Communications system utilizing FSK/PSK modulation techniques
US5521602A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 10, 1994 |
| Grant date | May 28, 1996 |
| Priority date | — |
| Expiry date | Feb 10, 2014 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06K7/0008
- WIPO fieldMeasurement
- WIPO sectorInstruments
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 da…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.