Abstract: Parallel compression is performed on an input data stream by processing circuitry. The processing circuitry includes hashing circuitry, match engines, pipeline circuitry and a match selector. The hashing circuitry identifies multiple locations in one or more history buffers for searching for a target data in the input data stream. The match engines perform multiple searches in parallel for the target data in the one or more history buffers. The pipeline circuitry performs pipelined searches for multiple sequential target data in the input data stream in consecutive clock cycles. Then the match selector selects a result from the multiple searches and pipelined searches to compress the input data stream.

Abstract: Apparatus, systems, and methods are disclosed such as those that operate to encode data bits transmitted on a plurality of channels according to at least one of multiple Data Bus Inversion (DBI) algorithms. Additional apparatus, systems, and methods are disclosed.

Abstract: In an RF source, a digital waveform synthesizer comprises a computational module to synchronously determine a desired periodic function, f(?), within a first bandwidth portion, to which computational result there is combined an injected digital noise increment in an adjustable range of bounded amplitude, specifically selected to average over discontinuities of the DAC transfer characteristic. The combination is effected after passing the injected noise increment through a programmable digital filter forming a composite tuning word having a total bandwidth at a selected Nyquist zone and thence passing the composite tuning word through a truncation component to a DAC. The programmable digital filter is constructed to displace the spectral distribution of the injected noise increment to a portion of the total bandwidth remote from the first bandwidth portion.

Abstract: A successive-approximation A/D converter includes a reference voltage generator configured to generate a reference voltage, a comparator configured to receive an input analog signal and generate a voltage difference by comparing the input analog signal and the reference voltage, an error-correction circuit including a variable capacitor configured to correct the voltage difference based on a capacitance of the variable capacitor, an error-correction controller configured to retrieve from memory a correction amount and control the error-correction circuit to vary the capacitance of the variable capacitor according to the correction amount, and a successive approximation register logic circuit configured to generate an output digital signal based on the voltage difference from the comparator.

Abstract: An analog-to-digital converter (ADC) includes an analog input stage including an output configured to generate an analog output signal and a digital stage coupled the output of the analog input stage. The digital stage is configured to classify the analog output signal into one of a plurality of consecutive voltage ranges. Responsive to the analog output signal being classified in a first enumerated voltage range of the plurality of voltage ranges during a rotation of a sample, a voltage for a subsequent rotation is determined as if the analog output signal is classified into a non-enumerated voltage range selected according to a state of a random number signal.

Abstract: In accordance with an embodiment, a method of calibrating a circuit includes coupling a first reference voltage to a first input of the circuit, coupling a programmable reference voltage to a reference node of a digital-to-analog converter (DAC), such that the gain of the DAC is dependent on an input value at the reference node. The method further includes providing a first predetermined input code to the DAC, summing an output of the DAC with the first reference voltage to produce a summed output, comparing the summed output to a threshold, and adjusting the programmable reference voltage until the summed output is within a predetermined range of the threshold.

Abstract: The discrete time analog circuit (100) is provided with: a rotate capacitor circuit (150); an amplifier (141) that is connected to the input line or the output line of the rotate capacitor (150), and amplifies the input potential or input charge; a coefficient circuit (140) that is positioned in series with the amplifier (141), and has two history capacitors (143-1, 143-2) positioned parallel to each other; a first active capacitor among the two history capacitors (143-1, 143-2) that is connected to and charges the amplifier (141); and a clock generation circuit (110) that is connected to the input line or the output line without the involvement of the amplifier (141), and that sequentially changes the pairing of the rotate capacitor circuit (150) a second active capacitor, which shares a charge with the rotate capacitor circuit (150).

Abstract: Continuous time sigma delta (??) analog-to-digital conversion (ADC) circuitry and method in which current mode ?? ADC circuitry is driven directly by current mode mixing circuitry, thereby avoiding a need for a current-to-voltage driver between the input signal mixing circuitry and ?? ADC circuitry.

Abstract: A sigma delta modulator may include a loop filter and an adder configured to accept an output of the loop filter and a dither input signal. The adder may be further configured to combine the output of the loop filter and the dither input signal into a combined output signal. The sigma delta modulator may further include a quantizer configured to accept the combined output signal from the adder, and quantize the combined signal into a quantizer output signal. The sigma delta modulator may further include a first subtractor configured to accept the quantizer output signal and subtract the dither input signal from the quantizer output signal.

Abstract: The disclosed device easily and precisely satisfies a requested output range, and is provided with: a ??-modulator (12) which converts a digital input signal to a pulse signal; an input comparison device (11) which compares an input value that corresponds to the digital input signal, and a pre-set threshold value; and a thinned output control unit (14) which, when the result of the comparison by the input comparison device (11) shows that the input value is less than the threshold value, reduces the output value corresponding to the input value in accordance with the size of the difference between the input value and the threshold value, and sets the output value to 0 when the input value is 0.

Abstract: A method and apparatus for performing modulation of a radio frequency, RF, signal within a digital-to-RF converter. The method includes determining a desired digital control word switching frequency value based at least partly on at least one parameter corresponding to a bandwidth of the RF signal to be modulated and at least one from a group including: at least one parameter corresponding to an RF channel frequency of the RF signal to be modulated; and at least one parameter corresponding to a power level of the RF signal to be modulated. The method further includes dynamically configuring at least one digital control module to output at least one digital control word signal in accordance with the desired digital control word switching frequency value, and performing modulation of the RF signal in accordance with the at least one digital control word signal output by the at least one digital control module.

Abstract: An intermediate set of bits of a SAR ADC are converted into first intermediate analog value and a second intermediate analog value respectively from a first set of representative capacitor and a second set of representative capacitor. A capacitor in the first set and second set are selected as not same. A SAR ADC output code is generated from the first intermediate analog value and the second intermediate analog value. The resolution of a N bit SAR ADC can be enhanced by generating more than one N bits digital codes correspondingly operating the N Bit SARADC with more than on transfer functions. Each transfer function is selected such that they are offset by a fraction of LSB value. The more than one N bits digital codes are then added to form P bits digital code such that P is greater than N due to addition.

Abstract: A system and method is disclosed for a digital input Class D amplifier which includes an interpolation filter to up-sample a digital signal, a noise shaping modulator to suppress in-band quantization errors due to digital pulse width modulation and truncation errors, and a hybrid finite impulse response filter/digital to analog converter coupled to an analog input Class D amplifier with digital pulse width modulation control loop. The hybrid finite impulse response filter/digital to analog converter uses N-taps implemented digitally and N-tap weights implemented in analog using resistors.

Abstract: A dynamically selectable resistor network is provided in a star configuration for producing a weighted sum of input values, without attenuation from near zero contributions. Each branch of the star connected network comprises sets of impedance components, preferably resistors, that are actively selectable to produce permutated combinations of effective weighting values. The resistors code digital control bits and the outputs of sets of resistors in respective branches that correspond to the least significant control bits provide their outputs to the summing output node independently of the sets of resistors corresponding to control bits of other significance.

Abstract: An analog to digital detector circuit includes a comparator circuit and a counter that generates a digital counter value. A digital to analog converter receives an inverse of the digital counter value of the counter and generates a first voltage. A variable current source receives the digital counter value of the counter and generates a first current.

Abstract: A comparator includes a first amplifier and a level holding part. The first amplifier includes differential-pair transistors and outputs a signal of a level corresponding to a comparison result from a first output node. The differential-pair transistors serve as a comparison part that receives a reference voltage, a signal level of which changes with a slope, at a gate of one of the differential-pair transistors, receives an input signal at a gate of the other of the differential-pair transistors, and compares the reference voltage with a potential of the input signal. The level holding part holds a level of the first output node such that the other transistor having an output part thereof connected to the first output node out of the differential-pair transistors of the first amplifier does not fall into a level at which a saturated operation condition is not satisfied.

Abstract: A method and apparatus for operating an analog-digital converter for converting an input signal into a multibit output in one conversion cycle. The method includes loading a capacitor array by applying a given input signal potential, evaluating a sampling potential provided by the capacitor array in a number of consecutive decision steps performed by at least two decision latches and changing the sampling potential by switching the capacitor array for each decision step based on a result of the step of evaluating the sampling potential, where the step of evaluating at least one of the decision latches performs the evaluating for two decision steps.

Abstract: A method and system for detecting the presence of subsurface objects within a medium is provided. In some embodiments, the detection system operates in a multistatic mode to collect radar return signals generated by an array of transceiver antenna pairs that is positioned across a surface and that travels down the surface. The detection system converts the return signals from a time domain to a frequency domain, resulting in frequency return signals. The detection system then performs a singular value decomposition for each frequency to identify singular values for each frequency. The detection system then detects the presence of a subsurface object based on a comparison of the identified singular values to expected singular values when no subsurface object is present.

Abstract: A vehicle with an accident prevention system is disclosed. The vehicle also has a foot brake for stopping the vehicle. The system includes a sensor arrangement for sensing an object behind a rear end of the vehicle that generates an object recognition signal when it senses an object within range behind the vehicle. The sensor arrangement includes passive IR sensors or reflected pulse sensors such as sonar or radar sensors on the rear end. A controller generates an accident prevention response signal on receiving an object recognition signal from the sensor arrangement. A brake applicator is operatively coupled to the brake to stop the vehicle when the controller generates a response signal. Conveniently the system includes an alarm for sounding an alarm signal. A method for preventing an accident where a vehicle which is reversing at low speed collides with a person is also disclosed.

Abstract: A method and an apparatus for acquiring information about a base station antenna, and the base station antenna. The apparatus includes at least two receiving antenna units that are configured to receive satellite signals sent by a satellite in a satellite positioning system. The receiving antenna units and the base station antenna accord with a preset position relationship. A processing unit is configured to obtain position information of the receiving antenna units according to the satellite signals and to obtain position information of the base station antenna according to the position information of the receiving antenna units and the preset position relationship between the receiving antenna units and the base station antenna.

Abstract: A method and system for estimating the position comprises measuring a first carrier phase of a first carrier signal and a second carrier phase of a second carrier signal received by a location-determining receiver. A primary real time kinematic (RTK) engine or receiver data processing system estimates a primary integer ambiguity set associated with at least one of the measured first carrier phase and the measured second carder phase. A quality evaluator determines if a primary integer ambiguity set is resolved correctly to the predefined reliability rate during an earlier evaluation period. A secondary real time kinematic (RTK) engine or receiver data processing system estimates a secondary integer ambiguity set associated with at least one of the measured first carrier phase and the measured second carrier phase during a later period following the earlier evaluation period.

Abstract: A mobile communication device includes, in part, a first wireless receiver adapted to determine, as it travels along a path, a multitude of positions of the mobile communication device using signals received from a primary positioning source, a second wireless receiver adapted to receive signals from one or more ambient wireless sources as the mobile communication device travels along the path, and a positioning module. An internal or external memory stores estimated positions and corresponding time references of the signals of the one or more ambient sources. The positioning module uses the data stored in the database to estimate the position of the mobile communication device when no primary positioning source signal is available. The positioning module optionally uses the data stored in the database to improve estimates of the position of the mobile communication device when primary positioning signal is available.

Abstract: A horizontal beam adjusting method and apparatus for an omni-directional antenna are provided. The horizontal beam adjusting apparatus may generate a switch control signal according to an inclination of the omni-directional antenna, and adjust a radiation direction of the omni-directional antenna according to the switch control signal. Accordingly, the adjusted radiation direction may have horizontal omni-directionality with respect to a ground surface.

Abstract: A butler matrix and a multi-port amplifier having the same, capable of splitting a single input signal into N-signals or combining N-signals into a single output are provided. The hybrids are provided in a predetermined disposition, the input port and the output port of the hybrids are provided in a predetermined direction and the waveguides are provided in a bended structure such that paths for connecting the hybrids have no crossing portion.

Abstract: An electronic device including a first antenna, a second antenna, a first sensor, a signal processing module and an antenna control module is provided. The first antenna has a function of transmitting a wireless signal and is disposed on a first side of the electronic device. The second antenna is disposed on a second side of the electronic device. The first sensor detects whether a first object is around the first antenna and generates a first sensing signal according to a detecting result. The signal processing module generates a first control signal according to the first sensing signal. The antenna control module switches the function of transmitting the wireless signal from the first antenna to the second antenna.

Abstract: A method is provided for adding an RF powder to a sheet-like object having a high property value, such as a variety of cards, paper money, and securities. The RF powder makes it very difficult to produce, for example, counterfeit cards, documents and bills. Also, an RF powder-added base sheet to which the RF powder has been added is provided. In the method for adding the RF powder, the RF powder includes a plurality of RF powder particles 11 and is disposed on a surface of a base sheet 10 to add the RF powder to the base sheet. Each RF powder particle 11 has a magnetic field coupling circuit element in a high frequency magnetic field having a specific frequency. The RF powder is disposed on a surface of a base sheet by a printing technique. The RF powder-added base sheet 10 includes an RF powder including a plurality of RF powder particles 11 disposed within a printed object on a surface of a base sheet.

Abstract: A bottom feed cavity aperture antenna is provided. The bottom feed cavity aperture antenna includes a patch and a ground structure. The patch feeds a signal to the bottom feed cavity aperture antenna. The ground structure includes a continuous wall, and a top end and a bottom end, wherein the continuous wall surrounds the patch, a thickness of the ground structure is formed between the top end and the bottom end, a patch height is formed between the patch and the bottom end, and a ratio of the patch height to the thickness is substantially lower than 1/2, and a magnetic field is formed at the top end, and magnetic resonance directions of the magnetic field are parallel to a first axis.

Abstract: A microstrip-fed antenna is disclosed having a first dielectric substrate and a second dielectric substrate. The second dielectric substrate is disposed on the first dielectric substrate and the first dielectric substrate has a relative permittivity greater than or equal to the second dielectric substrate. The antenna further includes a microstrip line formed in the second dielectric substrate and a metal layer formed in the second dielectric substrate. The metal layer is positioned between the microstrip line and the first dielectric substrate and includes a slot.

Abstract: A wideband antenna includes a grounding element electrically connected to a ground, a radiating element, a matching adjustment element electrically connected to the radiating element, a feed-in element electrically connected between the matching adjustment element and the grounding element for receiving feed-in signals, and a shorting element electrically connected between the matching adjustment element and the grounding element. A width of the matching adjustment element is related to a bandwidth of the wideband antenna.

Abstract: There are provided a first circuit substrate 22 on which an antenna 32 and electronic components are arranged, a case body 24 that is molded of a non-conductive material and that is attached to the first circuit substrate 22 so that the case body 24 overlaps the first circuit substrate 22 in the thickness direction of the first circuit substrate 22, and a housing 8 including the first circuit substrate 22 and the case body 24 in the housing 8. The case body 24 comprises a conductive layer formed on the surface of the case body 24, except for an antenna opposing area S where the case body 24 overlaps the antenna 32 in the thickness direction of the first circuit substrate 22.

Abstract: Electronic devices are provided that contain wireless communications circuitry. The wireless communications circuitry may include radio-frequency transceiver circuitry and antenna structures. The antenna structures may include antennas such as inverted-F antennas that contain antenna resonating elements and antenna ground elements. Antenna resonating elements may be formed from patterned conductive traces on substrates such as flex circuit substrates. Antenna ground elements may be formed from conductive device structures such as metal housing walls. Support and biasing structures such as dielectric support members and layer of foam may be used to support and bias antenna resonating elements against planar device structures. The planar device structures against which the antenna resonating elements are biased may be planar dielectric members such as transparent layers of display cover glass or other planar structures.

Abstract: Electronic devices may be provided that contain wireless communications circuitry. The wireless communications circuitry may include antenna structures that are formed from an internal ground plane and a peripheral conductive housing member. A conductive path may be formed that connects the peripheral conductive housing member and the internal ground plane. The conductive path may include a flex circuit. The flex circuit can include a solder flow barrier to constrain flow of solder. A metal structure may be welded to the peripheral conductive housing member. A solder pad and other traces in the flex circuit may be soldered to the metal structure at one end of the conductive path. At the other end of the conductive path, the flex circuit may be attached to the ground plane using a bracket, screw, and screw boss.

Abstract: A housing combination includes a housing, and at least two antenna modules embedded at corners of the housing. Each antenna module includes an antenna carrier and an antenna radiator. The antenna carrier defines a first receiving groove and a second receiving groove opposite to each other. The antenna radiator includes a main portion and a conductive contact. The main portion is received in the first receiving groove, and the conductive contact is received in the second receiving groove. The main portion is embedded in the housing, and the conductive contact is exposed from the housing.

Abstract: An electronic device with structure for enhancing antenna performance includes a base cover with rectangle-shaped, a metal plate setting on the base cover, three metal strips, and three conductive patches. The metal plate is rectangle-shaped and includes a first side, a second side, and a third side, the first side is paralleled to the second side. The three metal strips are respectively paralleled to one side of the base cover and the first side, the second side, and the third side of the metal plate to constitute a frame to limit the metal plate. Two of the three conductive patches are electrically contacted with both of the metal plate and the metal strip contacted to the first side, the other conductive patch is electrically contacted with both of the metal plate and the metal strip contacted to the second side.

Abstract: A signal feed apparatus for an antenna including a slot through a conductive wall, comprises a non-conductive slot insert, a non-conductive block fixed to the slot insert and including first and second cable conduits and first and second plug sockets coinciding with first and second signal feed-points of the antenna. A signal cable is inserted into the cable conduits and includes first and second conductors. Conductive plugs are inserted into the first and second plug sockets to electrically connect the conductors to the first and second signal feed-points.

Abstract: Provided is an antenna simply manufactured according to a frequency characteristic. The disk-shaped antenna having a screw tap structure includes a center post having a screw tap, a ground plane, and a disk radiator, so that a distance between a ground plane and a disk radiator can be finely tuned, and manufacturing and assembly error can be reduced to minimize differences in electrical characteristics between devices.

Abstract: Methods and systems for a smart antenna utilizing leaky wave antennas (LWAs) are disclosed and may include a programmable polarization antenna including one or more pairs of LWAs configured along different axes. One or more pairs of leaky wave antennas may be configured to adjust polarization and/or polarity of one or more RF signals communicated by the programmable polarization antenna. RF signals may be communicated via the configured programmable polarization antenna utilizing the configured one or more pairs of the leaky wave antennas. A resonant frequency of the LWAs may be configured utilizing micro-electro-mechanical systems (MEMS) deflection. The polarization and/or polarity may be configured utilizing switched phase modules. The LWAs may include microstrip or coplanar waveguides, wherein a cavity height of the LWAs is dependent on spacing between conductive lines in the waveguides. The LWAs may be integrated in one or more integrated circuits, packages, and/or printed circuit boards.

Abstract: An antenna device including: a reflector antenna including a primary radiator, a feed waveguide for feeding radio waves to the primary radiator, and a reflector; and a radome that covers the reflector antenna, in which the antenna device further includes a sidelobe reduction member attached to a vicinity of the primary radiator or the feed waveguide, the sidelobe reduction member reducing a sidelobe in a specific direction of an antenna by at least one of scattering and absorbing of radio waves reflected by the radome out of the radio waves radiated from the reflector antenna. Therefore, it is possible to reduce a sidelobe deterioration caused by reflection waves from the radome.

Abstract: A log periodic antenna includes first and second transmission lines parallel with each other; and a plurality of broadband radiation elements having first sides electrically connected to the first and second transmission lines, a predetermined angle being defined between the first sides of the broadband radiation elements and the first and second transmission lines, and second sides not electrically connected with the first and second transmission lines, the second sides having radiation surfaces larger than radiation surfaces of the first sides. A plurality of broadband radiation elements electrically connected with the first transmission line and a plurality of broadband radiation elements electrically connected with the second transmission line are positioned to face each other with reference to the first and second transmission lines.

Abstract: An antenna for MIMO communications includes a ground plane having a planar surface, a first feeding patch spaced apart from and parallel to the ground plane, and a first parasitic patch spaced apart from and parallel to the first feeding patch. The antenna further includes a second feeding patch spaced apart from and parallel to the ground plane and disposed adjacent the first feeding patch, and a second parasitic patch spaced apart from and parallel to the second feeding patch. The first parasitic patch may be capacitively coupled to the first feeding patch, and the second parasitic patch may be capacitively coupled to the second feeding patch. The ground plane may include an isolation notch therein arranged between the first and second feeding patches.

Abstract: A method (600) and an RF circuit (100, 400, 500) for a wireless communication device that mitigates near electric fields generated by the wireless communication device. At least one resonant structure (108, 408, 408?) can be configured to resonate at or near at least one operating frequency of an antenna (102) of the wireless communication device. The antenna can be a component of the RF circuit. The resonant structure can be electromagnetically coupled to the antenna to mitigate the near electric fields at the operating frequency in order to comply with an applicable hearing aid compatibility (HAC) specification.

Abstract: An antenna apparatus includes: a ground substrate; and a loop antenna having first and second polarized wave surfaces, which are perpendicular to the substrate. The substrate provides an antenna, which is excited and vibrated together with the loop antenna. The antenna has a first polarized wave component in parallel to the first polarized wave surface and a second polarized wave component in parallel to the second polarized wave surface. A polarized wave ratio between the first polarized wave component and the second polarized wave component in the substrate is substantially equal to a polarized wave ratio between the first polarized wave surface and the second polarized wave surface in the loop antenna.

Abstract: A multiple frequency band antenna is provided that includes a radiating unit having a slot formed on a first surface of the substrate that is closed at one end and open at the other end, and a feed unit formed on a second surface of the substrate to pass through an area on the second surface that corresponds with the same area on first surface between the center and the closed side of the slot. The feeding unit comprises at least one switch which adjusts the size of an area for feeding power to the antenna. The radiating unit is resonated in a plurality of frequency bands when the switch is turned off, and the radiating unit is resonated in a single frequency band which is different from the plurality of frequency bands when the switch is turned on. Consequently, an antenna is implemented for use in multiple frequency bands.

Abstract: Provided is an antenna device, including insulating base substrate (190), first monopole antenna (110), and second monopole antenna (120), the antennas being disposed on insulating base substrate (190), wherein first monopole antenna (110) and second monopole antenna (120) have: first portions extended in a same direction from power feeding ends connected to first power feeding section (180); and second portions extended from the first portions separately to left and right sides, and first passive element (130) is disposed between the first portion of first monopole antenna (110) and the first portion of second monopole antenna (120).

Abstract: Systems and methods are enclosed for processing antenna position information. The systems and methods involve positioning at least one magnetometer sensor in proximity to an antenna for measuring alignment of the antenna; at a ground station in proximity to a tower holding the antenna, periodically receiving antenna alignment information from the at least one sensor; and transmitting the alignment information to a control station for determination whether the alignment of the antenna complies with antenna specifications.

Abstract: Systems and methods are enclosed for processing antenna position information. The systems and methods involve positioning at least one sensor in proximity to an antenna for measuring alignment of the antenna; at a ground station in proximity to a tower holding the antenna, periodically receiving antenna alignment information from the at least one sensor; and transmitting the alignment information to a control station for determination whether the alignment of the antenna complies with antenna specifications.

Abstract: Disclosed is an apparatus and methodology for providing an RFID device for integration into a tire. A printed circuit board (PCB) is provided with notches in opposed ends of the PCB that are provided with guide portions as a part of the notches that function as threads to guide an end portion of a matching single pitch helical antenna into appropriately placed vias on the PCB. Threading of the helical antenna is assisted by use of an assembly jig having antenna guiding channels and PCB retaining positioning elements.

Abstract: An integrated stiffener and RF reflector (stiffener/reflector) (100) for a RF emitter which includes: a plurality of vertical ribs (102) constituting side walls of the stiffener/reflector; a plurality of horizontal ribs (104) formed in a width direction of the stiffener/reflector; a top cover (204) including metallization layer (308), the top cover being electrically coupled to a ground layer (312) of the RF emitter and configured in such a way to direct all of RF energy in an opposite direction to the top cover. Each of the vertical (102) and horizontal (104) ribs has a sandwich structure, which includes: a foam core layer (302) disposed on a layer of the RF emitter (314); a thin film layer (306) bonded to sides and top of the rib to form facesheets of the sandwich structure.

Abstract: The present invention relates to a projector for outputting advertisement images, and it is an aim of the present invention to provide a projector for advertisement images which can project advertisement images onto surfaces of windows in a train. For this purpose, the projector of the present invention comprises: an image-processing unit installed in the engine room of the train to play back advertisement images; image distribution units installed in the respective passenger cars of the train to receive the advertisement images by communicating with the image-processing unit; and a plurality of image output(display) units arranged at a predetermined interval and close to the windows in the passenger cars so as to output, onto the windows, the advertisement images transmitted from the image-processing unit and received by the image distribution units, such that the advertisement images can be projected onto the surfaces of the windows.

Abstract: A communication system in trains comprises a control data communication device 400 and an image data communication device 300 installed in each of the cars. The control data communication device 400 transmits train operation information, train location information, control instructions of train-mounted apparatuses, and the like. The image data communication device 300 transmits image information such as moving images and still images, audio information such as in-train announcement, textual information for caption display, and operation log information of apparatuses, which form the contents, to a display unit 200 installed in each of the cars and to apparatuses 500 such as a telephone. The display unit 200 switches the display on the screen in accordance with train control information transmitted from the control data communication device 400 through the image data communication device 300.