Beam forming method
AssigneeSiemens Aktiengesellschaft
InventorsChristopher Brunner, Martin Haardt, Joachim Hammerschmidt, Alexander Seeger
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Abstract
In a radio communication system, a beam is formed between subscriber stations and a base station which has an antenna device with several antenna elements. The antenna elements emit a downlink signal based on respective weighing with coefficients of a weighting vector. A plurality of weighting vectors are determined at the subscriber station in an initialization phase and transmitted to the base station. In a subsequent working phase, the subscriber station selects a dominant weighting vector from the weighting vectors and transmits a designation of the selected weighting vector to the base station.
Claims18
A method for beam formation in a radio communication system with subscriber stations and a base station, the base station having an antenna system with a plurality of antenna elements which radiate a downlink signal weighted in each case with coefficients wi of an actual weighting vector w, where i=1, . . . , M, comprising:
- at a subscriber station in an initialization phase thereof,
- producing a first spatial covariance matrix of a received downlink signal, based on averaging over a plurality of time slots of the received downlink signal,
- obtaining eigenvectors of the first spatial covariance matrix, and
- transferring the eigenvectors to the base station as initial weighting vectors for storage in memory;
- at the subscriber station in a working phase thereof,
- repeatedly selecting a dominant weighting vector from the initial weighting vectors, and
- conveying an identifier of the dominant weighting vector to the base station;
- and
- at the base station in the working phase,
- selecting the dominant weighting vector from among at least the initial weighting vectors stored in memory during the initialization phase of the subscriber station, and
- using the dominant weighting vector to form a direction of emission.
A method for beam formation in a radio communications system with subscriber stations and a base station, the base station having an antenna system with a plurality of antenna elements which radiate a downlink signal, weighted in each case with coefficients wi of an actual weighting vector w, where i=1, . . . , M, said method comprising:
- in an initialization phase at the base station,
- producing a first spatial covariance matrix of a received uplink signal, based on averaging over a plurality of time slots of the received uplink signal,
- obtaining eigenvectors of the first spatial covariance matrix, and
- using and storing the eigenvectors as initial weighting vectors;
- and
- in a working phase,
- repeatedly selecting a dominant weighting vector from at least the initial weighting vectors, and
- using at the base station the dominant weighting vector to form a direction of emission.
Dependencies are inferred from the claim text.