Patent application number | Description | Published |
20080205552 | METHOD AND APPARATUS FOR TRANSMISSION WITHIN A MULTI-CARRIER COMMUNICATION SYSTEM - Multiple transmit antenna transmission together with preferably pseudo-random, antenna-specific, scrambling (PRAS) is utilized to scramble incoming data differently on different antennas for those users requiring frequency diversity type transmissions. When PRAS is activated for a particular allocation, each transmit antenna applies a different scrambling sequence to the data symbols that are transmitted in the allocation. | 08-28-2008 |
20080267271 | METHOD AND APPARATUS FOR CLOSED LOOP TRANSMISSION - In a wireless communication system, a method and apparatus for closed loop transmission is disclosed. In accordance with the preferred embodiment of the present invention, a time frequency portion of an uplink frame is dynamically reserved as a sounding zone for uplink channel sounding. A first message is transmitted to a first subscriber station in a downlink frame assigning a time-frequency resource within the sounding zone, and a sounding waveform. Furthermore, a signal is received from the subscriber station within the assigned time-frequency resource, a partial channel response is determined from the received sounding signal, and the subsequent transmission to the subscriber station is tailored based on the at least partial channel response. | 10-30-2008 |
20080273494 | METHOD AND APPARATUS FOR CLOSED LOOP TRANSMISSION - In a wireless communication system, a method and apparatus for closed loop transmission is disclosed. In accordance with the preferred embodiment of the present invention, a time frequency portion of an uplink frame is dynamically reserved as a sounding zone for uplink channel sounding. A first message is transmitted to a first subscriber station in a downlink frame assigning a time-frequency resource within the sounding zone, and a sounding waveform. Furthermore, a signal is received from the subscriber station within the assigned time-frequency resource, a partial channel response is determined from the received sounding signal, and the subsequent transmission to the subscriber station is tailored based on the at least partial channel response. | 11-06-2008 |
20080285667 | METHOD AND APPARATUS FOR FEEDBACK IN CLOSED LOOP TRANSMITTING - A method an apparatus is described for providing feedback for closed-loop transmitting with multiple transmit and receive antennas. The method includes a first step | 11-20-2008 |
20080305805 | METHOD AND APPARATUS FOR PERFORMING SPATIAL-DIVISION MULTIPLE ACCESS - A method and apparatus for performing spatial-division multiple access within a communication system is provided herein. During operation, nodes will return null subspace information along with their channel subspace information. The null subspace is similar to the channel subspace except that the null subspace information directs a base station to the matrix in a predefined codebook that results in minimum power being received at the node. The null subspace for each node is taken into consideration when communicating with a particular node. | 12-11-2008 |
20090196164 | METHOD AND APPARATUS FOR CLOSED LOOP TRANSMISSION - In a wireless communication system, a method and apparatus for closed loop transmission is disclosed. In accordance with the preferred embodiment of the present invention, a time frequency portion of an uplink frame is dynamically reserved as a sounding zone for uplink channel sounding. A first message is transmitted to a first subscriber station in a downlink frame assigning a time-frequency resource within the sounding zone, and a sounding waveform. Furthermore, a signal is received from the subscriber station within the assigned time-frequency resource, a partial channel response is determined from the received sounding signal, and the subsequent transmission to the subscriber station is tailored based on the at least partial channel response. | 08-06-2009 |
20090225721 | HIERARCHICAL PILOT STRUCTURE IN WIRELESS COMMUNICATION SYSTEMS - A method for communicating control channel information in a wireless communication system, including transmitting a super-frame having a time-frequency resource region containing an allocation control channel and multiple pilot elements, at least some of which are associated with the allocation control channel, and indicating, in a configuration information control channel of the super-frame, a characteristic of the pilots elements associated with the allocation control channel. | 09-10-2009 |
20100111223 | METHOD AND APPARATUS FOR CHOOSING A MODULATION AND CODING RATE IN A MULTI-USER, MIMO COMMUNICATION SYSTEM - A method and apparatus for choosing a modulation and coding rate in a MU-MIMO communication system is provided herein. During operation, a node will determine the MCR to feed back to the base even though the mobile does not know which of the possible interferers (if any) will be using the same time/frequency resources as the mobile. This takes place via the mobile node calculating best antenna weights (codebook choice) for each group of subcarriers that can be potentially used by the mobile. Transmit weights v for each interferer are then determined and the weights are utilized to determine a best modulation and coding rate for the mobile. | 05-06-2010 |
20100189047 | COOPERATIVE COMMUNICATIONS USING MULTIPLE ACCESS POINTS TO IMPROVE DATA INTEGRITY | 07-29-2010 |
20100260234 | CLOSED-LOOP TRANSMISSION FEEDBACK IN WIRELESS COMMUNICATION SYSTEMS - Channel information feedback takes place by calculating channel information to feed back to the base station. The channel quality information is spread by a remote unit with spreading codes from mutually unbiased bases and transmitted to the base station. The advantages of spreading the feedback channel are that multiple mobiles can send their feedback on the same time-frequency resources making the feedback very efficient and also improving feedback performance through orthogonal spreading which gives a spreading gain above noise and interference. Using the spreading codes from mutually unbiased bases can reduce interference across sectors. | 10-14-2010 |
20110105051 | DIFFERENTIAL CLOSED-LOOP TRANSMISSION FEEDBACK IN WIRELESS COMMUNICATION SYSTEMS - A method and apparatus for providing channel feedback is provided herein. During operation a covariance matrix at time t (R) is calculated as a function of a received downlink signal. Matrix C | 05-05-2011 |
20110164691 | CLOSED-LOOP TRANSMISSION FEEDBACK IN WIRELESS COMMUNICATION SYSTEMS - A method and apparatus for providing channel feedback is provided herein. During operation a covariance matrix at time t (R) is calculated by the mobile as a function of a received downlink signal. In order to reduce overhead, R is normalized and quantized by the mobile using multiple codebook entries plus at least one constant for quantization. The mobile then transmits the normalized and quantized covariance matrix back to the base station as bit values indicating the selected entries from the codebook plus bit values corresponding to the at least one constant. The base unit then uses the covariance matrix estimate to determine appropriate channel beamforming weights, and instructs transmit beamforming circuitry to use the appropriate weights. | 07-07-2011 |
20110176439 | CLOSED-LOOP FEEDBACK IN WIRELESS COMMUNICATIONS SYSTEM - A method and apparatus for providing channel feedback is provided herein. During operation a covariance matrix at time t (R) is calculated as a function of a received downlink signal. In order to reduce overhead, R is normalized and quantized. The base unit then uses the covariance matrix estimate to determine appropriate channel beamforming weights, and instructs transmit beamforming circuitry to use the appropriate weights. In an embodiment, circuitry performs a method of calculating a first precoding matrix index I from a codebook using a received signal, calculating a second codebook index J* using the first precoding matrix index I to approximate a covariance matrix and calculating a quantized coefficient α* to approximate the covariance matrix wherein the quantized coefficient α* is determined using the first precoding matrix index I. | 07-21-2011 |
20110176581 | METHOD AND APPARATUS FOR PILOT SIGNAL PROCESSING IN A WIRELESS COMMUNICATION SYSTEM - A wireless communication system is provided that spreads pilot signals, or channel state information reference signals (CSI-RSs), using a spreading code chosen from a set of mutually unbiased bases (MUBs). The advantages of such spreading with MUBs are that multiple base stations can send their pilot signals on a same time-frequency resources, making the pilot signal design very efficient and also improving channel estimation at a user equipment through orthogonal and quasi-orthogonal spreading which gives a gain above noise and interference. A short spreading code chosen from MUBs may be used for spreading pilot signals transmitted from each antenna of a base station within a time-frequency resource comprising multiple closely-spaced subcarriers in frequency and/or multiple closely-spaced symbols in time. | 07-21-2011 |
20110254736 | MANIFOLD CALIBRATION FOR A COMMUNICATION SYSTEM - A method and apparatus for determining stream weights is provided herein. During operation, an uplink direction of arrival (DOA) and a downlink direction of departure (DOD) calibration procedure is implemented using uplink signals and GPS information from a subset of mobiles without the need of calibration circuitry at the base. Because the presented calibration procedure needs no new hardware it can be deployed in existing deployments with only a soft-ware upgrade. | 10-20-2011 |
20120069925 | METHOD AND APPARATUS FOR FEEDBACK IN CLOSED LOOP TRANSMITTING - A method an apparatus is described for providing feedback for closed-loop transmitting with multiple transmit and receive antennas. The method includes a first step | 03-22-2012 |
20120140843 | METHOD AND APPARATUS FOR TRANSMISSION WITHIN A MULTI-CARRIER COMMUNCATION SYSTEM - Multiple transmit antenna transmission together with preferably pseudo-random, antenna-specific, scrambling (PRAS) is utilized to scramble incoming data differently on different antennas for those users requiring frequency diversity type transmissions. When PRAS is activated for a particular allocation, each transmit antenna applies a different scrambling sequence to the data symbols that are transmitted in the allocation. | 06-07-2012 |
20120243501 | Method and Apparatus for Closed Loop Transmission - In a wireless communication system, a method and apparatus for closed loop transmission is disclosed. In accordance with the preferred embodiment of the present invention, a time frequency portion of an uplink frame is dynamically reserved as a sounding zone for uplink channel sounding. A first message is transmitted to a first subscriber station in a downlink frame assigning a time-frequency resource within the sounding zone, and a sounding waveform. Furthermore, a signal is received from the subscriber station within the assigned time-frequency resource, a partial channel response is determined from the received sounding signal, and the subsequent transmission to the subscriber station is tailored based on the at least partial channel response. | 09-27-2012 |
20130077705 | Codebook Performance For Non-Linear Arrays - A method to improve codebook performance for non-linear arrays is described. The method includes determining a unitary matrix for a plurality of transmission antennas arranged in a given array type, the unitary matrix being determined based on a codebook, where the given array type is configured to steer beams in at least one of elevation and azimuth. The method also includes applying the determined unitary matrix to a signal to be transmitted across the plurality of transmission antennas. Apparatus and computer readable media are also described. | 03-28-2013 |
20130094604 | Precoding For Coordinated Multi-Point Joint Transmission - The specification and drawings present a new method, apparatus and software related product (e.g., a computer readable memory) for implementing precoding for a coordinated multi-point joint transmission in LTE wireless systems using a specific product structure for a multi-point precoding matrix with designed and/or specified usage of multi-point codebooks for generating spatial data stream between a UE having multiple antennas and a plurality of cells. | 04-18-2013 |
20130162476 | Methods, Apparatuses, And Computer-Readable Storage Media for Performing Multidimensional Beamforming - Methods, apparatuses and computer-readable storage media perform phasing of a first array including one or more antenna elements and phasing of a second array including one or more antenna elements to provide a combined radiation pattern for the first and second arrays, the first array having a first radiation pattern and the second array having a second radiation pattern, wherein the first radiation pattern is substantially orthogonal to the second radiation pattern. The combined radiation pattern is controlled in a first dimension based upon an uplink channel measurement. The combined radiation pattern is controlled in a second dimension based upon a precoding feedback from a user equipment (UE). | 06-27-2013 |
20130259151 | Codebook Feedback Method for Per-User Elevation Beamforming - A method of operating an array of antennas in a wireless communication system to provide user-specific azimuth and elevation beamforming is described. The method includes providing a product codebook structure consisting of both an azimuth and elevation portion. A receiver receives reference signals from a transmitter corresponding to both the azimuth and elevation portions of the array of antennas. The method also includes determining the index of the azimuth codebook portion of the product codebook from the azimuth portion of the received reference signals and determining the index of the elevation codebook portion of the product codebook from the elevation portion of the received reference signals. Apparatus and computer readable media are also described. | 10-03-2013 |
20130272151 | Reference Signal Design And Signaling For Per-User Elevation MIMO - A method to use RSs for per-user elevation beamforming is described. An eNB sends, to a UE, an indication of which RSs in a plurality of RSs sound in the elevation dimension and which RSs in the plurality of RSs sound in the azimuthal dimension. Then, the eNB sends to the UE, the plurality of RSs using a plurality of antenna. The UE separates the plurality of RSs into the first portion and the second portion based at least in part on the indication and sends elevation and azimuthal feedback based on the received RSs to the eNB. The eNB determines beamforming weights for the plurality of antenna based at least in part on the elevation feedback and the azimuthal feedback. Apparatus and computer readable media are also described. | 10-17-2013 |
20130279615 | DIFFERENTIAL CLOSED-LOOP TRANSMISSION FEEDBACK IN WIRELESS COMMUNICATION SYSTEMS - A method and apparatus for providing channel feedback is provided herein. During operation a covariance matrix at time t (R) is calculated as a function of a received downlink signal. Matrix C | 10-24-2013 |