摘要:
A serial-parallel converter 102 of a transmitter apparatus receives an input of a signal to be transmitted and serial-parallel-converts this to output m (m≧2) number of intermediate signals. A unitary matrix modulator 103 modulates the output m number of intermediate signals into a unitary matrix of m rows and m columns whose components other than diagonal components are 0 and outputs the obtained matrix. A splitter 111 supplies the respective diagonal components of the output matrix to the input channels of an inverse Fourier transform unit 112 as input signals. The inverse Fourier transform unit 112 outputs m number of inverse-Fourier-transformed signals obtained by performing inverse Fourier transform of the supplied input signals. A parallel-serial converter 113 parallel-serial-converts the output m number of inverse-Fourier-transformed signals to output one transmission signal. A transmission unit 114 transmits the output transmission signal. The difference between the frequency of any two channels of the inverse Fourier transform unit 112 is equal to or larger than a predetermined coherent bandwidth.
摘要:
The present invention provides a radio node apparatus, a multi-hop radio system and a multi-hop radio system constructing method, capable of constructing a tree type multi-hop radio system in which mutual radio nodes determine a radio node which becomes a root node of a tree in an autonomous manner and the root node is set as a root in an autonomous manner. The radio node apparatus includes a storage unit for storing state information, used for constructing a multi-hop radio system, including information for specifying a root radio node apparatus positioned at a summit of the multi-hop radio system, with the radio node apparatus has a connection, and the number of hops from the root ratio node apparatus, a collection unit for collecting state information transmitted from surrounding radio node apparatus, and a selection unit for selecting a host connection-accepting radio node apparatus on the basis of the information for specifying the root radio node apparatus and the number of hops included in the collected state information.
摘要:
Herein are disclosed a cable television system, mobile communication terminal, a relay apparatus, a center apparatus, and a method of providing a cable television service using the system, which enable a user operating a CATV mobile terminal (6) to receive a CATV service regardless of the service area of the CATV station where the user is located. When a vehicle (5) having a CATV mobile terminal (6) mounted thereon moves into a service area of a CATV station (3, 4), the CATV mobile terminal (6) is operated to transmit a log-in request to the CATV station (3, 4). The CATV station (3, 4) is operated to inquire about the user to the subscriber station (2), and the subscriber station (2) is operated to judge whether or not the user is authentic. Subscriber station (2) is operated to deliver common contents to the CATV mobile terminal (6) through the CATV station (3, 4) when it is judged that the user is authentic.
摘要:
A receiving unit of a receiving device receives a signal arriving thereto through a transmission path as a reception signal. A delay unit outputs a delay signal obtained by delaying the reception signal by a predetermined delay time. An estimation unit estimates a transmission path characteristic. An equalizer/demodulator compensates for the delay signal with the transmission path characteristic, demodulates the compensation result, and outputs the demodulation result as a transmission signal. A replica unit compensates for the reception signal with the transmission path characteristic, demodulates the compensation result, modulates the demodulation result, and outputs the modulation result as a replica signal. The estimation unit estimates a transmission path characteristic by comparing the reception signal with the replica signal. The predetermined delay time is equal to or smaller than a time required for the processes by the replica unit and the estimation unit.
摘要:
A vehicle-vehicle communication system includes an in-vehicle wire LAN established in a vehicle. The in-vehicle wire LAN includes a plurality of devices connected by optical fiber links. A terminal for radio vehicle-vehicle communication is connected to the in-vehicle wire LAN by the optical fiber link. The terminal receives an optical digital signal in a predetermined format from the in-vehicle wire LAN. The terminal includes a light controlled oscillator and applies the received optical signal to the light controlled oscillator. The light controlled oscillator outputs a transmission signal of a frequency shifted from a predetermined frequency according to the intensity of the applied optical signal. Thus the terminal generates the transmission signal using FSK-modulation technique without converting the format of the optical signal into another format. The transmission signal is transmitted to a device in another vehicle via radio waves.
摘要:
A channel evaluator acquires a change predicted value from a known symbol, and a compensator compensates for a first symbol using the change predicted value. A demodulator restores a portion corresponding to this symbol with another subcarrier. A replica generator acquires a transmission replica of the restored symbol. The channel evaluator performs complex division on the replica with the symbol to acquire an amplitude phase ratio. A detector compares the amplitude phase ratio with an amplitude phase ratio acquired immediately previously. In case where an elimination condition is satisfied, the detector disregards the amplitude phase ratio acquired currently and uses an immediately previous value instead, an averaging unit averages amplitude phase ratios to acquire a next change predicted value, and the compensator compensates for a next symbol using the change predicted value. Hereinafter, the sequence of processes is repeated.
摘要:
Herein disclosed are a mobile communication terminal recognizing system, a mobile communication terminal, a relay apparatus, a center apparatus, and a mobile communication terminal recognizing method, which enable a user to receive contents related to a cable television service, as well as are capable of easily identifying the service area where the user is located and accordingly communicating with the user regardless of whether or not the user moves into a service area other than the service area of the CATV station which the user has subscribed to. When a vehicle (5) moves into a service area of a CATV station (3, 4) other than the service area of the CATV station which the user has subscribed to and a CATV mobile terminal (6) receives contents from the ATV station (3, 4) by wireless, the CATV station (3, 4) is operated to store therein delivery history information indicative of a history of delivering the contents, and the CATV mobile terminal (6) is operated to store therein utilization history information indicative of a history of utilizing the contents. A subscriber station (2) is operated to collect and count the delivery history information and the utilization history information after transmitting an inquiry about the delivery history information and the utilization history information to the CATV station (3, 4) and the CATV mobile terminal (6) by way of multicast communication.
摘要:
A serial-parallel converter 102 of a transmitter apparatus receives an input of a signal to be transmitted and serial-parallel-converts this to output m (m≧2) number of intermediate signals. A unitary matrix modulator 103 modulates the output m number of intermediate signals into a unitary matrix of m rows and m columns whose components other than diagonal components are 0 and outputs the obtained matrix. A splitter 111 supplies the respective diagonal components of the output matrix to the input channels of an inverse Fourier transform unit 112 as input signals. The inverse Fourier transform unit 112 outputs m number of inverse-Fourier-transformed signals obtained by performing inverse Fourier transform of the supplied input signals. A parallel-serial converter 113 parallel-serial-converts the output m number of inverse-Fourier-transformed signals to output one transmission signal. A transmission unit 114 transmits the output transmission signal. The difference between the frequency of any two channels of the inverse Fourier transform unit 112 is equal to or larger than a predetermined coherent bandwidth.
摘要:
A serial-parallel converter 102 of a transmitter apparatus receives an input of a signal to be transmitted and serial-parallel-converts this to output m (m≧2) number of intermediate signals. A unitary matrix modulator 103 modulates the output m number of intermediate signals into a unitary matrix of m rows and m columns whose components other than diagonal components are 0 and outputs the obtained matrix. A splitter 111 supplies the respective diagonal components of the output matrix to the input channels of an inverse Fourier transform unit 112 as input signals. The inverse Fourier transform unit 112 outputs m number of inverse-Fourier-transformed signals obtained by performing inverse Fourier transform of the supplied input signals. A parallel-serial converter 113 parallel-serial-converts the output m number of inverse-Fourier-transformed signals to output one transmission signal. A transmission unit 114 transmits the output transmission signal. The difference between the frequency of any two channels of the inverse Fourier transform unit 112 is equal to or larger than a predetermined coherent bandwidth.
摘要:
A receiving section outputs a received signal. An estimation section estimates transmission path characteristics, using the received signal and a modulated data signal. A compensation section outputs a compensated data signal, using the received signal and the transmission path characteristics. A demodulation section demodulates a modulated data signal, using the compensated data signal. A modulation section modulates a modulated data signal, using the demodulated data signal. The estimation section begins the estimation by comparing a result obtained by modulating known-data and a known-data portion of the received signal. The compensation section compensates for a non-compensated data signal portion, using the estimated transmission path characteristics.