Abstract: The present invention provides a method for transmitting/receiving a continuous pilot code in a multi-carrier system. The method for transmitting comprises: performing a time-frequency domain two dimensional encoding on an information bit stream to be transmitted; mapping the encoded bit stream to obtain a continuous pilot carrying encoding information; multiplexing a load, a discrete pilot and the mapped continuous pilot carrying the encoding information based on distribution of the load, the discrete pilot and the continuous pilot on a sub-carrier, to generate a frequency domain signal; and performing a frequency-time domain transforming on the generated frequency domain signal, to obtain a time domain sample. The method for receiving comprises: extracting the continuous pilot from an active carrier of a multi-carrier signal; and performing a time-frequency domain decoding on the extracted continuous pilots to obtain the decision of transmitted information bits.

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: 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: A method and apparatus for subcarrier selection for systems is described. In one embodiment, the system employs orthogonal frequency division multiple access (OFDMA). In one embodiment, a method for subcarrier selection comprises a subscriber measuring channel and interference information for subcarriers based on pilot symbols received from a base station, the subscriber selecting a set of candidate subcarriers, providing feedback information on the set of candidate subcarriers to the base station, and receiving an indication of subcarriers of the set of subcarriers selected by the base station for use by the subscriber.

Abstract: A method and apparatus for subcarrier selection for systems is described. In one embodiment, the system employs orthogonal frequency division multiple access (OFDMA). In one embodiment, a method for subcarrier selection comprises a subscriber measuring channel and interference information for subcarriers based on pilot symbols received from a base station, the subscriber selecting a set of candidate subcarriers, providing feedback information on the set of candidate subcarriers to the base station, and receiving an indication of subcarriers of the set of subcarriers selected by the base station for use by the subscriber.

Abstract: 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).

Abstract: 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.

Abstract: A method and apparatus for subcarrier selection for systems is described. In one embodiment, the system employs orthogonal frequency division multiple access (OFDMA). In one embodiment, a method for subcarrier selection comprises a subscriber measuring channel and interference information for subcarriers based on pilot symbols received from a base station, the subscriber selecting a set of candidate subcarriers, providing feedback information on the set of candidate subcarriers to the base station, and receiving an indication of subcarriers of the set of subcarriers selected by the base station for use by the subscriber.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: A method and apparatus for subcarrier selection for systems is described. In one embodiment, the system employs orthogonal frequency division multiple access (OFDMA). In one embodiment, a method for subcarrier selection comprises a subscriber measuring channel and interference information for subcarriers based on pilot symbols received from a base station, the subscriber selecting a set of candidate subcarriers, providing feedback information on the set of candidate subcarriers to the base station, and receiving an indication of subcarriers of the set of subcarriers selected by the base station for use by the subscriber.

Abstract: 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.

Abstract: 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.

Abstract: The present invention provides a method for transmitting/receiving a continuous pilot code in a multi-carrier system. The method for transmitting comprises: performing a time-frequency domain two dimensional encoding on an information bit stream to be transmitted; mapping the encoded bit stream to obtain a continuous pilot carrying encoding information; multiplexing a load, a discrete pilot and the mapped continuous pilot carrying the encoding information based on distribution of the load, the discrete pilot and the continuous pilot on a sub-carrier, to generate a frequency domain signal; and performing a frequency-time domain transforming on the generated frequency domain signal, to obtain a time domain sample. The method for receiving comprises: extracting the continuous pilot from an active carrier of a multi-carrier signal; and performing a time-frequency domain decoding on the extracted continuous pilots to obtain the decision of transmitted information bits.

Abstract: 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.