Abstract: In a spread spectrum transmitter, a number of spread spectrum channel signals are multiplexed into a digital amplitude signal by a multiplexer, and the time-average power of the digital amplitude signal is determined by an average calculator. The digital amplitude signal is interpolated by an interpolator, scaled according to a first scale factor by a bit shifter and converted to an analog amplitude signal by a D/A converter. The analog amplitude signal is then scaled according to a second scale factor in a gain controlled amplifier. The first and second scale factors are complementarily varied by a control circuit according to the output of the average calculator so that the carrier-to-noise ratio of the transmitter is maintained substantially constant regardless of the varying power level of the multiplexed signals.

Abstract: In a transmission power control unit for use in a transmitting apparatus, power control amount correctors carry out, on the basis of detected signals, correction of power control amounts on transmission amplitude data to produce corrected data. A power control correction code generator generates a power control correction code. Spreading sections carry out spread processings on the corrected data using replaced spreading codes into which respective parts of spreading codes are replaced with the power control correction code. A multiplexer multiplexes spread data into a multiplexed amplitude datum. A D/A converter converts the multiplexed amplitude datum into an analog signal. A radio section carries out modulation, frequency conversion, and power amplification on the analog signal to produce a transmission signal. A distributor extracts a part from the transmission signal as an extracted signal. A frequency converter converts the extracted signal into a frequency-converted signal.

Abstract: The invention provide a centralized maintenance management method and system for a portable telephone system by which fault recovery is performed efficiently. A remote maintenance console for use for maintenance of a portable telephone system accesses a web server of a portable telephone system concentrated maintenance management system over the Internet and searches a database server in which fault data and a diagnosis dictionary are stored to acquire data necessary for fault diagnosis and fault recover. Further, the remote maintenance console is connected to a terminal of a maintenance engineer or a developing engineer in charge of a maker and can receive supporting of maintenance operation on-line from a remote place. Further, request for repair from the remote maintenance console and issuance of a repair acceptance and a repair completion report and report of a repair progress situation from the maker side are performed on-line through an information providing server.

Abstract: A gain compensating apparatus for use with an amplifying portion corresponding to code division multiple access system is disclosed, that comprises a spreading/combining portion for outputting amplitude data that has been spread and quantized and transmission average value information, a D/A converting portion for outputting an analog base band signal, a modulating portion for outputting a modulation signal, a variable ATT portion for controlling the attenuation amount with a control signal and controlling the level of the modulation signal, an amplifying portion for amplifying a power, a HYB for branching an output signal of the amplifying portion, one output signal of the HYB being a transmission signal, a detecting portion for detecting an output signal of the HYB and outputting a detected signal, an A/D converting portion for converting the detected signal into quantized transmission power data, and a comparing/controlling portion for comparing the transmission power data with the transmission average val

Abstract: A communication base station system for transmitting data to a movable body includes a plurality of transmission sections, each of the transmission sections receiving a transmission data, modulating this received transmission data, and then converting the frequency of this modulated transmission data to a preset frequency and outputting a result. A control section monitors a status of use of the transmission sections, and if having confirmed at least two transmission sections that do not transmit any data, the control section outputs a specified signal instead of the transmission data to two transmission sections among the confirmed transmission sections. An amplification section collectively amplifies a plurality of output signals from the transmission section and a compensation circuit compensates for intermodulation distortion components generated in the amplification section based on an output of a transmission section that has received the specified signal and its respective transmission frequency.