Adaptivity on an OFDM fixed wireless access system

A special characteristic of multicarrier modulation techniques such as OFDM is that they can assign different modulation schemes to each subcarrier according to a reception quality measurement such as the signal-to-noise ratio (SNR) on a subcarrier. This process allocates different bits to subcarriers and is further known at the literature as bit loading. In the paper, a bit-loading algorithm has been modified to take into account the presence of variable location pilots in each OFDM symbol. The target of this enhancement is to measure the system performance increase and the bandwidth efficiency improvement obtained. The study has been done for a broadband fixed wireless system.