Abstract:
PROBLEM TO BE SOLVED: To provide a sector which estimates interference observed from terminals in neighbor sectors to perform interference control.SOLUTION: A sector may generate an over-the-air (OTA) other-sector interference (OSI) report and/or an inter-sector (IS) OSI report based on an interference estimate value. The sector may send the IS OSI report to neighbor sectors, receive IS OSI reports from the neighbor sectors, and regulate data transmissions for terminals in the sector based on the received IS OSI reports.
Abstract:
PROBLEM TO BE SOLVED: To provide techniques for performing erasure detection and power control for a transmission without error detection coding. SOLUTION: For erasure detection, a transmitter transmits codewords via a wireless channel. A receiver computes a metric for each received codeword, compares the computed metric against an erasure threshold (316), and declares the received codeword to be "erased" or "non-erased". The receiver dynamically adjusts the transmit power on the basis of whether or not the codewords meet the erasure threshold. COPYRIGHT: (C)2011,JPO&INPIT
Abstract:
PROBLEM TO BE SOLVED: To adjust transmission power to mitigate both intra-sector interference to a serving base station and inter-sector interference to neighbor base stations.SOLUTION: The amount of inter-sector interference caused by a terminal is roughly estimated based on the total interference observed by each neighbor base station, channel gains for the serving and neighbor base stations, and the current transmission power level. The transmission power is decreased if high interference is observed by a neighbor base station and increased otherwise. The transmission power is adjusted by a larger amount and/or more frequently if the terminal is located closer to the neighbor base station observing high interference and/or if the current transmission power level is higher. The intra-sector interference is maintained within an acceptable level by limiting a received SNR for the terminal to be within a range of allowable SNRs.
Abstract:
PROBLEM TO BE SOLVED: To provide systems and methodologies that facilitate performing scalable transmission power offsets for an access terminal to ensure that a listening base station can hear a signal transmitted from the access terminal.SOLUTION: The power offset is generated as a function of a reverse link channel quality indicator feedback loop to permit the access terminal to adjust transmission power sufficiently without excessive power boosting, such as can occur under a static power-boosting scheme. Monitored parameters associated with channel quality indications may comprise erasure rate indicators provided by base stations in response to CQI signals from the access terminal, as well as mean received power levels associated with superframe preamble received at the access terminal.
Abstract:
PROBLEM TO BE SOLVED: To provide a technique for adjusting a transmit power to alleviate both of an in-sector interference for a service base station and an inter-sector interference for a neighbor base station. SOLUTION: The amount of inter-sector interference caused by a terminal is approximately estimated based on a whole interference observed by each neighbor base station, channel gains relating to a service base station and a neighbor base station, and a current transmit power level. When a high interference is observed by the neighbor base station, the transited power is decreased and otherwise increased. When the terminal is situated closer to the neighbor base station that observes the high interference and/or the current transmit power level is higher, the transmit power is adjusted to a larger quantity and/or more frequently. By limiting a received SNR relating to the terminal within a tolerable SNR range, the in-sector interference is maintained within a tolerable level. COPYRIGHT: (C)2010,JPO&INPIT
Abstract:
PROBLEM TO BE SOLVED: To provide multi-carrier code division multiple access (MC-CDMA) being able to be used in an uplink of a wireless communication system.SOLUTION: Data symbols of each terminal from a modulator 214 are spread using a different set of orthogonal codes assigned to each terminal by an OFDM modulator 220, and each data symbol is mapped to a modulation symbol in a time-frequency block so that the data symbol is in a group not overlapping with a hopping duration based on FH sequence. An orthogonal waveform is generated and transmitted by an IFFT 224.
Abstract:
PROBLEM TO BE SOLVED: To provide a method for performing the communication of a frame having two or more modulation schemes in a single system. SOLUTION: Each part of the communication frames having first and second parts has a plurality of subcarriers, and includes a step of modulating at least one subcarrier in the first part by using a first modulation scheme and a step of modulating one or more subcarriers in the second part by using a second modulation scheme different form the first modulation scheme. First type information is transmitted on at least one of the subcarriers in the first part by using the first modulation scheme. Second type information different from the first type information is transmitted on at least one or more of the subcarriers in the second part by using the second modulation scheme. COPYRIGHT: (C)2011,JPO&INPIT
Abstract:
PROBLEM TO BE SOLVED: To provide techniques to support simultaneous transmissions for more terminals in a multiple-access system. SOLUTION: In a single-carrier frequency division multiple access (SC-FDMA) system that utilizes interleaved FDMA (IFDMA) or localized FDMA, transmitters may transmit their pilots, which are orthogonal to one another, using time division multiplexing (TDM), code division multiplexing (CDM), interleaved frequency division multiplexing (IFDM) or localized frequency division multiplexing (LFDMA). A receiver performs the complementary demultiplexing (non-multiplexing) for the pilots and may derive a channel estimate for each transmitter using an MMSE technique or a least-square technique. Data transmissions sent on the same time-frequency block are separated by spatial filter matrices. The spatial filter matrices are derived based on the channel estimates and using zero-forcing, MMSE, or maximal ratio combining technique. COPYRIGHT: (C)2011,JPO&INPIT
Abstract:
PROBLEM TO BE SOLVED: To provide an apparatus and a method for transmitting an indicator of channel quality while minimizing use of a broadcast channel. SOLUTION: A metric of forward link geometry of observed transmission signals is determined. An indicator of channel quality value is determined as a function of the observed transmission signals. An access sequence is selected randomly from one group of a plurality of groups of access sequences, wherein each of the plurality of groups of access sequences corresponds to a different range of channel quality value. COPYRIGHT: (C)2011,JPO&INPIT
Abstract:
PROBLEM TO BE SOLVED: To provide multiplexing for a multicarrier cellular communication system. SOLUTION: For quasi-orthogonal multiplexing in an OFDMA system, multiplex traffic channels are defined for each base station. The traffic channels in each set are orthogonal to one another and can be pseudo-random, with respect to the traffic channels in each of the other sets. The minimum number of sets of channels is used to support a given number of terminals selected for data transmission. Each terminal transmits the data and pilot symbols on its traffic channel. A base station receives data transmissions from all terminals and can perform receiver spatial processing on received symbols with spatial filter matrices to obtain detected data symbols. The spatial filter matrix for each subband can be derived, based on channel response estimates for all terminals transmitting on that subband. COPYRIGHT: (C)2011,JPO&INPIT