Abstract: The present invention is directed to a TDMA communication system which is adapted to different communication environments or prepares different communication environments and allows each mobile station to be set for working in any one of the different communication environments. The communication system commonly uses a TDMA format that has a fixed frame-length and a constant number of bits for each of the slots composing the frame. The communication environments have prepared respective sets of communication conditions, each set including a transmission power, a modulating method, the number of multiplexed signals, error-correction, an antenna gain, a frequency hopping value and a diversity value. At each mobile station and each base station, one of plural sets of communication conditions for respective environments is selected to establish communication with each other under the selected environment.

Abstract: According to a power control system for a CDMA mobile radio communication network, powers at which downlink pilot signals are transmitted from base stations are controlled so that the numbers of mobile stations managed by the respective base stations will be in a predetermined range. In addition, powers at which uplink signals are transmitted from the mobile stations are controlled so that communication qualities related to the uplink signals received by the base stations will converge on a predetermined threshold value. On the basis of the above-mentioned principle, the designing of cells in the CDMA mobile radio communication network is implemented.

Abstract: A transmitter used in a CDMA mobile communication system includes a pilot channel transmit unit which intermittently transmits a pilot signal in a spread spectrum formation, and traffic channel transmit units which respectively transmit data signals in respective traffic channels.

Abstract: The amount of calculations involved in the weight calculation is reduced in an adaptive array antenna CDMA receiver. A common correlation matrix is calculated by using the reception signals. Preferably, the inverse matrix of the common correlation matrix is also calculated. The common correlation matrix or the inverse matrix is used in common to the weight calculations for all the users or mobile stations. An inventive CDMA receiver includes a portion provided for each user. Each of the portions passes the reception signals through the respective matched filters to obtain respective despread signals; calculates a weight vector by using the common correlation matrix or the inverse matrix thereof; weighs the respective despread signals with the weight vector to obtain weighed despread signals; and combines the weighed despread signals into the transmission signal associated with each user.

Abstract: In a first CDMA communication method, a CDMA radio wave signal is transmitted at a first place (a base station). A mobile unit receives the first CDMA radio wave signal and stores at least a portion of the data in the received signal and returns it to the base station by attaching the portion of the data to second data to be transmitted through spectrum spreading, wherein the data rate of the attached data is higher than the second data. The base station detects an upward line transmission quality from the received second CDMA radio wave signal from the mobile unit and detects a downward line transmission quality from the attached data forwarded by the mobile station. The base station outputs the downward line transmission quality when the upward line transmission quality is higher than a reference.

Abstract: A spread spectrum communication receiver includes a transmission path state estimating unit which estimates states of paths from a received signal, and demodulator units independently performing demodulation processes on signals propagated through the respective paths. A symbol combiner combines output signals of the demodulator units. A decision unit is directly or indirectly coupled to the symbol combiner and makes a decision on an output signal of the symbol combiner. An unnecessary component eliminating unit eliminates a component of a first symbol which is an unnecessary component that is propagated through one of the paths and overlaps with a received component of a second symbol to be demodulated, so that the unnecessary component has been eliminated from the output signal of the decision unit.

Abstract: There is provided a method for a flow control to a mobile communication network in which an ATM virtual channel established between a first base station having a radio zone in which a mobile station exists and a terminating ATM node to which a remote station with which the mobile station communicates is connected. The first step of the method is to queue, in an ATM node, incoming cells to be sent to a second base station having a radio zone when the mobile station is handed over to the radio zone of the second base station. The second step of the method is to stop queuing and send the incoming cells queued in the ATM node to the second base station after the mobile station is handed over.

Abstract: A spread spectrum communication receiver includes a plurality of fingers each including a despreader part, an inverse-orthogonal conversion part and a demodulation part. A channel combining part combines demodulated symbols of the plurality of fingers. A control part controls the plurality of fingers on the basis of orthogonal channel allocation information and channel state information so that the fingers execute a RAKE process when the channel information indicates that data to be transmitted is allocated to one orthogonal channel at a transmitter and the fingers perform parallel demodulation processes then the channel information indicates that data to be transmitted is allocated to a plurality of orthogonal channels at the transmitter.