Nortel Networks Corporation

Apple Inc.

Research in Motion Corporation

Robert Matyas

Nimal Gamini Senarath

Shalini Suresh Periyalwar

Yoon Chae Cheong

Mo-Han Fong

Peiying Zhu

Hang Zhang

Geng Wu

Leo L Strawczynski

Claude Royer

James Mark Naden

Bill W Gage

Glenn G Algie

Alauddin Javed

Ahmad Jalali

David G Steer

Bassam M Hashem

Ning Guo

Farideh Khaleghi

Norman P Secord

Wookwon Lee

Amir Bigloo

Parsyna R Larijani

A method and apparatus for reducing signal interference within a cellular radio system to increase both coverage and capacity. The method and apparatus include altering the direction of beams within cell sectors is among discrete angular positions according to a predetermined, cyclic pattern. The predetermined, cyclic pattern varies in a group of adjacent cell sectors such that inter-cell interference is significantly reduced or eliminated by rotating at a different cycle the beams in adjacent cells. This discrete, angular movement of beams provides for downlink transmissions to be timed in such a way (i.e., scheduled) such that transmission to a user will occur in accordance with the beam and time slot having the best carrier to interference (C/I) ratio for that user.

Beam wobbling for increased downlink coverage and capacity

Some embodiments of the invention provide an implementation for a multi-hop wireless backhaul network, in particular an aggregation node (AGN). The AGN includes a plurality of spatially switched antennas and a transceiver configured to operate on the plurality of spatially switched antennas in a time divisional multiplexing (TDM) fashion to establish active connections with other network nodes in a hierarchical manner. The AGN is further configured to perform a bi-directional relay function for backhaul traffic with the other network nodes using at least one virtual circuit having an allocated bandwidth for delay sensitive traffic. The AGN may serve to aggregate and relay/amplify circuit traffic between network nodes in the up stream and down stream directions. If the AGN is interposed within a circuit between two other nodes, the AGN can switch the circuit traffic between the end-nodes of the circuit.

Multi-hop wireless backhaul network and method

Some embodiments of the invention provide an implementation for a multi-hop wireless backhaul network. These embodiments can advantageously be deployed in dense urban areas and/or co-located with wireless access nodes, such as base-stations of a cellular wireless communication system. Preferably wireless links between constituent network nodes are set-up hierarchically. A basic result of this is that peer-to-peer (child-to-child) communication is generally prohibited and circuits are forced to conform to a topology. The multi-hop wireless backhaul network may be used to carry delay sensitive, high-density last mile circuit traffic over Non-Line-Of-Sight (NLOS) broadband radio links. Moreover, some embodiments of the invention provide a method of path-healing for re-routing of circuit traffic from circuits that have experienced catastrophic failures.

The present invention relates to a method and apparatus for reducing interference arising from signal propagation delay in multipath signal environments in wireless communication systems. The present invention provides a method of operating a mobile communications base station which receives multipath components of signals from a number of high mobility subscriber terminals, the method comprising: for each subscriber terminal signal received, determining a best signal component; determining the difference in time between reception of said best signal component and a reference time; transmitting to said terminal a transmission timing offset in order to receive said best component at substantially said reference time.

Method and apparatus for using synchronous CDMA in a mobile environment

A method for reducing interference in a wireless system, and a system for performing the method. The wireless system should include at least two, and preferably four, beam formers and a plurality of mobile units. The method includes the steps of transmitting beams B, B, Band Binto first, second, third and fourth beam areas, respectively. At least two sub-areas are defined within each of the first, second, third and fourth beam areas based upon the degree of overlap with adjacent beam areas, whereby each of the beam areas includes at least one overlapping sub-area and at least one non-overlapping sub-area. The method further includes coding signals of the beams B, B, Band Bfor receipt by a particular mobile unit based upon which one of the sub-areas that the particular mobile unit is located within.

Multibeam wireless communications method and system including an interference avoidance scheme in which the area of each transmitted beam is divided into a plurality of sub-areas

In a wireless communications system, after a high data rate user is admitted and a supplemental channel is assigned to the user, a control message is sent to a receiver to communicate for power ramp-up and ramp-down profiles. The control message contains parameters of a data rate, a starting time and a duration of time as group in assigned fields in the message which is provided by a control signal source. In response to the control message, a controller provides a rate controllable signal with reference to the parameters of the control message to a data encoder. A bursty input data stream is fed to a buffer. The data encoder withdraws the data from the buffer in response to the rate controllable signal. The bit rate transitions in the bursty input data stream are smoothed with reference to the parameters. There is provided an output data stream having smoother data rate transitions than the input data stream. It is possible to solve problems with 3G CDMA systems which have sudden interference changes resulting from the bursty nature of high-speed data transmissions.

Signalling scheme and messaging structure to support the smoothing of large bit rate transmissions

Methods and apparatus for transmitting data over a multi-channel CDMA system are disclosed in accordance with the teachings of the present invention wherein the system includes an encoder for encoding a data stream with error correction, an interleaver for interleaving the data stream, a multiplexor for multiplexing a plurality of power control symbols onto the data stream, and an inverse-multiplexor for inverse-multiplexing the data stream onto multiple different communication channels. The system may also include additional error correction encoding and interleaving steps.

Systems and methods of channel coding and inverse-multiplexing for multi-carrier CDMA systems

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Ottawa, Canada

Robert Matyas