Multipath

A phenomenon where a transmitted signal reaches a destination at more than one time as a result of taking multiple paths along the way. For example, a radio signal may arrive at a receiver directly, but a slightly delayed (and usually lower in amplitude) version may also arrive as a reflection from a nearby building or mountain. This can also be the result of reflections and/or refractions in the atmosphere. Either way the result can cause a variety of problems as the receiver tries to respond to the signal and ignore the erroneous multipath versions that arrive. In television you can sometimes see this as a second or third ghost image on the screen. In radio signals you may experience phase cancellation or certain types of distortion.