Transceiver supporting multiple modulation schemes
First Claim
1. A transceiver for use in a communications system that uses magnetic field induction to transmit data, the transceiver comprising:
- an antenna;
a transmit section including;
an amplifier for driving an antenna;
a capacitance connected in parallel with the antenna;
a resistance connected in parallel with the capacitance and the antenna, such that the antenna, capacitance and resistance form a parallel resonant circuit, wherein the value of the resistance is variable to permit adjustment of the loaded quality factor of the resonant circuit; and
a processing unit configured to determine a signal to noise ratio (SNR) of a signal received by the transceiver and to select, based on the determined SNR of the signal received by the transceiver, a modulation scheme for modulating a signal to be transmitted subsequently by the transceiver; and
a receive section, separate from the transmit section, the receive section including;
a resonant circuit comprising a variable resistance, a capacitance and a self-impedance of the antenna, the variable resistance of the receive section being implemented by inductive or capacitive degeneration.
2 Assignments
0 Petitions
Accused Products
Abstract
The present application relates to a transceiver for use in a communications system that uses magnetic field induction to transmit data, the transceiver having an amplifier for driving an antenna, the amplifier forming, with a capacitance and a resistance connected in parallel with the antenna, a parallel resonant circuit. The resistance value of the resistance is adjustable, to permit adjustment of the loaded quality factor of the parallel resonant circuit. The transceiver includes a processing unit configured to determine the signal to noise ratio (SNR) of a signal received by the transceiver, and based on this SNR select a modulation scheme to apply to a data signal to be transmitted by the transceiver. The value of the resistance is adjusted to a level at which the loaded quality factor of the parallel resonant circuit is able to support the bandwidth and data rate required by the selected modulation scheme.
23 Citations
9 Claims
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1. A transceiver for use in a communications system that uses magnetic field induction to transmit data, the transceiver comprising:
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an antenna; a transmit section including; an amplifier for driving an antenna; a capacitance connected in parallel with the antenna; a resistance connected in parallel with the capacitance and the antenna, such that the antenna, capacitance and resistance form a parallel resonant circuit, wherein the value of the resistance is variable to permit adjustment of the loaded quality factor of the resonant circuit; and a processing unit configured to determine a signal to noise ratio (SNR) of a signal received by the transceiver and to select, based on the determined SNR of the signal received by the transceiver, a modulation scheme for modulating a signal to be transmitted subsequently by the transceiver; and a receive section, separate from the transmit section, the receive section including; a resonant circuit comprising a variable resistance, a capacitance and a self-impedance of the antenna, the variable resistance of the receive section being implemented by inductive or capacitive degeneration. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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Specification