Abstract: A radio apparatus forming a radio network system calculates a calculated distance, based on a tentative self-position and tentative positions of a plurality of radio apparatuses existing in the vicinity. The radio apparatus successively and autonomously corrects the tentative self-position so that the calculated distance comes closer to the measured distance, relying more heavily on the calculated distance than the measured distance between itself and each of the plurality of radio apparatuses, and determines the position of itself. Other radio apparatuses also successively correct the tentative self-positions by the same method as the radio apparatus, and determine the positions of themselves.

Abstract: A MC-CDMA transmitter and an MC-CDMA receiver are provided, which use a novel orthogonal spreading code that allows an effect by a delay wave to appear in only a specific user. An MC-CDMA system includes: a transmitter which multiplies a transmitting signal by a sinusoidal signal which has an amplitude of r and is orthogonal as a result that the frequency periods are different among users, in a frequency domain to be spread and split into orthogonal sub-carriers, and multiplexes the sub-carriers; and a receiver for receiving a transmitting signal from the transmitter in a manner that a sinusoidal signal, which has an amplitude of r and is orthogonal as a result that the frequency periods are different among users, is multiplied by the transmitting signal in a frequency domain, and the resultant is inversely spread.

Abstract: A MC-CDMA transmitter and an MC-CDMA receiver are provided, which use a novel orthogonal spreading code that allows an effect by a delay wave to appear in only a specific user. An MC-CDMA system includes: a transmitter which multiplies a transmitting signal by a sinusoidal signal which has an amplitude of r and is orthogonal as a result that the frequency periods are different among users, in a frequency domain to be spread and split into orthogonal sub-carriers, and multiplexes the sub-carriers; and a receiver for receiving a transmitting signal from the transmitter in a manner that a sinusoidal signal, which has an amplitude of r and is orthogonal as a result that the frequency periods are different among users, is multiplied by the transmitting signal in a frequency domain, and the resultant is inversely spread.

Abstract: A radio apparatus forming a radio network system calculates a calculated distance, based on a tentative self-position and tentative positions of a plurality of radio apparatuses existing in the vicinity. The radio apparatus successively and autonomously corrects the tentative self-position so that the calculated distance comes closer to the measured distance, relying more heavily on the calculated distance than the measured distance between itself and each of the plurality of radio apparatuses, and determines the position of itself. Other radio apparatuses also successively correct the tentative self-positions by the same method as the radio apparatus, and determine the positions of themselves.

Abstract: On the side of a mobile station, interference of a perch channel with call control information or a traffic channel is reduced, realizing stable communication. In a method of CDMA communication in which communication is made through the traffic channel for transmitting user data and the perch channel for transmitting a spreading code used for demodulation of the user data, the traffic channel has a call control channel subjected to the time division multiplex, and that call control channel and a part of the perch channel, which is non-orthogonal to the call control channel, are arranged not to overlap with each other in a time base.

Abstract: Methods and systems are provided for use in a wireless network that includes a base station and a mobile station. Service may be provided by the base station to the mobile station based on the traffic load on the network. When a request for a service is received at the base station, the cost of the service is determined. The request is granted if the determined cost is less than or equal to a threshold that is responsive to a load on the network.

Abstract: Methods and systems are provided for use in a wireless network that includes a base station and a mobile station. Service may be provided by the base station to the mobile station based on the traffic load on the network. When a request for a service is received at the base station, the cost of the service is determined. The request is granted if the determined cost is less than or equal to a threshold that is responsive to a load on the network.

Abstract: A mobile communication system includes a first and second systems. Each of the first and second systems has a land station and at least one mobile terminal capable of communicating with the land station. The land station of the first system has a broadcasting channel transmission unit for transmitting status information via a broadcasting channel, and the mobile terminal of the second system has a broadcasting channel receiving unit for receiving information in the broadcasting channel to obtain a broadcasting channel receiving condition and the status information, a giving interference estimation unit for estimating giving interference level onto communication of the first system by the second system based upon the obtained broadcasting channel receiving condition and the obtained status information, and an output signal level control unit for controlling output signal level of the mobile terminal of the second system based upon the estimated giving interference level.

Abstract: A system for communicating between mobile units and an exchange station, with a radio frequency signal, in which an electric signal from a telephone exchange of the telephone station is converted into an optical signal with an electricity-to-light converter. The optical signal is carried via an optical fiber cable to a transmission communication antenna for emission, with amplification of the optical signal if necessary. The emitted signal is received by a receiving communication antenna, amplified with an optical amplifier if necessary, and converted to an electric signal with a light-to-electricity converter.

Abstract: A CDMA communication system using a spreading code has a plurality of mobile stations and at least one base station. The mobile stations and the base station are provided with respective receiving sections, each of which has a path diversity function for reducing multipath fading. The base station includes an array antenna having a plurality of integrated antenna elements spaced by a distance substantially equal to one to several wavelengths from each other so as to produce a space diversity effect. A plurality of delay devices are coupled with the respective antenna elements, for applying time delays to signals which pass through the respective antenna elements. The time delay are different from each other by a one symbol period of the spreading code or more.

Abstract: Accordingly to the present invention, when an incidence angle of a direct wave or a satellite elevation angle reaches a predetermined value, signals from two (or more) antennas, which are disposed at positions where variations in the field intensities of radio waves recevied by the two antennas are negatively correlated (i.e. when the received signal level of one of them is low, the received signal level of the other is high) or uncorrelated (i.e. the variations are not related to each other), are successively or discretely switched at a suitable switching period, by which burst-like errors are spread with time to perform the de-interleave or interleave function in decoding transmitted signals.