Abstract: Interference detection involves detecting the interference component in the received signal if there is such a component, controlling a band reject filter according to the detected interference component to filter the received signal to suppress the interference component, and synchronizing the receiver to the received signal, wherein the step of detecting the interference component is started before synchronization is achieved. By starting the interference detection without waiting for synchronization to be achieved, rather than following the synchronization, then the interference detection is no longer dependent on the synchronization being achieved.

Abstract: A wireless receiver for UWB or other format receives a useful signal in a particular band of frequencies in spite of interference components. The wireless receiver has two or more different types of tunable band reject filter, involves detecting interference in the received signal, and selecting which of the different types of filter to use according to thresholds of parameters of the detected interference. The filter is then tuned according to the detected interference and the useful signal is then received with the interference suppressed using the selected BRF. As the different types of filters have different drawbacks and benefits, by having multiple types, and selecting which to use according to the detected interference, the filtering can be better matched to the detected interference, or the drawbacks can be reduced for example.

Abstract: A wireless receiver (110) for UWB or other format, receives a useful signal in a particular band of frequencies in site spite of interference components inside and outside the particular band of frequencies. An interference detector (130, 535, 555) detects the in band interference component in a first range of frequencies to include the particular band of frequencies. The same receiver circuitry (120, 300, 310, 505) is adapted to receive a second range of frequencies to include frequencies adjacent to the particular band, to detect the out of band interference component. The position of a second interfering signal in the second range is used to detect artifacts caused by spectral folding so that the required frequency of a band reject filter can be found.

Abstract: Interference detection involves detecting the interference component in the received signal if there is such a component, controlling a band reject filter according to the detected interference component to filter the received signal to suppress the interference component, and synchronizing the receiver to the received signal, wherein the step of detecting the interference component is started before synchronization is achieved. By starting the interference detection without waiting for synchronization to be achieved, rather than following the synchronization, then the interference detection is no longer dependent on the synchronization being achieved.

Abstract: A wireless receiver (110) for UWB or other format, receives a useful signal in a particular band of frequencies in site spite of interference components inside and outside the particular band of frequencies. An interference detector (130, 535, 555) detects the in band interference component in a first range of frequencies to include the particular band of frequencies. The same receiver circuitry (120, 300, 310, 505) is adapted to receive a second range of frequencies to include frequencies adjacent to the particular band, to detect the out of band interference component. The position of a second interfering signal in the second range is used to detect artifacts caused by spectral folding so that the required frequency of a band reject filter can be found.

Abstract: A wireless receiver for UWB or other format receives a useful signal in a particular band of frequencies in spite of interference components. The wireless receiver has two or more different types of tunable band reject filter, involves detecting interference in the received signal, and selecting which of the different types of filter to use according to thresholds of parameters of the detected interference. The filter is then tuned according to the detected interference and the useful signal is then received with the interference suppressed using the selected BRF. As the different types of filters have different drawbacks and benefits, by having multiple types, and selecting which to use according to the detected interference, the filtering can be better matched to the detected interference, or the drawbacks can be reduced for example.

Abstract: Data is received with a transceiver circuit with a receiver branch (14) that comprises a notch filter (140) and a digital Fourier transformer (146). Furthermore the transceiver circuit has a transmitter branch (16) comprising an inverse digital Fourier transformer (160). Prior to reception the transceiver circuit is switched to a calibration mode, wherein an output of the transmitter branch (16) is coupled to an input of the notch filter (140). The inverse digital Fourier transformer (160) of the transmitter is used to compute an inverse transform of a spectrum with a frequency component at a selected position. A signal derived from the inverse transform is applied to an input of the notch filter (140) in the calibration mode. The digital Fourier transformer (146) is used to Fourier transform an output signal of the notch filter (140). A control setting of the notch filter to suppress the frequency component from an output of the digital Fourier transformer (146) is determined.

Abstract: Data is received with a transceiver circuit with a receiver branch (14) that comprises a notch filter (140) and a digital Fourier transformer (146). Furthermore the transceiver circuit has a transmitter branch (16) comprising an inverse digital Fourier transformer (160). Prior to reception the transceiver circuit is switched to a calibration mode, wherein an output of the transmitter branch (16) is coupled to an input of the notch filter (140). The inverse digital Fourier transformer (160) of the transmitter is used to compute an inverse transform of a spectrum with a frequency component at a selected position. A signal derived from the inverse transform is applied to an input of the notch filter (140) in the calibration mode. The digital Fourier transformer (146) is used to Fourier transform an output signal of the notch filter (140). A control setting of the notch filter to suppress the frequency component from an output of the digital Fourier transformer (146) is determined.

Abstract: A method of signal processing and a signal processor for a receiver for OFDM encoded digital signals. OFDM encoded digital signals are transmitted as data symbol sub-carriers in several frequency channels. A subset of the sub-carriers is in the form of pilot sub-carriers having a pilot value (ap) known to the receiver. The method comprises estimation of a channel transfer function (H) and a derivative of the channel transfer function (H?) by means of a channel estimation scheme from a received signal (y). Then, an estimation of data (a) is performed from the received signal (y) and the channel transfer function (H). Finally, an estimation of a cleaned received signal (y2) is performed from the data (a), the derivative of the channel transfer function (H?) and the received signal (y) by removal of inter-carrier interference (ICI), by taking into account at least one of a previous and a future OFDM symbol, followed by an iteration of the above-mentioned estimations.

Abstract: A method of signal processing for a receiver for OFDM encoded digital signals, for counteracting inter-carrier interference (ICI) caused by Doppler broadening. The OFDM encoded digital signals are transmitted as sub-carriers in several channels, which form OFDM blocks. The method comprises estimation of a channel transfer function (?1) by a channel estimation scheme in each sub-carrier and estimation of data (â1) by a data estimation scheme from said channel transfer function (?1) and a received signal (y0). Then, a derivative (Hj?) of said channel transfer function in each sub-carrier is estimated by a temporal filtering; and the inter-carrier interference (ICI) is removed from said received signal by using the estimated data (â1) and the estimated derivative (Hj?) of the channel transfer function in order to obtain a cleaned received signal (y1).

Abstract: A method of signal processing for a receiver for OFDM encoded digital signals. The OFDM encoded digital signals are transmitted as data symbol sub-carriers in several frequency channels. A subset of the sub-carriers is in the form of pilot sub-carriers having a pilot value (ap) known to the receiver. First, a received signal (y0) is obtained, followed by a first estimation of a pilot channel transfer function (H0)at pilot sub-carriers from said received signal (y0) and said known pilot values (ap). Then a second estimation of a channel transfer function (H1) is performed at all sub-carriers from said pilot channel transfer function (H0). A third estimation of a derivative (H?1) of the channel transfer function (H1) is performed from the channel transfer function (H1) and a channel transfer function (H3) from a past OFDM symbol.

Abstract: A method of signal processing and a signal processor for a receiver for OFDM encoded digital signals. The OFDM encoded digital signals are transmitted as data symbol sub-carriers in several frequency channels. A subset of said sub carriers is in the form of pilot sub-carriers having a value known to the receiver. A first estimation of channel coefficients (H0) at said pilot sub-carriers is performed followed by cleaning of the estimated channel coefficients (H0) at the pilot sub-carriers. Then, a second estimation of channels coefficients (H1) is performed at the data symbol sub-carriers. The first estimation is performed by dividing received symbols (yp) at said pilot sub-carriers by the known pilot symbols (ap). the channel frequency response is supposed to vary linearly within one OFDM symbol. Therefore for each symbol and sub-band, a channel frequency response and its derivate are calculated or interpolated.

Abstract: A versatile traffic information system (1) comprises: a light source (10), designed for generating a relative narrow, intense light beam (11); housing means (100) adapted for being mounted adjacent or above a road surface (3), accommodating the light source (10), having a beam exit window (101) for allowing the light beam (11) to exit the housing; a controllable beam deflection system (20), capable of changing a direction of the light beam (11) towards a projection area (2) on the road surface (3) in order to form a relatively small light spot (12) on the projection area (2);- a control circuit (30) for controlling the controllable beam deflection system (20) such as to effectively make the light spot (12) draw a predefined pattern (4) on the projection area (2).

Abstract: An event detection system (100) comprises: a communication network of interconnected nodes (10) and a central control station (200), each node being capable of communicating to at least one adjacent node and/or to the central control station, each node comprising: at least one microphone (11); a GPS receiver (12, 13) providing information regarding its location and providing time information; a processing circuit (17), capable of processing the microphone signals, the processing circuit being designed to detect the occurrence of predetermined characteristic sound patterns, and if the occurrence of a predetermined characteristic sound pattern is detected, to communicate the detected event to the central station, together with information regarding location of the node and time of detection; wherein the central station is designed to process the information received from the nodes and to determine the location of the audio source and the occurrence time of the event.