Maximal-ratio combiner

In telecommunication, a maximal-ratio combiner is a diversity combiner in which (a) the signals from each channel are added together, (b) the gain of each channel is made proportional to the rms signal level and inversely proportional to the mean square noise level in that channel, and (c) the same proportionality constant is used for all channels. Synonyms ratio-squared combiner, post-detection combiner, predetection combining, selective combiner.

Source: from Federal Standard 1037C and from MIL-STD-188