What is AF (Amplify-and-Forward)?

Amplify-and-Forward (AF) is a combined strategy for ad-hoc networks with critical power constraints. It requires an amplification of the received signal in the analogue domain at the relays without further signal processing. The AF relay linearly amplifies the received signals and forwards these signals without decoding. The AF strategy is the most practical relay approach as the result of its low complexity transceiver design.