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 the present disclosure, there is provided methods of processing a signal using quantized symbols. More particularly, in one example, the method comprises the steps of processing a signal (206), said method comprising the steps of: receiving a signal (206) comprising a plurality of raw symbols, each raw symbol having a plurality of bits and being conveyed in a channel; estimating a channel state information value (206) of the channel used to convey each raw symbol to generate a corresponding plurality of channel state information values; quantizing the plurality of raw symbols based on their channel state information values to generate a sequence of quantized symbols (214); and quantizing the channel state information values to generate a sequence of quantized channel state values (216).

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: According to the present disclosure, there is provided methods of processing a signal using quantized symbols. More particularly, in one example, the method comprises the steps of processing a signal (206), said method comprising the steps of: receiving a signal (206) comprising a plurality of raw symbols, each raw symbol having a plurality of bits and being conveyed in a channel; estimating a channel state information value (206) of the channel used to convey each raw symbol to generate a corresponding plurality of channel state information values; quantizing the plurality of raw symbols based on their channel state information values to generate a sequence of quantized symbols (214); and quantizing the channel state information values to generate a sequence of quantized channel state values (216).

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: 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: Among other subject matter, storage architectures are provided that store data reliably in connection with a system. The storage architecture (14) includes a first data reliability facility (32), and a second data reliability facility (34), where the second data reliability facility (34) is encoded compliant with the first data reliability facility (32). The storage architecture (14) of this example embodiment also includes a first storage medium (20), the first storage medium (20) storing the second data reliability facility (34).

Abstract: A relay, for use in an indoor multi-carrier radio frequency wireless communications system, stores multiple predetermined phase adjustment profiles. The best of the stored phase adjustment profiles is selected by a receiver, which sends a message to the relay, indicating the profile to be used. The selected stored phase adjustment profiles is then applied to a multi-carrier signal received at the relay, to form a phase adjusted multi-carrier signal, and this phase adjusted signal is then transmitted from the relay.

Abstract: The present invention relates to an encoding apparatus and method for encoding a user data stream (m) into a channel data stream (y) as well as to a corresponding decoding apparatus and method.

Abstract: When processing a two dimensional data area it is known to be advantageous to divide the two dimensional are into stripes and process each stripe using a stripe-wise detector. The stripe being processed shifts row per row downwards. Each stripe has as its output the bit-decisions of the top bit-row of the stripe which is the most reliable. That output bit-row is also used as side-information for the bit detection of the next stripe which is the stripe which is shifted one bit-row downwards. The bit-row just across the bottom of the stripe on the other hand still needs to be determined in the current iteration, so only the initialisation bit-values can be used in the first iteration of the stripe-wise bit-detector. In order to prevent the propagation of errors towards the top bit row of the stripe the relative weight for the bottom branch bit in the figure-of-merit is reduced from the full 100% to a lower fraction.

Abstract: When performing bit detection on a 2 dimensional recording, for instance a broad spiral, the detection of the bit rows of the broad spiral becomes very complex. In order to reduce this complexity the detection is performed on subsets of adjacent rows. Together detection of all the subsets result in a detection that covers the width of the broad spiral. Instead of performing the detection sequentially with a single detector, multiple detectors are used where each detector uses side information as obtained from the adjacent detector. The side information improves the reliability of the detection and links the detection of the subsets to arrive at the detection over the full width of the broad spiral.

Abstract: When processing a two dimensional data area it is known to be advantageous to divide the two dimensional are into stripes and process each stripe using a stripe-wise detector. When processing a data area delimited by more than one guard band it is advantageous to start a subset of bit detectors from each guard band in order to propagate the improved reliability of the side information obtained from the guard band through the subset of detectors. Because the subsets can start processing at the same time the overall detection delay is reduced.

Abstract: When processing a two dimensional data area it is known to be advantageous to divide the two dimensional are into stripes and process each stripe using a stripe-wise detector. When using several iterations it is advantageous to use higher complexity detectors in later iterations and lower complexity detectors in the initial iterations.