Communications system utilizing FSK/PSK modulation techniques
First Claim
1. A communications system for reading data from and writing data to an RF transponder by means of an RF controller comprising:
- a microcomputer associated with said controller for formulating a first digital message;
an antenna drive circuit associated with said controller and controlled by said microcomputer for FSK modulating an RF signal by said first digital message to produce an FSK signal;
a first antenna associated with said controller and coupled to said antenna drive circuit for transmitting said FSK modulated RF signal to said transponder;
a second antenna associated with said transponder for receiving said FSK signal;
an FSK detector circuit associated with said transponder and coupled to said second antenna for detecting said first digital message from said FSK signal;
a control logic circuit associated with said transponder and responsive to said first digital message for controlling transponder functions;
a memory array associated with said transponder and responsive to said control logic circuit and said FSK detector circuit for selectively reading data from or writing data to said memory array in accordance with said first digital message;
a data encoder circuit coupled to said memory array for generating a second digital message;
a PSK modulator coupled to said data encoder circuit and said second antenna for PSK modulating and transmitting an RF signal to said controller in accordance with said second digital message; and
a PSK signal data recovery circuit associated with said controller and coupled to said first antenna and said microcomputer for decoding said second digital message from said PSK signal and supplying said second digital message to said microcomputer.
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Accused Products
Abstract
A passive transponder incorporating non-volatile ferroelectric memory is powered by inductive coupling to a proximately located controller. A communication system and method utilizes the controller to send data and commands to the transponder by an FSK modulated RF signal in order to cause the transponder to either read selected data from, or write selected data to, the non-volatile memory and transmit the same back to the controller utilizing PSK RF modulation. The communication system and method operates either full duplex or half duplex with the controller causing the transponder to simultaneously write data to its non-volatile memory as the memory is read out and transmitted to the controller thereof. Features of the invention include, signal transmission between the controller and transponder occur concurrently; the controller'"'"'s FSK signal is modulated between 125 KHz and 116.3 KHz; the transponder'"'"'s PSK signal is 62.5 KHz; the controller formulates a digital message that includes the address of information stored in the transponder, synchronization bits, and command bits; the controller'"'"'s digital message is detected by the transponder and causes the transponder to read its data information and then transmit a signal back to the controller that is modulated with the data information; the controller'"'"'s digital message includes a complement signal that is transmitted coincident with each bit of the transponder'"'"'s data information to be changed; and the controller'"'"'s digital message includes a memory address whereby blocks of transponder data information are read, beginning with this address.
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Citations
41 Claims
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1. A communications system for reading data from and writing data to an RF transponder by means of an RF controller comprising:
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a microcomputer associated with said controller for formulating a first digital message; an antenna drive circuit associated with said controller and controlled by said microcomputer for FSK modulating an RF signal by said first digital message to produce an FSK signal; a first antenna associated with said controller and coupled to said antenna drive circuit for transmitting said FSK modulated RF signal to said transponder; a second antenna associated with said transponder for receiving said FSK signal; an FSK detector circuit associated with said transponder and coupled to said second antenna for detecting said first digital message from said FSK signal; a control logic circuit associated with said transponder and responsive to said first digital message for controlling transponder functions; a memory array associated with said transponder and responsive to said control logic circuit and said FSK detector circuit for selectively reading data from or writing data to said memory array in accordance with said first digital message; a data encoder circuit coupled to said memory array for generating a second digital message; a PSK modulator coupled to said data encoder circuit and said second antenna for PSK modulating and transmitting an RF signal to said controller in accordance with said second digital message; and a PSK signal data recovery circuit associated with said controller and coupled to said first antenna and said microcomputer for decoding said second digital message from said PSK signal and supplying said second digital message to said microcomputer. - View Dependent Claims (2, 3, 4, 5, 6)
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7. A method for communicating between an RF controller and an associated RF transponder comprising the steps of:
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formulating a first digital message at said controller; FSK modulating an RF signal with said first digital message to produce an FSK signal at said controller; transmitting said FSK signal to said transponder from said controller; receiving said FSK signal at said transponder; formulating a second digital message at said transponder in response to said FSK signal; PSK modulating an RF signal with said second digital message to produce a PSK signal at said transponder; transmitting said PSK signal to said controller from said transponder; receiving said PSK signal at said controller; and detecting said second digital message from said PSK signal at said controller. - View Dependent Claims (8, 9, 10, 11, 12, 13, 14, 15, 16, 17)
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18. A method for communication between an active RF controller and an associated passive RF transponder comprising the steps of:
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transmitting a first RF signal from said controller to a predetermined radius therefrom, said first RF signal being FSK modulated with a digital data signal; placing said transponder within said predetermined radius from said controller; receiving said first RF signal at said transponder; deriving a power source for said transponder from said received first RF signal; reading configuration information stored in said transponder; and transmitting a second RF signal from said transponder to said controller, said second RF signal being PSK modulated with said configuration information. - View Dependent Claims (19, 20, 21, 22, 23, 24, 25, 26)
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27. A method for writing data to a transponder from a controller that is located remotely from said transponder comprising the steps of:
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transmitting a first RF signal from said controller to said transponder, said first RF signal being FSK modulated with a digital data signal; receiving said first RF signal at said transponder; demodulating said received first RF signal at said transponder to derive said digital data signal; retrieving selected data information at said transponder in response to said demodulated digital data signal; transmitting a second RF signal from said transponder to said controller, said second RF signal being PSK modulated with said selected data information, and deriving a power source for said transponder from said first RF signal. - View Dependent Claims (28, 29, 30, 31)
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32. A method for communicating data between a controller and a transponder comprising the steps of:
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repeatedly transmitting a configuration signal from said transponder to said controller, said configuration signal including a first plurality of synchronization data bits; receiving said configuration signal at said controller; identifying said configuration signal inclusive of said synchronization data bits at said controller; synchronously transmitting a command signal from said controller to said transponder, said command signal including a second plurality of synchronization data bits coincident with said first plurality of synchronization data bits, and said command signal further including a number of command data bits; receiving said command signal at said transponder; identifying said command signal inclusive of said command data bits at said transponder; reading a selected portion of a memory array at said transponder in response to said command data bits; alternatively transmitting a data signal from said transponder to said controller, said data signal including a data bit stream representing said selected portion that is read from said memory array; receiving said data signal at said controller; and identifying said data signal inclusive of said data bit stream at said controller. - View Dependent Claims (33, 34, 35, 36, 37, 38, 39, 40, 41)
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Specification