Small Scale Fading time varying or position varying
Small scale fading results from a superposition of a large number of propagation paths between TX and RX, which can be constructive or desctructive depending on their phase offset. As the phase offset varies rapidly with the propagation distance, the phase offsets between different paths are likely to vary rapidly too, leading to a pseudo-random behaviour of the received amplitude. We refer to this as small scale fading.

Technically, this behavior requires some form of change to the propagation conditions. So again, technically, if you did an experiment in a closed chamber with noone inside and no movements, there would not be any fading but the amplitude would remain constant. 

However, in reality, there is always some movement. Most of the propagation paths are due to reflections and reflecting objects can move on their own (think of wind, people, cars, etc.). So in practice, even if TX and RX are stationary, you should expect small-scale fading to be present. A way to reduce it is using directive antennas that put stronger emphasis on the line of sight component, if that is an option.