Abstract: A demodulation section 13 receives a TDMA-TDD based phase-modulated burst signal of mobile communications and demodulates the burst signal by a synchronous detection system (or a quasi-synchronous detection system). The demodulation section 13 includes a frequency deviation compensation section and a carrier recovery section each having a loop filter 14 with three or more stages of time constants. The time constants are switched by a selector switch 15 based on a control signal from a demodulation control section 16. This achieves quick pull-in and jitter after convergence is minimized, thereby allowing highly efficient performance of frequency deviation compensation, etc. that is required for synchronous detection (or quasi-synchronous detection) without increasing the size of circuit.

Abstract: The present invention relates to a radio communications system and a radio communications method, and an object of the invention is to readily reduce the occurrence of collisions of contention channels. In order to achieve the object, radio resources are assigned in different orders between one radio communication and another one radio communication.

Abstract: [Object] A base station synchronization system, a synchronization controller, and a base station are provided which are capable of establishing precise synchronization among a plurality of base stations. [Solving Means] In a base station synchronization system including a plurality of base stations 13 and a base station concentrator 12, the base station concentrator 12 includes a control information generator 21 for generating synchronization control information, and each base station 13 includes a VCO 30 oscillating at a frequency corresponding to an input control voltage, and a corrector 33 for correcting the input control voltage to the VCO 30 according to the synchronization control information. This configuration makes it possible to establish synchronization among the master clocks of the plurality of base stations so as to suppress phase differences among the base stations and precisely synchronize the base stations with each other.

Abstract: A base station control apparatus for controlling a radio base station which carries out radio communications with a mobile communication terminal is characterized in that it includes a control unit for performing a control process of making the radio base station selectively perform either of two or more processes with different throughputs according to the scale of the radio base station. With this structure, the radio base station can have only a function based on to the scale thereof. For this reason, by omitting unnecessary functions, the radio base station can be miniaturized and the manufacturing cost of the radio base station can be reduced.

Abstract: A wireless apparatus which performs a frequency conversion on a received signal with a mixer and an analog filter, and which corrects for distortion of the received signal, which occurs because the analog filter is not an ideal one, using a digital filter disables the filtering of the received signal by the digital filter when determining from the reception power level (or reception amplitude level) of the received signal that the filtering of the received signal by the digital filter will increase the distortion of the received signal.