摘要:
A secondary synchronization channel (S-SCH) for E-UTRA downlink is applied to any orthogonal frequency division multiple access (OFDMA) based system to reduce interference on S-SCHs among sectors of the same Node-B in an evolved universal terrestrial radio access (E-UTRA) system.
摘要:
A method of providing transmit diversity for a secondary synchronization channel (S-SCH) includes generating a S-SCH signal, performing a frequency switched transmit diversity (FSTD) process on the S-SCH signal to create a first processed signal, performing a precoding vector switching (PVS) process on the first processed signal to create a processed S-SCH signal, and transmitting the processed S-SCH signal.
摘要:
A method for transmitting feedback information for a wireless transmit receive unit (WTRU) includes multiplexing the feedback information with an uplink shared channel, mapping the multiplexed feedback information to orthogonal frequency division multiplex (OFDM) symbols and transmitting the feedback information to an e Node B. The method also includes multiplexing the feedback information with the uplink shared channel using distributed frequency division multiplexing (FDM), mapping the feedback information to a first OFDM symbol, and distributing the mapped feedback information equidistantly across the transmission bandwidth.
摘要:
A method and apparatus for reducing the number of time slots allocated to a wireless transmit/receive unit (WTRU) by a serving cell in a time division duplex (TDD) wireless communication system that comprises a plurality of cells and a radio network controller (RNC) wherein each cell serves WTRUs in a coverage area of the cell and the RNC controls radio resource assignments in the cells comprises the RNC determining whether it is possible to reduce the number of time slots allocated to a target WTRU based on an interference level at each time slot in the serving cell. The RNC reduces the number of time slots allocated to the target WTRU where the determination is positive.
摘要:
A wireless communication method and apparatus for selecting cells in an orthogonal frequency division multiple access (OFDMA) system are disclosed. A wireless transmit/receive unit (WTRU) measures a downlink path loss of a current serving cell and at least one other cell. The WTRU determines whether a path loss difference between the serving cell and the other cell is below a threshold. If the path loss difference is below the threshold, the WTRU measures a channel quality indicator (CQI) for each of the plurality of subcarrier blocks in the downlink of the current serving cell and the other cell, respectively. The WTRU reports the CQIs to a serving Node-B which selects a new cell based on the CQIs. Alternatively, a centralized access gateway (aGW) may select the new serving cell/Node-B, or the cell selection decision made by the serving Node-B may be forwarded to another Node-B via the centralized aGW.
摘要:
A method and system is disclosed for optimizing resource management in wireless communication systems wherein resources in neighboring and serving cells may be reassigned so that fragmentation may be reduced in serving cells. Resources in wireless communication systems are preferably managed to minimize fragmentation and where fragmentation can not be reduced based on current resource allocations, resources may be reassigned to allow fragmentation to be reduced.
摘要:
An orthogonal frequency division multiplexing (OFDM)-code division multiple access (CDMA) system is disclosed. The system includes a transmitter and a receiver. At the transmitter, a spreading and subcarrier mapping unit spreads an input data symbol with a complex quadratic sequence code to generate a plurality of chips and maps each chip to one of a plurality of subcarriers. An inverse discrete Fourier transform is performed on the chips mapped to the subcarriers and a cyclic prefix (CP) is inserted to an OFDM frame. A parallel-to-serial converter converts the time-domain data into a serial data stream for transmission. At the receiver, a serial-to-parallel converter converts received data into multiple received data streams and the CP is removed from the received data. A discrete Fourier transform is performed on the received data streams and equalization is performed. A despreader despreads an output of the equalizer to recover the transmitted data.
摘要:
The present invention relates to secret key generation and authentication methods that are based on joint randomness not shared by others (JRNSO), in which unique channel response between two communication terminals generates a secret key. Multiple network access points use a unique physical location of a receiving station to increase user data security. High data rate communication data is encrypted by generating a random key and a pseudo-random bit stream. A configurable interleaving is achieved by introduction of JRNSO bits to an encoder used for error-correction codes. Databases of user data are also protected by JRNSO-based key mechanisms. Additional random qualities are induced on the joint channel using MIMO eigen-beamforming, antenna array deflection, polarization selection, pattern deformation, and path selection by beamforming or time correlation. Gesturing induces randomness according to uniquely random patterns of a human user's arm movements inflected to the user device.
摘要:
In an orthogonal frequency division multiple access (OFDMA) system including at least one base station and at least one wireless transmit/receive unit (WTRU), sub-carriers are allocated for data transmissions to multiple access WTRUs, where sub-carriers are allocated according to a consecutive sub-carrier allocation (CSA) type and a distributed sub-carrier allocation (DSA) type. Pilot signals with distributed pilot sub-carriers are transmitted and measured at each WTRU to obtain a channel quality metric for each pilot sub-carrier. Each WTRU sends feedback to the base station reporting channel quality based on the measured channel quality metrics. An allocation type is selected and adaptively switched according to channel variations in time and frequency domain.
摘要:
Tokens/keys are produced for wireless communications. These tokens/keys are used for watermarks, signature insertion, encryption and other uses. In one embodiment, contextual information is used to generate tokens/keys. The tokens/keys may be derived directly from the contextual information. The contextual information may be used in conjunction with other information to derive the tokens/keys. Tokens/keys may be exchanged between transmit/receive units. The exchange of these tokens/keys may be encrypted.