Patent application number | Description | Published |
20090129458 | METHOD AND APPARATUS FOR ESTIMATING THE STEP-SIZE OF AN ADAPTIVE EQUALIZER - A step-size estimator for controlling the step-size of an adaptive equalizer incorporated in a transceiver (e.g., a wireless transmit/receive unit (WTRU)). The step-size estimator updates at least one adaptive equalizer tap used by the adaptive equalizer based on an apparent speed of a channel established between the transceiver and another transceiver. The step-size estimator includes a speed estimator, a signal-to-noise ratio (SNR) averager and a step-size mapping unit. The speed estimator is used to estimate the apparent speed of the channel (i.e., the observed and/or measured rate of change of the channel impulse response). The SNR averager generates a common pilot channel (CPICH) SNR estimate. The step-size mapping unit uses the speed estimate and the CPICH SNR estimate to generate a step-size parameter, μ, and a filter taps leakage factor parameter, α, used by the adaptive equalizer to update the filter tap coefficient. | 05-21-2009 |
20090175214 | METHOD AND APPARATUS FOR COOPERATIVE WIRELESS COMMUNICATIONS - A method and apparatus for cooperation in wireless communications. Cooperation is considered among a number of network elements, including at least one wireless transmit-receive unit, at least one relay station, and at least one base station. | 07-09-2009 |
20100003977 | METHOD AND APPARATUS FOR USE IN COOPERATIVE RELAYS USING INCREMENTAL REDUNDANCY AND DISTRIBUTED SPATIAL MULTIPLEXING - A method and apparatus are used in cooperative relays with incremental redundancy (IR) and distributed spatial multiplexing. A wireless transmit/receive unit (WTRU) may listen to the base station (BS) transmission during Phase 1 of the communication, and use cooperation between a relay station (RS) and the BS for the data transmission during Phase 2 to improve performance. During Phase 2, both the BS and the RS may transmit data to the WTRU, using either distributed Space Time Block Codes/Space Frequency Block Codes (STBC/SFBC) or distributed spatial multiplexing. | 01-07-2010 |
20100008283 | FRAME STRUCTURES TO SUPPORT MULTICAST COOPERATIVE RELAY SCHEMES - A plurality of time frame structures that support the use of multicast cooperative relay schemes are disclosed. These time frame structures are used in IEEE 802.16j networks as well as other wireless networks. Furthermore, modifications to the frame structures used in IEEE 802.16j networks are disclosed. | 01-14-2010 |
20100137017 | UPLINK POWER CONTROL FOR DISTRIBUTED WIRELESS COMMUNICATION - A method and apparatus for power control for distributed wireless communication is disclosed including one or more power control loops associated with a wireless transmit/receive unit (WTRU). Each power control loop may include open loop power control or closed loop power control. A multi-phase power control method is also disclosed with each phase representing a different time interval and a WTRU sends transmissions at different power levels to different set of node-Bs or relay stations during different phases to optimize communications. | 06-03-2010 |
20100239040 | DATA AND CONTROL MULTIPLEXING FOR UPLINK MIMO WITH CARRIER AGGREGATION AND CLUSTERED-DFT - A method and apparatus for signal processing in a wireless transmit receive unit (WTRU), including generating a plurality of data bits and a plurality of control bits, mapping the data bits and control bits to one or more codewords, multiplexing the data bits and control bits, dividing the bits into layers, allocating control bits to each layer based on a channel quality of each codeword and a channel quality of each layer, and channel interleaving each layer for output to one or more antennas. | 09-23-2010 |
20100315989 | METHOD AND APPARATUS FOR COOPERATIVE RELAYING IN WIRELESS COMMUNICATIONS - A method and apparatus for cooperative relaying in wireless communications is provided. An efficient and simplified relay scheme is disclosed that transitions between different modes on a per packet basis using scheduling information or switching information included in the packet, without requiring link reconfiguration. The cooperative relay scheme benefits further from the use of cooperative relaying protocols that emphasize centralized scheduling. One protocol emphasizes physical layer cooperation via synchronized transmissions and distributed space-time coding and the other protocol emphasizes medium access control (MAC) layer cooperation using different MAC flows or messages. | 12-16-2010 |
20100316096 | METHOD AND APPARATUS FOR SYNCHRONOUS HARQ OPERATION AND INTERFERENCE AVOIDANCE - A method and apparatus for avoiding a collision. A collision may be avoided by allocating a first set of subframes to a backhaul link transmission, and allocating a second set of subframes to an access link transmission. In one example, the second set of subframes may be a non-overlapping set of subframes with respect to the first set of subframes. In a second embodiment, a collision may be avoided by receiving a data transmission from an evolved Node-B (eNB) and transmitting an uplink (UL) grant to a wireless transmit/receive unit (WTRU) and a first acknowledgement (ACK) to the eNB. The transmission may be in response to the received data transmission. The RN may avoid a collision by further transmitting an automatic ACK to the WTRU and transmitting a second UL grant to the WTRU. In a third embodiment, a collision between an access link transmission and a backhaul link transmission may be avoided by detecting a collision and determining an interface priority based on a collision occurrence type. | 12-16-2010 |
20110096815 | POWER CONTROL FOR DEVICES HAVING MULTIPLE ANTENNAS - Power control for devices having multiple transmit antennas are disclosed, including power control methods for Physical Uplink Control Channel (PUCCH) and Sounding Reference Signal (SRS) transmissions for a wireless transmit/receive unit (WTRU). The PUCCH and SRS power control methods include selecting a multiple input multiple output (MIMO) mode and changing the power of the PUCCH or SRS transmission based on the selected MIMO mode. Another power control method estimates an antenna gain imbalance (AGI) for a WTRU having at least two transmit antennas. The AGI is based on measuring a Reference Signal Received Power (RSRP) on each transmit antenna. Each transmit antenna is then scaled by an AGI scaling factor based on the estimated AGI. | 04-28-2011 |
20110103292 | DL Backhaul Control Channel Design For Relays - Methods and apparatus are described for providing compatible mapping for backhaul control channels, frequency first mapping of control channel elements (CCEs) to avoid relay-physical control format indicator channel (R-PCFICH) and a tree based relay resource allocation to minimize the resource allocation map bits. Methods and apparatus (e.g., relay node (RN)/evolved Node-B (eNB)) formapping of the Un downlink (DL) control signals, Un DL positive acknowledgement (ACK)/negative acknowledgement (NACK) and/or relay-physical downlink control channel (R-PDCCH) (or similar) in the eNB to RN (Un interface) DL direction are described. This includes time/frequency mapping of above-mentioned control signals into resource blocks (RBs) of multimedia broadcast multicast services (MBMS) single frequency network (MBSFN)-reserved sub-frames in the RN cell and encoding procedures for these. Also described are methods and apparatus for optimizing signaling overheads by avoiding R-PCFICH and minimizing bits needs for resource allocation. | 05-05-2011 |
20110170589 | APPARATUS FOR ESTIMATING AND CORRECTING BASEBAND FREQUENCY ERROR IN A RECEIVER - An apparatus for estimating and correcting baseband frequency error in a receiver is disclosed. An equalizer performs equalization on a sample data stream and generates filter tap values based on the equalization. An estimated frequency error signal is generated based on at least one of the filter tap values. A rotating phasor is generated based on the estimated frequency error signal. The rotating phasor signal is multiplied with the sample data stream to correct the frequency of the sample data stream. Alternatively, a channel estimator performs channel estimation and generates Rake receive finger weights based on at least one of the finger weights. An estimated frequency error signal is generated based on at least one of the finger weights. | 07-14-2011 |
20110261747 | METHOD AND APPARATUS FOR SUPPORTING COMMUNICATION VIA A RELAY NODE - A method and apparatus for supporting communication via a relay node are disclosed. A relay node may receive wireless transmit/receive unit (WTRU) buffer status reports (BSRs) from a plurality of WTRUs that are served by the relay node. The WTRU BSRs indicate uplink buffer status at the WTRUs. The relay node then may forward the WTRU BSRs to a donor evolved Node B (DeNB). The relay node may send a relay node BSR to the DeNB. The relay node BSR indicates a relay node uplink buffer status and/or a relay node downlink buffer status at the relay node. The relay node may send a radio resource control (RRC) message to the DeNB for requesting radio resource reconfiguration. | 10-27-2011 |
20110268028 | UPLINK SOUNDING REFERENCE SIGNALS CONFIGURATION AND TRANSMISSION - Methods and apparatus for sounding reference signals (SRS) configuration and transmission. The methods include receiving configuration of wireless transmit/receive unit (WTRU)-specific SRS subframes for transmitting SRS and upon receipt of a trigger, transmitting the SRS for a number of antennas. The SRS transmissions may occur in each subframe of a duration of WTRU-specific SRS subframes that start a number of WTRU-specific SRS subframes after a triggering subframe. For multiple SRS transmissions from multiple antennas, cyclic shift multiplexing and different transmission combs may be used. The cyclic shift for an antenna may be determined from a cyclic shift reference value. The cyclic shift determined for each antenna providing a maximum distance between cyclic shifts for the antennas transmitting SRS in a same WTRU-specific subframe. SRS transmissions from multiple antennas in the WTRU-specific subframe may be done in parallel. Methods for handling collisions between SRS and physical channels are presented. | 11-03-2011 |
20120106465 | DOWNLINK CONTROL IN HETEROGENEOUS NETWORKS - Embodiments contemplate a wireless transmit/receive unit (WTRU) that may operate in a heterogeneous wireless communication network (HetNet). The WTRU may detect the presence of an extended physical downlink control channel (E-PDCCH) and may decode a physical downlink control channel (PDCCH) upon detecting the E-PDCCH. The WTRU may obtain scheduling information of the E-PDCCH on a physical downlink shared control channel (PDSCH) from the decoded PDCCH. The WTRU may also determine control information for the WTRU from the E-PDCCH using the scheduling information of the E-PDCCH. The HetNet may further include a first eNB and a second eNB and the WTRU may receive the E-PDCCH from the first eNB and another E-PDCCH from the second eNB. The other E-PDCCH may be coordinated with the E-PDCCH such that the interference between the other E-PDCCH and the E-PDCCH from the perspective of the WTRU may be reduced relative to no coordination. | 05-03-2012 |
20120113831 | Determination of Carriers and Multiplexing for Uplink Control Information Transmission - Embodiments contemplate methods and devices that may select uplink (UL) transmission resources for transmitting uplink control information (UCI). A determination may be made that UCI should be transmitted. A physical channel resource for transmission of the UCI may be selected and a wireless transmit/receive unit (WRTU) may transmit the UCI over a physical uplink channel capable of supporting multiple component carriers using the selected physical channel resource. The selection of the physical channel resource may include at least one of: selecting a pre-determined UL component carrier (CC) for uplink transmission on a physical uplink control shared channel (PUSCH) upon a PUSCH resource being available in a subframe, or, selecting a pre-determined UL CC for uplink transmission on a physical uplink control channel (PUCCH) capable of UCI transmission in the subframe upon a PUSCH resource not being available in the subframe. | 05-10-2012 |
20130095878 | UPLINK POWER CONTROL FOR DISTRIBUTED WIRELESS COMMUNICATION - A method and apparatus for power control for distributed wireless communication is disclosed including one or more power control loops associated with a wireless transmit/receive unit (WTRU). Each power control loop may include open loop power control or closed loop power control. A multi-phase power control method is also disclosed with each phase representing a different time interval and a WTRU sends transmissions at different power levels to different set of node-Bs or relay stations during different phases to optimize communications. | 04-18-2013 |