Abstract: A communication channel allocation method allocates a communication channel to communications between a mobile terminal device and a second radio base station using a second frequency band which is close to a first frequency band used by a first radio base station, by detecting a first distance between the second radio base station and the first radio base station, detecting a second distance between the second radio base station and the mobile terminal device when the first distance is less than a first threshold, and allocating a communication channel of a frequency far from the first frequency band in the second frequency band to the communications between the second radio base station and the mobile terminal device when the second distance is less than a second threshold.

Abstract: In the case where two wireless communication systems are located close to each other and possibly interfere with each other, it is detected if broad band interference takes place, and, when broad band interference takes place, the use of frequencies is limited within such a frequency range in which the wireless communication systems are little affected by the interference. An interference detection system for detecting interference between one system and another system in a wireless communication making use of frequency division multiplexing is described. The interference detection system includes a radio frequency signal receiving unit; a signal level storing unit; a calculation result storing unit; a threshold level comparing unit; and a carrier number storing unit.

Abstract: A channel assigning method and a communication apparatus for executing appropriate channel assignment in a mobile communication system when both a channel for a service area based on a FDD method and a channel for a service area based on a TDD method can be assigned are provided. For example, if both a channel for a service area based on a CDMA-FDD method and channels for service areas based on a CDMA-TDD method can be assigned to a request for channel assignment, and a handover frequency of the mobile station related to the request is high, the channel for the service area based on the CDMA-FDD method is assigned.

Abstract: In an apparatus for measuring absorbed power including an electromagnetic field probe 1 fixedly mounted within a head simulation phantom 2 which simulates the configuration and the electromagnetic characteristics of a head of a human body, and wherein the strength of an electric field or a magnetic field of a radio wave externally irradiated upon the head simulation phantom 2 is measured by the electromagnetic field probe 1, and the power of the radio wave absorbed by the head is estimated on the basis of measured values, the head simulation phantom 2 comprises a solid dielectric 10? which simulates the configuration and the electromagnetic characteristics of a head of a human body or a liquid dielectric 10 which simulates the electromagnetic characteristics of a head of a human body and which is filled in an enclosed vessel 10 which simulates the configuration of a head of a human body. The volume of the solid dielectric 10? or the volume of the enclosed vessel 11 is equal to or less than 5×105 mm3.

Abstract: A specific absorption rate measuring system, a method thereof, and a biological tissue equivalent phantom unit are disclosed. The biological tissue equivalent phantom unit to be used by the specific absorption rate measuring system for evaluating absorption of electromagnetic wave energy includes a biological tissue equivalent phantom for absorbing an electromagnetic wave; two or more electro-optical crystals that are arranged at two or more measurement points in the biological tissue equivalent phantom, the electro-optical crystals having a dielectric constant that is approximately equal to that of the biological tissue equivalent phantom; and two or more optical fibers laid in the biological tissue equivalent phantom for optically connecting each of the electro-optical crystals to an external destination.

Abstract: A specific absorption rate measuring apparatus comprises a probe configured to measure, in a two-dimensional plane, the amplitude and the phase of an electric or magnetic field generated in a phantom of which electrical properties similar to a human body tissues; an electric and/or magnetic field estimation unit configured to estimate a three-dimensional electric field distribution to be produced from a wave source defined by the two-dimensional electric and magnetic fields at a measuring point, based on the measurement results of the probe; and a specific absorption rate estimation unit configured to estimate a three-dimensional distribution of specific absorption rate based on the estimation result of the electric field estimation unit.

Abstract: A weight determining apparatus is disclosed. The weight determining apparatus includes two or more antenna elements that receive a test wave transmitted by one or more test wave sources prepared outside of a phantom that simulates an object that attenuates a radio wave, the antenna elements being prepared in a mobile terminal. The weight determining apparatus further includes a weight determining unit that determines weights for the antenna elements such that a signal received by the antenna elements as a whole may be maximized.

Abstract: A signal transmission method checks, when detecting an occurrence of a communication request, whether the communication request is a high speed communication (step S302). In the case of the high speed communication, it checks whether the number of current high speed communications (m) plus one is greater than the upper limit (mmax) of the high speed communication (step S312). If greater, it cancels the request as a call loss (S316), and sets to a variable a the ratio (h) of the rate of the high speed communication to that of a low speed communication. If the communication request is the low speed communication, it sets one to the variable a (step S304). It compares n plus a with nmax (step S306), where n is the total number of all the current communications, a is the value associated with the communication request, and nmax is the upper limit of the number of communications acceptable in a bandwidth, all of which are expressed in terms of the number of the low speed communications.

Abstract: A communication channel allocation method allocates a communication channel to communications between a mobile terminal device and a second radio base station using a second frequency band which is close to a first frequency band used by a first radio base station, by detecting a first distance between the second radio base station and the first radio base station, detecting a second distance between the second radio base station and the mobile terminal device when the first distance is less than a first threshold, and allocating a communication channel of a frequency far from the first frequency band in the second frequency band to the communications between the second radio base station and the mobile terminal device when the second distance is less than a second threshold.

Abstract: A communication channel allocation method allocates a communication channel to communications between a mobile terminal device and a second radio base station using a second frequency band which is close to a first frequency band used by a first radio base station, by detecting a first distance between the second radio base station and the first radio base station, detecting a second distance between the second radio base station and the mobile terminal device when the first distance is less than a first threshold, and allocating a communication channel of a frequency far from the first frequency band in the second frequency band to the communications between the second radio base station and the mobile terminal device when the second distance is less than a second threshold.

Abstract: A weighting parameter estimation system for estimating a weight parameter for the antenna elements of a mobile terminal is provided. The system includes a prohibited space forming part to which electromagnetic waves should not be directed when the mobile terminal transmits a signal in wireless communications, and a weighting parameter determination unit configured to determine the weighting parameter for each of the antenna elements of the mobile terminal such that the power level of a test wave transmitted from or received in the prohibited space becomes the minimum.

Abstract: A simplified interference elimination system is provided for eliminating from a first radio signal transmitted from a first radio terminal to a first radio base station, the effect of interference due to a second radio signal transmitted from a second radio terminal to a second radio base station. The second radio base station has an extractor for extracting the second radio signal from radio signals received in the second radio base station, and a transmitter for transmitting the extracted second radio signal to the first radio base station. The first radio base station has an interference eliminator for eliminating the second radio signal transmitted from the second radio base station from radio signals received in the first radio base station.

Abstract: A DS-CDMA transmission method capable of improving the accuracy of channel estimation using pilot symbols by eliminating cross-correlation between pilot symbols inserted into code channels in CDMA multiplexing carrying out fast signal transmission. In each frame assembler, the pilot symbols, which are used for channel estimation for coherent detection, are inserted into coded information data on code channels at fixed intervals, and then the data is modulated by the modulator. The modulated data symbols in each code channel from the modulator are spread by the spreading modulator, the pilot symbols are spread using a spreading code, whereas the information symbols are spread using different spreading codes assigned to respective code channels. The spread signals of the code channels are summed up by the adder to be transmitted.

Abstract: In an apparatus for measuring absorbed power including an electromagnetic field probe 1 fixedly mounted within a head simulation phantom 2 which simulates the configuration and the electromagnetic characteristics of a head of a human body, and wherein the strength of an electric field or a magnetic field of a radio wave externally irradiated upon the head simulation phantom 2 is measured by the electromagnetic field probe 1, and the power of the radio wave absorbed by the head is estimated on the basis of measured values, the head simulation phantom 2 comprises a solid dielectric 10′ which simulates the configuration and the electromagnetic characteristics of a head of a human body or a liquid dielectric 10 which simulates the electromagnetic characteristics of a head of a human body and which is filled in an enclosed vessel 10 which simulates the configuration of a head of a human body.

Abstract: A signal transmission method checks, when detecting an occurrence of a communication request, whether the communication request is a high speed communication (step S302). In the case of the high speed communication, it checks whether the number of current high speed communications (m) plus one is greater than the upper limit (mmax) of the high speed communication (step S312). If greater, it cancels the request as a call loss (S316), and sets to a variable a the ratio (h) of the rate of the high speed communication to that of a low speed communication. If the communication request is the low speed communication, it sets one to the variable a (step S304). It compares n plus a with nmax (step S306), where n is the total number of all the current communications, a is the value associated with the communication request, and nmax is the upper limit of the number of communications acceptable in a bandwidth, all of which are expressed in terms of the number of the low speed communications.

Abstract: A signal transmission method checks, when detecting an occurrence of a communication request, whether the communication request is a high speed communication (step S302). In the case of the high speed communication, it checks whether the number of current high speed communications (m) plus one is greater than the upper limit (mmax) of the high speed communication (step S312). If greater, it cancels the request as a call loss (S316), and sets to a variable a the ratio (h) of the rate of the high speed communication to that of a low speed communication. If the communication request is the low speed communication, it sets one to the variable a (step S304). It compares n plus a with nmax (step S306), where n is the total number of all the current communications, a is the value associated with the communication request, and nmax is the upper limit of the number of communications acceptable in a bandwidth, all of which are expressed in terms of the number of the low speed communications.

Abstract: A DS-CDMA transmission method capable of improving the accuracy of channel estimation using pilot symbols by eliminating cross-correlation between pilot symbols inserted into code channels in CDMA multiplexing carrying out fast signal transmission. In each frame assembler, the pilot symbols, which are used for channel estimation for coherent detection, are inserted into coded information data on code channels at fixed intervals, and then the data is modulated by the modulator. The modulated data symbols in each code channel from the modulator are spread by the spreading modulator, the pilot symbols are spread using a spreading code, whereas the information symbols are spread using different spreading codes assigned to respective code channels. The spread signals of the code channels are summed up by the adder to be transmitted.

Abstract: A radio terminal (10) and a radio relay (20, 30, 40) perform radio communications therebetween by a radio communications system else than a TDMA system, ian interference measurer (13a) measures a degree of interference of each of radio slots constituting a radio channel employed in the radio communications system, a decision maker (13b, 13c) makes a decision, depending on a measurement result of the degree of interference, whether or not the radio communications by the radio communications system is able to be continued, and a switcher (42) switches, as the decision is made of the radio communications by the radio communications system to be unable to be continued, the radio communications system to a radio communications system of the TDMA system.

Abstract: A simplified interference elimination system is provided for eliminating from a first radio signal transmitted from a first radio terminal to a first radio base station, the effect of interference due to a second radio signal transmitted from a second radio terminal to a second radio base station. The second radio base station has an extractor for extracting the second radio signal from radio signals received in the second radio base station, and a transmitter for transmitting the extracted second radio signal to the first radio base station. The first radio base station has an interference eliminator for eliminating the second radio signal transmitted from the second radio base station from radio signals received in the first radio base station.

Abstract: A communication channel allocation method allocates a communication channel to communications between a mobile terminal device and a second radio base station using a second frequency band which is close to a first frequency band used by a first radio base station, by detecting a first distance between the second radio base station and the first radio base station, detecting a second distance between the second radio base station and the mobile terminal device when the first distance is less than a first threshold, and allocating a communication channel of a frequency far from the first frequency band in the second frequency band to the communications between the second radio base station and the mobile terminal device when the second distance is less than a second threshold.