I am working on hardware implementation of Maximal Ratio Combiner for OFDM based system. 

Consider a two antenna receiver performing MRC over received signals y1 and y2 on antennas 1 and 2 respectively.  Ideally the MRC should combine both the antenna branch signals as follows : 

What should be the behavior of MRC when one of the antenna is not able to detect frame and hence h , i.e., channel estimate for that branch is not available ? 

Regards

Sumit 

Hi Sumit,

I think that the MRC is

Hence, when one branch is not available, its channel estimate is 0.

Let say h2 is null, the equation reduces to:

Ok in other words, the system acts as Selection Combiner. 

Yes, because this is the optimal way to behave in that case.