Abstract: Example embodiments relate to methods for estimating a location of at least one mobile network node and respective network. An example method for estimating a location of at least one mobile network node of a wireless communication network including the at least one mobile network node and at least two static network nodes includes performing initial range measurements between the at least two static network nodes in a pairwise manner. The method also includes determining an initial location estimate. Additionally, the method includes determining an estimate for corresponding noise samples. Further, the method includes estimating corresponding initial parameters of a Gaussian mixture noise model. In addition, the method includes determining a weighted sum of respective refined parameters of the Gaussian mixture noise model and the corresponding initial parameters of the Gaussian mixture noise model.

Abstract: A method for automatic multi-object localization and/or vital sign monitoring is provided. The method comprises the steps of receiving a radar signal in order to form a corresponding observation matrix, reducing noise by applying singular value decomposition to the observation matrix, processing the result of the singular value decomposition by an independent component analysis in order to estimate the corresponding sources, and estimating propagation channels of the estimated sources by minimizing the corresponding residual error based on the observation matrix and the estimated sources.

Abstract: Example embodiments relate to methods for distance determination. One embodiment includes a method for determining a distance between a first radio signal transceiver and a second radio signal transceiver. The method includes receiving a first set and a second set of measurement results. The first set is acquired by the first radio signal transceiver based on signals transmitted from the second radio signal transceiver and the second set is acquired by the second radio signal transceiver based on signals transmitted from the first radio signal transceiver. The first set is representable as including, for each of a plurality of frequencies, a measurement pair. The method also includes calculating, for each frequency of the plurality of frequencies, a preliminary estimate of a value proportional to a one-way frequency domain channel response. Additionally, the method includes determining a final estimate of the value proportional to the one-way frequency domain channel response.

Abstract: A system is provided for performing secure key exchange between a plurality of nodes of a communication network. The system comprises a master node and at least two slave nodes. In this context, the master node is configured to authenticate the at least two slave nodes with a pair-wise authentication key corresponding to each pair of master node and slave nodes. The master node is further configured to generate a group authentication key common to the plurality of nodes. Furthermore, the master node is configured to encrypt the group authentication key with the pair-wise authentication key for each respective pair of master node and slave nodes, thereby generating a respective encrypted group authentication key. Moreover, the master node is configured to communicate the encrypted group authentication key to the respective slave nodes.

Abstract: A beam-steering antenna system for improving the angular coverage comprises a transmission line comprising a first end and a second end. The antenna system further comprises a plurality of antenna elements selectively coupled to the transmission line for selectively coupling energy within the transmission line to the plurality of antenna elements. Furthermore, the antenna system comprises a power amplifier coupled to the first end of the transmission line configured to couple-in an input signal into the transmission line during a first operating period. Moreover, the antenna system comprises a delay line coupled to the second end of the transmission line configured to reflect a portion of the input signal into the transmission line, thereby providing a reflection signal during a second operating period.

Abstract: A device for light-based analysis of a substance in a liquid sample comprises: an analysis cell for holding the liquid sample; wherein the analysis cell comprises a first wall portion for passing light generated by a light source into the analysis cell, and a second wall portion for passing light from the analysis cell to a light detector; and a plunger configured for movement along walls of the analysis cell for allowing entry of the liquid sample into the analysis cell and pushing the liquid sample out of the analysis cell; wherein at least one wiper is arranged on the plunger for cleaning the first and second wall portions during movement of the plunger.

Abstract: A device for light-based analysis of a substance in a liquid sample comprises: an analysis cell for holding the liquid sample during analysis; a plunger configured for movement along walls of the analysis cell for allowing entry of the liquid sample into the analysis cell and pushing the liquid sample out of the analysis cell, wherein a first analysis measurement is allowed to be performed while a second portion of the plunger is arranged between a light source and a light detector; wherein the plunger is movable to a completely retracted position in the analysis cell for allowing a second analysis measurement to be performed such that light being detected by the light detector is passed through the liquid sample filling a space between opposite walls of the analysis cell.

Abstract: A radio frequency receiver comprising mixer circuitry to down-convert a received signal, which is transported on a signal line to baseband signal components, is provided. The mixer circuitry comprises a plurality of switched capacitors, each connected to the signal line through a signal side node and to a corresponding switch through a switch side node. In this context, a voltage is sensed at each switch side node of the plurality of switched capacitors and is read out through a respective grounded capacitor.

Abstract: A method for estimating a measure of cardiovascular health of a subject (102) comprises: receiving (302) an electrocardiogram, ECG, signal (202); receiving (304) an artery signal (210) representative of pressure pulse wave propagation at a location in an artery; determining (306) a fiducial point in time based on the ECG signal (202) providing an indication of onset of isovolumetric contraction; determining (308) a pre-systolic pressure pulse arrival point in time (212) based on the artery signal (210) to correspond to the onset of the isovolumetric contraction being reflected in the artery signal (210), determining (310) a time period between the onset of the isovolumetric contraction and the pre-systolic pressure pulse arrival point in time, said time period representing a vascular transit time; and determining (312) a pulse wave velocity of the subject (102) based on a physical distance between an aortic valve and the location in the artery and on the vascular transit time.

Abstract: A powering apparatus for wireless powering of a power receiving device comprises: a plurality of power transmitters configured to provide inductive coupling to the power receiving device; and an oscillator configured to provide a reference oscillator signal; wherein each power transmitter comprises an inductive element and a driving circuitry for providing a current signal for driving the inductive element, wherein the driving circuitry of each power transmitter is configured to receive the reference oscillator signal and a feedback signal of a current through the inductive element for controlling a phase of the current signal in relation to a phase of the reference oscillator signal, each of the plurality of power transmitters being configured for outputting a powering signal controlled by a common phase relation to the reference oscillator signal.

Abstract: A method of generating an impulse for impulse radio transmission signals and an impulse-radio ultra-wideband transmitter are provided. In one aspect, the method includes distributing input digital data according to time information data and amplitude information data along a first modulation path and a second modulation path, respectively. Pulse position modulation is performed based on the time information data along the first modulation path to define a timing position of the impulse. Pulse amplitude modulation is performed based on the amplitude information data along the second modulation path to define an envelope of the impulse. The input digital data can be distributed according to phase information data along a third modulation path, and phase shift keying modulation can be performed based on the phase information data along the third modulation path to define a phase of a carrier signal of the impulse.

Abstract: According to an aspect there is provided a method for automatic maintenance of a dialysis system. The dialysis system includes a plurality of filter sections where each filter section includes a blood flow channel, a dialysate flow channel, and a membrane separating the blood flow channel from the dialysate flow channel and having a plurality of pores through which substances are exchanged between a blood flow in the blood flow channel and a dialysate flow in the dialysate flow channel. The method includes determining, for each filter section of the plurality of filter sections, whether a maintenance criterion is fulfilled. The method also includes triggering a maintenance event for a filter section of the plurality of filter sections for which the maintenance criterion is fulfilled. The method also includes executing the maintenance event and optionally administering a thrombolytic agent to the blood flow channel of the filter section.

Abstract: A system for electrical impedance tomography comprises: a plurality of electrodes; a plurality of impedance measurement units, each being associated with two or more electrodes, and wherein each impedance measurement unit comprises a current generator for generating a stimulation current between the electrodes and an amplifier for amplifying a measurement voltage between the electrodes; wherein the system is configured to perform a plurality of impedance measurements, wherein, for each impedance measurement, one impedance measurement unit is set in a stimulation mode for providing a stimulation current into the object, and wherein the impedance measurement unit being set in the stimulation mode is switched among the plurality of impedance measurement units, and wherein each impedance measurement unit is configured to be set in a calibration mode during at least one of the plurality of impedance measurements.

Abstract: A method of ranging between a first and a second radio signal transceiver comprises calculating a preliminary estimate of a value proportional to a one-way frequency domain channel response, for a frequency of a plurality of frequencies and for each of a first antenna combination and a second antenna combination of a plurality of antenna combinations; calculating a comparison value for the preliminary estimate, for the frequency and for each of the first antenna combination and the second antenna combination; determining, for the frequency and the first antenna combination, a corrected estimate of the value proportional to the one-way frequency domain channel response based on the preliminary estimate and the comparison value, for the first antenna combination and the second antenna combination; and performing a ranging calculation between the first and the second radio signal transceiver based on a plurality of such corrected estimates.

Abstract: A smart contact lens (400) for detecting a ratiometric change in an incident light (126) intensity is provided, including one or more, preferably concentric, rings (410-1, 410-2, . . . , 410-N) of a liquid crystal display, LCD, type, each ring being operable between a state having a lower attenuation of light and a state having a higher attenuation of light; a circuit (420, 100, 101) for detecting a ratiometric change in an incident light intensity; and a controller (430) configured to operate the one or more rings based on an intensity of an incident light and to, as a response to the circuit (420, 100, 10 101) detecting a ratiometric change in the intensity of the incident light from a higher intensity state to a lower intensity state indicating that at least a beginning of a blinking of an eye of a user has occurred, initiate a re-polarization of the one or more rings. A method of operating the smart contact lens and various uses of the circuit are also provided.

Abstract: A light-to-digital converter (2) comprises a light-to-current converter (10); a current integrator (4) with an integrator output (30) resettable to a baseline level; and a counter (18) with a digital output (26), wherein the light-to-current converter (10) is switchably connectable as a positive integration input to the current integrator (4), for, during a light-collecting phase (404-406), integrating a current from the light-to-current converter (10), the integrator output (30) starting from the baseline value and ending at a value to be digitized; a reference current source (14) is switchably connectable as a negative integration input to the current integrator (4), for, during a counting phase (406-408) subsequent to the light-collecting phase (404-406), integrating a reference current from the reference current source (14), the integrator output (30) starting from the value to be digitized and ending at the baseline value, the time spent integrating the reference current corresponding to the value to be

Abstract: A system for respiratory monitoring of a subject comprises: a bioimpedance measurement sensor, which is configured for arrangement in relation to the subject for acquiring a bioimpedance signal; a processing unit, which is configured to receive the acquired bioimpedance signal and receive a reference signal, the reference signal representing a respiratory effort of the subject or a respiratory airflow at a time of bioimpedance signal acquirement, the processing unit being further configured to divide the bioimpedance signal into an effort component representing a respiratory effort of the subject and a flow component representing a respiratory airflow of the subject based on the received bioimpedance signal and the received reference signal.

Abstract: A method for extracting spatial resolution and/or velocity resolution of a single-input single-output radar acquiring raw radar data with a frequency scanning antenna is provided. The method includes steering a radar beam with the aid of the frequency scanning antenna with respect to an area to be illuminated by the radar, and dividing the area into at least two angular sectors. In this context, the at least two angular sectors are configured in a manner that the at least two angular sectors overlap with respect to each other.

Abstract: A method of secure wireless ranging between a verifier node and a prover node comprises performing a measurement procedure resulting in a two-way phase measurement and a round-trip time measurement between the verifier node and the prover node. The measurement procedure comprises the verifier node transmitting on the frequency a verifier packet, the prover node receiving the verifier packet and performing a phase measurement of a verifier carrier signal and a time-of-arrival measurement of a verifier frame delimiter, the prover node transmitting a prover packet, and the verifier node receiving the prover packet and performing a phase measurement of the prover carrier signal and a time-of-arrival measurement of the prover frame delimiter. The method further comprises calculating a distance between the verifier node and the prover node based on the two-way phase measurements and the round-trip time measurements for the plurality of frequencies.

Abstract: A circuit for optoelectronic down-conversion of a terahertz, THz, signal comprises a first photodiode and a second photodiode configured to be excited by an optical beat signal. The photodiodes are coupled in series through a common antenna. The terminals of the antenna are coupled to form an output terminal and the antenna is configured to receive the terahertz, THz, signal. The photodiodes thereby, via the optical beat signal, respectively, down-convert the THz signal and generate a current comprising an intermediate frequency, IF, component and a direct current, DC, component. The respective generated currents are summed at the output terminal, thereby obtaining the IF components and cancelling the DC components.