Low complexity bit mapping algorithm for multi-carrier communication systems with fading channels

This paper presents a new bit loading algorithm to adaptively assign data bits to subchannels in a multi-carrier system. A low complexity mapping scheme using an adjustable look-up table to accommodate a time varying channel is introduced. In this way, as long as the feedback channel is secured, the proposed algorithm can perform well even in a fading channel due to its significantly reduced complexity, while a conventional bit loading algorithm may totally fail. This algorithm may also provide the best potentially implementable solution closer to the water-filling's by iteratively searching for the optimal bandwidth. The simulation result shows that this method is less sensitive to channel variation, which implies that it is robust to channel estimation errors.