The Short Bounce: An Impairment Unique to QAM Digital Microwave Radio Signals

Explore the physics of what is often called inter-symbol interference (ISI) and the counter measures to overcome the issue if you have the problem. Short Bounce: This term refers to a phenomenon, uniquely prevalent in QAM or other amplitude modulated digital wireless communications systems, where a signal transmitted from the source reaches the receiver via multiple paths. Some of these paths might be slightly longer than the direct path, leading to images of the direct signal arriving at the receiver at slightly delayed times. This is not the classic second Fresnel zone cancellation we were taught in microwave propagation class.

Inter-Symbol Interference (ISI): This is a broader term which describes a type of signal distortion where one transmitted symbol interferes with subsequent symbols in the data stream. This interference makes it harder for the receiver to accurately decode the individual symbols, leading to errors