摘要:
Techniques to transmit pilot on a CDMA segment on the reverse link in a wireless communication system are described. A terminal generates a scrambling sequence based on its pilot information. The pilot information may be used for the entire duration of a call by the terminal and for all sectors with which the terminal communicates during the call. The terminal generates pilot symbols based on the scrambling sequence, maps the pilot symbols to the CDMA segment, generates OFDM symbols with the mapped pilot symbols, and sends the OFDM symbols to one or more sectors. A base station processes received OFDM symbols to obtain received symbols for the CDMA segment. The base station generates the scrambling sequence based on the pilot information for the terminal and processes the received symbols with the scrambling sequence to obtain at least one parameter (e.g., received signal strength) for the terminal.
摘要:
Techniques for selecting serving sectors and performing handoff for a terminal on the forward and reverse links are described. The terminal may obtain pilot measurements for pilots transmitted on the forward link and may update an active set based on the pilot measurements. The terminal may send a transmission (e.g., for pilot, signaling, etc.) on the reverse link and may receive channel quality information indicative of reverse link channel quality for the terminal at multiple sectors in the active set. The transmission may include pilot, and the channel quality information from each sector may include a pilot carrier-over-thermal ratio (pCoT) determined by that sector based on the pilot. The terminal may select a serving sector based on the channel quality information, interference information, and/or other information and may send a request for handoff (e.g., via a signaling message an/or an access probe) to the selected serving sector.
摘要:
Techniques for controlling transmit power of a terminal are described. The terminal may send a first transmission (e.g., for pilot or signaling) on the reverse link, receive feedback (e.g., a power control command or an erasure indicator) for the first transmission, and adjust a reference power level based on the feedback. The terminal may also receive interference information and possibly other parameters such as a pilot quality indicator (PQI), an offset factor, and a boost factor from a sector. The terminal may determine transmit power for a second transmission to the sector based on the interference information, the reference power level, and/or the other parameters. The terminal may receive the feedback from one sector and may send the second transmission with CDMA or OFDMA to the same sector or a different sector.
摘要:
Transmission schemes that can flexibly achieve the desired spatial multiplexing order, spatial diversity order, and channel estimation overhead order are described. For data transmission, the assigned subcarriers and spatial multiplexing order (M) for a receiver are determined, where M≧1. For each assigned subcarrier, M virtual antennas are selected from among V virtual antennas formed with V columns of an orthonormal matrix, where V≧M. V may be selected to achieve the desired spatial diversity order and channel estimation overhead order. Output symbols are mapped to the M virtual antennas selected for each assigned subcarrier by applying the orthonormal matrix. Pilot symbols are also mapped to the V virtual antennas. The mapped symbols are provided for transmission from T transmit antennas, where T≧V. Transmission symbols are generated for the mapped symbols, e.g., based on OFDM or SC-FDMA. Different cyclic delays may be applied for the T transmit antennas to improve diversity.
摘要:
Transmission schemes that can flexibly achieve the desired spatial multiplexing order, spatial diversity order, and channel estimation overhead order are described. For data transmission, the assigned subcarriers and spatial multiplexing order (M) for a receiver are determined, where M≧1. For each assigned subcarrier, M virtual antennas are selected from among V virtual antennas formed with V columns of an orthonormal matrix, where V≧M. V may be selected to achieve the desired spatial diversity order and channel estimation overhead order. Output symbols are mapped to the M virtual antennas selected for each assigned subcarrier by applying the orthonormal matrix. Pilot symbols are also mapped to the V virtual antennas. The mapped symbols are provided for transmission from T transmit antennas, where T≧V. Transmission symbols are generated for the mapped symbols, e.g, based on OFDM or SC-FDMA. Different cyclic delays may be applied for the T transmit antennas to improve diversity.
摘要:
Methods and apparatuses are disclosed for providing flexible channel information feedback. In some cases this may be according to reporting types assigned by one or more sectors, with different reporting types for each sector. In other cases, a reporting mode is determined to determine the reporting types to be utilized.
摘要:
Methods and apparatuses are disclosed for providing flexible channel information feedback. In some cases this may be according to reporting types assigned by one or more sectors, with different reporting types for each sector. In other cases, a reporting mode is determined to determine the reporting types to be utilized.
摘要:
Techniques for controlling transmit power of a terminal are described. The terminal may send a first transmission (e.g., for pilot or signaling) on the reverse link, receive feedback (e.g., a power control command or an erasure indicator) for the first transmission, and adjust a reference power level based on the feedback. The terminal may also receive interference information and possibly other parameters such as a pilot quality indicator (PQI), an offset factor, and a boost factor from a sector. The terminal may determine transmit power for a second transmission to the sector based on the interference information, the reference power level, and/or the other parameters. The terminal may receive the feedback from one sector and may send the second transmission with CDMA or OFDMA to the same sector or a different sector.
摘要:
Transmission schemes that can flexibly achieve the desired spatial multiplexing order, spatial diversity order, and channel estimation overhead order are described. For data transmission, the assigned subcarriers and spatial multiplexing order (M) for a receiver are determined, where M≧1. For each assigned subcarrier, M virtual antennas are selected from among V virtual antennas formed with V columns of an orthonormal matrix, where V≧M. V may be selected to achieve the desired spatial diversity order and channel estimation overhead order. Output symbols are mapped to the M virtual antennas selected for each assigned subcarrier by applying the orthonormal matrix. Pilot symbols are also mapped to the V virtual antennas. The mapped symbols are provided for transmission from T transmit antennas, where T≧V. Transmission symbols are generated for the mapped symbols, e.g., based on OFDM or SC-FDMA. Different cyclic delays may be applied for the T transmit antennas to improve diversity.
摘要:
Apparatuses and methodologies are described that enhance performance in a wireless communication system using beamforming transmissions. According to one aspect, the channel quality is monitored. Channel quality indicators can be used to select a scheduling technique, such as space division multiplexing (SDM), multiple-input multiple output (MIMO) transmission and opportunistic beamforming for one or more user devices. In addition, the CQI can be used to determine the appropriate beam assignment or to update the beam pattern.