The disclosure relates to an apparatus configured to: receive, from a device, a response signal to an activation signal over a channel; generate a first vector in a time domain including samples of the response signal; perform a transformation of the first vector in the time domain to obtain a second vector y.sub.i in a frequency domain including pilot symbols and data symbols; estimate a channel response H.sub.i of the channel based on the pilot symbols; equalize the data symbols based on the channel response H.sub.i; determine a waveform of the response signal, from among a plurality of waveforms the apparatus is configurable to handle, based on configuration information; and process the equalized data symbols based on the determined waveform.

A device may obtain an input symbol sequence for transmission. The device may further obtain a set of DPS sequences associated with N.sub.i highest eigenvalues of a Slepian matrix and a set of extended sequences comprising the set of DPS sequences appended with extension symbols derived based on a convolution of respective DPS sequences. The device may modulate the set of extended sequences based on the input symbol sequence to generate a signal comprising Slepian-based waveform symbol(s). Another device may receive the signal, remove the extension symbols, and demodulate Slepian-based waveform symbol(s) of the signal based on the set of DPS sequences.

A system and method perform channel sounding for modeling ultrawideband RF channels. The method includes modulating an ultrawideband RF signal with a sounding waveform including streaming data with conforming sounding symbols including no gaps and having zero signal phase at the boundaries; receiving, digitizing and performing digital down conversion of the ultrawideband RF signal to obtain a baseband digitized signal that includes the streaming data; converting the streaming data into packets based on a notional start time, where each packet is formed of at least two consecutive conforming sounding symbols; performing coherent averaging of the packets; determining an equalized CFR and an equalized CIR for each coherently averaged packet; modeling an ultrawideband RF channel or sub-band of the ultrawideband RF channel using the equalized CIR and/or the equalized CFR, and converting the modeled ultrawideband RF channel or sub-band into a sparse tap-delay channel model for each coherently averaged packet.

A method and device for filtering-based channel estimation. A method comprises configuring a filter design with a stopband region between at least two bandpass regions in a time domain associated with channel behavior, suppressing, via the filter design, multi-user interference (MUI) or orthogonal cover code (OCC) interference in the time domain, and providing frequency domain-based channel estimation (CE) based on the filter design.

Systems and methods of assessing a plausibility of a ranging measurement are provided. In some embodiments, a method of assessing a plausibility of a ranging measurement includes: obtaining the ranging measurement from a remote device; obtaining one or more measurements associated with the ranging measurement; and based on the one or more measurements associated with the ranging measurement, determining the plausibility of the ranging measurement. The embodiments disclosed herein determine the reliability of the measured range and thus enforce the security 10 level of Ultra-WideBand (UWB) transactions to be secured. Some embodiments are based on existing and standardized metrics. Some embodiments include a capability to auto-assess whether it is reliable to estimate the plausibility of the transaction range. In some embodiments, the computations needed are relatively simple and can be performed by relatively simple devices.

The present application discloses a wireless sensing method, a communication device and a storage medium. The method includes: building a real-time state machine model for a sensing object; and determining an environmental state of the sensing object based on the real-time state machine model.

A method for use in a wireless communication system comprising a transmitter and a receiver, the method comprising receiving, in the receiver, data comprising a plurality of channel-distorted synchronization codes and plurality of channel-distorted cipher codes, generating a receiver cipher sequence, the receiver cipher sequence comprising a plurality of receiver cipher codes, analyzing the received data to identify correlations between the plurality of channel-distorted cipher codes in the received data and the plurality of receiver cipher codes, accumulating the identified correlations as accumulator data in an accumulator, identifying one or more peaks in the accumulator data, identifying a first correlation peak in the accumulator data that meets one or more criteria and using the first correlation peak to identify the first path of a data packet from the transmitter.

This invention relates to methods and systems for determining whether a reference point in a location system has changed using the entropy of channel impulse responses. In one embodiment a method of determining whether the location of a first one of a plurality of reference points used in a location system has changed is provided. The reference points each have a known initial position and the method includes the steps of: estimating a channel impulse response of a wireless channel between the first reference point and a second of said plurality of reference points; determining the difference between the estimated channel impulse response and a previously-estimated channel impulse response of the wireless channel; estimating an entropy of the difference between the channel impulse responses; and determining, from said comparison, whether the location of the first reference point has changed. In another embodiment the method includes the steps of: estimating an entropy of the channel impulse response of a wireless channel between the first reference point and a second of said plurality of reference points; comparing the estimated entropy to a previously-estimated entropy for the channel impulse response of the wireless channel; determining, from said comparison, whether the location of the first reference point has changed.

The present invention relates to a method and apparatus for detecting the type of signal propagation, the method comprising: calculating a plurality of similarity values when a location base station in an ultra-wideband location system currently receives a pulse response from a location tag, wherein each of the similarity values represents the degree of similarity between the currently received pulse response and one of a plurality of reference pulse responses, and the plurality of reference pulse responses are pulse responses from at least one location tag that were previously received by the location base station where the type of signal propagation between the location base station and the at least one location tag is a specific type of signal propagation; and determining, based on the plurality of similarity values, a current type of signal propagation between the location base station and the location tag. The method and apparatus can be used to detect the type of signal propagation between the location base station and the location tag in the UWB location system.

A method is provided for generating a corrected channel impulse response (CIR) estimate by a receiver of a ultra-wideband (UWB) device. The method includes, computing a correction matrix based on a sequence of chips, a number of the chips being N; receiving a pulse signal corresponding to the sequence of chips, the pulse signal being a multi-path propagated signal corresponding to a non-zero chip in the sequence of chips; determining a CIR estimate for the pulse signal; and computing the corrected CIR estimate for the pulse signal based on the correction matrix and the CIR estimate.