A wireless terminal determines the position of a moving base station and determines timing andor frequency corrections. The apparatus includes at least one camera mounted on a first region of the portable terminal, a flexible display including a first area defined in the first region including the mounted camera and a second area defined in a second region not including the mounted camera, when the portable terminal is bent, and a controller for controlling the flexible display. A buffer has m storage stages to store m-bit parallel data received from the last sub-storage of the PS-LFSR.