Closed form singular value decomposition
View Patent ↗The subject matter disclosed herein provides methods and apparatus for determining a singular value decomposition, providing feedback from a client station to a base station, and closed loop operation of a wireless system implementing multiple-input multiple-output (MIMO). The method may include determining one or more singular vectors using a closed form singular value decomposition. The one or more determined singular vectors may be provided to a precoder at the base station as feedback. The method may include aligning a phase of one or more singular vectors. The method may also include determining, at a client station, a plurality of singular vectors for channels used in a MIMO transmission from a base station to a client station. The client station may provide an indication to the base station regarding whether to use a singular value decomposition or a uniform channel decomposition. Related systems, apparatus, methods, and/or articles are also described.
1. A method comprising:
determining, at a client station, a plurality of singular vectors for channels used in a multiple-input multiple-output (MIMO) transmission from a base station to the client station;
providing, by the client station, a first indication to the base station to use a singular value decomposition, when a first one of the plurality of singular vectors is substantially larger than a second one of the plurality of singular vectors; and
providing, by the client station, a second indication to the base station to use a uniform channel decomposition, when the first one of the plurality of singular vectors is not substantially larger than the second one of the plurality of singular vectors.
2. The method of claim 1 , further comprising:
receiving a single stream of symbols, when the first one of the plurality of singular vectors is substantially larger than the second one of the plurality of singular vectors.
3. The method of claim 1 , further comprising:
receiving a plurality of streams of symbols, when the first one of the plurality of singular vectors is not substantially larger than the second one of the plurality of singular vectors.
4. A method comprising:
receiving, at a base station from a client station, a first indication to use a singular value decomposition, when a first one of a plurality of singular vectors is substantially larger than a second one of the plurality of singular vectors;
receiving, at the base station from the client station, a second indication to use a uniform channel decomposition, when the first one of the plurality of singular vectors is not substantially larger than the second one of the plurality of singular vectors; and
configuring the base station for transmission based on at least one of the first indication or the second indication received from the client station.
5. A client station comprising:
a channel estimator and a processor configured to:
determine a plurality of singular vectors for channels used in a multiple-input multiple-output (MIMO) transmission from a base station to the client station;
provide, via a radio interface, a first indication to the base station to use a singular value decomposition, when a first one of the plurality of singular vectors is substantially larger than a second one of the plurality of singular vectors; and
provide, via the radio interface, a second indication to the base station to use a uniform channel decomposition, when the first one of the plurality of singular vectors is not substantially larger than the second one of the plurality of singular vectors.
6. The client station of claim 5 , further comprising:
the radio interface configured to receive a single stream of symbols, when the first one of the plurality of singular vectors is substantially larger than the second one of the plurality of singular vectors.
7. The client station of claim 5 , further comprising:
the radio interface configured to receive a plurality of streams of symbols, when the first one of the plurality of singular vectors is not substantially larger than the second one of the plurality of singular vectors.
8. A base station comprising:
a precoder and a processor configured to:
receive from a client station, via a radio interface, a first indication to use a singular value decomposition, when a first one of a plurality of singular vectors is substantially larger than a second one of the plurality of singular vectors;
receive from the client station, via the radio interface, a second indication to use a uniform channel decomposition, when the first one of the plurality of singular vectors is not substantially larger than the second one of the plurality of singular vectors; and
configure the base station for transmission based on at least one of the first indication or the second indication received from the client station.