Patent application number | Description | Published |
20080239938 | Method and system for uplink coordinated reception in orthogonal frequency division multiple access systems - Embodiments disclose a method of coordinating reception of uplink transmissions in order to reduce interference among transceivers in an OFDM wireless transmission system, or similar communication system, including a number of receivers communicating with one or more basestations in cell or sector arrangements. A basestation within each sector includes an uplink coordinated reception process that imposes coordinated reception techniques across sector or cell boundaries in order to improve uplink transmission quality between target terminals and basestations within each sector. | 10-02-2008 |
20090092199 | Estimating frequency offset at a subscriber station receiver - A method and system of estimating frequency offset at a subscriber station is disclosed. One method includes the subscriber station receiving a composite signal, wherein the composite signal includes multi-carrier signals transmitted from a plurality of base stations. The subscriber station selects a first pair of multi-carrier symbols of the composite signal, wherein each multi-carrier symbol of the first pair of multi-carrier symbols includes a pilot sub-carrier having a common sub-carrier index. The subscriber station selects a second pair of multi-carrier symbols of the composite signal, the second pair having different symbol indices than the first pair, but having a same symbol index separation, wherein each of the multi-carrier symbols of the second pair of multi-carrier symbols includes a pilot sub-carrier having a second common sub-carrier index. The subscriber station estimates a phase based on a first sum of complex conjugate products between received symbols on the pilot sub-carriers of the first pair of multi-carrier symbols, and/or based on a second sum of complex conjugate products between received symbols on the pilot sub-carriers of the second pair of multi-carrier symbols. The subscriber station provides the phase to a filter of a frequency tracking loop of the subscriber station. | 04-09-2009 |
20090116575 | Method of a receiver estimating a plurality of channels - A method and apparatus of a receiver estimating a plurality of channels is disclosed. The method includes the receiver receiving a composite signal. The composite signal includes a signal from each of a plurality of transmission antennas, wherein the signal of each transmission antenna includes a delay relative to other signals of other antennas. The receiver estimates channels between the receiver and the plurality of transmission antennas based on amplitude and a phase of a received composite signal, at a plurality of frequencies. | 05-07-2009 |
20090141832 | Method for estimating frequency offset at a subscriber station receiver in a multi-carrier system - A method and system of estimating frequency offset of a subscriber station is disclosed. The method includes the subscriber station receiving a composite signal, wherein the composite signal includes multi-carrier signals transmitted from a plurality of base stations. The subscriber station selects a subset of the plurality of base stations. The subscriber station selects at least one pair of multi-carrier symbols of the composite signal, wherein each of the at least one pair of multi-carrier symbols includes a plurality of pilot sub-carriers. The subscriber station selects at least one group of the plurality of pilot sub-carriers within the at least one pair of multi-carrier symbols based on transmit pilot symbols of the pilot sub-carriers of the multi-carrier signals transmitted by the subset of the plurality of base stations. The frequency offset is estimated based on a conjugate product between a linear combination of received symbols of a first multi-carrier symbol of a pair of multi-carrier symbols with a linear combination of received symbols of a second multi-carrier symbol of the pair of multi-carrier symbols on each of the pilot sub-carriers of the at least one group of the plurality of pilot sub-carriers. | 06-04-2009 |
20090190488 | Method of aiding uplink beamforming transmission - A method and apparatus of aiding uplink beamforming transmission is disclosed. One method includes a base station downlink transmitting beamformed signals to at least a first terminal, the beam formed signals directed and conveying data to at least the first terminal. The method further includes a second terminal eavesdropping the transmitted beamformed signals, and measuring a signal quality. The second terminal estimates uplink channel information based on the measured signal quality, for aiding uplink transmission. Based at least in part on the estimated transmission channel, the second terminal transmits beamformed uplink signals to the base station. | 07-30-2009 |
20090190520 | Method of updating transmission channel information based on eaves-dropping of beamformed signals - A method and apparatus of providing a base station with updated transmission channel information is disclosed. The method includes the base station transmitting beamformed signals to a first terminal. A second terminal receives the transmitted beamformed signals, and measures a signal quality. The second terminal conveys back to the base station the measured signal quality, and a transmission identifier of the beamformed data signal. | 07-30-2009 |
20090310550 | Method and apparatus for link adaptation in wirless communication network - A method and apparatus for link adaptation in a wireless communication network is provided. The method includes computing a first channel quality parameter based on one or more channel quality parameters. The one or more channel quality parameters are associated with a communication link between a Mobile Station (MS) and a Base Station (BS). The method further includes determining a qualifying transmission unit to compute a correction parameter. The correction parameter is computed based on the first channel quality parameter and one or more transmission parameters. The one or more transmission parameter is associated with the communication link. Thereafter, the method schedules a transmission mode of the communication link based on a second channel quality parameter. The second channel quality parameter is estimated based the first channel quality parameter and the correction parameter. | 12-17-2009 |
20090316636 | Selecting a transmission mode between a subscriber and a base station - Embodiments for a method and apparatus of selecting a transmission mode between the subscriber and a base station are disclosed. One method includes determining a predictive window. Instantaneous channel quality measurements are averaged, wherein the averaging is dependent upon a size of the predictive window. A first estimate of the transmission mode is determined based on the averaged instantaneous channel quality measurements. A margin is calculated based on reception of a qualifying downlink transmission. The transmission mode is selected by updating the first estimate with the margin. | 12-24-2009 |
20100009689 | Method and apparatus for managing uplink communication in wireless communication network - A method for managing uplink communication in wireless communication network is provided. The method includes selecting one or more Mobile Stations (MSs) from a plurality of MSs based on a first signal parameter corresponding to each MS of the one or more MSs, one or more second signal parameters corresponding to each MS of the one or more MSs, and one or more threshold parameters. The first signal parameter is associated with a Base Station (BS) serving a MS. Further, the one or more second signal parameters are associated with one or more BSs neighboring to the MS. The one or more threshold parameters are associated with a communication parameter. Thereafter, the method includes modifying uplink Modulation and Coding Scheme (MCS) level of the one or more MSs. | 01-14-2010 |
20100195526 | Multi-Stream Priority-Based Space-Time Coding - Embodiments for space-time coding are disclosed. One method includes establishing a priority for each of a plurality of data streams. A number of data bits for each of the plurality of data streams are allocated. A desired signal quality for each of the plurality of data streams is determined based on the corresponding priority. Each of the plurality of data streams are modulated according to the allocated number of data bits of each of the plurality of data streams. A space-time code is selected for each of the plurality of data streams based at least partially on the desired signal quality for each of the plurality of data streams, wherein at least one of the space-time codes is at least one of a vector or a matrix. Each of the modulated data streams are space-time coded with the selected space-time code. The space-time coded modulated data streams are summed, and transmitted. | 08-05-2010 |
20100329370 | Selection of a Subset of Antennas for Transmission - A method and apparatus of a subscriber station selecting a subset of a plurality of antennas for uplink transmission are disclosed. One method includes a base station transmitting a cyclic delay diversity transmission signal. The subscriber station receives the cyclic delay diversity transmission signal through the plurality of antennas. The subscriber station selects a subset of the plurality of antennas based on a received quality signal parameter. The subscriber station transmits uplink signals to the base station through the selected subset of the plurality of antennas. | 12-30-2010 |
20110021210 | Estimating a subscriber location - A method and apparatus of estimating a location of a subscriber are disclosed. One method includes receiving a request for the location of the subscriber. The subscriber's serving base station, and a plurality of neighboring base stations sensed by the subscriber, are identified. At least two of the neighboring base stations are selected to aid in estimating the location of the subscriber. Stored locations of the serving base station and the selected neighboring base stations are accessed. The subscriber obtains a time delay from the serving base station for maintaining synchronization of the subscriber with the serving base station. The subscriber estimates a distance between the subscriber and the serving base station based on the time delay. The subscriber receives frames including preambles from each of the selected neighboring base stations, and estimates a delta time for each of the selected neighboring base stations for the subscriber to synchronize to each of the selected neighboring base stations. The subscriber estimates distances between the subscriber and each of the selected neighboring base stations based on the time delay and the delta time of each of the selected neighboring base stations. The subscriber location is estimated by trilateration of the distance between the subscriber and the serving base station, and the distances between the subscriber and each of the selected neighboring base stations. | 01-27-2011 |
20110216716 | Mobile Subscriber Information Transmission Over Multiple Uplink Frames - Methods and apparatuses of a mobile subscriber transmitting information to a base station are disclosed. One method includes identifying an uplink transmission condition. If the uplink transmission condition is identified, the mobile subscriber transmits a message over multiple uplink frames. The mobile subscriber informs the base station that it is transmitting the message over the multiple uplink frames. | 09-08-2011 |
20110223870 | Allocating Antennas for Cyclic Delay Diversity Transmission - Methods and apparatus of allocating antennas for cyclic delay diversity (CDD) transmission are disclosed. One method includes estimating a transmission channel of a transceiver having a plurality of antennas. A subset of a plurality of transceiver antennas is selected based on the estimated transmission channel. A single transceiver antenna of the subset is identified based on a channel quality of a transmission path of the single transceiver antenna. Cyclic delay diversity (CDD) signals are transmitted from the subset of the plurality of antennas, wherein a minimally delayed CDD signal is transmitted from the identified single transceiver antenna of the subset of the plurality of transceiver antennas. | 09-15-2011 |
20120327805 | Method of Aiding Uplink Beamforming Transmission - A method of aiding uplink transmission is disclosed. One method includes a base station downlink transmitting signals to at least a first terminal, the transmitted signals directed and conveying data to at least the first terminal. The method further includes a second terminal eavesdropping the transmitted signals, and measuring a signal quality. The second terminal estimates uplink channel information based on the measured signal quality, for aiding uplink transmission. Based at least in part on the estimated transmission channel, the second terminal transmits uplink signals to the base station. | 12-27-2012 |
20130005358 | Estimating a Subscriber Location - Estimating a location of a subscriber, including receiving a request for the location, identifying a serving base station of the subscriber, receiving a downlink frame from the serving base station, obtaining a time delay of a signal transmitted between the subscriber and the serving base station, the obtaining including estimating a time of arrival by extracting information from the received downlink frame, the extracting including, determining a channel impulse response of the downlink frame, and estimating the time of arrival by comparing a peak time of the determined channel impulse response with a start time of the downlink frame, the start time being estimated based on the channel impulse response exceeding a predetermined threshold value, estimating a distance between the subscriber and the serving base station based on the time delay, and estimating the location based on the estimated distance between the subscriber and the serving base station. | 01-03-2013 |
20130010734 | SELECTING A TRANSMISSION MODE BETWEEN A SUBSCRIBER AND A BASE STATION - Embodiments for a method and apparatus of selecting a transmission mode between the subscriber and a base station are disclosed. One method includes determining a predictive window. Instantaneous channel quality measurements are averaged, wherein the averaging is dependent upon a size of the predictive window. A first estimate of the transmission mode is determined based on the averaged instantaneous channel quality measurements. A margin is calculated based on reception of a qualifying downlink transmission. The transmission mode is selected by updating the first estimate with the margin. | 01-10-2013 |