Method and system for minimizing effects of transmitter impairments in multiple input multiple output (MIMO) beamforming communication systems
View Patent ↗Aspects of a method and system for minimizing effects of transmitter impairments in multiple input multiple output (MIMO) beamforming communication systems are presented. In one aspect of a system for minimizing effects of transmitter impairments, a MIMO transmitter may enable nulling of transmitter-induced noise by adjusting at least a portion of a plurality of signals transmitted based on a transmitter error vector magnitude (EVM). The transmitter may enable transmission of the plurality of signals subsequent to the nulling. In another aspect of a system for minimizing effects of transmitter impairments a MIMO receiver may enable nulling of transmitter-induced noise contained in a plurality of received signals based on a transmitter EVM. Each of the plurality of received signals may include information contained in a plurality of spatial streams. The receiver may enable detecting estimated values for the information contained in the plurality of spatial streams based on the nulling.
1. A system for processing signals in a communication system, the system comprising:
circuitry, in a MIMO communication system, that enables nulling of transmitter-induced noise by adjusting at least a portion of a plurality of signals transmitted based on a transmitter error vector magnitude;
wherein said circuitry enables:
transmission of said plurality of signals subsequent to said nulling;
computation of a modified channel estimate matrix based on one or more of the following: a channel estimate matrix, a channel noise matrix, a channel noise value based on said channel noise matrix, and said transmitter error vector magnitude; and
computation of beamforming weights utilized for said adjusting said at least a portion of said plurality of signals based on said modified channel estimate matrix.
2. The system according to claim 1 , wherein said circuitry enables combination of a plurality of spatial streams based on said beamforming weights to generate said plurality of signals.
3. The system according to claim 2 , wherein a signal to noise ratio for one or more of said plurality of spatial streams is approximately equal to a corresponding signal to noise ratio for each remaining one or more of said plurality of spatial streams.
4. The system according to claim 3 , wherein a modulation type of said one or more of said plurality of spatial streams is also utilized for said each remaining one or more of said plurality of spatial streams.
5. The system according to claim 2 , wherein a signal to noise ratio for one or more of said plurality of spatial streams differs from a corresponding signal to noise ratio for one or more of a remainder of said plurality of spatial streams.
6. The system according to claim 5 , wherein a modulation type of said one or more of said plurality of spatial streams is a different modulation type from a corresponding modulation type utilized for said one or more of said remainder of said plurality of spatial streams.