Locating a backscatter-based transponder
First Claim
Patent Images
1. A method comprising:
- receiving, by a transponder, a locating command for locating the transponder;
in response to receiving the locating command, transmitting, by the transponder, in a persistent operating state, a locating signal for locating the transponder;
comparing, by an impedance control device coupled to a memory and a counter, a counter state of the counter with a counter value stored in the memory;
in response to determining that the counter state matches the stored counter value, changing, by the impedance control device, a state of a modulation signal, such that a phase of the locating signal is changed;
in the persistent operating state, receiving, by the transponder, a switch-off command while simultaneously transmitting, without an interruption for receiving the switch-off command, the locating signal; and
discontinuing transmission of the locating signal in response to one or more of;
receiving the switch-off command; and
an expiration of a pre-determined period of time.
19 Assignments
0 Petitions
Accused Products
Abstract
A method and apparatus for locating a transponder is provided. A carrier signal is transmitted by a base station and a transponder transmits a locating signal that is generated through phase modulation and backscattering of the carrier signal sent by the base station when the transponder is within a transmission range of the base station, whereby the transponder is located on the basis of the locating signal.
-
Citations
24 Claims
-
1. A method comprising:
-
receiving, by a transponder, a locating command for locating the transponder; in response to receiving the locating command, transmitting, by the transponder, in a persistent operating state, a locating signal for locating the transponder; comparing, by an impedance control device coupled to a memory and a counter, a counter state of the counter with a counter value stored in the memory; in response to determining that the counter state matches the stored counter value, changing, by the impedance control device, a state of a modulation signal, such that a phase of the locating signal is changed; in the persistent operating state, receiving, by the transponder, a switch-off command while simultaneously transmitting, without an interruption for receiving the switch-off command, the locating signal; and discontinuing transmission of the locating signal in response to one or more of; receiving the switch-off command; and an expiration of a pre-determined period of time. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
-
-
10. An apparatus comprising:
-
means for receiving a locating command for locating a transponder; means for transmitting, in a persistent operating state, a locating signal for locating the transponder in response to receiving the locating command, comparing, by an impedance control device coupled to a memory and a counter, a counter state of the counter with a counter value stored in the memory, in response to determining that the counter state matches the stored counter value, changing, by the impedance control device, a state of a modulation signal, such that a phase of the locating signal is changed, and, in the persistent operating state, receiving a switch-off command while simultaneously transmitting, without an interruption for receiving the switch-off command, the locating signal; and means for discontinuing transmission of the locating signal in response to one or more of; receiving the switch-off command; and an expiration of a pre-determined period of time. - View Dependent Claims (11, 12, 13, 14, 15, 16)
-
-
17. An apparatus comprising:
-
a memory; and circuitry configured to perform operations comprising; receiving, by a transponder, a locating command for locating the transponder; in response to receiving the locating command, transmitting, in a persistent operating state, a locating signal for locating the transponder; comparing, by an impedance control device coupled to the memory and a counter, a counter state of the counter with a counter value stored in the memory; in response to determining that the counter state matches the stored counter value, changing, by the impedance control device, a state of a modulation signal, such that a phase of the locating signal is changed; in the persistent operating state, receiving, by the transponder, a switch-off command while simultaneously transmitting, without an interruption for receiving the switch-off command, the locating signal; and discontinuing transmission of the locating signal in response to one or more of; receiving the switch-off command; and an expiration of a pre-determined period of time. - View Dependent Claims (18, 19, 20, 21, 22, 23, 24)
-
Specification