In one embodiment, a receiver implements a method of demodulating a set of symbols dispersed within a time-frequency grid of a received OFDM signal. For each MOS transistor, an impurity-doped channel region is formed between adjacent trenches, the channel region having a conductivity type equal to conductivity type of the substrate and a concentration higher than a concentration of the substrate. The bridge portion connects the first and second weight portions at an approximate center thereof in a long side direction. The at least one roller is a roller within the loop of the first belt and between a first end roller disposed at an end of the first belt facing a plane of a conveyance path.