New Reference (2008)
I knew there were newer references. This is from a computer science paper.
www.tucs.fi/publications/attachment.php?fname=TR884.pdf
The paper concludes pre-detection maximal ratio combining is optimal to maximize SNR of the received signal.
Post-detection combining may...
Reference (1977)
Design Handbook for Line of Sight Microwave Communication Systems
www.everyspec.com/MIL-HDBK/MIL-HDBK+(0300+-+0499)/download.php?spec=MIL_HDBK_416.2088.pdf
para 4.4.25.2 - "...the earlier the signals are combined the better is the ultimate performance."
sec 4.5.34 Diversity...
Troposcatter was the primary longhaul multi-channel communications network for the world-wide Defense Communications System. Sometimes called radio relay.
BTW - The transmit string was baseband feeding 1 IF modulator (70MHz) feeding two up-converters (2.1 & 2.4 GHz, for example) feeding RF...
Here is an address to a site with a paper on pre/post-detection combining.
http://citeseer.ist.psu.edu/rahman05pre.html
While in the USAF, I worked on troposcatter (2GHz) systems with analog post-detection quad diversity combining receivers (tubes). These were upgraded to pre-detection quad...
