Abstract: A node apparatus calculates the arrival rate in a link, discretizes the calculated arrival rate according to thresholds that are set so that the intervals between thresholds in the range in which a large number of the arrival rates in the links with a high frequency of usage exist become narrower, and calculates the link cost according to the value after the discretization. The node apparatus then obtains, from adjacent node apparatuses, the route cost for each route to each final destination that may be reached, and integrates the obtained route cost by the calculated link cost to calculate the route cost to each final destination that can be reached from the local node apparatus via the adjacent node apparatus. The node apparatus then selects the adjacent node apparatus to be the transmission destination according to the route cost of the route to the final destination of a data frame.

Abstract: Node device calculates reception rate of frames of particular frame type transmitted from adjacent node device, calculates arrival rate of unicast frames on the basis of calculated reception rate and frame length, and calculates inverse number of calculated arrival rate as link cost. Node device obtains from adjacent node device route cost for each route from adjacent node device to each node device that is reachable final destination, calculates route cost of route from node device itself to each node device that is final destination reachable via adjacent node device by integrating calculated link cost and obtained route cost. Node device selects adjacent node device that is transmission destination of data frame on the basis of route cost of route from node device itself to node device that is final destination of data frame when data frame is transmitted.

Abstract: A communication device includes a sending unit that sends a plurality of signals that are to be wirelessly sent with different frequencies; an acquiring unit that acquires a reception signal to which an intermodulation signal that is produced due to intermodulation of the plurality of signals is added; and a processor that is connected to the sending unit and the acquiring unit. The processor generates, on the basis of the plurality of signals sent by the sending unit, a cancellation signal corresponding to the intermodulation signal and combines the generated cancellation signal with the reception signal acquired by the acquiring unit.

Abstract: Node device calculates reception rate of frames of particular frame type transmitted from adjacent node device, calculates arrival rate of unicast frames on the basis of calculated reception rate and frame length, and calculates inverse number of calculated arrival rate as link cost. Node device obtains from adjacent node device route cost for each route from adjacent node device to each node device that is reachable final destination, calculates route cost of route from node device itself to each node device that is final destination reachable via adjacent node device by integrating calculated link cost and obtained route cost. Node device selects adjacent node device that is transmission destination of data frame on the basis of route cost of route from node device itself to node device that is final destination of data frame when data frame is transmitted.

Abstract: A node apparatus calculates the arrival rate in a link, discretizes the calculated arrival rate according to thresholds that are set so that the intervals between thresholds in the range in which a large number of the arrival rates in the links with a high frequency of usage exist become narrower, and calculates the link cost according to the value after the discretization. The node apparatus then obtains, from adjacent node apparatuses, the route cost for each route to each final destination that may be reached, and integrates the obtained route cost by the calculated link cost to calculate the route cost to each final destination that can be reached from the local node apparatus via the adjacent node apparatus. The node apparatus then selects the adjacent node apparatus to be the transmission destination according to the route cost of the route to the final destination of a data frame.

Abstract: A method for selecting a connection destination for wireless communication from a plurality of base stations in a wireless terminal that is in service areas of the plurality of base stations, which includes a first step (#11) of receiving dispatch information from each of the plurality of base stations, a second step (#12) of obtaining information about each reception power when the dispatch information is received, a third step (#13) of obtaining information about an antenna that is used by each of the base stations for wireless communication after connection from each of the received dispatch information, and a fourth step (#14) of selecting a base station having a highest quality of a communication channel in the wireless communication as the connection destination based on the information about the reception power and the information about the antenna of each of the base stations.

Abstract: A cognitive radio system includes cognitive radio apparatuses and a management server via a network. The cognitive radio apparatus includes a terminal communication part selecting a communication protocol, a communication quality acquisition part acquiring a communication quality including a current location of the selected protocol, and a communication quality notification part notifying the server of the information. The server includes a server communication part communicating with the apparatus, a communication quality collecting part collecting the information, a communication quality managing part recording and managing the information, and an area communication condition providing part providing the information to the apparatus.

Abstract: A method for forming a beam in an array antenna to orient a null point of the array antenna to a mobile station which acts as interference, includes the step of: forming a beam in such a manner that, based on a moving speed of the mobile station acting as interference, a moving direction and a distance between the array antenna and the mobile station, a signal power to interference power ratio may be equal, regardless of the distance, between before and after movement when the mobile station acting as interference moves.

Abstract: An adaptive control apparatus that adaptively controls directivity of an array antenna is disclosed. The adaptive control apparatus that can be used by a radio apparatus and a receiver includes a setting unit configured to set up parameters such as the distance between the radio apparatus and the receiver that receives a radio frequency signal transmitted by the radio apparatus, the relative moving speed, and the moving direction of the receiver in reference to the radio apparatus. The adaptive control apparatus further includes an evaluating unit configured to evaluate how much received power at the receiver or the radio apparatus changes after a predetermined period, and a weight control unit configured to adjust two or more weighting factors about two or more antenna elements that constitute the array antenna.

Abstract: A method for selecting a connection destination for wireless communication from a plurality of base stations in a wireless terminal that is in service areas of the plurality of base stations, which includes a first step (#11) of receiving dispatch information from each of the plurality of base stations, a second step (#12) of obtaining information about each reception power when the dispatch information is received, a third step (#13) of obtaining information about an antenna that is used by each of the base stations for wireless communication after connection from each of the received dispatch information, and a fourth step (#14) of selecting a base station having a highest quality of a communication channel in the wireless communication as the connection destination based on the information about the reception power and the information about the antenna of each of the base stations.

Abstract: The present invention is a multi-carrier communication method for carrying out communication between a mobile station and a base station with the use of a plurality of carrier frequencies within the same area, wherein a reception quality correspondent value of each of the plurality of carrier frequencies in the mobile station is detected, a carrier frequency to be used for communication is determined based on the reception quality correspondent values, so that communication is carried out with the carrier frequency having high reception quality and reception quality can be improved.

Abstract: A receiver is disclosed that demodulates an Orthogonal Frequency Division Multiplexing (OFDM) symbol transmitted by an OFDM method. The receiver includes a delay profile generation unit that generates a delay profile regarding a preceding wave and a delayed wave included in a received signal, a demodulation unit that demodulates the received signal so as to output a demodulated signal per sub-carrier, a hard-decision unit that makes a hard decision per sub-carrier on a signal point based on the demodulated signal so as to output a hard-decision signal, a replica generation unit that uses the hard-decision signal to generate a replica signal per sub-carrier, and an inter-carrier interference suppression unit that adds a difference between the hard-decision signal and the replica signal to the demodulated signal so as to suppress an inter-carrier interference.

Abstract: A CDMA receiver is disclosed wherein (1) a despreader despreads a receive signal to thereby demodulate a control-data signal and a transmit-data signal; (2) a channel estimation unit derives a channel estimation value from a pilot signal that is contained in the despread control-data signal; (3) a channel compensation unit performs channel compensation of the transmit-data and control-data signals based upon the channel estimation value; (4) a power calculation unit calculates power of the transmit-data signal and power of the control-data signal after the channel compensation thereof and calculates a power ratio representing the ratio of the calculated power of the transmit-data signal to the calculated power of the control-data signal; (5) a signal-level changing unit raises, on the basis of the power ratio, the level of whichever of the signals has the lower power; and (6) a decoder executes decoding processing based upon the signal the level of which has been changed by the signal-level changing unit.

Abstract: An object of the present invention is to provide a method for suppressing peak power at a high encoding rate in a multi-carrier transmission system. The present invention provides a transmitter for transmitting a multi-carrier signal, in which when generating 128 patterns used to suppress the peak power of 8-bit sub-carrier mapping signals from 7-bit information bits in a encoding unit 9, a sub-carrier generation unit 11, for example, divides the signal point of QPSK modulation into orthogonal groups, generates a sub-carrier mapping signal in which a part of sub-carriers is dependent on the signal point of another sub-carrier and a receiver for receiving such a multi-carrier signal.

Abstract: An adaptive control apparatus that adaptively controls directivity of an array antenna is disclosed. The adaptive control apparatus that can be used by a radio apparatus and a receiver includes a setting unit configured to set up parameters such as the distance between the radio apparatus and the receiver that receives a radio frequency signal transmitted by the radio apparatus, the relative moving speed, and the moving direction of the receiver in reference to the radio apparatus. The adaptive control apparatus further includes an evaluating unit configured to evaluate how much received power at the receiver or the radio apparatus changes after a predetermined period, and a weight control unit configured to adjust two or more weighting factors about two or more antenna elements that constitute the array antenna.

Abstract: A method for forming a beam in an array antenna to orient a null point of the array antenna to a mobile station which acts as interference, includes the step of: forming a beam in such a manner that, based on a moving speed of the mobile station acting as interference, a moving direction and a distance between the array antenna and the mobile station, a signal power to interference power ratio may be equal, regardless of the distance, between before and after movement when the mobile station acting as interference moves.

Abstract: A receiver is disclosed that demodulates an Orthogonal Frequency Division Multiplexing (OFDM) symbol transmitted by an OFDM method. The receiver includes a delay profile generation unit that generates a delay profile regarding a preceding wave and a delayed wave included in a received signal, a demodulation unit that demodulates the received signal so as to output a demodulated signal per sub-carrier, a hard-decision unit that makes a hard decision per sub-carrier on a signal point based on the demodulated signal so as to output a hard-decision signal, a replica generation unit that uses the hard-decision signal to generate a replica signal per sub-carrier, and an inter-carrier interference suppression unit that adds a difference between the hard-decision signal and the replica signal to the demodulated signal so as to suppress an inter-carrier interference.

Abstract: A method of providing unequal error protection in a multi-carrier transmission, includes the steps of coding data for a multi-carrier-symbol duration by a coding process of a given minimum code distance, the given minimum code distance being a minimum of a distance between two codes that is measured in multidimensional code space with N sub-carriers; and changing the minimum code distance for each multi-carrier-symbol duration by changing the coding process.

Abstract: An object of the present invention is to provide a method for suppressing peak power at a high encoding rate in a multi-carrier transmission system.

Abstract: A CDMA receiver is disclosed wherein (1) a despreader despreads a receive signal to thereby demodulate a control-data signal and a transmit-data signal; (2) a channel estimation unit derives a channel estimation value from a pilot signal that is contained in the despread control-data signal; (3) a channel compensation unit performs channel compensation of the transmit-data and control-data signals based upon the channel estimation value; (4) a power calculation unit calculates power of the transmit-data signal and power of the control-data signal after the channel compensation thereof and calculates a power ratio representing the ratio of the calculated power of the transmit-data signal to the calculated power of the control-data signal; (5) a signal-level changing unit raises, on the basis of the power ratio, the level of whichever of the signals has the lower power; and (6) a decoder executes decoding processing based upon the signal the level of which has been changed by the signal-level changing unit.