Graph-Based Determination of Initial-Synchronization Beam Scanning
First Claim
1. A method, in one or more nodes of a wireless communications system, of jointly determining beam-sweeping patterns for synchronization signals transmitted in a region by each of a plurality of access nodes in a wireless network, wherein each access node is connected to a corresponding array of horizontally and/or vertically spaced antenna elements and is configured to sweep a synchronization signal in a node-specific beam sequence, using the corresponding array, where, for each access node, the node-specific beam sequence is defined by a sequence of power levels corresponding to distinct beam angles available to the access node, the method comprising:
- modeling a total power function corresponding to a total power transmitted in the synchronization signals by the plurality of access nodes, for a given period, wherein said modeling of the total power function comprises modeling the total power function as a factor graph having a plurality of check nodes and variable nodes, each of the check nodes corresponding to one of a plurality of emulated virtual wireless devices in the region and each of the variable nodes corresponding to one of the access nodes and to one of the beam angles available to the one of the access nodes;
emulating the plurality of virtual wireless devices so as to implement quality-of-service constraints on synchronization signals received by the virtual wireless devices;
applying an iterative message-passing algorithm to the modeled total power function, to determine the sequence of power levels for each of the plurality of access nodes, so as to minimize the total power function, subject to one or more iteration-stopping criteria.
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Accused Products
Abstract
Techniques for determining beam-sweeping patterns for synchronization signals transmitted in a region by several access nodes in a network, where each access node is connected to a corresponding array of antenna elements. An example method includes modeling a total power function for the power transmitted in the synchronization signals, as a factor graph having a plurality of check nodes and variable nodes, each check node corresponding to a virtual wireless device in the region and each variable node corresponding to an available beam for an access node. The virtual wireless devices are emulated so as to implement quality-of-service constraints on synchronization signals received by the virtual wireless devices. An iterative message-passing algorithm, such as a min-sum algorithm, is applied to the modeled total power function, to determine a sequence of power levels, for each access node, for sweeping synchronization signal beams, so as to minimize the total power function.
4 Citations
22 Claims
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1. A method, in one or more nodes of a wireless communications system, of jointly determining beam-sweeping patterns for synchronization signals transmitted in a region by each of a plurality of access nodes in a wireless network, wherein each access node is connected to a corresponding array of horizontally and/or vertically spaced antenna elements and is configured to sweep a synchronization signal in a node-specific beam sequence, using the corresponding array, where, for each access node, the node-specific beam sequence is defined by a sequence of power levels corresponding to distinct beam angles available to the access node, the method comprising:
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modeling a total power function corresponding to a total power transmitted in the synchronization signals by the plurality of access nodes, for a given period, wherein said modeling of the total power function comprises modeling the total power function as a factor graph having a plurality of check nodes and variable nodes, each of the check nodes corresponding to one of a plurality of emulated virtual wireless devices in the region and each of the variable nodes corresponding to one of the access nodes and to one of the beam angles available to the one of the access nodes; emulating the plurality of virtual wireless devices so as to implement quality-of-service constraints on synchronization signals received by the virtual wireless devices; applying an iterative message-passing algorithm to the modeled total power function, to determine the sequence of power levels for each of the plurality of access nodes, so as to minimize the total power function, subject to one or more iteration-stopping criteria. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
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12. A system for jointly determining beam-sweeping patterns for synchronization signals transmitted in a region by each of a plurality of access nodes in a wireless network, wherein each access node is connected to a corresponding array of horizontally and/or vertically spaced antenna elements and is configured to sweep a synchronization signal in a node-specific beam sequence, using the corresponding array, where, for each access node, the node-specific beam sequence is defined by a sequence of power levels corresponding to distinct beam angles available to the access node, the system comprising one or more nodes adapted to:
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model a total power function corresponding to a total power transmitted in the synchronization signals by the plurality of access nodes, for a given period, wherein said modeling of the total power function comprises modeling the total power function as a factor graph having a plurality of check nodes and variable nodes, each of the check nodes corresponding to one of a plurality of emulated virtual wireless devices in the region and each of the variable nodes corresponding to one of the access nodes and to one of the beam angles available to the one of the access nodes; emulate the plurality of virtual wireless devices so as to implement quality-of-service constraints on synchronization signals received by the virtual wireless devices; apply an iterative message-passing algorithm to the modeled total power function, to determine the sequence of power levels for each of the plurality of access nodes, so as to minimize the total power function, subject to one or more iteration-stopping criteria. - View Dependent Claims (13, 14, 15, 16, 17, 18, 19, 20, 21)
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22. A computer program product for jointly determining beam-sweeping patterns for synchronization signals transmitted in a region by each of a plurality of access nodes in a wireless network, wherein each access node is connected to a corresponding array of horizontally and/or vertically spaced antenna elements and is configured to sweep a synchronization signal in a node-specific beam sequence, using the corresponding array, where, for each access node, the node-specific beam sequence is defined by a sequence of power levels corresponding to distinct beam angles available to the access node, the computer program product comprising instructions for execution by one or more nodes, the instructions comprising instructions for:
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modeling a total power function corresponding to a total power transmitted in the synchronization signals by the plurality of access nodes, for a given period, wherein said modeling of the total power function comprises modeling the total power function as a factor graph having a plurality of check nodes and variable nodes, each of the check nodes corresponding to one of a plurality of emulated virtual wireless devices in the region and each of the variable nodes corresponding to one of the access nodes and to one of the beam angles available to the one of the access nodes; emulating the plurality of virtual wireless devices so as to implement quality-of-service constraints on synchronization signals received by the virtual wireless devices; applying an iterative message-passing algorithm to the modeled total power function, to determine the sequence of power levels for each of the plurality of access nodes, so as to minimize the total power function, subject to one or more iteration-stopping criteria.
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Specification