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 |
20080248800 | Managing handoffs between overlaid networks - A method and apparatus of managing a subscriber handoff between types of wireless networks is disclosed. The method includes the subscriber maintaining a wireless connection with a first wireless network. The subscriber simultaneously monitors availability of a second wireless network during open time slots of frames of transmission scheduling of the subscriber. The subscriber activates communication support circuitry for supporting a wireless connection to the second wireless network, if the second wireless network is detected to be available. | 10-09-2008 |
20080273453 | Methods and systems for channel estimation in a collaborative Multi Input Multiple Output (MIMO) communication system - Methods and systems for estimating channel of one or more MSs in a collaborative MIMO communication system are provided. The method includes receiving a signal transmitted from a transmit antenna of a first MS and a transmit antenna of a second MS at a BTS using one or more receiver antennas. The method further includes computing one or more conjugate products for each of the first MS and the second MS using the signal. Thereafter, an average is determined over the plurality of receiver antennas and the plurality of tiles of the plurality of conjugate products for each of the first MS and the second MS. A phase determined based on the average of the plurality of conjugate products for the first MS and the second MS is divided into a first phase and a second phase for each of the first MS and the second MS. Additionally, the method includes determining a channel estimate for each tile of the first MS and the second MS at each receiver antennas. The method further includes performing predefined computations on the channel estimate of each tile of the first MS and the second MS at each receiver antenna of the BTS using the corresponding first phase and the corresponding second phase. | 11-06-2008 |
20080273510 | Methods of transmitting pilot tones and data in spatial multiplexing transmission - A method and apparatus of transmitting pilot tones and data in multi-carrier spatial multiplexing transmission is disclosed. The method includes a plurality of subscribers transmitting data to a base station through common frequency sub-carrier and symbol time tiles. Each of the multiple subscribers rotating frequency sub-carrier and symbol time locations of pilot tones within the frequency sub-carrier and symbol time tiles. | 11-06-2008 |
20080273621 | Method and apparatus for estimating frequency offset and timing offset of one or more mobile stations (MSs) - A method and apparatus for estimating frequency offset and timing offset of a first Mobile Station (MS) in a communication system is provided. The method includes receiving a composite signal at a plurality of receiver antennas of a Base Transceiver Station (BTS). The composite signal includes a first signal transmitted from a first MS and a second signal transmitted from a second MS. The composite signal includes one or more tiles. Each tile includes a plurality of data sub-carriers, a plurality of first pilot sub-carriers, and a plurality of second pilot sub-carriers. A total phase offset of the first MS is estimated based on a complex conjugate product of pilot symbols of the plurality of first pilot sub-carriers. Thereafter, a first phase offset corresponding to the timing offset of the first MS is estimated based on a Power Delay Profile (PDP) of one or more first pilot sub-carriers. Finally, a second phase offset corresponding to the frequency offset of the first MS is determined based on the total phase offset and the first phase offset. | 11-06-2008 |
20080285537 | System and method for communicating packet in a wireless multicast and broadcast communication network - A method and system for communicating packets in a Wireless Multicast and Broadcast communication network is provided. The method includes selecting a Modulation and Coding Scheme (MCS) for transmission of a packet. The packet is then transmitted using the selected MCS on at least one of a subset of available time slots, a subset of available frequency sub-carriers and a subset of available antennas. Thereafter, it is autonomously decided whether the plurality of transmitters are to retransmit the packet. Then, the packet is retransmitted on at least one of a different subset of time slots, a different subset of frequency sub-carriers and a different subset of antennas. | 11-20-2008 |
20090034558 | Method and system for detecting a presence and a start of a zone in a frame - The present invention provides methods and systems for detecting a start symbol of a second zone of a frame. One or more symbol indices corresponding to one or more symbols of the second zone of a frame are derived. One or more codes on pilot sub-carriers corresponding to the one or more symbol indices may also be derived. Based on the one or more symbol indices a set of possible start symbol indices is established. Thereafter, a frame is received comprising one or more of a preamble symbol, a first zone and the second zone. It is determined if the received frame comprises the second zone. If the second zone is present in the received frame, the start symbol index of the second zone of the received frame is determined based on the detection of one or more codes and the set of possible start symbol indices. The present invention further provides methods and systems for detecting a N | 02-05-2009 |
20090049358 | Methods and systems for terminating an iterative decoding process of a forward error correction block - The invention provides methods and systems for terminating an iterative decoding process of a Forward Error Correction block (FEC). The iterative decoding process of the FEC block is terminated upon determining that the FEC block cannot be decoded successfully. A method comprises calculating a metric based on one or more Log Likelihood Ratios (LLRs) corresponding to a first number of iterations of the iterative decoding process of the FEC block. The method further comprises, formulating one or more stopping criteria for the iterative decoding process based on a variation pattern of the metric over a second predetermined number of iterations of the iterative decoding process. The second predetermined number of iterations is a subset of the first number of iterations. Moreover, the method comprises terminating the iterative decoding process of the FEC block based on the one or more stopping criteria. | 02-19-2009 |
20090049362 | Method and system for decoding a data burst in a communication system - The present invention provides methods and systems for decoding a data burst in a communication system. A data burst, including a plurality of forward error correction (FEC) blocks, is received. At least one FEC block of the data burst is decoded. Thereafter, it is detected if one or more errors are present in the at least one FEC block of the data burst. Upon detecting one or more errors in the at least one FEC block, the method halts the decoding of the data burst. In response to detecting the one or more errors, a retransmitted data burst corresponding to the data burst is received. One or more FEC blocks of the data burst may be combined with corresponding one or more FEC blocks of the retransmitted data burst. The one or more FEC blocks of the data burst includes the at least one FEC block that had the one or more errors detected as present. Thereafter, the decoding of the retransmitted data burst is commenced starting from the at least one FEC block that had the one or more errors detected as present in the previous transmission. | 02-19-2009 |
20090069022 | Method and system for estimating channel of a mobile station in a communication system - A method of estimating a channel between a desired Mobile Station (MS) and a Base Transceiver Station (BTS) antenna of a one of a plurality of sectors of a BTS. The method includes receiving a composite signal at the BTS antenna. The composite signal comprises a desired MS signal and an interfering MS signal. Thereafter, a known desired random sequence and a known interfering random sequence is applied to pilot symbols of the composite signal, resulting in a first de-randomized signal and a second de-randomized signal. Finally, the channel estimate is obtained by weighting and summing the first de-randomized signal and second de-randomized signal. | 03-12-2009 |
20090074045 | Estimating frequency offset at a subscriber station receiver - A method and system of estimating frequency offset at a subscriber station is disclosed. The method includes the subscriber station receiving a composite signal, in which 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 include a plurality of pilot sub-carriers. The subscriber station selects a subset of the plurality of pilot sub-carriers of 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 received symbols across at least one pair of multi-carrier symbols of each of the pilot sub-carriers of the selected subset of the plurality of pilot sub-carriers. | 03-19-2009 |
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 |
20090154388 | Link adaptation of a broadcast system - A method and apparatus of link adaptation of a broadcast system is disclosed. The method includes a base station adaptively determining a signal quality threshold. The base station broadcasts a signal, wherein the signal includes the signal quality threshold. A plurality of subscribers receives the signal, and measure a signal quality. Each of a subset of the plurality of subscribers transmits back to the base station an indicator of whether the received signal has a measured signal quality that is either above or below the signal quality threshold. A percentage of subscribers that receive the signal having a received signal quality above the signal quality threshold is estimated. A transmission modulation format and coding is selected based on the estimated percentage. | 06-18-2009 |
20090207762 | Assigning mobile users in a half-frequency division duplex (HFDD) system to uplink (UL) sub-frames and to downlink (DL) sub-frames - Methods assigning mobile users in a half-frequency division duplex (HFDD) system to a first UL group and second UL group of an uplink (UL) sub-frame, and to a first DL group and a second DL group of a downlink (DL) sub-frame, wherein the UL sub-frame is assigned a first carrier frequency and the DL sub-frame is assigned a second carrier frequency, are disclosed. One method includes determining a type of data, determining a receive CINR (carrier interference plus noise ratio), and determining a Doppler frequency parameter, for each mobile user of a plurality of mobile users. The plurality of mobile users to are assigned to the first UL group, the second UL group, the first DL group and the second DL group based on time durations of the first UL group, the second UL group, the first DL group and the second DL group, and based on and at least one of the data type, CINR, Doppler frequency spread of the mobile user, and a number of mobile users previously assigned to the first UL group, the second UL group, the first DL group and the second DL group. | 08-20-2009 |
20090247091 | Selecting receiver chains of a mobile unit for receiving wireless signals - A method and apparatus of selecting which of a plurality of receiver chains of a mobile unit to receive wireless signals, is disclosed. One method includes measuring a first receive signal quality while all of the plurality of receiver chains are receiving wireless signals, and measuring a second receive signal quality while a subset of the plurality of receiver chains are receiving wireless signals. The subset of the plurality of receiver chains are selected to receive wireless signal unless the first receive signal quality is a threshold better than the second receive signal quality. If the first receive signal quality is a threshold better than the second receive signal quality then all the plurality of receiver chains are selected to receive wireless signals. | 10-01-2009 |
20090275335 | Determining a handoff metric - A method and apparatus of determining a hand-off metric is disclosed. One method includes a subscriber receiving identifications of a neighboring set of base stations from a serving base station. From the neighboring set, the subscriber determines an active set of base stations. The active set is determined by the subscriber measuring received signal power from each of the base stations of the neighboring set at first discrete points in time, averaging the received signal power for each of the base stations of the neighboring set, and selecting the active set based on the average received signal power of the base stations of the neighboring set. Determining the at least one hand-off metric further includes the subscriber measuring at second discrete points in time an excess received signal power for each base station of the active set, wherein the excess received signal power includes signal power received by the subscriber in excess of power received from the base station. The subscriber averages the excess received signal power. The subscriber calculates the hand-off metric by calculating a ratio of average receive signal power to average excess received signal power, for each base station of the active set. | 11-05-2009 |
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 |
20100081467 | Subscriber Station Transceiver Allocation of Groups of Subcarriers Between a Plurality of Transceiver Antennas - Embodiments for at least one method and apparatus of a subscriber station transceiver allocating and transmitting groups of subcarriers between a plurality of transceiver antennas are disclosed. One method includes the subscriber station transceiver receiving at least one downlink signal through each of the plurality of subscriber station antennas. The subscriber station transceiver characterizes a received signal of the at least one downlink signal over multiple subcarriers. The subscriber station transceiver allocates groups of subcarriers for uplink transmission through each of the plurality of subscriber antennas, wherein the allocation is based on the characterized received signal of the at least one downlink signal over multiple subcarriers. | 04-01-2010 |
20100158139 | Method and system for communication in a wireless orthogonal frequency division multiplexing (OFDM) Communication system - Method and system for wireless communication in an Orthogonal Frequency Division Multiplexing (OFDM) communication system is disclosed. The method involves receiving a plurality of receive-signals over a first set of antennas. Further, one or more of the plurality of receive-signals are cyclically delayed to generate one or more cyclically delayed receive-signal. Subsequently, one or more of the plurality of receive-signals are combined with one or more of the cyclically delayed receive-signals. In other words, the method involves performing receive Cyclic Delay Diversity (CDD). | 06-24-2010 |
20100215032 | Synchronization and Frame Structure Determination of a Base Station - A method and apparatus of synchronization and frame structure determination of a base station are disclosed. One method includes the base station determining an initial frame structure including an active region and a dummy region, wherein the regions are sets of OFDM symbols. The base station receives timing information from at least one of a mobile station and a second base station, wherein the mobile station is simultaneously communicating with the base station and the second base station. The base station adjusts its frame structure based at least in part on the timing information, wherein adjusting its frame structure includes at least one of adjusting the active region and the dummy region. The base station adjusts its internal timing to improve synchronization with the second base station based on the timing error information. | 08-26-2010 |
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 |
20110019778 | Estimating Frequency Offset at a Subscriber Station Receiver - A method and system of estimating frequency offset at a subscriber station is disclosed. The method includes the subscriber station receiving a composite signal, in which 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 include a plurality of pilot sub-carriers. The subscriber station selects a subset of the plurality of pilot sub-carriers of 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 received symbols across at least one pair of multi-carrier symbols of each of the pilot sub-carriers of the selected subset of the plurality of pilot sub-carriers. | 01-27-2011 |
20110064154 | Methods and Systems For Performing Channel Estimation In A Wireless Communication System - The invention provides methods and systems for channel estimation. A method comprises receiving a plurality of signal frames, comprising at least a first zone and a second zone, from a plurality of base stations in the wireless communication system. Two or more first delay profiles corresponding to two or more base stations are determined using the first zone. The method further comprising detecting at least one aliased tap in a time domain channel response of the second zone using the two or more first delay profiles. Another method comprises receiving a signal frame, comprising at least a preamble symbol and a data part, from a base station. A first delay profile corresponding to the preamble symbol is determined and a second delay profile corresponding to the data part is obtained. The first delay profile is analyzed in conjunction with the second delay profile to detect one or more aliased taps in a time domain channel response of the data part. The detected one or more aliased taps are nulled/rectified. | 03-17-2011 |
20110069793 | Method and Apparatus for Estimating Frequency Offset and Timing Offset of One or More Mobile Stations - A method and apparatus for estimating frequency offset and timing offset of a first Mobile Station (MS) in a communication system is provided. The method includes receiving a composite signal at a plurality of receiver antennas of a Base Transceiver Station (BTS). The composite signal includes a first signal transmitted from a first MS and a second signal transmitted from a second MS. The composite signal includes one or more tiles. Each tile includes a plurality of data sub-carriers, a plurality of first pilot sub-carriers, and a plurality of second pilot sub-carriers. A total phase offset of the first MS is estimated based on a complex conjugate product of pilot symbols of the plurality of first pilot sub-carriers. Thereafter, a first phase offset corresponding to the timing offset of the first MS is estimated based on a Power Delay Profile (PDP) of one or more first pilot sub-carriers. Finally, a second phase offset corresponding to the frequency offset of the first MS is determined based on the total phase offset and the first phase offset. | 03-24-2011 |
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 |
20120201160 | ASSIGNING MOBILE USERS IN A HALF-FREQUENCY DIVISION DUPLEX (HFDD) SYSTEM TO UPLINK (UL) SUB-FRAMES AND TO DOWNLINK (DL) SUB-FRAMES - Methods assigning mobile users in a half-frequency division duplex (HFDD) system to first and second UL groups of an uplink (UL) sub-frame, and to first and second UL groups of a downlink (DL) sub-frame, where the UL sub-frame has a first carrier frequency and the DL sub-frame has a second carrier frequency, are disclosed. One method includes determining a type of data, a receive CINR (carrier interference plus noise ratio), and a Doppler frequency parameter, for a plurality of mobile users. The mobile users to are assigned to the first UL group, second UL group, first DL group and second DL group based on time durations of the first UL group, second UL group, first DL group and second DL group, and at least one parameter of the determined parameters of the mobile users. | 08-09-2012 |
20120250612 | Method for Scanning in a Multi-Mode Multi-Antenna Device - A method and system are provided in which a device comprising a first or main phase locked loop (PLL) and a second or reference PLL, is operable to communicate utilizing a first and a second receiving antenna. The first PLL may generate a first signal based on a reference signal generated by the second PLL. A second signal may also be generated based on the reference signal. Data associated with a first radio access technology (RAT) may be received via the first receiving antenna utilizing the generated first signal. The first RAT or another RAT may be scanned via the second receiving antenna utilizing the generated second signal. The scan via the second receiving antenna may be performed concurrently with the reception of data via the first receiving antenna. A switch may be utilized to enable or disable scanning operations via the second receiving antenna. | 10-04-2012 |
20120257593 | Subscriber Station Transceiver Allocation of Groups of Subcarriers Between a Plurality of Transceiver Antennas - Embodiments for at least one method and apparatus of a subscriber station transceiver allocating and transmitting groups of subcarriers between a plurality of transceiver antennas are disclosed. One method includes the subscriber station transceiver receiving at least one downlink signal through each of the plurality of subscriber station antennas. The subscriber station transceiver characterizes a received signal of the at least one downlink signal over multiple subcarriers. The subscriber station transceiver allocates groups of subcarriers for uplink transmission through each of the plurality of subscriber antennas, wherein the allocation is based on the characterized received signal of the at least one downlink signal over multiple subcarriers. | 10-11-2012 |
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 |
20130072191 | Determining a Handoff Metric - A method and apparatus of determining a hand-off metric are disclosed. One method includes a subscriber receiving identifications of a neighboring set of base stations from a serving base station, determining an active set of base stations by measuring received signal power from each of the base stations of the neighboring set at first discrete points in time, averaging the received signal power for each of these base stations, and selecting the active set based on the average received signal power. Determining the hand-off metric further includes calculating a ratio of average receive signal power to average excess received signal power, for each base station of the active set, wherein the excess received signal power includes signal power received by the subscriber in excess of power received from the base station. | 03-21-2013 |
20130308483 | Selecting Receiver Chains of a Mobile Unit for Receiving Wireless Signals - A method and apparatus of selecting which of a plurality of receiver chains of a mobile unit to receive wireless signals, is disclosed. One method includes measuring a first receive signal quality while all of the plurality of receiver chains are receiving wireless signals, and measuring a second receive signal quality while a subset of the plurality of receiver chains are receiving wireless signals. The subset of the plurality of receiver chains are selected to receive wireless signal unless the first receive signal quality is a threshold better than the second receive signal quality. If the first receive signal quality is a threshold better than the second receive signal quality then all the plurality of receiver chains are selected to receive wireless signals. | 11-21-2013 |
20130329679 | Subscriber Station Transceiver Allocation of Groups of Subcarriers Between a Plurality of Transceiver Antennas - Embodiments for at least one method and apparatus of a subscriber station transceiver allocating and transmitting groups of subcarriers between a plurality of transceiver antennas are disclosed. One method includes the subscriber station transceiver receiving at least one downlink signal through each of the plurality of subscriber station antennas. The subscriber station transceiver characterizes a received signal of the at least one downlink signal over multiple subcarriers. The subscriber station transceiver allocates groups of subcarriers for uplink transmission through each of the plurality of subscriber antennas, wherein the allocation is based on the characterized received signal of the at least one downlink signal over multiple subcarriers. | 12-12-2013 |
20140194116 | Method for Scanning in a Multi-Mode Multi-Antenna Device - A method and system are provided in which a device comprising a first or main phase locked loop (PLL) and a second or reference PLL, is operable to communicate utilizing a first and a second receiving antenna. The first PLL may generate a first signal based on a reference signal generated by the second PLL. A second signal may also be generated based on the reference signal. Data associated with a first radio access technology (RAT) may be received via the first receiving antenna utilizing the generated first signal. The first RAT or another RAT may be scanned via the second receiving antenna utilizing the generated second signal. The scan via the second receiving antenna may be performed concurrently with the reception of data via the first receiving antenna. A switch may be utilized to enable or disable scanning operations via the second receiving antenna. | 07-10-2014 |