Multi-cell processing architectures for modeling and impairment compensation in multi-input multi-output systems
The present invention relates to a method for multiple-input multiple-output impairment pre-compensation comprising: receiving a multiple-input signal; generating a pre-distorted multiple-input signal from the received multiple-input signal; generating a multiple-output signal by feeding the pre-distorted multiple-input signal into a multiple-input and multiple-output transmitter; estimating impairments generated by the multiple-input and multiple-output transmitter; and adjusting the pre-distorted multiple-input signal to compensate for the estimated impairments. The present invention also relates to a pre-compensator for use with a multiple-input and multiple-output transmitter, comprising: a multiple-input for receiving a multiple-input signal; a matrix of pre-processing cells for generating a pre-distorted multiple-input signal from the received multiple-input signal; and a multiple-output for feeding the pre-distorted multiple-input signal to the multiple-input and multiple-output transmitter. The pre-processing cells are configured so as to estimate impairments generated by the multiple-input and multiple-output transmitter and adjust the pre-distorted multiple-input signal to compensate for the estimated impairments.
1. A method for multiple-input multiple-output impairment pre-compensation comprising:
receiving a plurality of input signals forming a multiple-input signal in a multiple-input multiple-output system;
generating a pre-distorted multiple-input signal from the plurality of input signals;
generating a multiple-output signal by feeding the pre-distorted multiple-input signal into a multiple-input and multiple-output transmitter;
estimating impairments generated by the multiple-input and multiple-output transmitter, the impairments comprising nonlinear crosstalk between distinct ones of the plurality of input signals in the transmitter; and
adjusting the pre-distorted multiple-input signal to compensate for the estimated impairments of the transmitter, wherein generating the pre-distorted multiple-input signal comprises feeding the received multiple-input signal to a matrix of pre-processing cells, comprising, in each of the pre-processing cells of the matrix:
nonlinear processing blocks compensating for multiple-input multiple-output nonlinear distortions and an effect of interferences between signal paths of the multiple-input signal and signal paths of the multiple-output signal; and
linear processing blocks compensating for the multiple-input multiple-output linear distortions and the effect of interferences between the signal paths of the multiple-input signal and the signal paths of the multiple-output signal, including in the nonlinear processing blocks:
processing a feedback signal to determine a desired multiple-output signal that pre-compensates for the nonlinear distortions; and estimating a nonlinear function for each nonlinear processing block.
2. The method of claim 1 , wherein the pre-distorted multiple-input signal being a plurality of predistorted digital signals, each being for a different generated inter-band inter-modulation frequencies resulting from a mixing of the plurality of frequency bands of the multi-band signal.
3. The method of claim 2 wherein the plurality of predistorted digital signals based on a set of predistortion coefficients to provide a different one of the plurality of predistorted signals includes those of generated inter-band intermodulation frequencies.
4. The method of claim 3 , including adaptively configuring the set of predistortion coefficients for inter-band intermodulation frequencies.
5. The method of claim 2 , wherein the plurality of predistorted digital signals includes compensating for the plurality of frequency bands and the generated inter-band intermodulation frequency bands.