Abstract: A linear system and an EER system are used in combination such that the EER system can also be used in a cellular phone with a wide output dynamic range. In the EER system, linear control of an amplifier becomes difficult in a low output range. Thus, use of the EER system is limited to a high output range, and the linear system is used in the low output range as in the past. A power efficiency is improved while requirements of linearity are satisfied by this structure. An effective circuit structure is proposed for a switching control system for two systems. In addition, an up-converter is constituted in combination with a step-down element with high responsiveness, whereby a power supply voltage control circuit for the EER system with a wide control range and high responsiveness is provided.

Abstract: A spread spectrum receiver having a smaller circuit scale is accomplished by a circuit construction wherein the number of taps is set to a number smaller than a spread factor, and a cyclic accumulation process for determining a correlation value of one symbol is executed by a circuit construction using an input sequence register block in common with an addition block of a spread spectrum receiver by MF according to the prior art.

Abstract: A beam is irradiated to an information recording medium having land tracks and groove tracks alternately formed on a track formed in turn on an information recording surface thereof and pre-pits so pre-formatted as to deviate from the center of the track, a return beam of the irradiated beam is received by detectors split into two parts in a track direction to obtain a differential signal, the pre-pit is detected from this differential signal and control of recording and reproducing processings is executed by using the pre-pit detection signal so obtained as the reference.