Adaptive Modulation and Coding (AMC) technique exploits the high frequency diversity in wideband OFDM channels to obtain higher data rates. While prior work has discussed the value of AMC from a theoretical perspective, this work presents the design and performance of a real-time sub-carrier AMC system. The measurements from this AMC scheme implemented on an OFDM transceiver prototype indicate how this design achieves accurate and consistent Signal-to-Noise estimates, which are critical for the success of AMC. The performance of this design is compared with a uniform-adaptation scheme that...