# Gain of multipath fading components

For the Rayleigh fading model, I want use four multipath components, each component has its delay and gain.

• Can the gain in $\textrm{dB}$ of any of the individual four components be positive value?

I can understand that it can be zero or maybe negative indicating reduction in its amplitude due to delay and effects of channel, but I can not understand how it can be positive.

• The overall signal resulting from the four components at the receiver may be with positive gain. This is reasonable, due to constructive addition of maybe inphase components, but how can a single component be with positive gain?
• In addition to Maximilian's answer: in a frequency-flat channel, what is simulated as a single channel tap is actually the sum of many scattered signals, whose delays are very similar and much smaller than the symbol period. These may also add constructively, resulting in a larger-than-one gain. – MBaz Nov 10 '16 at 13:47