Abstract:
A method and system for improving responsiveness in exchanging management and control frames in a wireless local area network are disclosed. An initiator sends a frame (action frame, management frame, CSI frame, control frame, or data frame) to a responder. Upon correctly receiving the frame, the responder sends a response frame to the initiator instead of directly sending an acknowledgement (ACK) packet. The responder preferably accesses the wireless medium to send the response frame in a short inter-frame spacing (SIFS). With this scheme, a long delay associated with having to contend for the wireless medium to send the response frame is avoided and therefore, the responsiveness and timeliness of the feedback mechanism is significantly enhanced. The response frame may be piggybacked on or aggregated with another packet.
Abstract:
A wireless transmit/receive units (WTRUs) receives a downlink transmission from a Node-B and decodes the downlink transmission. If the decoding is not successful, the WTRU sends a pre-defined burst signifying a negative acknowledgement (NACK) to the Node-B via a contention-based shared feedback channel. The pre-defined burst may be sent only once without requiring an acknowledgement. The Node-B calibrates a downlink transmit power so that the downlink transmission is transmitted to the WTRUs with a high likelihood. The Node-B may send a downlink transmission including multiple data streams processed using different modulation and coding schemes so that a WTRU having a high signal quality decodes all data streams while a WTRU having a low signal quality decodes less than all data streams. The Node-B sends a channel quality indicator (CQI) threshold so that each WTRU determines a data stream to report feedback based on the CQI threshold and a measured CQI.
Abstract:
A method and apparatus for implementing spatial processing with unequal modulation and coding schemes (MCSs) or stream-dependent MCSs are disclosed. Input data may be parsed into a plurality of data streams, and spatial processing is performed on the data streams to generate a plurality of spatial streams. An MCS for each data stream is selected independently. The spatial streams are transmitted via multiple transmit antennas. At least one of the techniques of space time block coding (STBC), space frequency block coding (SFBC), quasi-orthogonal Alamouti coding, time reversed space time block coding, linear spatial processing and cyclic delay diversity (CDD) may be performed on the data/spatial streams. An antennal mapping matrix may then be applied to the spatial streams. The spatial streams are transmitted via multiple transmit antennas. The MCS for each data stream may be determined based on a signal-to-noise ratio of each spatial stream associated with the data stream.
Abstract:
A method and apparatus may be used to broadcast a first beacon and a second beacon in a beacon interval. The first beacon may include an indicator that indicates whether a second beacon will be transmitted within the beacon interval. The first beacon may be a legacy beacon and the second beacon may be a non-legacy beacon. A legacy beacon may be decodable by any station (STA) and a non-legacy beacon may be decodable only by non-legacy STAs.
Abstract:
The present invention is related to a method and apparatus for implementing space frequency block coding (SFBC) in an orthogonal frequency division multiplexing (OFDM) wireless communication system. The present invention is applicable to both a closed loop mode and an open loop mode. In the closed loop mode, power loading and eigen-beamforming are performed based on channel state information (CSI). A channel coded data stream is multiplexed into two or more data streams. Power loading is performed based on the CSI on each of the multiplexed data streams. SFBC encoding is performed on the data streams for each of the paired subcarriers. Then, eigen-beamforming is performed based on the CSI to distribute eigenbeams to multiple transmit antennas. The power loading may be performed on two or more SFBC encoding blocks or on each eigenmodes. Additionally, the power loading may be performed across subcarriers or subcarrier groups for weak eigenmodes.
Abstract:
A method and apparatus for adjusting power grants in wireless communications. Multiple power grant tables are stored and one or more tables are designated during communication.
Abstract:
A method and apparatus for adjusting power grants in wireless communications. Multiple power grant tables are stored and one or more tables are designated during communication.
Abstract:
A user equipment (UE) includes circuitry configured to receive control information on a downlink control channel from a base station. The control information indicates an allocation of an uplink channel and the control information is sent in response to the base station determining that the UE is to send an adaptive modulation and coding report. The circuitry is further configured in response to the control information to transmit a communication in the allocated uplink channel in a time interval including at least one time slot. The communication includes an adaptive modulation and coding report, and a transmission power level of the communication is derived from the control information and a pathloss measured by the UE.
Abstract:
A method for downlink power control for use in a spread spectrum time division communication system having time slots for communication, implemented in a user equipment, includes receiving data in a command per coded composite transport channel (CCTrCH) transmitted over a plurality of time slots. An interference power for each time slot of the plurality of time slots is measured and a single power command for the entire CCTrCH is transmitted in response to a signal to interference ratio of the received CCTrCH and the measured interference power measurement for each time slot. A subsequent data is received in the CCTrCH communication having a transmission power level for each downlink communication time slot set individually in response to the interference power measurement for that time slot and the single power command for the entire CCTrCH.
Abstract:
A wireless hybrid time division multiple access/code division multiple access (TDMA/CDMA) user equipment (UE) includes a signaling receiver and a data detection device in communication with the signaling receiver. The signaling receiver is configured to receive and recover signaled information of code and timeslot assignments of the UE to suport an RF communication. The data detection device is configured to recover from the signaling information an identifier of a plurality of assigned timeslots and an indication of a first and last code of a set of consecutive codes. The last code is identified by an identifier associated with the last code.