Coding and decoding system for wireless telecommunication

• US 20020125995A1
• Filed: 03/06/2001
• Published: 09/12/2002
• Est. Priority Date: 03/06/2001
• Status: Active Grant

• Current Assignee: Kohji Toda
• Original Assignee: Kohji Toda
• Inventors: Toda, Kohji
• Granted Patent: US 6,693,509 B2
• Time in Patent Office: Days
• US Class Current: 340/5.64
• CPC Class Codes: H03H 9/6406 Filters characterised by a particular frequency characteristic
• CPC Class Codes: H04W 12/12 Detection or prevention of fraud
• CPC Class Codes: H04W 12/122 Counter-measures against attacks; Protection against rogue devices

Abstract

A coding and decoding system for wireless telecommunication comprises a wireless telecommunication device and a personal card. The wireless telecommunication device consists of a first piezoelectric substrate, a coded IDT, a first electrode-group, a first amplifier, an antenna, a second amplifier, a second electrode-group, a first intermediary IDT, and a signal analyzer. The personal card attached to the wireless telecommunication device consists of a second piezoelectric substrate, a personal coded IDT, a third electrode-group, a second intermediary IDT. The coding and decoding system for wireless telecommunication has four sections, that is, (1) a personal transmitting section composed of the second piezoelectric substrate, the personal coded IDT, the third electrode-group, the first amplifier, and the antenna; (2) a main transmitting section composed of the first piezoelectric substrate, the coded IDT, the first electrode-group, the first amplifier, and the antenna; (3) a personal receiving section composed of the antenna, the second amplifier, the first piezoelectric substrate, the second electrode-group, the second piezoelectric substrate, the second intermediary IDT, the personal coded IDT, and the signal analyzer; and (4) a main receiving section composed of the antenna, the second amplifier, the first piezoelectric substrate, the second electrode-group, the first intermediary IDT, the coded IDT, and the signal analyzer.

Claims

1. A coding and decoding system for wireless telecommunication comprising:

a wireless telecommunication device consisting of

a first piezoelectric substrate,

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

a first amplifier,

an antenna,

a second amplifier,

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

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

a first intermediary IDT,

a signal analyzer; and

a personal card consisting of

a second piezoelectric substrate,

a personal coded IDT including said interdigital electrode pairs P_i, and having a personal coded pattern,

a third electrode-group consisting of an interdigital electrode C₀ and an interdigital electrode C_i (i=1) at said distance iL (i=1) from said interdigital electrode C₀, and

a second intermediary IDT,

said second piezoelectric substrate, said personal coded IDT, said third electrode-group, said first amplifier, and said antenna constructing a personal transmitting section, in which

said personal coded IDT receiving a pulse, and exciting a personal coded SAW on said second piezoelectric substrate,

said interdigital electrode C₀ detecting a personal coded burst-signal corresponding to said personal coded pattern,

said interdigital electrode C₁ detecting said personal coded burst-signal after a time corresponding to said distance iL, said personal coded burst-signals at said interdigital electrodes C₀ and C₁ forming a personal double-coded burst-signal,

said antenna emitting said personal double-coded burst-signal via said first amplifier;

said first piezoelectric substrate, said coded IDT, said first electrode-group, said first amplifier, and said antenna constructing a main transmitting section, in which

said coded IDT receiving a transmitting-message digital-signal, and exciting a coded SAW on said first piezoelectric substrate,

said interdigital electrode A₀ detecting a coded burst-signal corresponding to said coded pattern of said input coded IDT,

said interdigital electrode A, detecting said coded burst-signal after a time corresponding to said distance iL, said coded burst-signals at said interdigital electrodes A₀ and A₁ forming a double-coded burst-signal,

said antenna emitting said double-coded burst-signal via said first amplifier;

said antenna, said second amplifier, said first piezoelectric substrate, said second electrode-group, said second piezoelectric substrate, said second intermediary IDT, said personal coded IDT, and said signal analyzer constructing a personal receiving section, in which

said antenna receiving a private double-coded burst-signal,

said right interdigital electrode B<sub>−

1</sub> and said left interdigital electrode B_i receiving said private double-coded burst-signal via said second amplifier, respectively, and exciting first- and second SAWs on said first piezoelectric substrate, respectively,

said central interdigital electrode B₀ detecting a private mono-coded burst-signal made from said first- and second SAWs,

said second intermediary IDT receiving said private mono-coded burst-signal, and exciting a private mono-coded SAW along the reverse direction to said personal coded SAW on said second piezoelectric substrate,

said personal coded IDT detecting a private decoded pulse if said private mono-coded SAW correlates to said personal coded pattern,

said signal analyzer receiving said private decoded pulse;

said antenna, said second amplifier, said first piezoelectric substrate, said second electrode-group, said first intermediary IDT, said coded IDT, and said signal analyzer constructing a main receiving section, in which

said antenna receiving a receiving-message double-coded burst-signal,

said right interdigital electrode B<sub>−

1</sub> and said left interdigital electrode B_i receiving said receiving-message double-coded burst-signal via said second amplifier, respectively, and exciting third- and fourth SAWs on said first piezoelectric substrate, respectively,

said central interdigital electrode B₀ detecting a mono-coded burst-signal made from said third- and fourth SAWs,

said first intermediary IDT receiving said mono-coded burst-signal, and exciting a mono-coded SAW along the reverse direction to said coded SAW on said first piezoelectric substrate,

said coded IDT detecting a decoded pulse if said mono-coded SAW correlates to said coded pattern,

said signal analyzer receiving said decoded pulse.

2. A coding and decoding system for wireless telecommunication as defined in claim 1, wherein said coded IDT consists of at least three interdigital electrode pairs.

3. A coding and decoding system for wireless telecommunication as defined in claim 1, wherein said personal coded IDT comprises a row of multiple times four blocks, of which at least one has the same construction as said coded IDT and all the others have no-electrode-pair constructions with the same outward size as said coded IDT.

4. A coding and decoding system for wireless telecommunication as defined in claim 1, wherein

said first electrode-group includes at least two interdigital electrodes A₁ {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 left 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, and

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

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

1)}, respectively, from said interdigital electrode C₀.

5. A coding and decoding system for wireless telecommunication comprising:

a wireless telecommunication device consisting of

a first piezoelectric substrate,

a bipolar-pulse generator

a first coded IDT consisting of interdigital electrode pairs P_i (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 interdigital electrode pairs P_i (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,

a first amplifier,

an antenna,

a second amplifier,

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

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

a first intermediary IDT,

a signal analyzer; and

a personal card consisting of

a second piezoelectric substrate,

a personal coded IDT consisting of said interdigital electrode pairs P_i (i=1, 2, . . . , n), and having a personal coded pattern,

a third electrode-group consisting of an interdigital electrode C₀ and an interdigital electrode C_i (i=1) at said distance iL (i=1) from said interdigital electrode C₀, and

a second intermediary IDT,

said second piezoelectric substrate, said personal coded IDT, said third electrode-group, said first amplifier, and said antenna constructing a personal transmitting section, in which

said personal coded IDT receiving a pulse, and exciting a personal coded SAW on said second piezoelectric substrate,

said interdigital electrode C₀ detecting a personal coded burst-signal corresponding to said personal coded pattern,

said interdigital electrode C_i detecting said personal coded burst-signal after a time corresponding to said distance iL, said personal coded burst-signals at said interdigital electrodes C₀ and C_i forming a personal double-coded burst-signal,

said antenna emitting said personal double-coded burst-signal via said first amplifier;

said first piezoelectric substrate, said bipolar-pulse generator, said first- and second coded IDTs, said first electrode-group, said first amplifier, and said antenna constructing a main transmitting section, in which

said bipolar-pulse generator generating bipolar pulses (−

1 and

     1) that form a transmitting-message digital-signal,

said first- and second coded IDTs receiving said bipolar pulses (−

1 and

     1), and exciting first- and second coded SAWs on said first piezoelectric substrate, respectively,

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

said interdigital electrode A_i detecting said coded burst-signal after a time corresponding to said distance iL, said coded burst-signals at said interdigital electrodes A₀ and A_i forming a double-coded burst-signal,

said antenna emitting said double-coded burst-signal via said first amplifier;

said antenna, said second amplifier, said first piezoelectric substrate, said second electrode-group, said second piezoelectric substrate, said second intermediary IDT, said personal coded IDT, and said signal analyzer constructing a personal receiving section, in which

said antenna receiving a private double-coded burst-signal,

said right interdigital electrode B<sub>−

1</sub> and said left interdigital electrode B_i receiving said private double-coded burst-signal via said second amplifier, respectively, and exciting first- and second SAWs on said first piezoelectric substrate, respectively,

said central interdigital electrode B₀ detecting a private mono-coded burst-signal made from said first- and second SAWs,

said second intermediary IDT receiving said private mono-coded burst-signal, and exciting a private mono-coded SAW along the reverse direction to said personal coded SAW on said second piezoelectric substrate,

said personal coded IDT detecting a private decoded pulse if said private mono-coded SAW correlates to said personal coded pattern,

said signal analyzer receiving said private decoded pulse;

said antenna, said second amplifier, said first piezoelectric substrate, said second electrode-group, said first intermediary IDT, said first- and second coded IDTs, and said signal analyzer constructing a main receiving section, in which

said antenna receiving a receiving-message double-coded burst-signal,

said right interdigital electrode B<sub>−

1</sub> and said left interdigital electrode B_i receiving said receiving-message double-coded burst-signal via said second amplifier, respectively, and exciting third- and fourth SAWs on said first piezoelectric substrate, respectively,

said central interdigital electrode B₀ detecting a mono-coded burst-signal made from said third- and fourth SAWs,

said first intermediary IDT receiving said mono-coded burst-signal, and exciting a mono-coded SAW along the reverse direction to said first- and second coded SAWs on said first piezoelectric substrate,

said first- and second coded IDTs detecting first- and second decoded pulses if said mono-coded SAW correlates to said first- and second coded patterns, respectively,

said signal analyzer receiving said first- and second decoded pulses.

6. A coding and decoding system for wireless telecommunication as defined in claim 5, wherein said first- and second coded IDTs consist of at least three interdigital electrode pairs, respectively.

7. A coding and decoding system for wireless telecommunication as defined in claim 5, wherein said personal coded IDT comprises a row of multiple times four blocks, of which each has the same construction as one of said first- and second coded IDTs.

8. A coding and decoding system for wireless telecommunication as defined in claim 5, 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 left 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, and

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

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

1)}, respectively, from said interdigital electrode C₀.