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BELL SYSTEM TECHNICAL JOURNAL 



This treatment of diversity action has been made from the point of 

 view of MUSA reception but is appHcable to ordinary space diversity 

 using two stations or antennas. In the case of a single bundle of 

 waves no modification of the analysis need be made; the signal gen- 

 erators then represent the spaced antenna outputs which are fading 

 randomly. In this case voltage addition of the audio outputs may be 



* AUTOMATIC GAIN CONTROL 

 Fig. 39 — Summar}' of results of diversity analysis. 



expected to occur since a single bundle will typically include only a 

 small delay interval. In the general case of two or more wave bundles 

 the signal generators must be interpreted to represent not the carrier 

 but the side-band average, for fading will then be essentially selective 

 and the audio output will not be proportional to carrier as was assumed 

 in the analysis. If this interpretation is made the signal-to-noise ratio 

 in each receiver becomes proportional to the generator amplitudes e^A 



