摘要:
A Micro-cell is formed to include a plurality of spot-cells. Communication is executed between a micro-cell base station and a mobile terminal in the micro-cell, and between a spot-cell base station and the mobile terminal in the spot cell. The micro-cell base station and spot-cell base stations are connected to an integrated base station. A signal transmitted to the micro-cell base station from the mobile terminal is transferred to the integrated base station and information transmitted to the mobile terminal is transferred to the micro-cell base station and/or spot-cell base station from the integrated base station. The respective integrated base stations are connected to a server via a dedicated backbone to enable a large-capacity transmission.
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 radio communication system between a mobile terminal station of a vehicle and a plurality of roadside fixed base stations is so constructed that communication areas of the base stations do not overlap with each other and satisfy the following two conditions. Condition (i): each communication area is defined so that there cannot be a plurality of terminal stations simultaneously. Condition (ii): it is needless to perform multiple access such as time division in the communication area and capable of affording the whole band and all the communication time allocated to one communication area to one terminal station and broad band communication becomes possible. Thus, each mobile terminal station can utilize all the frequency band allocated for service.
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.
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 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:
A communication zone is defined by a plurality of cells, which are separated from one another and has respective fixed base stations. The base stations in the first cell and the last cell are capable of bidirectional communication with a mobile station, while other base stations are capable of unidirectional communication. The base stations are connected to a zone control station, which controls communications with the mobile station within the zone.
摘要:
A multimode service radio communication apparatus, that provides a hand-held or vehicle-mounted terminal with radio communication and radio broadcasting information of a radio information and communication providing system including mobile communication systems and intelligent transport systems, includes a frequency division multiplexer that integration-converts individual radio or intermediate frequencies modulated for mobile telephones and broadcasts so that the modulated frequencies are included in a specific frequency band, and produces radio signals in the specific frequency band; supply device for supplying the radio signals; an antenna for receiving and transmitting the supplied radio signals; a shared antenna for receiving the transmitted radio signals; and terminals to which specific frequencies in the specific frequency band are selectively linked.
摘要:
A multimode service radio communication apparatus, that provides a hand-held or vehicle-mounted terminal with radio communication and radio broadcasting information of a radio information and communication providing system including mobile communication systems and intelligent transport systems, includes a frequency division multiplexer that integration-converts individual radio or intermediate frequencies modulated for mobile telephones and broadcasts so that the modulated frequencies are included in a specific frequency band, and produces radio signals in the specific frequency band; supply device for supplying the radio signals; an antenna for receiving and transmitting the supplied radio signals; a shared antenna for receiving the transmitted radio signals; and terminals to which specific frequencies in the specific frequency band are selectively linked.
摘要:
In order to utilize several radio communication systems with a radio terminal 1, by preparing the common modulator and demodulator part 2a and reconfigurable modulator and demodulator part 2b in advance and performing function selection means 4 with specified means of differential information 5 which information consists of the list of differential specification information of each radio communication system such as the tap coefficients of filter, frame format and the like, and their hardware address to allocate the information into digital signal processing hardware, the required radio communication systems are realized as users like.