Methods and apparatus for beamforming
AssigneeNokia Siemens Networks Oy
InventorsTimothy A. Thomas, Frederick Vook, Eugene Visotsky
Life of this patent
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Abstract
Systems and techniques for beamforming are disclosed. Codebook antenna ports, such as ports defined by the 8 transmit antenna LTE codebook, are mapped to sub-elements of an antenna array arranged to form a plurality of elevation and azimuth ports, such as 4 elevation and 2 azimuth ports or 2 elevation and 4 azimuth ports. The mapping is chosen so as to optimize performance. Phasing values may also be applied to signal components provided as inputs to the sub-elements, with the values chosen to maximize performance, such as rank 1 gain or rank 2 or higher performance.
Claims21
A method comprising:
- creating a set of associations between codebook antenna ports and physical sub-elements of an antenna array, wherein each of the set of associations associates an antenna port specified by a codebook accessible to a base station with one of a set of physical sub-elements of an antenna array of the base station, wherein the physical sub-elements are arranged in cross-polarized pairs, and wherein the pairs are arranged at least in according to elevation;
- interpreting feedback information from a user device to select from the codebook an entry comprising a vector of weighting values, wherein each of the weighting values defines a relative weighting for a signal component to be input to an antenna port specified by an entry of the codebook;
- applying the vector of weighting values to a signal configured for transmission to a user device to form a signal vector comprising a vector of weighted signal components;
- and
- mapping each component of the vector of weighted signal components to a physical sub-element of the antenna array according to the set of associations.
A method comprising:
- determining a phasing value for each of a vector of signal components to be provided as inputs to an antenna array comprising a plurality of elevation ports, wherein the phasing values are determined based on the particular RF beams used in the elevation dimension;
- and
- applying the phasing values to signal components corresponding to antenna ports defined by a codebook accessible to a base station.
An apparatus comprising:
- at least one processor;
- memory storing computer program code;
- wherein the memory storing the computer program code is configured to, with the at least one processor, cause the apparatus to at least:
- create a set of associations between codebook antenna ports and physical sub-elements of an antenna array, wherein each of the set of associations associates an antenna port specified by a codebook accessible to a base station with one of a set of physical sub-elements of an antenna array of the base station, wherein the wherein the physical sub-elements are arranged in cross-polarized pairs, and wherein the pairs are arranged at least in part by elevation;
- interpret feedback information from a user device to select from a codebook an entry comprising a vector of weighting values, wherein each of the weighting values defines a relative weighting for a signal component to be input to an antenna port specified by entry of the codebook;
- apply the vector of weighting values to a signal configured for transmission to a user device to form a signal vector comprising a vector of weighted signal components;
- and
- map each component of the vector of weighted signal components to a physical sub-element of the antenna array according to the set of associations.
Dependencies are inferred from the claim text.