bipolar-pulse generator,

an intermediary IDT,

a third coded IDT having a third coded pattern in reverse to said first coded pattern,

a fourth coded IDT having a fourth coded pattern in reverse to said second coded pattern,

a detecting device, and

a detecting terminal,

said bipolar-pulse generator receiving monopolar pulses of a message digital-signal via said input terminal, and transducing said monopolar pulses to bipolar pulses (−

1 and

     1),

said first- and second coded IDTs exciting first- and second SAWs, respectively, on said first piezoelectric substrate when receiving said bipolar pulses (−

1 and

     1), respectively,

said interdigital electrode A₀ detecting a coded burst-signal corresponding to said first- and second coded patterns, respectively,

said interdigital electrode A_i detecting said coded burst-signal after a time corresponding to said distance iL,

said monopolar-pulse generator causing a double-coded digital-signal from said coded burst-signal at said interdigital electrode A₀ and that at said interdigital electrode A_i, via said envelope detecting device, and delivering said double-coded digital-signal into said electric power-lines via said mixer,

said receiving connector receiving said double-coded digital-signal from said electric power-lines,

said left interdigital electrode B<sub>−

1</sub> and said right interdigital electrode B_i exciting third- and fourth SAWs, respectively, on said second piezoelectric substrate when receiving said double-coded digital-signal,

said second bipolar-pulse generator causing a monocoded digital-signal from said third- and fourth SAWs via said central interdigital electrode B₀,

said intermediary IDT exciting a fifth SAW on said second piezoelectric substrate when receiving said monocoded digital-signal,

said third- and fourth coded IDTs detecting two decoded pulses, respectively, if said fifth SAW corresponds to said third- and fourth coded patterns, respectively,

said detecting device delivering an output digital-signal, which is based on said two decoded pulses and is equivalent to said message digital-signal, via said detecting terminal.

8. A transmitting and receiving system for digital communication on electric power-lines as defined in claim 7, wherein said first-, second-, third-, and fourth coded patterns are changed in accordance with a designated time region, respectively.

9. A transmitting and receiving system for digital communication on electric power-lines as defined in claim 7, wherein the propagation direction of said third- and fourth SAWs is orthogonal to that of said fifth SAW.

10. A transmitting and receiving system for digital communication on electric power-lines as defined in claim 7, wherein said first- and second piezoelectric substrates are made of a piezoelectric ceramic plate, respectively, the polarization axis thereof being parallel to the thickness direction thereof.

11. A transmitting and receiving system for digital communication on electric power-lines as defined in claim 7 further comprising a third bipolar-pulse generator in place of said monopolar-pulse generator.

12. A transmitting and receiving system for digital communication on electric power-lines as defined in claim 7, wherein

said first electrode-group includes at least two interdigital electrodes A_i {i=1, 2, . . . , (n− 1)} at a distance iL {i=1, 2, . . . , (n−

1)}, respectively, from said interdigital electrode A₀,

said second electrode-group includes at least two right interdigital electrodes B_i {i=1, 2, . . . , (n−

1)} at a distance L₀+iL {i=1, 2, . . . , (n−

1)}, respectively, from said central interdigital electrode B₀,

said at least two interdigital electrodes A_i take turns in connecting with said envelope detecting device, and at the same time,

said at least two right interdigital electrodes B_i take turns in connecting with said receiving connector.