Abstract: Various exemplary embodiments relate to a method of communicating by a transmitter. Embodiments of the method may include creating information to be used by a receiver to define a spreading sequence for a subsequent packet, coding the information into a current communications packet, and transmitting the current communications packet.

Abstract: According to an aspect of the invention a localization method for localizing a host device (100) in a control system, in particular a building control system, is provided, the localization method comprising determining geographical location information of the host device (100) by means of a localization device (102) and associating the geographical location information with a unique identifier of the host device (100). According to another aspect of the invention a computer program product is provided that comprises program instructions which, when being executed by one or more processing units, cause said processing units to carry out or control the steps of the inventive localization method. According to another aspect of the invention, a localization device (102), in particular a portable localization device is provided for use in the inventive localization method.

Abstract: According to a first aspect of the present disclosure, a signal processing system is provided, comprising: a receiving unit configured to receive at least one signal that comprises a plurality of multipath components; a verification unit configured to correlate at least one multipath component under test with a reference signal derived from one or more of said plurality of multipath components. According to a second aspect of the present disclosure, a corresponding signal processing method is conceived. According to a third aspect of the present disclosure, a corresponding computer program is provided.

Abstract: A receiver, including: a tuner receiving an input signal; a signal processor configured to process the input signal; an automatic gain control (AGC) controller configured to: initialize the receiver in a low gain state; determine the presence of a signal; and increase the receiver gain to determine if a weak signal is present prior to a strong signal.

Abstract: According to a first aspect of the present disclosure, a signal processing system is provided, comprising: a receiving unit configured to receive at least one signal that comprises a plurality of multipath components; a verification unit configured to correlate at least one multipath component under test with a reference signal derived from one or more of said plurality of multipath components. According to a second aspect of the present disclosure, a corresponding signal processing method is conceived. According to a third aspect of the present disclosure, a corresponding computer program is provided.

Abstract: Distance-based authentication is provided for mitigating undesirable interaction and/or attacks upon ranging systems, such as those involving vehicle entry or secure payment. As may be implemented in accordance with one or more embodiments, a leading edge of one or more pulses in a waveform of a signal is obscured as part of distance-based authentication. For instance, noise may be generated via a noise modulation circuit and combined with some or all of a leading edge of a pulse. Distance-based authentication is provided by transmitting a signal with a waveform having the obscured portion of the leading edge, which operates to mitigate detection of the polarity of the leading edge or otherwise of the leading edge itself.

Abstract: A receiver for receiving an input signal is disclosed. The receiver includes a processor, a memory, a plurality of sub-receivers configured to receive a plurality of versions of the input signal through a plurality of transmission channels, a sub-receiver selection module configured to select one more of the plurality of sub-receivers using expected contributions to signal-to-noise (SNR) of an output signal based on an uncertainty of the estimated contributions. The receiver also includes a combiner to combine outputs of the selected sub-receivers to produce the output signal.

Abstract: A receiver for receiving an input signal is disclosed. The receiver includes a processor, a memory, a plurality of sub-receivers configured to receive a plurality of versions of the input signal through a plurality of transmission channels, a sub-receiver selection module configured to select one more of the plurality of sub-receivers using expected contributions to signal-to-noise (SNR) of an output signal based on an uncertainty of the estimated contributions. The receiver also includes a combiner to combine outputs of the selected sub-receivers to produce the output signal.

Abstract: Using a clock circuit, a clock signal is generated at a base frequency. A frequency adjustment circuit selects, based upon a frequency offset value, a particular frequency adjustment value from a plurality of frequency adjustment values. An adjusted clock signal is provided that has a frequency corresponding to the base frequency as modified by the particular frequency adjustment value. Wireless communication signals are received at a wireless communication circuit. From the communication signals, a set of received wireless communication pulses are identified that have a pulse repetition frequency that corresponds to the adjusted clock signal. A distance ranging protocol is applied, using a processing circuit, to the identified set of received communication pulses.

Abstract: Various exemplary embodiments relate to a method of communicating by a transmitter. Embodiments of the method may include creating information to be used by a receiver to define a spreading sequence for a subsequent packet, coding the information into a current communications packet, and transmitting the current communications packet.

Abstract: Using a clock circuit, a clock signal is generated at a base frequency. A frequency adjustment circuit selects, based upon a frequency offset value, a particular frequency adjustment value from a plurality of frequency adjustment values. An adjusted clock signal is provided that has a frequency corresponding to the base frequency as modified by the particular frequency adjustment value. Wireless communication signals are received at a wireless communication circuit. From the communication signals, a set of received wireless communication pulses are identified that have a pulse repetition frequency that corresponds to the adjusted clock signal. A distance ranging protocol is applied, using a processing circuit, to the identified set of received communication pulses.

Abstract: Distance-based authentication is provided for mitigating undesirable interaction and/or attacks upon ranging systems, such as those involving vehicle entry or secure payment. As may be implemented in accordance with one or more embodiments, a leading edge of one or more pulses in a waveform of a signal is obscured as part of distance-based authentication. For instance, noise may be generated via a noise modulation circuit and combined with some or all of a leading edge of a pulse. Distance-based authentication is provided by transmitting a signal with a waveform having the obscured portion of the leading edge, which operates to mitigate detection of the polarity of the leading edge or otherwise of the leading edge itself.

Abstract: Aspects of the present disclosure provide communications between local and remote devices having low-frequency (LF) and high-frequency (HF) circuits. As may be implemented in accordance with one or more embodiments, the local device transmits an LF signal to the remote device, which synchronizes its clock based on the LF signal. Another LF signal is communicated from the local device to the remote device using a reduced quality factor, which can be implemented to facilitate synchronization. The clock is resynchronized based on the second LF signal and used to transmit an HF signal with a time delay. The local device synchronizes its clock based on the HF signal, and transmits another HF signal to the remote device using the clock and another time delay. The remote device re-synchronizes its clock based on the second HF signal while accounting for a trip time for communicating the first and/or second HF signals.

Abstract: Various exemplary embodiments relate to a device for performing a method of communication transmission. The device may include a memory; a processor configured to: determine a spreading code with low sidelobe levels in its autocorrelation sequence to be used; create a Start of Frame Delimiter (SOFD) for a packet including the spreading code and a cyclic prefix, wherein the cyclic prefix is a portion of the spreading code; and transmit the packet with the SOFD.

Abstract: Aspects of the present disclosure provide communications between local and remote devices having low-frequency (LF) and high-frequency (HF) circuits. As may be implemented in accordance with one or more embodiments, the local device transmits an LF signal to the remote device, which synchronizes its clock based on the LF signal. Another LF signal is communicated from the local device to the remote device using a reduced quality factor, which can be implemented to facilitate synchronization. The clock is resynchronized based on the second LF signal and used to transmit an HF signal with a time delay. The local device synchronizes its clock based on the HF signal, and transmits another HF signal to the remote device using the clock and another time delay. The remote device re-synchronizes its clock based on the second HF signal while accounting for a trip time for communicating the first and/or second HF signals.

Abstract: A receiver, including: a tuner receiving an input signal; a signal processor configured to process the input signal; an automatic gain control (AGC) controller configured to: initialize the receiver in a low gain state; determine the presence of a signal; and increase the receiver gain to determine if a weak signal is present prior to a strong signal.

Abstract: Aspects of the present disclosure are directed to communications between devices. As consistent with one or more embodiments, a local device has a first clock, a low-frequency (LF) transmitter and a high-frequency (HF) transceiver. A remote device includes a second clock, a LF receiver and a HF transceiver. An LF signal is transmitted from the local device to the remote device and used to synchronize the second clock. The first clock is synchronized based on an HF signal transmitted to the local device using the synchronized second clock and a first predetermined time delay relative to receipt of the LF signal. The second clock is re-synchronized based on a second HF signal transmitted to the remote device using the first clock and a second predetermined time delay relative to receipt of the first HF signal, while accounting for a trip time for communicating one or both of the HF signals.

Abstract: Aspects of the preset disclosure are directed to processing an analog signal transmitted during active portions of a duty cycle. As may be implemented in accordance with one or more embodiments, an apparatus includes a high-speed sampling circuit that samples portions of such an analog signal at a first rate corresponding to the active portion of the duty cycle, and stores the sampled portions of the analog signal. A low-speed analog-to-digital converter accesses the stored sampled portions and converts the sampled portions to a digital form at a second rate that is slower than the first rate.

Abstract: A passive keyless system including a base that selectively allows access to a restricted environment through a base transceiver operating with an encrypted link on first and second frequencies, and a base recording element storing base measured movement history information. Also, a passive keyless device with at least one sensor detects a movement property of the device, a device recording element stores movement history information about the device and reflecting the detected movement property, and a device transceiver communicating with the base transceiver, and transmitting to the base transceiver encrypted security information identifying the device in accordance with a passive keyless protocol and/or the movement history information, and an access request element that causes the device transceiver to request access to the base transceiver. The base uses the base measured movement history information and movement history information when allowing access to the restricted environment.

Abstract: A passive keyless system including a base that selectively allows access to a restricted environment through a base transceiver operating with an encrypted link on first and second frequencies, and a base recording element storing base measured movement history information. Also, a passive keyless device with at least one sensor detects a movement property of the device, a device recording element stores movement history information about the device and reflecting the detected movement property, and a device transceiver communicating with the base transceiver, and transmitting to the base transceiver encrypted security information identifying the device in accordance with a passive keyless protocol and/or the movement history information, and an access request element that causes the device transceiver to request access to the base transceiver. The base uses the base measured movement history information and movement history information when allowing access to the restricted environment.