Abstract: Transmission timing of the control signal is controlled such that each transmission timing differs between at least adjacent base stations. Thus, the mobile station can reproduce the control signal using only a predetermined spreading signal for the base station which transmits the control single. Therefore the time for reproducing process of the control signal can be reduced.

Abstract: There is provided a radio communication apparatus which is capable of both improving communication quality and reducing power consumption. An integrating clock generated by a clock generating section is supplied to each of integration damp filters contained in each data demodulator. Synchronizing with the integrating clock, each integration damp filter samples a despread receiving signal to integrate values of levels in each sampling timing for one symbol period. Based on an integrating method selecting signal supplied from a main control section, the clock generating section generates the integrating clock having the same frequency with a spread code rate (chip rate) or the integrating clock having the frequency of eight times of the spread code rate (chip rate).

Abstract: A radio communication system which keeps to a minimum the number of slots which cannot be used due to interference from a neighboring base station, and which can increase the slot usage efficiency. A slot/frame setting unit for a base station extracts the slot/frame timing of a neighboring base station based on the reception output of a radio unit, and sets the communication frame by displacing it in such a way that two slots in the own base station do not coincide in time with a slot of the neighboring base station based on this timing. This setting ensures that there is always just a single slot which cannot be used when interference is detected.

Abstract: According to the system of the present invention, in a base station, a radio transmission characteristic of a forward link is estimated by a parameter estimating section 18b based on a receiving state of a radio signal arrived from a mobile station through a reverse link. Then, RAKE control data to be set to a RAKE receiver of the mobile station is generated based on the result of the estimation, and RAKE control data is notified to the mobile station. On the other hand, in the mobile station, RAKE control data is extracted by a RAKE control data extracting section. Then, a tap coefficient is initialized to be set to a transversal filter of the RAKE receiver based on RAKE control data.

Abstract: A spread spectrum radiocommunication device includes a plurality of digital data demodulators which are independently operated to track the paths of a multipath radio signal transmitted from a to-be-communicated device and PN code generators each of which has a ROM storing PN codes and which are respectively provided in the digital data demodulators. In a control section, a ROM address latched by an address latch circuit is monitored and a PN address relative value is generated, and the PN address relative value is added to a basic address generated from an address counter in an address adder and the added address is supplied to the PN code ROM to generate a PN code.

Abstract: In a mobile radio communication system for performing radio communication between a base station and a plurality of mobile stations by a code division multiple access method, a plurality of slots (T1 to T4) for a forward link from a base station (BS) to a mobile station (MS) and a plurality of slots R1 to R4 for a reverse link from the mobile station (MS) to the base station (BS) are set on a first radio frequency f2 in a time-division multiplexing manner. The slots are set in accordance with the distance between the base station and the mobile station, and the transmission power of the base station in each slot is associated with this distance. The transmission power is low in the slot associated with a short distance between the base station and the mobile station, and the transmission power is high in the slot associated a long distance between the base station and the mobile station.

Abstract: A baseband signal demodulator which ensures, when digital signal processing for data corresponding to one time slot fails to be terminated within a duration of the time slot, a processing clock for the data even in a period exceeding the time slot. In the demodulator, a receive clock reproducer reproduces a receive clock based on a received baseband signal and a phase error data generator generates phase error data indicative of a phase error between the reproduced receive clock and a system clock for control of an entire receiver. Further, a sampling clock generator changes a phase of the system clock based on the phase error data to generate an optimum sampling clock to the baseband signal and a receive data generator generates receive data corresponding to the baseband signal sampled at its optimum positions based on the optimum sampling clock. Thereafter, a data timing adjustor adjusts synchronization of the receive data with the system clock based on the phase error data.

Abstract: A clock synchronization control check system for a digital baseband signal receiver which digitally provides a phase error to digital data generated by a digital modulator without the need for conversion of the digital data to analog data so that clock synchronization control in its demodulating section can be checked easily and precisely. In the system, a digital filter is used to suppress inter-symbol interference, and a set of filter coefficients for the digital filter is shifted along the time axis of an impulse response so as to provide a plurality of filter coefficient sets. By selecting one of the coefficient sets, a desired phase shift is given to the digital data signal.