Hi

Specific attenuation model for rain for use in prediction methods published by ITU is here

              http://www.itu.int/dms_pubrec/itu-r/rec/p/R-REC-P.838-3-200503-I!!PDF-E.pdf

The Rain height model for prediction methods provides all data available for Earth here

              http://www.itu.int/dms_pubrec/itu-r/rec/p/R-REC-P.839-4-201309-I!!PDF-E.pdf

Multipath propagation and parameterization of its characteristics is available here

              http://www.itu.int/dms_pubrec/itu-r/rec/p/R-REC-P.1407-5-201309-I!!PDF-E.pdf

Propagation data and prediction methods required for the design of terrestrial line-of-sight systems

             http://www.itu.int/dms_pubrec/itu-r/rec/p/R-REC-P.530-15-201309-I!!PDF-E.pdf

Read during you spare time the papers below

http://www.ericsson.com/res/thecompany/docs/publications/ericsson_review/2010/lte-mimo.pdf

http://www.ericsson.com/res/docs/review/Microwave-Capacity-Evolution.pdf

Best Regards

I don't have a direct answer, but there's an interesting consideration here depending on the MIMO array design at the base station.  The near field effects of water/rain and high humidity in the MIMO array itself could significantly de-tune the antennas and alter the correlation behavior.  That may not be an issue as long as the entire array is under a radome of some sort, but if you envision an array of sleeve dipole stubs distributed around a base station radio, changes in the near field environment could significantly alter the array.

Dear Dr. Reddy,

Wherever is water / waterbody present, energy loss increases means signal faces more losses.

MIMO or any antenna set need to be re-tuned.

Further details are specifically/mathematically discussed by wireless designers as Xavier enlisted.

Best wishes