Patent application number | Description | Published |
20090067518 | Interpolation Method and a Related Device for Channel Estimation in Communication Systems - A method for interpolating between a first and a second point includes the steps of calculating a first distance between a first and a second independent value and a second distance between a first and a second dependent value, right shifting the first and the second distances by a predetermined number of bits for obtaining respectively a hold step and a variations step and generating a number of interpolated points, having independent values between the first and the second independent values and corresponding dependent values obtained by alternating hold and variations phases, wherein the hold phase consists of generating a number of points corresponding to the hold step having the same dependent value, and wherein the variations phase consists of varying the dependent value by the variations step until the number of interpolated points has been calculated. The method is particularly suitable for channel estimation in communication systems. | 03-12-2009 |
20090296585 | Frequency Domain Channel Estimation in a Single Carrier Frequency Division Multiple Acess System - A channel estimator for use in a receiver node receiving signals from a plurality of user terminals wherein each user terminal is allotted a respective set of transmission subcarriers and respective test signal sequences for transmission over the channel to be estimated. The channel estimator has stored therein information as to the respective sets of transmission subcarriers allotted to the user terminals for transmission as well as the discrete spectra of the respective test signal sequences allotted to the user terminals. Upon receiving from a plurality of user terminals signals including the respective test signal sequences transmitted over the channel by using the respective sets of transmission subcarriers allotted thereto, the estimator generates the discrete spectrum of the combined test signal received and performs channel estimation as a function of the discrete spectrum of the combined test signal and the discrete spectra of the test signal sequences allotted to the user terminals. A frequency domain channel estimation is performed for a single carrier frequency division multiple access system. | 12-03-2009 |
20100022193 | Method and System for Multiple Antenna Communications Using Multiple Transmission Modes, Related Apparatus and Computer Program Product - A system for diversity processing a signal propagated via two diversity antennas includes: respective propagation paths for propagating two replicas of the signal, these propagation paths being coupled to the two diversity antennas so that the replicas are propagated via different antennas; a time variable delay element for subjecting at least one of the replicas to a time variable delay; and a level adjusting element, such as an asymmetric splitter, to produce a level imbalance between the power levels of the replicas propagated via the two diversity antennas. | 01-28-2010 |
20100130150 | SWITCHED BEAM ANTENNA WITH DIGITALLY CONTROLLED WEIGHTED RADIO FREQUENCY COMBINING - A wireless communication system, wherein a sub-set of radio frequency signals received from corresponding antenna elements is selected and combined into a single radio frequency signal, the single radio frequency signal being processed and demodulated in a single processing chain, includes a radio frequency phasing network for co-phasing the selected radio frequency signals before combining and a processor for controlling combining and phasing in order to obtain a single radio frequency signal having a radio performance indicator which satisfies predetermined conditions. | 05-27-2010 |
20100267347 | METHOD AND SYSTEM FOR MULTIPLE ANTENNA COMMUNICATIONS, RELATED APPARATUS AND CORRESPONDING COMPUTER PROGRAM PRODUCT - A system for diversity processing two signals transmitted and/or received via two diversity antennas includes at least four respective propagation paths coupling the signals to the two diversity antennas. Diversity processing is primarily in the form of decorrelation achieved by means of time variable delay elements that apply time variable delays to the signals propagating over at least two of the propagation paths in the system. The related processing may take place either at RF or IF, or at baseband, whereby the time variable delays are applied by subjecting the baseband signals to multiplication by a complex signal. | 10-21-2010 |
20110019775 | METHOD AND SYSTEMS FOR RECEIVING PLURAL INFORMATIONS FLOWS IN A MIMO SYSTEM - In a communication system, such as a Multiple Input Multiple Output system operating in a spatial multiplexing mode, for use, e.g., in a WLAN or HSPDA device, a plurality of information flows are received via a set of receive antennas by deriving from at least some, and possibly all, of the receive antennas, respective RF signals, and producing from the RF signals thus derived, a plurality of receive signals, each receive signal to be demodulated to recover one of the information flows transmitted. The receive signals are produced as combinations of the RF signals having applied thereto relative RF phase shift weights. | 01-27-2011 |
20110026418 | METHOD AND SYSTEM FOR SWITCHED BEAM ANTENNA COMMUNICATIONS - A system for processing an RF signal received via a plurality of antenna elements includes a connection arrangement for selecting a sub-set of a given number of RF signals received from the antenna elements as well as a processing arrangement for combining the received RF signals of the selected sub-set into a single RF signal for demodulation. The system includes an RF phasing circuit for producing selective combinations of the received RF signals by applying relative RF phase shift weights to the RF signals that are combined; each combination includes RF signals received from a number of adjacent antenna elements equal to the number of the RF signals in the sub-set to be selected. A radio performance estimator generates for each selective combination of RF signals at least one non-RF radio performance indicator representative of the quality of the RF signals in the combination. A decision block identifies the sub-set of received RF signals to be selected as a function of the one radio performance indicator generated for the selective combinations of the received RF signals. | 02-03-2011 |
20110149780 | Method of Transmitting Data, Corresponding Systems and Computer Program Product Therefor - A method of transmitting signals from a base station towards user terminals in a cellular communication system. The method includes generating diversity signals, wherein at least one of the diversity signals is subjected to a selectively variable RF phase shift. Specifically, a set of radio link quality indicators is determined at the base station, wherein each radio link quality indicator is representative of the quality of the radio link between the base station and a respective one of the user terminals. The set of radio link quality indicators is used to generate an aggregated radio quality indicator, which in turn is used to selectively vary the variable RF phase shift. For example, the phase shift may be selected, which optimizes the aggregated radio quality indicator. | 06-23-2011 |
20110158180 | METHOD OF PROCESSING RECEIVED SIGNALS, CORRESPONDING RECEIVER AND COMPUTER PROGRAM PRODUCT THEREFOR - Signals received from channels exposed to multi-path propagation via a plurality of diversity antennas and including at least one pilot signal are processed by detecting a set of multi-path components for each received signal and computing a set of channel coefficients from multi-path components of the at least one pilot signal in the set of multi-path components. The set of channel coefficients is organized as a channel coefficient vector. From the channel coefficient vector, a set of combining weights is estimated to be applied to the received signals by: computing a spatial correlation matrix of the channel coefficient vector by neglecting the correlations between multi-path components of the channel coefficient vector having different delays, whereby the correlation matrix is a block diagonal matrix including null coefficients other than for non-null sub-matrixes arranged along the diagonal of the correlation matrix, wherein the sub-matrixes have a size equal to the number of diversity antennas; deriving from the spatial correlation matrix a resulting matrix by calculating the inverse of the sub-matrixes or a scaled version thereof; and multiplying the resulting matrix and the channel coefficient vector in order to obtain the desired set of combining weights. | 06-30-2011 |
20110176532 | METHOD OF TRANSMITTING DIGITAL SIGNALS, CORRESPONDING TRANSMISSION SYSTEM, SIGNAL AND COMPUTER PROGRAM PRODUCT THEREFOR - Digital signals are transmitted over a communication channel having a given bandwidth, by simultaneously transmitting: one or more Spread Spectrum signals, such as, Code Division Multiple Access signals, wherein the spectrum of the Spread Spectrum signals exhibits roll-off transition bands at the boundaries of the spectrum, and one or more multi-carrier transmission signals, such as, Orthogonal Frequency Division Multiplexing signals, which are transmitted over the transition bands of the Spread Spectrum signals | 07-21-2011 |
20110268033 | METHOD FOR DISTRIBUTED MOBILE COMMUNICATIONS, CORRESPONDING SYSTEM AND COMPUTER PROGRAM PRODUCT - A method of arranging exchange of signals between user terminals in a cellular communication system and at least one base station. The base station includes a central unit and a plurality of remote units. The signals are exchanged between the central unit and the remote units as aggregated signals for plural user terminals. The signals are processed at the remote units as distinct signals each associated with a respective one of the plural user terminals. | 11-03-2011 |
20110275376 | METHOD FOR ADAPTIVE DISTRIBUTED MOBILE COMMUNICATIONS, CORRESPONDING SYSTEM AND COMPUTER PROGRAM PRODUCT - A method of arranging exchange of signals between user terminals in a cellular communication system and at least one base station including a central unit and a plurality of remote units. The method includes exchanging signals with at least one user terminal simultaneously via at least two remote units by applying at the at least two remote units, separate distributing weighting functions to the signals exchanged with the at least one user terminal. | 11-10-2011 |
20130003812 | METHOD FOR SELECTING A PRECODING MATRIX IN A MULTIPLE INPUT MULTIPLE OUTPU ("MIMO") SYSTEM - A method for selecting a precoding matrix to be used in a MIMO communication system includes a transmitter, a receiver and a communication channel, wherein the precoding matrix is used by the transmitter to precode codewords to be transmitted to the receiver over the communication channel. At the receiver, an optimum precoding matrix within a codebook of precoding matrices is determined on the base of a metric related to the power of received signal layers. An indication is then fed back from the receiver to the transmitter useful to enable the transmitter to select the optimum precoding matrix from the codebook. | 01-03-2013 |
20140009347 | TWO-POLARIZATION SWITCHED-BEAM ANTENNA FOR WIRELESS COMMUNICATION SYSTEMS - An antenna device including: a first antenna assembly configured to receive first radiofrequency signals polarized according to a first polarization; a second antenna assembly configured to receive second radiofrequency signals polarized according to a second polarization orthogonal to the first polarization; and a radiofrequency signal handling assembly coupled with the first and second antenna assemblies, and configured to handle the received first radiofrequency signals separately from the received second radiofrequency signals. | 01-09-2014 |