Patent application number | Description | Published |
20080304586 | Reduced Lattice Demodulation Method and Apparatus - RAKE-based receivers utilize lattice reduction for improving symbol estimation accuracy. Channel response estimates and received signal streams are transformed from a constellation lattice basis to an integer lattice basis to increase the orthogonality of symbol estimation decision regions. In one embodiment, received signal streams are processed by generating despread signal samples from received signal streams transmitted using different spreading codes. Channel response associated with the different received signal streams is estimated and transformed from a first lattice basis to a second lattice basis having greater orthogonality between decision regions than the first lattice basis. The despread signal samples are aligned to the second lattice and combining weights generated based on the transformed channel response estimate. Symbol estimation decision statistics are generated based on the combining weights and the aligned despread signal samples. Soft bit values are generated for decoding based on the symbol estimation decision statistics. | 12-11-2008 |
20100061472 | METHOD AND ARRANGEMENT FOR PILOT PATTERN BASED CONTROL SIGNALLING IN MIMO SYSTEMS - The present invention relates to control signaling in wireless communication systems. In particular, the present invention relates to control signaling in MIMO based communication systems. In the method according to the invention control information is transferred from a base station to at least one user equipment, via a plurality of common pilot channels. A set of unique pilot sequences has been pre-defined, and the base station assigns specific pilot sequences from the set of pilot sequences to specific common pilot channels, forming a pilot sequence assignment pattern representing a specific control information. The user equipment, having knowledge of the relations between pilot sequence assignment patterns and control information, interprets the received pilot sequence assignment pattern as specific control information. The method is particularly well suited for broadcast type control information. | 03-11-2010 |
20100098030 | Method and Arrangement for SINR Feedback in MIMO Based Wireless Communication Systems - The present invention relates to a method and arrangement to enhance the communication performance in wireless communication systems. The method of the invention provides better adjustment of reported SINR in MIMO, and PARC-MIMO based communication systems. According to the method information relating to signal-to-interference-plus-noise ratio is determined by the user equipment and reported to the base station. The base station adjust reported SINRs using a model of the SINR dependences of power and code allocation. The dependences is modeled by a function comprising a first parameter relating only to power allocation and a second parameter relating only to code allocation. The first parameter has a power allocation exponent and the second parameter has a code allocation exponent. Both the power allocation exponent and the code allocation exponent are data stream dependent. | 04-22-2010 |
20100112952 | BASE STATION AND METHOD FOR IMPROVING COVERAGE IN A WIRELESS COMMUNICATION SYSTEM USING ANTENNA BEAM-JITTER AND CQI CORRECTION - A base station and method are described herein that improves the coverage in a fixed-beam wireless communication system by using antenna beam-jitter and Channel Quality Information (CQI) correction. In one embodiment, the method includes the steps of: (a) modifying a beam by introducing a beam-jitter in a beam-forming pattern; (b) receiving an estimated channel quality information, CQI, from a user terminal; (c) accounting for effects of the beam-jitter on the estimated CQI to obtain a jitter-adjusted CQI estimate; (d) and using the jitter-adjusted CQI estimate during user scheduling for a future transmission to the user terminal. | 05-06-2010 |
20100159930 | BASE STATION AND METHOD FOR VERTICAL TILT ANTENNA BEAM SWEEPING - A base station and method are described herein that vertically sweeps an antenna beam within a cell to improve the signal quality at scheduled times for a user terminal located within a coverage area of the cell. In one embodiment, the method improves a signal quality for a user terminal by: (a) vertically sweeping a beam within a cell coverage area to vary a signal quality at scheduled times for the user terminal located within the cell coverage area; and (b) performing one or more scheduling functions while taking into account variations in the vertical sweep of the antenna beam. For instance, the scheduling function(s) can include a link adaptation function, a resource allocation function, a user admittance/dropping function, a handover function, and/or a hybrid automatic repeat request function. | 06-24-2010 |
20100167657 | UPLINK CHANNEL QUALITY FEEDBACK REDUCTION IN A MOBILE COMMUNICATION SYSTEM - Operating a user equipment in a mobile communication system includes generating a measure of reliability of a predicted channel estimate and of impairment stability, wherein the predicted channel estimate is a predicted estimate of a channel between the user equipment and a node of the mobile communications system. Transmission of a channel quality report to the node of the mobile communication system is controlled as a function of the generated measure of reliability of the predicted channel estimate and of impairment stability. Transmission control includes inhibiting transmission of the channel quality report to the node of the mobile communication system for a duration of time corresponding to the measure of reliability of the predicted channel estimate and of impairment stability. | 07-01-2010 |
20100222008 | Method and Arrangements for Communication of Channel Quality Information in a Telecommunications System - The present invention relates to a mobile terminal device, a base station and a method that make it possible to use a channel quality indicator, CQI, reporting format for CQI reporting from the mobile terminal device to the base station, which CQI reporting format depends on a selected transmit antenna configuration. The mobile terminal device is arranged to receive a signal from a number of transmit antennas, which signal includes a number of subcarriers, and to determine the CQI, reporting format for a collection of the subcarriers based on the selected transmit antenna configuration. The mobile terminal device is further arranged to determine a number of CQI values relating to said subcarriers in accordance with the determined CQI reporting format and to transmit the CQI values to the base station in a feedback signal. The CQI reporting format is adapted to the selected transmit antenna configuration such that the granularity of CQI reporting depends on the selected transmit antenna configuration. | 09-02-2010 |
20100232379 | Interference Randomization of Control Channel Elements - A method and a radio base station for interleaving control channel data to be transmitted in a telecommunications system are described. The method comprises grouping the control channel elements CCE | 09-16-2010 |
20100260036 | CONTROL CHANNEL FORMULATION IN OFDM SYSTEMS - Control channel information is formulated for transmission in orthogonal frequency division multiplexing (OFDM) systems. In an example embodiment, a method entails formulating control channel information for a transmitting device operating in an OFDM system in which a control channel spans n OFDM symbols, with n being an integer. The method includes acts of allocating, creating, and mapping. Control channel data is allocated to at least one set of resource element groups. At least one order for the set of resource element groups is created in accordance with one or more permutation mechanisms that involve at least one interleaving sequence having a low cross-correlation property. The set of resource element groups is mapped to resource elements of the n OFDM symbols of the control channel responsive to the order that is created using the permutation mechanism(s). The permutation mechanisms may include interleaving sequence(s) and/or cyclic shift(s). | 10-14-2010 |
20110013556 | INTERFERER REGION IDENTIFICATION USING IMAGE PROCESSING - Demodulation and interference parameter estimation in an OFDM receiver is improved by identifying regions, in a two-dimensional array of time-frequency transmission positions, having related interference parameters, such as resulting from the same pre-coding scheme, transmission rank, transmitting antennas, and the like. An interference measure is estimated for each of a plurality of time-frequency positions. The interference measures are analyzed by considering them as pixels, or picture elements, in a two-dimensional image, and applying image processing algorithms to identify the regions having related interference parameters. The image processing algorithms may include operations such as edge detection, segmentation, and/or clustering. The receiver may perform interference suppression or cancellation such as interference rejection combining of data extracted from signals received within an identified time-frequency region having related interference parameters. | 01-20-2011 |
20110081871 | CHANNEL-DEPENDENT SCHEDULING AND LINK ADAPTATION - A mobile terminal measures interference over multiple measurement periods and generates interference probability data based on the statistical distribution of the interference measured. The interference probability data may describe, for example, the probability of each possible level of interference expected at the mobile terminal. The mobile terminal derives channel quality information as feedback to a base station based on this interference probability data (e.g., when noise at the mobile terminal falls below a threshold). In one embodiment, the mobile terminal does so by estimating from the interference probability data the probability of successfully receiving a transmission if certain feedback information is reported. Derived in this way, the feedback information more reliably indicates interference likely present at the mobile terminal when the base station sends the transmission. Accordingly, the base station controls the transmission based on the feedback information, and in some embodiments, also based on the interference probability data. | 04-07-2011 |
20110103520 | METHOD AND APPARATUS FOR INTERFERER PARAMETER ESTIMATION USING MULTIPLE RECEIVER ARBITRATION - In one embodiment, a receiver implements a method of demodulating a set of symbols dispersed within a time-frequency grid of a received OFDM signal. The method includes determining which one of two or more demodulators is preferred for use in a given region of the time-frequency grid by evaluating detection statistics generated by the demodulators for the set of symbols. Each demodulator operates according to different demodulation parameters that correspond to different interference assumptions. The method further includes recovering the set of symbols for decoding using whichever demodulator is preferred for each symbol according to the region from which the symbol is recovered. The method may be further extended by updating each demodulator's demodulation parameters using reference and/or data symbols from the region(s) where that demodulator is preferred, and recovering the desired symbols using the updated demodulation parameters. Such updating can be further iterated, for additional demodulation parameter refinement. | 05-05-2011 |
20120058767 | SIGNALING SUPPORT FOR ANTENNA SELECTION USING SUBSET LISTS AND SUBSET MASKS - A communication device is described herein that has control (or at least partial control) over which virtual antenna(s) in one or more base stations to use for transmissions. In one embodiment, the mobile phone performs the following steps: ( | 03-08-2012 |
20120214530 | BASE STATION AND METHOD FOR IMPROVING COVERAGE IN A WIRELESS COMMUNICATION SYSTEM USING ANTENNA BEAM-JITTER AND CQI CORRECTION - A base station and method are described herein that improves the coverage in a fixed-beam wireless communication system by using antenna beam-jitter and Channel Quality Information (CQI) correction. In one embodiment, the method includes the steps of: (a) modifying a beam by introducing a beam-jitter in a beam-forming pattern; (b) receiving an estimated channel quality information, CQI, from a user terminal; (c) accounting for effects of the beam jitter on the estimated CQI to obtain a jitter-adjusted CQI estimate; (d) and using the jitter-adjusted CQI estimate during user scheduling for a future transmission to the user terminal. | 08-23-2012 |
20130223379 | Interference Randomization of Control Channel Elements - A method and a radio base station for interleaving control channel data to be transmitted in a telecommunications system are described. The method comprises grouping the control channel elements CCE | 08-29-2013 |