Multipath propagation is the propagation of non-directional radio frequencies. Such non-directional radio frequencies propagate in different directions during transmission and cover different distances due to diffraction, refraction, fading and reflection before arriving at the receiver with different phase positions.
If the input frequencies arrive at the receiver input in different phase positions, then interference is formed, which is noticeable in strong field strength fluctuations. Multipath propagation minimizes the phase shifts caused by the different propagation times and thus achieves more efficient utilization of the available frequency ranges. Multipath propagation allows the scarce resources of bandwidth and transmit power to be used optimally.
Multipath in this context means the parallel transmission of the same information via multiple antenna systems, the transmission of the same information via different carrier frequencies or different information via different carrier frequencies, as in spatial multiplexing. In Space Time Block Coding( STBC), multiple dimensions, spatial, spectral and temporal are linked.