Method of allocating digital data coming from transponders and a reader thereto
First Claim
1. A method of allocating digital data coming from transponders, comprising the steps of:
- receiving at a reader a first signal that comprises a first signal component coming from a first transponder and a second signal component coming from a second transponder during a same time slot in which the first and second transponders respond to an inventory command from the reader at different time points, wherein digital data coming from the first transponder are encoded in the first signal component and digital data coming from the second transponder are encoded in the second signal component;
generating second and third signals by subjecting the first signal to an in-phase and to an in-quadrature demodulation; and
allocating clusters of the digital data associated with a constellation diagram, which is related to the second and third signals, to the first and second transponders, wherein a first pair of the clusters is only related to the first transponder, a second pair of the clusters is only related to the second transponder, the centers of gravity of the first pair of the clusters are symmetric to the origin of the constellation diagram, and the centers of gravity of the second pair of the clusters are symmetric to the origin of the constellation diagram.
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Accused Products
Abstract
In a method of allocating digital data (55a, 55b) coming from transponders, a reader (1) receives a first signal (13) that comprises a first signal component (7) coming from a first transponder (2) and a second signal component (8) coming from a second transponder (3). The digital data (55a) coming from the first transponder (2) are encoded in the first signal component (7) and digital data (55b) coming from the second transponder (3) are encoded in the second signal component (8). Second and third signals (10, 11) are generated by subjecting the first signal (13) to an in-phase and to an in-quadrature demodulation. The digital data (55a, 55b) of the first and second transponders (2, 3) are encoded in the second and third signals (10, 11). Clusters (51-54) of the digital data (55 a, 55b) associated with a constellation diagram, which is related to the second and third signals (10, 11), are allocated to the first and second transponder (2, 3).
15 Citations
12 Claims
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1. A method of allocating digital data coming from transponders, comprising the steps of:
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receiving at a reader a first signal that comprises a first signal component coming from a first transponder and a second signal component coming from a second transponder during a same time slot in which the first and second transponders respond to an inventory command from the reader at different time points, wherein digital data coming from the first transponder are encoded in the first signal component and digital data coming from the second transponder are encoded in the second signal component; generating second and third signals by subjecting the first signal to an in-phase and to an in-quadrature demodulation; and allocating clusters of the digital data associated with a constellation diagram, which is related to the second and third signals, to the first and second transponders, wherein a first pair of the clusters is only related to the first transponder, a second pair of the clusters is only related to the second transponder, the centers of gravity of the first pair of the clusters are symmetric to the origin of the constellation diagram, and the centers of gravity of the second pair of the clusters are symmetric to the origin of the constellation diagram. - View Dependent Claims (2, 3, 4, 9, 10)
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5. A reader configured to communicate with a plurality of transponders, comprising:
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a receiver configured to receive a first signal that comprises a first signal component coming from a first transponder and a second signal component coming from a second transponder during a same time slot in which the first and second transponders respond to an inventory command from the reader at different time points, wherein digital data coming from the first transponder are encoded in the first signal component and digital data coming from the second transponder are encoded in the second signal component; and an IQ-demodulator configured to generate second and third signals by subjecting the first signal to an in-phase and to an in-quadrature demodulation; wherein the reader is configured to allocate clusters of the digital data associated with a constellation diagram, which is related to the second and third signals, to the first and second transponders, wherein a first pair of the clusters is only related to the first transponder, a second pair of the clusters is only related to the second transponder, the centers of gravity of the first pair of the clusters are symmetric to the origin of the constellation diagram, and the centers of gravity of the second pair of the clusters are symmetric to the origin of the constellation diagram. - View Dependent Claims (6, 7, 8, 11, 12)
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Specification