Asynchronus communication system for remote monitoring of objects or an environment
First Claim
1. A transponder comprising:
- a clock generator that generates a transmit clock based on an interrogation signal;
a code generator that generates an n-bit spreading code from a unique set of at least two spreading codes allocated to the transponder from among a plurality of available spreading codes using the transmit clock, wherein the code generator inputs a set of address bits and a set of data bits from a storage device and generates the n-bit spreading code based on the set of address bits and the set of data bits, wherein the unique set of at least two spreading codes are allocated to the transponder based on transponder identification information; and
a signal generator that transmits a transponder signal that includes the n-bit spreading code, the transponder signal having a transmit frequency determined by the transmit clock.
1 Assignment
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Accused Products
Abstract
A system provides for remote monitoring using asynchronous code division multiple access (CDMA) communication techniques between a base station and one or more transponders. Each transponder is attached or otherwise associated with an object or an environment to be monitored. Upon receipt of an interrogation signal, a transponder generates and transmits a coded transponder signal containing the monitored data. The coded transponder signal is generated using a spreading code. Each transponder is associated with a unique, mutually exclusive set of spreading codes. Each spreading code is based on a unique transponder address and the monitored data to be sent. A detector asynchronously monitors received signals for any of the available spreading codes. Once the detector detects a particular spreading code, the base station can identify the source transponder and extract the monitored data.
29 Citations
53 Claims
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1. A transponder comprising:
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a clock generator that generates a transmit clock based on an interrogation signal; a code generator that generates an n-bit spreading code from a unique set of at least two spreading codes allocated to the transponder from among a plurality of available spreading codes using the transmit clock, wherein the code generator inputs a set of address bits and a set of data bits from a storage device and generates the n-bit spreading code based on the set of address bits and the set of data bits, wherein the unique set of at least two spreading codes are allocated to the transponder based on transponder identification information; and a signal generator that transmits a transponder signal that includes the n-bit spreading code, the transponder signal having a transmit frequency determined by the transmit clock. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 17, 18, 19, 20, 21, 22, 23, 24)
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16. A system, comprising:
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a set of one or more transponders, wherein each of the transponders comprises; a clock generator that generates a transmit clock based on an interrogation signal; a code generator that generates an n-bit spreading code from a unique set of at least two spreading codes allocated to the transponder from among a plurality of available spreading codes using the transmit clock, wherein the code generator inputs a set of address bits and a set of data bits from a storage device and generates the n-bit spreading code based on the set of address bits and the set of data bits, wherein the set of at least two spreading codes are allocated to the transponder based on transponder identification information; a signal generator that transmits a transponder signal that includes the n-bit spreading code, the transponder signal having a transmit frequency determined by the transmit clock; and a detector that receives transponder signals transmitted by the one or more transponders and examines the received transponder signals to detect presence of one or more spreading codes. - View Dependent Claims (25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37)
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38. A system, comprising:
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an interrogator that sends an interrogation signal; a set of one or more transponders, each of which is allocated a unique set of at least two spreading codes from a plurality of spreading codes, and each of which transmits a transponder signal containing an n-bit spreading code from among the allocated spreading codes in response to the interrogation signal, each transponder including a code generator that inputs a set of address bits and a set of data bits from a storage device and generates the n-bit spreading code based on the set of address bits and the set of data bits, wherein the set of at least two spreading codes are allocated to each of the one or more transponders based on transponder identification information; and a detector that asynchronously examines received signals to detect presence of one or more of the plurality of spreading codes. - View Dependent Claims (39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49)
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50. A transponder comprising:
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a clock generator that receives an interrogation signal having an interrogation frequency and generates therefrom a transmit clock having a transmit frequency that is a defined fraction of the interrogation frequency; a code generator that generates an n-bit spreading code from transponder identification information and monitored data information, wherein the code generator inputs a set of address bits and a set of data bits from a storage device and generates the n-bit spreading code based on the set of address bits and the set of data bits, wherein the n-bit spreading code is generated from a unique set of at least two spreading codes allocated to the transponder based on the transponder identification information; and a signal generator that transmits, at the transmit frequency, a transponder signal that includes the n-bit spreading code. - View Dependent Claims (51, 52, 53)
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Specification