Abstract: 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.

Abstract: A system and method are provided for automatic gain control (AGC) using an adaptive reference and a threshold. An adaptive reference allows for adjusting the target power based on variations in operating parameters and conditions, such as a change to a modulation schemes which requires a different signal to noise ratio (SNR) to maintain performance. A gain adjustment threshold allows for rapid AGC response while reducing the potential effects of hysterisis. AGC levels may be changed during symbol prefixes or suffixes, and avoided during a data portion of a signal. Embodiments allow for symbol-by symbol AGC changes in OFDM, OFDMA, and TDD systems.

Abstract: 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.

Abstract: A communications base station is installed at a selected new location and the base station, prior to going “online” monitors the wireless traffic from other base stations within interference range of the new base station's coverage area. The new base station also monitors the wireless traffic between mobile devices within its coverage area and these other base stations. Based upon these monitored conditions, as well as other known conditions, the new base station then determines the transmitting parameter configuration it should imply in order to achieve a desired optimization between capacity and coverage area. After the new base station is online, a central control can monitor the entire network to determine if any additional changes are necessary and if so the new transceiver, or any other transceiver, can be instructed to monitor itself with respect to interference and to take corrective action to improve overall network coverage and capacity.

Abstract: 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.

Abstract: 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.

Abstract: An OFDMA communication system includes a plurality of terminals, with at least one of the terminals including at least one type of multi-user decoder adapted to decode a signal intended for the at least one terminal received on a subchannel of the system and adapted to decode at least a portion of an interfering signal received on the subchannel. The system also includes a plurality of base stations. Each of the base stations may be in communication with others of the base stations for exchanging information about data throughput for particular terminals in cells of the system using particular subchannels in the cells. Each of the base stations assigns the subchannels to terminals in the cell of the base station so as to maximize data throughput in the entire system.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: Systems and methods are disclosed for transporting data across an air interface using a blending of protocol layers to achieve reduced bandwidth. Advantage is taken of the fact that the extra overhead from, for example, the Ethernet protocol is addressing information pertaining to the destination of the packet. This destination information (for example, the Ethernet address) can be stripped from the transmission prior to the air interface and recreated after the air interface. In one embodiment, the concepts of a proper Layer 2 CS are merged on top of the 802.16 protocol and still retain the benefits of a Layer 2 transparent bridged service layer to the network layer. In one embodiment, the MAC address of the destination is used for the air interface and the Ethernet address is recreated and added on the far side of the air interface.

Abstract: A communications base station is installed at a selected new location and the base station, prior to going “online” monitors the wireless traffic from other base stations within interference range of the new base station's coverage area. The new base station also monitors the wireless traffic between mobile devices within its coverage area and these other base stations. Based upon these monitored conditions, as well as other known conditions, the new base station then determines the transmitting parameter configuration it should imply in order to achieve a desired optimization between capacity and coverage area. After the new base station is online, a central control can monitor the entire network to determine if any additional changes are necessary and if so the new transceiver, or any other transceiver, can be instructed to monitor itself with respect to interference and to take corrective action to improve overall network coverage and capacity.

Abstract: A method and apparatus for allocating subcarriers in an orthogonal frequency division multiple access (OFDMA) system is described. In one embodiment, the method comprises allocating at least one diversity cluster of subcarriers to a first subscriber and allocating at least one coherence cluster to a second subscriber.

Abstract: The present invention is directed to a system and method which base stations send informational messages to neighbor base stations when conditions change, so that the neighbor base stations can update its database to keep itself current on the parameters (including availability, traffic load, modulation scheme, etc.) to use in effecting efficient base station to base station handoffs. In one embodiment, the receiving base station marks the time of the received message from a neighbor base station and if a new updated message is not received within a time window then the receiving base station assumes that there is a problem with that neighbor.

Abstract: A system and method are provided for automatic gain control (AGC) using an adaptive reference and a threshold. An adaptive reference allows for adjusting the target power based on variations in operating parameters and conditions, such as a change to a modulation schemes which requires a different signal to noise ratio (SNR) to maintain performance. A gain adjustment threshold allows for rapid AGC response while reducing the potential effects of hysterisis. AGC levels may be changed during symbol prefixes or suffixes, and avoided during a data portion of a signal. Embodiments allow for symbol-by symbol AGC changes in OFDM, OFDMA, and TDD systems.

Abstract: An apparatus and process for allocating carriers in a multi-carrier system is described. In one embodiment, the process comprises determining a location of a subscriber with respect to a base station, selecting carriers from a band of carriers to allocate to the subscriber according to the location of the subscriber with respect to the base station, and allocating selected carriers to the subscriber.

Abstract: There is disclosed a system and method for improving wireless system capacity by reducing collisions where the Signal to Interference Ratio (SIR) is high in systems having a channel reuse of 1. By ordering the channel assignment in each of the interfering cells according to a pattern, for example, according to the distance from a base station (determined by power levels), the mobile stations will become paired on the same channel in a manner to reduce interference between them. In one embodiment, this intelligent assignment is accomplished by assigning mobile stations in one cell such that the mobile station having the strongest signal is assigned channel. A while in the interfering cell the mobile station with the weakest signal is assigned to channel A. In another embodiment, certain preferred mobile stations are assigned either interference-free channels or channels paired with weak interference mobile stations.

Abstract: A method and apparatus for wireless communication are described. In one embodiment, a method for communicating with a subscriber comprises transmitting orthogonal frequency domain multiplexing (OFDM) signals to the subscriber, and receiving direct-sequence spread spectrum (DSSS) signals from the subscriber.

Abstract: The present invention is directed to a system and method which base stations send informational messages to neighbor base stations when conditions change, so that the neighbor base stations can update its database to keep itself current on the parameters (including availability, traffic load, modulation scheme, etc.) to use in effecting efficient base station to base station handoffs. In one embodiment, the receiving base station marks the time of the received message from a neighbor base station and if a new updated message is not received within a time window then the receiving base station assumes that there is a problem with that neighbor.