摘要:
A wireless communication apparatus according to the present invention is composed of a first section for carrying out wireless communication with a multichannel signal and a second section having a plurality of channel units each process a predetermined frequency signal as a channel signal. The wireless communication apparatus is arranged to have a plurality of variable attenuators each provided for corresponding one of the channel signals received from each channel unit of the second section, a combiner for combining outputs from the respective variable attenuators together and outputting the resultant combined signal to the first section, and a control unit for controlling the degree of attenuation of the individual variable attenuators according to the variation of the number of the channel signals. According to the arrangement, the wireless communication apparatus can not only communicate with an opponent station by transmitting a multichannel signal but also effectively suppress negative influence on existing channel even if a new channel unit is additionally provided.
摘要:
A wireless communication apparatus according to the present invention is composed of a first section for carrying out wireless communication with a multichannel signal and a second section having a plurality of channel units each process a predetermined frequency signal as a channel signal. The wireless communication apparatus is arranged to have a plurality of variable attenuators each provided for corresponding one of the channel signals received from each channel unit of the second section, a combiner for combining outputs from the respective variable attenuators together and outputting the resultant combined signal to the first section, and a control unit for controlling the degree of attenuation of the individual variable attenuators according to the variation of the number of the channel signals. According to the arrangement, the wireless communication apparatus can not only communicate with an opponent station by transmitting a multichannel signal but also effectively suppress negative influence on existing channel even if a new channel unit is additionally provided.
摘要:
A space diversity receiver apparatus receives signals by two spatially separated antennas, controls the phase of the signal received by one of the antennas by a phase control circuit, combines the phase-controlled signal and the signal received by the other antenna by a combiner and outputs the combined signal. A digital detector digitally detects the center frequency level and the levels on high- and low-frequency sides of the center frequency of the combined signal. Phase is controlled in such a manner that the center frequency level will coincide with a set level and a deviation between the levels on the high- and low-frequency sides of the center frequency will become zero.
摘要:
A communication device includes a number of transmitter/receiver/modem blocks installed in vertical positions. Each of the transmitter/receiver/modem blocks includes a supporting board having a front surface and a back surface, the supporting board including a plurality of fins on the front surface and a plurality of forced air-cooling fans on the supporting board. A front cover encloses the front surface of the supporting board, the front cover and the fins forming a plurality of ducts, the front cover and the front surface forming an internal opening under the fins. A back cover encloses the back surface of the supporting board. First heat-radiating circuit modules are provided at positions adjacent to the fins on the front surface. A second heat-radiating circuit module is provided within the opening. When the forced air-cooling fans operate, the fans produce a flow of air along the plurality of ducts to cool the first heat-radiating circuit modules, and the fans producing a flow of air within the opening to cool the second heat-radiating circuit board.
摘要:
The present invention is directed to a multiplex radio transmission/receiving system. The system includes a plurality of transmission sections provided so as to correspond to a plurality of channels, and a plurality of receiving sections provided so as to correspond to the plurality of channels. Each transmission section includes a modulation section, a first frequency conversion section, a first band-pass filter, a second frequency conversion section, and a second band-pass filter. Each receiving section includes a third band-pass filter, a third frequency conversion section, a fourth band-pass filter, a fourth frequency conversion section, and a demodulation section. By selection of an optimum value for a second intermediate frequency of a transmitter and for a third intermediate frequency of a receiver, a group of transmission radio frequencies (RF) signals and a group of local frequency signals are allocated without overlap. As a result, there can be prepared one type of band-pass filter which has broad band-pass characteristics and which is common among the transmission and receiving sections disposed within the multiplex radio transceiver or among repeaters, thus allowing use of common members.
摘要:
A method of communicating between a base band unit and a plurality of remote radio heads includes the steps of receiving a first signal through an antenna in a first remote radio head, transmitting the first signal to a second remote radio head through a digital radio interface, receiving a second signal through an antenna in the second remote radio head, compensating for a delay accrued in the first signal, adding the first signal and the second signal to obtain a resulting signal, and transmitting the resulting signal to a base band unit through a digital radio interface.
摘要:
A method of communicating between a base band unit and a plurality of remote radio heads includes the steps of receiving a first signal through an antenna in a first remote radio head, transmitting the first signal to a second remote radio head through a digital radio interface, receiving a second signal through an antenna in the second remote radio head, compensating for a delay accrued in the first signal, adding the first signal and the second signal to obtain a resulting signal, and transmitting the resulting signal to a base band unit through a digital radio interface.
摘要:
The present invention relates to a clock phase detecting circuit and a clock regenerating circuit each arranged in a receiving unit of multiplex radio equipment. The receiving unit of the multiplex radio equipment includes an identifying circuit for identifying a signal obtained by demodulating a multilevel orthogonal modulation signal; a clock regenerating circuit for regenerating a signal identification clock for the identifying circuit to supply the clock to the identifying circuit; an equalizing circuit for subjecting the signal obtained by demodulating a multilevel orthogonal modulation signal to an equalizing process. A clock phase detecting unit detects the phase component of the signal identification clock based on signals input to or output from the equalizing circuit and then supplies the phase component to the clock regenerating circuit. The phase component of a signal identification clock can be certainly detected and accurately adjusted so that the signal identification clock can be regenerated with high accuracy.
摘要:
The present invention relates to a clock phase detecting circuit and a clock regenerating circuit each arranged in a receiving unit of multiplex radio equipment. The receiving unit of the multiplex radio equipment includes an identifying circuit for identifying a signal obtained by demodulating a multilevel orthogonal modulation signal; a clock regenerating circuit for regenerating a signal identification clock for the identifying circuit to supply the clock to the identifying circuit; an equalizing circuit for subjecting the signal obtained by demodulating a multilevel orthogonal modulation signal to an equalizing process. A clock phase detecting unit detects the phase component of the signal identification clock based on signals input to or output from the equalizing circuit and then supplies the phase component to the clock regenerating circuit. The phase component of a signal identification clock can be certainly detected and accurately adjusted so that the signal identification clock can be regenerated with high accuracy.
摘要:
In a cross polarization interference eliminating apparatus, a signal demodulating section receives a first signal resulting from one of radio signals, which are transmitted in a modulated, decoded and equalized form from respectively using two kinds of polarized plain waves intercrossing at right angles in a common frequency band, and analog-to-digital converts, demodulates and equalizes the received first signal to output a first baseband signal, and an interference eliminating section receives a second signal resulting from the other radio signal, analog-to-digital converts the received digital signal to obtain a digital signal, delays the obtained digital signal. And an adding section adds the second baseband signal from the interference eliminator to the first baseband signal from the signal demodulator to output a composite signal. With this arrangement, it is possible to vary the amount of delay without a cell breathing and in accordance with the change of environment, such as temperature, without requiring the manipulation by an operator even during operation of the system. The apparatus can be compact in size and can be stabilized in operation without making an adjustment.