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Leif Wilhelmsson, Dalby SE

Leif Wilhelmsson, Dalby SE

Patent application numberDescriptionPublished
20080212697Doppler Dependent Power Control and Sub-Carrier Allocation in ofdm Multiple Access Systems - Digital data Symbols from a transceiver are transmitted to at least two remote transceivers in a wireless Communications System employing Orthogonal Frequency Division Multiplexing, wherein a number of available sub-carriers are shared between said remote transceivers. Information about magnitudes of Doppler effect experienced by the remote transceivers is provided; sub-carriers are allocated to each remote transceiver in dependence of the information about magnitudes of Doppler effect; and a power level transmitted to each of said remote transceivers is controlled in dependence of the Information about magnitudes of Doppler effect. In this way the reception of OFDM Signals for transceivers moving at high speed and thus experiencing a high Doppler effect is improved without degrading the reception quality for transceivers with low or no Doppler effect. Thus the Performance of a System based on OFDM and multiple access is improved.09-04-2008
20080292036Method and Device for Signal Processing11-27-2008
20080304405Signal Generating Unit and Signal Receiving Unit - A signal generating unit (12-11-2008
20080316911Simultaneous Cell Group and Cyclic Prefix Detection Method, Apparatus and System - A method, and associated apparatus and system, for simultaneous cell group and cyclic prefix (CP) detection, having the steps of determining primary synchronization signal (P-SyS) timing τ using the P-SyS; based on τ, determine a secondary synchronization signal (S-SyS) timing; placing a single Fast Fourier Transform (FFT) window; FFT processing the signal to obtain the frequency domain S-SyS symbols; equalizing the frequency domain S-SyS signal; phase correcting the S-SyS signal; and detecting the cell group and CP length by the correlation giving maximum energy.12-25-2008
20090080557Quality of Service Based Antenna Mapping for Multiple-Input Multiple-Output Communication Systems - The teachings presented herein provide methods and apparatus for use in a multiple-input multiple-output (MIMO) system transmitting a plurality of data substreams to a receiver employing ordered successive interference cancellation detection according to a predetermined sequence for decoding the data substreams. In an exemplary method, a quality of service (QoS) requirement is determined for each of two or more application-specific data streams, and the application-specific data streams are assigned to the data substreams according to the determined QoS requirements and the predetermined sequence, so that application-specific data streams having more stringent QoS requirements are decoded earlier than application-specific data streams having less stringent QoS requirements. In some embodiments, the determined QoS requirements comprise maximum delay requirements, and application-specific data streams requiring shorter maximum delays are assigned to earlier-decoded data substreams than application-specific data streams having less stringent maximum delay requirements. In other embodiments, the determined QoS requirements comprise an application-specific robustness, wherein application-specific data streams corresponding to less robust applications are assigned to earlier-decoded data substreams than application-specific data streams corresponding to more robust applications.03-26-2009
20090110112Method and Apparatus for Reducing Phase Noise in Orthogonal Frequency Division Multiplexing Systems - Method and apparatus for reducing phase noise from a multi-carrier modulation (MCM) system, such as an orthogonal frequency division multiplexing (OFDM) system, by transmitting known data on a sub-carrier at a power level adapted to allow for accurate estimation. Preferably, the sub-carrier is the DC sub-carrier.04-30-2009
20090116568Method and Apparatus for Interference Rejection Combining and Detection - A multi-branch OFDM receiver combines diversity signals received over different receiver branches using interference rejection combining. The receiver generates first channel estimates associated with a serving base station, second channel estimates associated with at least one non-serving base station, and a time offset between the serving base station and non-serving base station. The receiver computes a noise covariance matrix based on the second channel estimates and the time offset, and then combines the diversity signals received over different branches using the first channel estimates and the noise covariance matrix.05-07-2009
20090176453METHOD AND SYSTEM FOR DYNAMIC CARRIER SELECTION - A dynamic carrier selection method and system permit units operating on a first carrier to change to a second carrier when performance of the first carrier becomes unacceptable. Carrier quality measurements are taken in which carrier quality is a function of interference and multi-path fading and carrier-signal strength. The carriers are ranked according to measured quality in a carrier candidate list. The carrier candidate list is used to permit units to determine which carrier they should switch to when the carrier there currently operating on is determined to have unacceptable performance. Carrier measurements are retaken in response to a carrier change by unit or a predetermined time period having elapsed.07-09-2009
20090254598Folding of Input Data Values to a Transform Function - A method of processing a set of input data values comprises the steps of providing said input data values serially to circuitry comprising a number of memory elements; and performing in said circuitry a transform function to obtain a set of transformed data values. The method further comprises the steps of delaying a subset of said set of input data values under use of said memory elements; providing a modified set of data values by adding individual delayed data values to individual non-delayed data values from said set of input data values; and performing said transform function on said modified set of data values. In this way a transform function can be evaluated at fewer output data values than available input data values without increasing the memory requirements considerably.10-08-2009
20090262785Adaptive Coexistence Between Different Wireless Communication Systems - A first transceiver is operated in a first frequency band in the presence of a second transceiver operating in a second frequency band. Operation includes ascertaining an interference level at the first transceiver due to the second transceiver. A coexistence strategy for the second transceiver is dynamically selected by selecting a frequency division strategy if the ascertained interference level is less than a threshold level and selecting a time division strategy if the ascertained interference level is above the threshold level. The second transceiver is then caused to operate in accordance with the dynamically selected coexistence strategy.10-22-2009
20100135423Determining a Frequency Error in a Receiver of a Wireless Communications System - A frequency error of received signals in an OFDM receiver of a wireless communications system is determined. Symbols of a given duration are transmitted as cells on sub-carrier frequencies; and some of the cells are pilot cells modulated with reference information. The method comprises the steps of selecting at least three pilot cells (p06-03-2010
20100144326Method and a Device for Receiving Data in a Mobile Communication Device in a Broadcast System - In a method for receiving data in a mobile communication device (06-10-2010
20100189203Automatic Gain Control Based on Bandwidth and Delay Spread - A gain control circuit adjusts the signal level of a received signal responsive to the bandwidth a received signal and/or the delay spread of the channel in which the signal has propagated. The bandwidth and delay spread are evaluated to estimate the amount of signal variation that is expected due to fast fading. Adjustments to the signal level are then made to avoid clipping while at the same time ensuring that the dynamic range of a receiver component is efficiently utilized.07-29-2010
20100195584Data Packet Transmission Scheduling in a Mobile Communication System - A communication device has a first transceiver that operates in a first communication system in the presence of a second transceiver that operates in a second communication system that is unrelated to the first communication system. A scheduler of packets for transmission by the first transceiver uses information about when the second communication system will be transmitting a signal that will interfere with reception by the first transceiver, and schedules data for which re-transmission is not essential in those time slots in which an implicit NACK is expected due to the second transceiver's operation.08-05-2010
20100197235Coexistence of Plural Wireless Communication Transceivers in Close Proximity - A communication device has a plurality of concurrently operating transceivers, each operating in a respectively different one of a plurality of communication systems, wherein the plurality of concurrently operating transceivers includes a first transceiver and a second transceiver. Operation of the communication device includes the first transceiver ascertaining whether transmissions by the second transceiver are causing interference in a receiver of the first transceiver and if so, performing one or more interference response actions. The one or more interference response actions include ascertaining whether the interference is at an acceptable level and if so then taking no further interference response actions. If the interference is ascertained to be at an unacceptable level, an interference mitigation request is communicated to the second transceiver. The second transceiver can, for example, shift its use of frequencies to a region whereby the first transceiver's band select filter can sufficiently attenuate the second transceiver's signal.08-05-2010
20100202416Data Packet Communication Scheduling in a Communication System - A communication device has a plurality of concurrently operating transceiver systems, each operating in a respectively different one of a plurality of communication systems. Operation of the transceiver systems is coordinated by receiving a plurality of requests from different ones of the transceiver systems, each of the requests being a request to access a communication medium for the purpose of transmitting or receiving a data packet. Utilization of an available time period is scheduled by selecting which one or ones of the requests to grant based, at least in part, on how many remaining times out of a maximum number of times each of the transmission systems' data packet is permitted to be retransmitted compared to other requests, on whether the requests are requests to transmit a data packet, and on whether the requests are requests to receive a data packet.08-12-2010
20100272219Method and Device for Automatic Gain Control - A method and apparatus for adjusting the gain of an amplifier (10-28-2010
20110002403Method and Apparatus for Positioning an FFT-Window in an OFDM-Receiver - Methods for positioning an FFT-window in an OFDM-receiver are disclosed as well as electronic apparatuses and computer program products for performing the methods. The method comprises determining a position of the FFT-window in relation to one or more OFDM-symbols of a received OFDM-signal, using the position of the FFT-window to obtain a first OFDM-symbol from the received OFDM-signal, and applying an FFT to the first OFDM-symbol to produce an FFT-output signal. The method also comprises determining a frequency dependent phase rotation component of the FFT-output signal, and removing the determined frequency dependent phase rotation component from the FFT-output signal to obtain a compensated FFT-output signal. A delay spread estimate is calculated based on at least one of the FFT-output signal and the compensated FFT-output signal, and the position of the FFT-window is adjusted based on at least the determined frequency dependent phase rotation component and the calculated delay spread estimate.01-06-2011
20110019749METHOD AND APPARATUS FOR DELAY SPREAD ESTIMATION - Methods for calculating a delay spread estimate in an OFDM-receiver are described, along with computer program products and electronic apparatuses for performing the methods. The methods comprise determining a position of an FFT-window in relation to one or more OFDM-symbols of a received OFDM-signal and using the determined position to obtain a first OFDM-symbol from the received OFDM-signal. An FFT is applied to the first OFDM-symbol to produce an FFT-output signal. A frequency dependent phase rotation component of the FFT-output signal is determined and removed from the FFT-output signal. A number of zero-crossings of at least one of a real component and an imaginary component of a transfer function of a channel, over which the received OFDM-signal has been transmitted, derived from the FFT-output signal where the frequency dependent phase rotation component has been removed is determined, and a delay spread estimate is calculated based on the determined number of zero-crossings.01-27-2011
20110045790Method and Computer Program for Estimating Signal Quality Value, and Signal Quality Estimator, Receiver and Communication Apparatus - A method of estimating a signal quality value in a receiver, the method comprising receiving a plurality of reference symbols; determining error rate for the plurality of received reference symbols; mapping the determined error rate to a signal quality value model; and determining mapped signal quality from the model to be signal quality value estimate. A signal quality estimator, a receiver, a communication apparatus, and a computer program for estimating signal quality are also disclosed.02-24-2011
20110053539RADIO ENVIRONMENT SCANNER - A device may include a measurement receiver, a communication receiver, and a transmitter. The measurement receiver may include a receiver (RX) down-conversion component to receive an amplified signal from a low-noise amplifier of the communication receiver, selectively receive a signal from a first local oscillator associated with the communication receiver or a second local oscillator associated with the transmitter, and down-convert the amplified signal to baseband using the received signal from the first local oscillator or the second local oscillator. The measurement receiver may further include a delta-sigma analog-to-digital converter (ADC) to provide low quantization noise only for a particular frequency range to be measured, and a control component to configure the delta-sigma ADC to provide the low quantization noise at the particular frequency range.03-03-2011
20110090995SIMULTANEOUS CELL GROUP AND CYCLIC PREFIX DETECTION METHOD, APPARATUS AND SYSTEM - A method, and associated apparatus and system, for simultaneous cell group and cyclic prefix (CP) detection, having the steps of determining primary synchronization signal (P-SyS) timing τ using the P-SyS; based on τ, determine a secondary synchronization signal (S-SyS) timing; placing a single Fast Fourier Transform (FFT) window; FFT processing the signal to obtain the frequency domain S-SyS symbols; equalizing the frequency domain S-SyS signal; phase correcting the S-SyS signal; and detecting the cell group and CP length by the correlation giving maximum energy.04-21-2011
20110103497CHANNEL ESTIMATION IN OFDM RECEIVER EQUIPMENT - A receiver is operated so as to receive data conveyed on an Orthogonal Frequency Division Multiplexed (OFDM) signal transmitted on a plurality of sub-carriers. Such operation includes ascertaining which of the plurality of sub-carriers have a channel quality that satisfies one or more criteria. Then, sub-carriers are selected based at least in part on whether they have the channel quality that satisfies one or more criteria. The receiver then fully processes data streams only from the selected sub-carriers, wherein fully processing data streams comprises sub-carrier channel estimation or sub-carrier equalization or both sub-carrier channel estimation and sub-carrier equalization.05-05-2011
20110116490Coexistence of Plural Wireless Communication Transceivers in Close Proximity - A communication device has a controller operatively connected to at least a first transceiver and a second transceiver, wherein the first transceiver receives signals on one or more channels within a first frequency band and the second transceiver transmits signals on one or more channels within a second frequency band, wherein the first and second frequency bands are adjacent one another so that each of the first and second frequency bands has an adjacent border and a nonadjacent border. Coexistence between the first and second transceivers is achieved by adjusting receive and/or transmit filters associated with the transceivers to create a guard band that is located more in the first frequency band if the second transceiver is using frequencies close to its adjacent border, and a guard band that is more in the second frequency band if the second transceiver is not using frequencies close to its adjacent border.05-19-2011

Patent applications by Leif Wilhelmsson, Dalby SE