Adaptix Limited

Manyuan Shen

Guanbin Xing

Hui Liu

Xun Shao

Xuan Li

Advantage is taken of adaptive allocation techniques by intentionally creating multi-user diversity in an otherwise flat fading environment in order to improve system capacity. In one embodiment, multi-path distortion can be resolved to determine subscriber station (SS) diversity gain. Overall network capacity can be increased by allocating channel assignments to SSs within the network based on determined SS diversity gains. In one embodiment, intentional multi-path distortion is produced by transmitting a signal and a time-delayed version of the signal from a base station (BS).

Systems and methods for wireless communication system channel allocation using intentional delay distortion

A method and apparatus for antenna switching, grouping, and channel assignments in wireless communication systems. The invention allows multiuser diversity to be exploited with simple antenna operations, therefore increasing the capacity and performance of wireless communications systems. Channel characteristics indicative of signal reception quality for downlink or bi-directional traffic for each channel/antenna resource combination are measured or estimated at a subscriber. Corresponding channel characteristic information is returned to the base station. Channel characteristics information may also be measured or estimated for uplink or bi-directional signals received at each of multiple receive antenna resources. The base station employs channel allocation logic to assign uplink, downlink and/or bi-directional channels for multiple subscribers based on channel characteristics measured and/or estimated for the uplink, downlink and/or bi-directional channels.

Method and system for switching antenna and channel assignments in broadband wireless networks

A system and method of wireless communication power control is provided which allows for adjusting power levels without requiring high bandwidth for control. Embodiments allocate subcarriers into unequal power groups, each group having a consistent subcarrier power level. Using interference parameter information from a user, a subcarrier is assigned from a group having adequate power to maintain the user's required power level. In general, users with higher power requirements, such as those near cell boundaries, will be assigned subcarriers from a group having a higher power level. A cell may use a different allocation than a neighbor, so that subcarriers with the highest power level in one cell may not also have the highest power level in a neighboring cell. Such diversity may reduce inter-cell interference of the subcarriers near a cell boundary, since no two subcarriers are transmitted with highest power simultaneously by neighboring base stations.

Subcarrier group based power control for OFDMA systems

A method and system for cooperative multiple-input multiple output (MIMO) transmission and reception operations in a multicell wireless network. Under the method, antenna elements from multiple base stations and/or multiple antennas are utilized to from an augmented MIMO antenna array that is used to transmit and receive MIMO transmissions at base stations and/or terminals. The cooperative MIMO transmission scheme supports higher dimension space-time-frequency processing for increased capacity and system performance.

Cooperative MIMO in multicell wireless networks

Systems and methods which implement cooperative random or quasi-random beam forming as between a plurality of base stations in a wireless network to reduce multi-cell interference are shown. For example, a plurality of base stations in a wireless network cooperate to provide frequency resources, such as channels, subchannels, subcarriers, etc., in a plurality of randomesque beams. In operation, subscriber stations preferably analyze signals as received on a plurality of the randomesque beams to determine one or more 'best' beams for use in communication between the subscriber station and base station. Assuming an identified beam is available for use by the subscriber station, payload communications may be provided using one or more beams identified by the subscriber station as a 'best' beam. The base stations of the wireless network preferably cooperate to periodically reform the randomesque beams.

Reducing multi-cell interference using cooperative random beam forming

Methods and systems for improved channel estimation that jointly consider interference contributions and noise contributions separately. Associated method involve measuring pilot channel signals at a receiver and then determining what component of the measured pilot channel signals are attributable to a serving BS and what component of the measured pilot channel signals are attributable to an interfering BS. This information is used to determine a product of the pilot channel signals attributable to the serving BS and the pilot channel signal attributable to the interfering BS, where the found product is used to estimate said channel.

Methods and systems for channel estimation in a wireless communication network

Rapid uplink synchronization is enabled by reducing a 2D search problem to two 1D search problems, which can generally be performed in less time. Advantage is taken of fact that a mobile device sends a ranging code on multiple sub-carriers. Using the assumption that adjacent sub-carriers will have approximately equivalent channel characteristics, phase ambiguity can be removed by differentially combining pairs of adjacent sub-carriers. Once the phase ambiguity is removed, the code, timing, and power level may be determined relatively quickly. In one embodiment, the values of correlations between received signals and possible codes are compared with a threshold.

Systems and methods for rapid uplink air interface synchronization

Systems and methods for intelligently switching between communication modes. An optimum communication mode is selected based upon determining the mobility of the subscriber station, the location of the subscriber station, and orthogonality of signals received from the subscriber station with respect to a signal of another subscriber station. Each determination may be continually or incrementally performed according to the passage of a time interval or upon observation of changes in relevant conditions.

Intelligent mode switching in communication networks

Systems and methods for wireless communication system channel allocation using international delay distortion

A method and apparatus for combining signals of multiple users onto a common channel is disclosed. In one embodiment, the method comprises identifying one or more traffic channels that are of one or more predetermined quality levels to a plurality of subscriber units based on channel profiles of the plurality of subscriber units and transmitting phase modulation multiplexed signals to the plurality of subscriber units through a common set of one or more channels having higher quality than the one or more predetermined quality levels.

Exploiting multiuser diversity through phase modulation multiplexing

A method and system for cooperative multiple-input multiple output (MIMO) transmission operations in a multicell wireless network. Under the method, antenna elements from two or more base stations are used to from an augmented MIMO antenna array that is used to transmit and receive MIMO transmissions to and from one or more terminals. The cooperative MIMO transmission scheme supports higher dimension space-time-frequency processing for increased capacity and system performance.

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Bellevue, WA, United States of America

Manyuan Shen