Maximum-ratio combining is the optimum combiner for independent additive white Gaussian noise channels.
MRC can restore a signal to its original shape.
The technique was invented by American engineer Leonard R. Kahn[1] in 1954.
MRC has also been found in the field of neuroscience, where it has been shown that neurons in the retina scale their dependence on two sources of input in proportion to the signal-to-noise ratio of the inputs.
The least square solution in this case is also known as maximum-ratio-combining (MRC).
In the case of N antennas the LS can be written as which means that the signal from each antenna is rotated and weighted according to the phase and strength of the channel, such that the signals from all antennas are combined to yield the maximum ratio between signal and noise terms.