A mobile personal digital assistant allows a user to enter information using both a touch screen and voice commands with a stylus. According to the method, a system automatically determines a plurality of available user information entry devices in communication with the workstation. Movement of one of the shafts at an angle relative to the longitudinal axis of the coupling yoke is transmitted to the other shaft by the centering mechanism and the centering mechanism causes the other shaft to likewise move at the same angle relative to the longitudinal axis of the coupling yoke. Retarder rows of the pattern retarder film are positioned to pixel row pairs of the display panel, respectively. The estimation pilot is transmitted at the same time and frequency established among the radio base station apparatuses by use of the same directivity beam as used for transmitting the data after the unified time.