I'm trying to understand something which is really confusing me and I made my best to understand it but still confused.

If I have transmitted and receiver. Assume I want to transmit S(t) data and there's two multipath ways L1 , L2 in order to arrive the receiver. Why when I have constructive interference then it's good for me ? in the paths/multipath there's might be destructive interference or constructive interference...my question why constructive interference is good for me..assume I get 2S(t) -constructive interference- in the received signal on the receiver ..why it's good for me ? what does it mean that I have 2S(t) and not S(t) ?

Im confused on the term constructive interference and how it's related to my received signal ..?

My confusion exactly is that- I received 2X although I transmitted X , so 2X isn't X ..and we say that we received a good signal? if we received 2X which isn't equal to transmitted Data X so it's not the same data so it's considered distortion and it's not a good received signal.

thanks alot