END OF COMMUNICATION DETECTION

• US 20150372787A1
• Filed: 08/31/2015
• Published: 12/24/2015
• Est. Priority Date: 12/20/2013
• Status: Active Grant

• Current Assignee: NXP B.V. (NXP Semiconductors NV)
• Original Assignee: NXP B.V. (NXP Semiconductors NV)
• Inventors: van de Beek, Remco, Ciacci, Massimo, Al-kadi, Ghiath
• Granted Patent: US 9,686,041 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G06K 19/067 Record carriers with conductive marks, printed circuits or semiconductor circuit elements, e.g. credit or identity cards also with resonating or responding marks without active components
• CPC Class Codes: H04B 5/266 One coil at each side, e.g. with primary and secondary coils
• CPC Class Codes: H04B 5/72 for local intradevice communication
• CPC Class Codes: H04B 5/77 for interrogation
• CPC Class Codes: H04L 1/0039 other detection of signalling, e.g. detection of TFCI explicit signalling H04L1/0046, H04L27/0012 and H04L25/0262 take precedence
• CPC Class Codes: H04L 2027/0036 using a recovered symbol clock
• CPC Class Codes: H04L 2027/0057 quadrature phase
• CPC Class Codes: H04L 2027/0095 in a preamble or similar structure
• CPC Class Codes: H04L 27/22 Demodulator circuits; Receiver circuits
• CPC Class Codes: H04L 27/227 using coherent demodulation
• CPC Class Codes: H04L 27/2271 wherein the carrier recovery circuit uses only the demodulated signals
• CPC Class Codes: H04L 27/2272 using phase locked loops H04L27/2273 takes precedence
• CPC Class Codes: H04L 27/2273 associated with quadrature demodulation, e.g. Costas loop
• CPC Class Codes: H04L 5/001 the frequencies being arranged in component carriers
• CPC Class Codes: H04L 7/041 using special codes as synchronising signal
• CPC Class Codes: H04L 7/042 Detectors therefor, e.g. correlators, state machines digital correlators in general G06F17/15

Abstract

An apparatus for detecting the end of a communication is disclosed. The apparatus includes an interface circuit for receiving an encoded signal and a carrier signal recovery circuit coupled to an output of the interface circuit. The carrier signal recovery circuit is configured to output a carrier signal of the encoded signal and a second signal that is out of phase with the carrier signal. The apparatus also includes a decoding circuit configured to decode the encoded signal as a function of both the encoded signal and the carrier signal output by the carrier signal recovery circuit. The apparatus also includes a detection circuit configured to detect an indication of an end of a communication in the encoded signal as a function of both the encoded signal and the second signal.

Claims

1. An apparatus, comprising:

an interface circuit for receiving an encoded signal;

a carrier signal recovery circuit coupled to an output of the interface circuit and configured and arranged to

determine and output a carrier signal of the encoded signal, and

generate and output a second signal that is out of phase with the carrier signal;

a decoding circuit, coupled to the output of the interface circuit and to the carrier signal recovery circuit, configured and arranged to decode the encoded signal as a function of the encoded signal and the carrier signal output by the carrier signal recovery circuit; and

a detection circuit, coupled to the output of the interface circuit and to the carrier signal recovery circuit, configured and arranged to detect an indication of an end of a communication in the encoded signal as a function of the encoded signal and the second signal.