Abstract: An object of the present invention is to provide a communications system etc., which can reduce the influence of interference from other systems which results from a difference in symbol length, in an area where a plurality of systems using different transmission methods are mixed. The present invention relates to a communications system in which a plurality of systems share the same frequency bandwidth so as to transmit information symbols. One of the plurality of systems 1 includes an identifying unit 109 configured to identify the symbol length of an information symbol transmitted in a different system 2; and an adjusting unit 102, 107 configured to adjust the symbol length of an information symbol to be transmitted, in accordance with an identified symbol length.

Abstract: An OFDM signal frame generator includes a rate determiner configured to determine rate information to generate a signal frame to be transmitted as an OFDM signal based on a value of a received signal quality. The signal frame generator further includes a pilot and data arrangement format determiner configured to determine a pilot and data arrangement format of the signal that is to be transmitted; power amplification rate determiner configured to determine a power amplification rate for the signal frame; data symbol generator configured to generate data symbol series to be transmitted based on the rate information and based on the power amplification rate; and transmission signal frame generator configured to generate the signal frame based on the generated data symbol series, on the number of pilot symbols, and based on the pilot & data arrangement format.

Abstract: A communication node that relays signals between a source node and a destination node includes (a) a first unitary matrix calculation unit configured to calculate a first unitary matrix based on a first channel between the source node and the relay node, (b) a second unitary matrix calculation unit configured to calculate a second unitary matrix based on a second channel between the relay node and the destination node, (c) a transformation matrix estimation unit configured to estimate a transformation matrix based on a triangular matrix derived from QR decomposition of the first and/or second channel matrix, (d) a relaying signal generator configured to generates a relaying signal by multiplying a received signal by at least one of the first unitary matrix, the second unitary matrix, and the transformation matrix, and (e) a transmission unit configured to transmit the relaying signal to the destination node.

Abstract: A communication node relays a transmission signal transmitted from a desired source node to a target destination node among multiple source nodes and multiple destination nodes. The communication node includes a first unitary matrix estimation unit that estimates a first unitary matrix by performing singular value decomposition involving one or more channel matrices between the relay node and the source nodes other than the desired source node; a second unitary matrix estimation unit that estimates a second unitary matrix by performing singular value decomposition involving one or more channel matrices between the relay node and the destination nodes other than the target destination node; and a transmission unit configured to transmit a relaying signal generated by multiplying a received signal by the first and second unitary matrices toward the target destination node.

Abstract: A receiver comprises multiple receiving antennas configured to receive bitstreams transmitted from multiple transmission antennas; a bitstream candidate estimator configured to estimate a prescribed number of bitstream candidates among possible combinations of the received bitstreams and to calculate reliability information for each of the candidates; a bit-based estimator configured to produce a bit-based estimation result for each bit of the transmitted bitstreams based on the estimated candidates and the associated reliability information, the bit-based estimation result being adjusted by an adjusting criterion determined by the reliability information; and a decoder configured to decode the transmitted bitstreams based on the adjusted bit-based estimation result.

Abstract: In an adaptive equalizing apparatus for MIMO (Multi-Input Multi-Output) turbo reception, an interference component in a received signal is subtracted therefrom using a replica of an interference component in an interference canceling part 31n, the subtracted output is filtered by a filter 32n, to cancel the remaining interference component and to perform multi-path combining, and in a degree-of-interference-cancellation estimation part 41n the degree of interference cancellation ?(i) is set such that it is 0 for the iteration number i=1, 0.8+0.05 (i?1) for 5?i?2 and 1 for i?6, and at the beginning of each iteration filter coefficients are calculated using ?(i) and a channel estimation value in a filter coefficient calculating part 33n and the filter coefficient thus calculated are set in the filter 32n. An average value of soft decision symbol estimation values used in the interference canceling part may be used as ?.

Abstract: The accuracy of an equalization start timing, an equalization duration and a channel estimation is improved in an application including an increased number of users. An equalization start timing t0, an equalization duration te and channel H estimation are performed for each user signal, and using these, received signal replicas Re1 ro ReN for the respective users are generated. The replicas are subtracted from the received signal to provide an error signal, and Re1 to ReN are added to Es to provide an interference suppressed received signals for the users 1 to N. to, te, H and Re1 to ReN are generated from these to generate Es in a repeated fashion to improve the accuracy of t0, te and H.

Abstract: A receiver for mobile communication includes a wireless scheme parameter storing unit (23) configured to store a plurality of characteristics of multiple wireless schemes, a wireless scheme estimation unit (22) configured to estimate one of the characteristics of a currently used wireless scheme from a received signal and select one of the wireless schemes corresponding to the estimated characteristic from the wireless scheme parameter storing unit, and a demodulator (24) configured to demodulate the received signal based on the selected wireless scheme.

Abstract: An impluse response hmn(q) of each transmission path is estimated from N received signals rm (m=1, . . . , M) and a known signal (for a number of users equal to N, n=1, . . . , N). M×N matrix H (q) having hmn(q) as an element and a Q×Q matrix H having H(q) as an element are determined (where Q represents a number of multipaths of each transmitted wave and q=0, . . . , Q?1). A soft decision value b?n(k) is determined from decoded ?2 [bn(k)], and this is used to generate an interference component matrix B?(k) to generate an interference replica H·B?(k). The interference replica H·B?(k) is subtracted from a received matrix y(k) to determine y?(k). y(k) and H are used to determine an adaptive filter coefficient wn(k) to be applied to an n-th user in order to eliminate residual interference components in y?(k) according to the minimum mean square error criteria. y(k) is passed through wn(k) to provide a log-likelihood ratio as a received signal from the user n from which interferences are eliminated.

Abstract: A communication node relays a transmission signal transmitted from a desired source node to a target destination node among multiple source nodes and multiple destination nodes. The communication node includes a first unitary matrix estimation unit that estimates a first unitary matrix by performing singular value decomposition involving one or more channel matrices between the relay node and the source nodes other than the desired source node; a second unitary matrix estimation unit that estimates a second unitary matrix by performing singular value decomposition involving one or more channel matrices between the relay node and the destination nodes other than the target destination node; and a transmission unit configured to transmit a relaying signal generated by multiplying a received signal by the first and second unitary matrices toward the target destination node.

Abstract: A shared frequency transmitter for use in a network environment where transmitters and receivers of plural radio communication systems in which the same frequency is used exist is disclosed. The shared frequency transmitter includes (a) a communicating unit configured to detect peripheral transmitters existing in a peripheral area, and to exchange information with the detected peripheral transmitters; and (b) a signal generating unit configured to generate a transmit signal by applying an interference cancellation technique based on the information obtained through the exchange of information.

Abstract: A communication node that relays signals between a source node and a destination node includes (a) a first unitary matrix calculation unit configured to calculate a first unitary matrix based on a first channel between the source node and the relay node, (b) a second unitary matrix calculation unit configured to calculate a second unitary matrix based on a second channel between the relay node and the destination node, (c) a transformation matrix estimation unit configured to estimate a transformation matrix based on a triangular matrix derived from QR decomposition of the first and/or second channel matrix, (d) a relaying signal generator configured to generates a relaying signal by multiplying a received signal by at least one of the first unitary matrix, the second unitary matrix, and the transformation matrix, and (e) a transmission unit configured to transmit the relaying signal to the destination node.

Abstract: A transceiver of a MIMO method communication system, and a transmitting-receiving method thereof are disclosed. The transceiver includes one or more antennas for receiving two or more signals transmitted using two or more transmission antennas, a channel estimating unit for estimating a channel of each of the signals, an error detecting unit for performing error detection of each signal based on reliability information added to the signal, and for determining a transmission rate of the signals based on at least one of the channel estimation result and the error detection result of each signal, and a transmission rate determining unit for adjusting the number of signals to be transmitted from the transmission antennas at a predetermined interval.

Abstract: A receiver comprises multiple receiving antennas configured to receive bitstreams transmitted from multiple transmission antennas; a bitstream candidate estimator configured to estimate a prescribed number of bitstream candidates among possible combinations of the received bitstreams and to calculate reliability information for each of the candidates; a bit-based estimator configured to produce a bit-based estimation result for each bit of the transmitted bitstreams based on the estimated candidates and the associated reliability information, the bit-based estimation result being adjusted by an adjusting criterion determined by the reliability information; and a decoder configured to decode the transmitted bitstreams based on the adjusted bit-based estimation result.

Abstract: A receiver (100) in a communication system for detecting a data signal included in a received signal transmitted by a transmitter is disclosed. The receiver comprises a channel estimator (101-1) for estimating a channel and outputting a channel estimation value; an interference signal removing unit (101-2, 101-3) for generating a received signal replica of a non-data signal included in the received signal using the channel estimation value, and removing the received signal replica of the non-data signal from the received signal; and a data signal detector (102) for detecting the data signal using an output from the interference signal removing unit.

Abstract: An object of the present invention is, in a communication path of which received signal quality is extremely poor, to prevent such a state of the communication failure. To a frame generator 13 in a transmitter 10, which transmits OFDM signal, a pilot & data arrangement format determiner 20, which determines pilot & data arrangement format of an OFDM signal based on the value of received signal quality at a receiver 30, a pilot symbol number determiner 19, which determines the number of pilot symbols based on the value of received signal quality, and a power amplification rate determiner 18, which determines power amplification rate based on the value of received signal quality, are newly provided. Thereby, it is possible to change the pilot & data arrangement format, the number of pilot symbols and the power amplification rate depending on the value of received signal quality to generate transmission signal frame of the OFDM signal.

Abstract: In an adaptive equalizing apparatus for MIMO (Multi-Input Multi-Output) turbo reception, an interference component in a received signal is subtracted therefrom using a replica of an interference component in an interference canceling part 31n, the subtracted output is filtered by a filter 32n, to cancel the remaining interference component and to perform multi-path combining, and in a degree-of-interference-cancellation estimation part 41n the degree of interference cancellation &bgr;(i) is set such that it is 0 for the iteration number i=1, 0.8+0.05 (i−1) for 5≧i≧2 and 1 for i≧6, and at the beginning of each iteration filter coefficients are calculated using &bgr;(i) and a channel estimation value in a filter coefficient calculating part 33n and the filter coefficient thus calculated are set in the filter 32n. An average value of soft decision symbol estimation values used in the interference canceling part may be used as &bgr;.

Abstract: The accuracy of an equalization start timing, an equalization duration and a channel estimation is improved in an application including an increased number of users. An equalization start timing t0, an equalization duration te and channel H estimation are performed for each user signal, and using these, received signal replicas Re1 ro ReN for the respective users are generated. The replicas are subtracted from the received signal to provide an error signal, and Re1 to ReN are added to Es to provide an interference suppressed received signals for the users 1 to N. to, te, H and Re1 to ReN are generated from these to generate Es in a repeated fashion to improve the accuracy of t0, te and H.

Abstract: An impluse response hmn(q) of each transmission path is estimated from N received signals rm (m=1, . . . , M) and a known signal (for a number of users equal to N, n=1, . . . , N). M×N matrix H (q) having hmn(q) as an element and a Q×Q matrix H having H(q) as an element are determined (where Q represents a number of multipaths of each transmitted wave and q=0, . . . , Q−1). A soft decision value b′n(k) is determined from decoded &lgr;2 [bn(k)], and this is used to generate an interference component matrix B′(k) to generate an interference replica H·B′(k). The interference replica H·B′(k) is subtracted from a received matrix y(k) to determine y′(k). y(k) and H are used to determine an adaptive filter coefficient wn(k) to be applied to an n-th user in order to eliminate residual interference components in y′(k) according to the minimum mean square error criteria.

Abstract: (Cycloalkylamino)methylenebis(phosphonic acid) represented by the general formula: ##STR1## in which, R, R.sup.1, R.sup.2, R.sup.3 and R.sup.4 represent a hydrogen atom or a lower alkyl group, and n represents an integer from 3 to 10, a lower alkyl ester thereof or a pharmaceutically acceptable salt thereof; and a bone-resorption inhibitor and an anti-arthritis containing the same.