Abstract: In a wireless repeater apparatus communicating with wireless communication apparatuses, a switching circuit transfers a data packet received through any one of antennas to any one of antennas for transmission. A correspondence table memory stores a correspondence table that includes relations of an identifier of each antenna between an identifier of each wireless communication apparatus. A wireless repeater apparatus control circuit controls transfer of the data packet by the switching circuit based on the correspondence table.

Abstract: A transmitting system includes an Internet connecting unit, directly or indirectly connected with the Internet, which allows a plurality of communication units to perform communication through the Internet, and a media converter, connected with the Internet connecting unit by the first transmission medium, which converts a signal from the first transmission medium into a signal to a second transmission medium, converts a signal from the second transmission medium into a signal to the first transmission medium, and has a function of linking to the communication units. The transmitting system also includes a signal distributor, connected with the media converter and each of the plurality of communication units by the second transmission medium, which distributes a signal from the media converter and transfers the signal to the communication units, and transfers a signal from the communication units to the media converter.

Abstract: The device includes a cable interface module having a diplexer that outputs a first signal input from a first connector part connected to a cable television network to a third connector part and outputs a second signal input from a second connector part to a first connector part; a video tuner module having a distributor that branches a first signal input from a fourth connector part having a shape capable of connecting to the cable television network and connected to a third connector part and outputs to a fifth connector part, and inputs the other branched signal into a video tuner; and a communication tuner that selects another channel of the signal output from a fifth connector part.

Abstract: A transmitting and receiving apparatus including a modulating circuit for modulating an input digital data; a first frequency converting circuit for converting a signal output from the modulating circuit into a signal of a predetermined frequency; an amplifying/branching circuit for amplifying and branching a signal output from the first frequency converting circuit; a second frequency converting circuit for converting a signal output from the amplifying/branching circuit, into a signal of a predetermined frequency; and a demodulating circuit for demodulating digital data from a signal output from the second frequency converting circuit.

Abstract: A signal distribution system has a transmission means of respectively allocating different frequencies to a plurality of signals and of transmitting the signals by utilizing the allocated frequencies and communication paths for transmitting the plurality of signals to be transmitted and a plurality of reception means of receiving signals to which the corresponding frequencies are allocated based on predetermined corresponding relationships from among the transmitted plurality of signals characterized in that wherein the corresponding relationships are corresponding relationships between each of the frequencies and each of the reception means that have been predetermined based on substantial distances between the transmission means and each of the reception means along the communication paths.

Abstract: A repeating installation includes transmission speed detection units which detect respective transmission speeds of a plurality of transmission lines connected to a plurality of communication apparatuses, a transmission speed determination unit which determines the slowest transmission speed among the detected transmission speeds of respective transmission lines as a reference transmission speed, a transmission speed adjusting unit which adjusts a transmission speed of a transmission line, whose detected transmission speed is faster than the reference transmission speed, so as to become a speed equal to or slower than the reference transmission speed, and the like.

Abstract: The present invention provides a TV terminal embedded communication apparatus, which has a shape compliant with predetermined existing standard dimensions of a type of TV terminal set on a wall surface, including a TV antenna terminal connectable to a TV antenna terminal of an existing TV terminal connected to a coaxial cable connected to a TV antenna, a communication connector terminal, a coaxial communication processing function section connected to the TV antenna terminal and having a coaxial communication function, a connector communication processing function section connected to the communication connector terminal and having a communication connector communication processing function and a data transfer function section that transfers data between the coaxial communication processing function section and the connector communication processing function section, and can construct a high-speed home network without removing the existing TV antenna terminal.

Abstract: A communication system includes communication devices; a switch device having coaxial terminal units to which the communication device are connected, a switch unit of entirely or individually connecting the coaxial terminal units, and a switch control unit of controlling the connection status of the switch unit; and a transmittal right control device. The transmittal right control device is connected to the terminal, and manages the connection status of the switch unit, receives from the communication devices requests for time for communication with other communication devices, determines assignment of time for communications between the communication devices, notifies the communication devices of the assignment, and instructs the switch control unit not to make signals interfere among the communication devices in different combinations for communications in the same time period.

Abstract: If trouble or the like occurs in a central device or repeater in an Internet system, and the device becomes unable to operate normally, a link between each terminal and the central device may become invalid, and communication between terminals may become impossible.

Abstract: A transmitting and receiving apparatus including a modulating circuit for modulating an input digital data; a first frequency converting circuit for converting a signal output from the modulating circuit into a signal of a predetermined frequency; an amplifying/branching circuit for amplifying and branching a signal output from the first frequency converting circuit; a second frequency converting circuit for converting a signal output from the amplifying/branching circuit, into a signal of a predetermined frequency; and a demodulating circuit for demodulating digital data from a signal output from the second frequency converting circuit.

Abstract: A transmitting and receiving apparatus including a modulating circuit for modulating an input digital data; a first frequency converting circuit for converting a signal output from the modulating circuit into a signal of a predetermined frequency, an amplifying/branching circuit for amplifying and branching a signal output from the first frequency converting circuit; a second frequency converting circuit for converting a signal output from the amplifying branching circuit, into a signal of a predetermined frequency; and a demodulating circuit for demodulating digital data from a signal output from the second frequency converting circuit.

Abstract: A signal of a vestigial sideband modulated wave is generated by use of a first oscillator, an amplitude-modulator and a surface acoustic wave filter for vestigial sideband filtering at a frequency being higher than the carrier frequency of a video signal, the signal is frequency-converted to a given transmission channel by use of a first PLL frequency synthesizer, a first control circuit, a frequency converter and a filter.

Abstract: A signal distribution system has

Abstract: A sampler (1) samples an inputted base band signal in accordance with a sampling clock, and holds a sample value (S.sub.n). Delay circuits (7, 8) hold sample values (S.sub.n-1, S.sub.n-2), respectively. A decision circuit (2) determines the sample value (S.sub.n-1), and outputs data (d.sub.n-1). A constant multiplier (16) multiplies the data (d.sub.n -1) by a constant (.alpha.). A subtracter (17) subtracts the data (d.sub.n-1) from the sample value (S.sub.n-1). Another subtracter (13) subtracts the sample value (S.sub.n) from the sample value (S.sub.n-2). A multiplier (14) multiplies the output of the subtracter (17) by that of the subtracter (13), and outputs a timing error signal. A low-pass filter (15) extracts a low frequency component of the timing error signal, and supplies a control voltage to a voltage controlled oscillator (6). The voltage controlled oscillator (6) outputs a sampling clock having a frequency which depends on the control voltage.

Abstract: A level detector 2 detects variation of the amplitude of an input signal a to output a level signal b representing HIGH or LOW in order to define the head portion of the input circuit a. A time constant control signal 3 generates a time constant control signal c based on the level signal b to control a time constant of an estimator 4 so as to make the time constant small for a prescribed period from a time when the level signal b varies from HIGH to LOW. The estimator 4 estimates DC offset included in the input signal a with the a time constant variation according to the time constant control signal c to output an estimate d. A compensator 1 subtracts the estimate d from the input signal a to obtain a compensation output. Therefore, in the estimator 4, the speed of estimating the DC offset is different between a period corresponding to the head portion of the input signal a and other periods.

Abstract: A data frame which is transmitted from a transmitting station is provided with an individual response part (RS) having response bits (S1 to SN) corresponding to all stations on a network, so that the transmitting station initializes the individual response part (RS) in data transfer. Each receiving station outputs its own state to a prescribed position of the individual response part, and the transmitting station monitors the individual response part. Thus, it is possible to correctly confirm whether or not the data is normally transferred to those of the receiving stations which are to receive data.

Abstract: A position detector 1 detects the position of a display screen 4, an image memory 2 stores image information, a selector 3 selects a portion of the image information stored in the image memory 2 in accordance with the position of the display screen 4 detected by the position detector 1 and supplies the selected portion to the display screen 4, and the display screen 4 displays the selected image information. The invention is characterized in that when it is assumed that the entire image information stored in the image memory 2 is drawn in a viewing field space fixed relative to the eye, the selector 3 selects the image information to be drawn on the display screen 4 lying in the viewing field space.

Abstract: A signal adding device and a differential signal detecting device, wherein the signal adding device adds n input signals using n A/D converters, a selector and a lowpass filter. The n input signals are sampled in sequence by the A/D converter and digitized. Each digitized data is time-division multiplexed by the selector and input to the lowpass filter. The output of the lowpass filter is equal to an added signal of n input signals. The differential signal detecting device detects from inphase and quadrature-phase baseband signals the sine and cosine components of a phase difference at two instants of the phase-modulated signal. Two A/D converters digitize and convert the inphase and quadrature-phase baseband signals to inphase data and quadrature-phase data at predetermined intervals. A cosine component calculating unit calculates the cosine component by alternately selecting the inphase data and the quadrature-phase data.