摘要:
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.
摘要:
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.
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:
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:
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.
摘要:
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.
摘要:
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.
摘要:
A method for performing cell search in an orthogonal frequency division multiple access (OFDMA) based cellular communication network in which a primary synchronization channel (P-SCH), and optionally a secondary synchronization channel (S-SCH), carries cell search information. A downlink signal is received containing P-SCH symbols. The P-SCH symbols are processed to obtain an initial detection of frame timing, orthogonal frequency division multiplexing (OFDM) symbol timing, a cell identifier (ID), a frequency offset, and a cell transmission bandwidth. Optionally, an OFDM symbol timing self-check and error correction is then performed.
摘要:
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.
摘要:
A method and apparatus for selecting a serving cell/Node-B in a single carrier frequency division multiple access (SC-FDMA) system are disclosed. For intra-Node-B serving cell selection, a serving Node-B measures channel quality indicators (CQIs) of each subcarrier block in an uplink of each cell controlled by the serving Node-B and selects a new serving cell based on the CQIs. The serving Node-B reports the selected new serving cell to a wireless transmit/receive unit (WTRU). For inter-Node-B serving cell selection, each of a plurality of Node-Bs measures a CQI of each of a plurality of subcarrier blocks in an uplink transmission in each cell controlled by each Node-B and forwards the CQIs to a serving cell selection entity. The serving cell selection entity selects a new serving cell/Node-B based on the CQIs. The serving cell selection entity may be a centralized access gateway, a current serving Node-B or a WTRU.