Transmitter beamforming at base station with partial channel information and ue feedback

A system for obtaining a beamforming matrix, the system comprising:

• a processor;
• and
• a memory storing non-transitory processor-executable instructions that, when executed by the processor, cause the processor to:
• input partial channel estimation derived from sounding reference signal (SRS) switching;
• input precoding matrix indicator (PMI) feedback;
• compose a precoding matrix using the PMI feedback and partial channel estimation.

A method of composing a final beamforming matrix, the method comprising:

• performing a first singular value decomposition (SVD) of a partial channel estimation matrix to obtain a first singular matrix, the partial channel estimation matrix being based on one or more uplink sounding reference signals (SRS) or one or more other reference signals;
• obtaining a first beamforming matrix based on precoding matrix indicator (PMI) feedback;
• calculating a projection of the first beamforming matrix to the first singular vector;
• performing, after removing the projection of the first beamforming matrix to the first singular matrix, a second SVD of a residual of the first beamforming matrix to obtain a second singular matrix;
• and
• using, the first singular matrix and a first set of columns of the second singular matrix to compose the final beamforming matrix.

A non-transitory computer-readable medium comprising instructions for deriving a beamforming matrix, wherein execution of the instructions by one or more processors causes the one or more processors to carry out the steps of:

• estimating a partial channel based on one or more received sounding reference signals (SRS);
• deriving a first beamforming matrix based on a received precoding matrix indicator (PMI) feedback;
• and
• deriving a second beamforming matrix based on the partial channel and the first beamforming matrix.