Abstract:
A method and apparatus for adaptive uplink/downlink resource assignment may include determining uplink interference associated with each of several uplink resources. The method and apparatus may produce an uplink list with values for the uplink resources. The method and apparatus may compare a downlink power level to a threshold for each of the downlink resources and produce a downlink list. The downlink list may be a bit stream providing an indication, for each downlink resource, indicating whether each of the downlink resources have a downlink power level which is less than or equal to the threshold. The method and apparatus may send the uplink and downlink lists. The method and apparatus may receive an uplink list and a downlink list from each of several neighboring wireless network devices. The method and apparatus may schedule uplink and downlink resources to a user equipment based on the uplink and downlink lists received.
Abstract:
One out of sixteen preamble signatures is selected. A code is produced based on the selected preamble signature. The produced code is phase rotated to produce a processed preamble signature signal. The processed preamble signature signal is used in processing the CDMA RACH signal and the CDMA RACH signal is used to access a CDMA system.
Abstract:
A multiple-input multiple-output (MIMO) beamforming-based single carrier frequency division multiple access (SC-FDMA) system is disclosed. At the transmitter, a fast Fourier transform (FFT) is performed on transmission data to generate frequency domain data. The frequency domain transmit data is mapped to assigned subcarriers. An inverse fast Fourier transform (IFFT) is performed on the transmit data mapped to the assigned subcarriers to generate time domain transmit data. The time domain transmit data is transmitted via antennas. At a receiver, an FFT is performed on the received data to generate frequency domain received data. Subcarrier demapping is performed to extract data mapped on the assigned subcarriers. A channel estimator generates a channel matrix which is decomposed into U, D and VH matrices. A channel distortion and interference between transmit and receive antennas are equalized based on the decomposed channel matrices to the extracted frequency domain received data.
Abstract:
A method and apparatus for transmitting data in code division multiple access communications. The method includes processing spread first data with a channel response matrix using an equalization circuit to pre-equalize the spread data to compensate for a channel response prior to transmission. The pre-equalized data is received and recovered by a receiver. Second data, transmitted from the receiver, is received and recovered using the equalization circuit to equalize the second data to compensate for a channel response that the first data encountered.
Abstract:
A method and apparatus for accessing a contention-based uplink random access channel (RACH) in a single carrier frequency division multiple access (SC-FDMA) system are disclosed. A wireless transmit/receive unit (WTRU) randomly selects a RACH subchannel and a signature among a plurality of available RACH subchannels and signatures. The WTRU transmits a preamble using the selected signature via the selected RACH subchannel at a predetermined or computed transmission power. A base station monitors the RACH to detect the preamble and sends an acquisition indicator (AI) to the WTRU when a signature is detected on the RACH. When receiving a positive acknowledgement, the WTRU sends a message part to the base station. If receiving a negative acknowledgement or no response, the WTRU retransmits the preamble.
Abstract:
A device capable of operating in a wireless communication environment. The device may be configured to determine a plurality of control signaling bits. The device may determine a plurality of cyclic redundancy check (CRC) bits based on the plurality of control signaling bits. The device may apply a channel coding scheme to the plurality of control signaling bits and the plurality of CRC bits. The plurality of CRC bits may be distributed among the plurality of control signaling bits prior to applying the channel coding scheme. The device may transmit the channel coded plurality of control signaling bits and CRC bits.
Abstract:
A method of feedback in a wireless transmit receive unit includes providing a precoding matrix index (PMI), error checking the (PMI) to produce an error check (EC) bit, coding the PMI and the EC bit and transmitting the coded PMI and EC bit.
Abstract:
A method and apparatus for synchronization in an orthogonal frequency division multiplexing (OFDM) network is disclosed. A wireless transmit/receive unit (WTRU) is configured to receive a primary synchronization signal and a secondary synchronization signal from a cell. The primary synchronization signal and the secondary synchronization signal are spaced by a known number of OFDM symbols. The primary synchronization signal and the secondary synchronization signal are received in a same number of subcarriers in their respective OFDM symbol. A location of at least the secondary synchronization signal in the system bandwidth is variable.
Abstract:
A method for reducing cross cell interference in a wireless time division duplex communication system using code division multiple access, the system having at least one user equipment (UE) and a base station (BS) is disclosed. The method begins by measuring an interference level of each timeslot at the BS. A timeslot is eliminated for additional uplink communication if the measured interference level exceeds a first threshold. UEs in nearby cells that are large interferers are identified and their downlink timeslot usage is gathered. A timeslot is eliminated for uplink communication for a large interferer UE that uses the timeslot for downlink communication.
Abstract:
A method and apparatus for efficient precoding matrix verification in a multiple-input multiple-output MIMO wireless communication system are disclosed. A wireless transmit/receive unit WTRU sends a precoding matrix index PMI to an eNodeB. The eNodeB sends a verification message including a PMI indicator indicating whether or not the PMI of the WTRU and a PMI of the eNodeB are identical. If the PMI of the WTRU and of the eNodeB are identical, the eNodeB sends just a PMI indicator otherwise the eNodeB sends to the WTRU a PMI indicator and the PMI of the eNodeB. A plurality of PMIs may be sent simultaneously, and the PMIs may be partitioned into a plurality of groups. The PMI indicator may be either attached to or inserted into control signaling. PMI validation messages can be signaled to WTRU by control signaling or use of a dedicated reference signal.