US 9,794,036 B2 · Optimizations for zero-forcing precoding

Abstract

Massive MIMO systems provide impressive spectral efficiencies through beam forming techniques such as Zero-Forcing Precoding (ZFP). Unfortunately, ZFP imposes a considerable computational burden for each additional user. Relationships between the antennas, the users, and the environment must be rapidly, and accurately, reassessed during ZFP on an ongoing basis. Brute force approaches to these reassessments may be unfeasible for certain hardware and design conditions. Accordingly, various of the proposed embodiments implement representational optimizations which reduce the computational burden for each reassessment. Some embodiments employ “dynamic sectorization”, whereby the serviced environment is divided into regions and the corresponding representation is modified to reduce the computations of each reassessment. A backplane, antenna separation/directivity and thresholds for environment noise may each be adjusted to reduce the computational burden.

Claims15

Dependent claims

A communications system, comprising:

a plurality of antennas;
a backplane configured to physically separate a first group of the plurality of antennas and a second group of the plurality of antennas;
at least one processor;
at least one memory comprising instructions configured to cause the at least one processor to:
transmit a pilot signal from an antenna of the plurality of antennas;
receive feedback from a user device based upon the pilot signal;
generate a channel matrix based upon the feedback;
assign zero values to entries in the channel matrix below a threshold;
determine a precoder matrix based upon the channel matrix, wherein determining the precoder matrix comprises using Cholesky Factorization and the Minimum Degree Algorithm upon assigning the zero values;
and
adjust a directional pattern of a third group of the plurality of antennas based upon the precoder matrix.

8 more elements

Dependencies are inferred from the claim text.

Optimizations for zero-forcing precoding

Life of this patent

Optimizations for zero-forcing precoding

Life of this patent

Abstract

Claims15