Abstract: The disclosed method and apparatus include an WTRU-specific reference signal scheme that provides efficient precoded pilot transmission and effective channel estimation using dedicated pilot signals. The disclosed methods are efficient for both a single user (SU) and a multi user (MU) Multiple Input Multiple Output (MIMO) system.

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 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 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.

Abstract: The disclosed method and apparatus include an WTRU-specific reference signal scheme that provides efficient precoded pilot transmission and effective channel estimation using dedicated pilot signals. The disclosed methods are efficient for both a single user (SU) and a multi user (MU) Multiple Input Multiple Output (MIMO) system.

Abstract: A hybrid orthogonal frequency division multiple access (OFDMA) wireless transmit/receive unit (WTRU) and method are disclosed. A WTRU includes a transmitter and a receiver. The receiver processes received data to recover data mapped to the subcarriers using OFDMA. The receiver recovers first input data by separating user data from multi-user spread data and recovers second input data from non-spread data.

Abstract: A hybrid orthogonal frequency division multiple access (OFDMA) wireless transmit/receive unit (WTRU) and method are disclosed. A WTRU includes a transmitter and a receiver. The receiver processes received data to recover data mapped to the subcarriers using OFDMA. The receiver recovers first input data by separating user data from multi-user spread data and recovers second input data from non-spread data.

Abstract: A system and method for providing variable security levels in a wireless communication network. The present invention optimizes the often conflicting demands of highly secure wireless communications and high speed wireless communications. According to a preferred embodiment of the present invention, various security sensors are scanned to determine the likely presence of an intruder within a predetermined trust zone. If an intruder is likely present, the security level is changed to the highest setting, and consequently a lower data rate, while the intruder is identified. If the identified intruder is in fact a trusted node, the security level is returned to a lower setting. If the identified intruder is not a trusted node, the security level is maintained at an elevated state while the intruder is within the trust zone.

Abstract: A system and method for providing variable security levels in a wireless communication network. The present invention optimizes the often conflicting demands of highly secure wireless communications and high speed wireless communications. According to a preferred embodiment of the present invention, various security sensors are scanned to determine the likely presence of an intruder within a predetermined trust zone. If an intruder is likely present, the security level is changed to the highest setting, and consequently a lower data rate, while the intruder is identified. If the identified intruder is in fact a trusted node, the security level is returned to a lower setting. If the identified intruder is not a trusted node, the security level is maintained at an elevated state while the intruder is within the trust zone.

Abstract: A system and method for providing variable security levels in a wireless communication network. The present invention optimizes the often conflicting demands of highly secure wireless communications and high speed wireless communications. According to a preferred embodiment of the present invention, various security sensors are scanned to determine the likely presence of an intruder within a predetermined trust zone. If an intruder is likely present, the security level is changed to the highest setting, and consequently a lower data rate, while the intruder is identified. If the identified intruder is in fact a trusted node, the security level is returned to a lower setting. If the identified intruder is not a trusted node, the security level is maintained at an elevated state while the intruder is within the trust zone.

Abstract: A hybrid orthogonal frequency division multiple access (OFDMA) wireless transmit/receive unit (WTRU) and method are disclosed. A WTRU includes a transmitter and a receiver. The receiver processes received data to recover data mapped to the subcarriers using OFDMA. The receiver recovers first input data by separating user data from multi-user spread data and recovers second input data from non-spread data.

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: 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.

Abstract: 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.

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 hybrid orthogonal frequency division multiple access (OFDMA) wireless transmit/receive unit (WTRU) and method. A WTRU includes a transmitter and a receiver. The receiver processes received data to recover data mapped to the subcarriers using OFDMA. The receiver recovers first input data by separating user data from multi-user spread data and recovers second input data from non-spread data.

Abstract: A system and method for providing variable security levels in a wireless communication network. The present invention optimizes the often conflicting demands of highly secure wireless communications and high speed wireless communications. According to a preferred embodiment of the present invention, various security sensors are scanned to determine the likely presence of an intruder within a predetermined trust zone. If an intruder is likely present, the security level is changed to the highest setting, and consequently a lower data rate, while the intruder is identified. If the identified intruder is in fact a trusted node, the security level is returned to a lower setting. If the identified intruder is not a trusted node, the security level is maintained at an elevated state while the intruder is within the trust zone.

Abstract: A hybrid orthogonal frequency division multiple access (OFDMA) system including a transmitter and a receiver is disclosed. The transmitter includes a first spread OFDMA subassembly, a first non-spread OFDMA subassembly and a first common subassembly. The first spread OFDMA subassembly spreads input data and maps the spread data to a first group of subcarriers. The first non-spread OFDMA subassembly maps input data to a second group of subcarriers. The first common subassembly transmits the input data mapped to the first and second group of subcarriers using OFDMA. The receiver includes a second spread OFDMA subassembly, a second non-spread OFDMA subassembly and a second common subassembly. The second common subassembly processes received data to recover data mapped to the subcarriers using OFDMA. The second spread OFDMA subassembly recovers the first input data by separating user data in a code domain and the second non-spread OFDMA subassembly recovers the second input data.

Abstract: The present invention is related to a method and system for transmit power control in a multiple-input multiple-output (MIMO) wireless communication system. Both a transmitter and a receiver comprise multiple antennae for transmission and reception. The transmitter comprises a power allocation unit for controlling transmit power based on a feedback received from the receiver. The receiver comprises a channel estimator and a singular value decomposition (SVD) unit. The channel estimator generates a channel matrix from a signal received from the transmitter and the SVD unit decomposes the channel matrix into D, U and V matrices. The receiver sends a feedback generated based on output from the SVD unit to the transmitter for controlling the transmit power. The feedback may be one of an eigenvalue, a transmit power level or a power control bit or command. A hybrid scheme for selecting one of them based on channel condition may be implemented.

Abstract: A method and apparatus for providing fast detection of a high speed shared control channel (HS-SCCH). The HS-SCCH carries information necessary for receiving data via a high speed downlink shared channel (HS-DSCH). The apparatus receives messages transmitted via a plurality of HS-SCCHs. The apparatus measures a channel quality for the messages received via each HS-SCCH. The apparatus performs a threshold test by comparing the channel quality with a predetermined threshold. The apparatus then selects a HS-SCCH having the best channel quality among the HS-SCCHs.