Abstract: A compact package whose inner walls can be located near a radio frequency circuit without changing the characteristics of the radio frequency circuit has a planar circuit on the bottom of the package, which is enclosed with metal walls. A high impedance plate is formed in two dimensions on the metal plate of a lid. The high impedance plate has a dielectric sheet on which is formed a conductor sheet on which is formed a two-dimensional periodic array of right hexagonal metal patches. The high impedance plate blocks surface propagation of electromagnetic waves in a certain frequency band (band gap). The operating frequency of the planar circuit is set within the band gap, so that the lid and the planar circuit can be put close to each other with no change in the operation characteristics of the planar circuit.

Abstract: An frequency division multiplexing (OFDM) system transceiver for transmitting frequency dividing data in parallel includes antenna elements for receiving known reception and reception data signals. The fast Fourier transforms (FFTs) transform the known reception signals and the reception data signals to obtain known reception sub-carrier signals and reception data sub-carrier signals. The estimator estimates propagation path estimating values of each of the reception data sub-carrier signals with respect to each of the known reception sub-carrier signals. The weight calculator calculates a maximum ratio composition weight to composite the reception data sub-carrier signals. The setting means sets a transmission weight based on the maximum ratio composition weight. The generator generates a transmission data signal by arranging transmission sub-carrier signals on the frequency axis.

Abstract: A communication device using orthogonal multiplexing carrier method for determining delay information of received radio waves. In this device, a known signal demodulator performs OFDM demodulation to output demodulated signal, and a divider performs a complex division of the demodulated signal with a data sector of known signal of a database for each sub-carrier. By the data section of the known signal, the computation result of the amount of shift can be determined for each of sub-carriers. A delay analytical calculation circuit uses the computation result of the amount of shift for sub-carriers to analyze the delayed waves. For delay analysis, ESPRIT method is used to determine delay information by means of computation result of the amount of shift for each sub-carrier.

Abstract: In a gain control device for packet signal receiver, a variable gain amplifier amplifies an input signal with a gain corresponding to a control voltage applied thereto, and a power detector detects output power of the variable gain amplifier. A packet detection circuit detects a packet signal based on the detected output power. A control circuit outputs the control voltage variable with the detected output power, and the control voltage is provided for the amplifier. Thus high-speed gain control is performed immediately after the start of detection of the packet signal. When the elapsed time after the start of detection of the packet signal exceeds a predetermined time, a sample-hold circuit sample-and-holds the control voltage. This control voltage is provided for the amplifier up to the end of reception of the packet signal thereafter. Thus low-speed gain control is performed to provide stable power without distorting the signal wave.

Abstract: A first metal plate for transmission and a second metal plate for transmission are closely-attached to a first surface and a second surface of a dielectric body, respectively. An outer edge of the first metal plate substantially symmetrically faces an outer edge of the second metal plate via the dielectric body. A metal plate for matching is arranged inside a hole formed on the second metal plate, with a slit formed with an inner wall of the hole, and is fixed to the dielectric body. The metal plate for matching is electrically connected to the first metal plate via a through hole penetrating the dielectric body. An IC chip is surface-mounted to connect the second metal plate with the metal plate for matching.

Abstract: Images are efficiently collected or delivered so that uncomfortable feeling given to users who view picked images picked up at vehicles and delivered by an image server is lessened. An image server is so constructed that the following operation is performed: the picked image of the surroundings of a vehicle, picked up with a camera mounted on the vehicle, and the image pickup information of the picked image, including information about the image pickup point, are stored on a storing medium; and picked images stored on the storing medium are delivered to users who view received picked images. One is selected from among picked images inputted from a vehicle with respect to each of areas to which the image pickup points of those picked images belong based on the image pickup information and a predetermined selection condition. The selected picked image is stored on the storing medium.

Abstract: A download method forms a download user network with a plurality of user terminals which are going to download the same data. The delivery server divides the data into data portions, and assigns the data portions to the respective user terminals belonging to the download user network. Then each of the user terminals downloads the assigned data portion from the delivery server. Thereafter the downloaded data portions are mutually transmitted among the user terminals within the download user network so that each of the user terminals can obtain all the data portions which constitute the data. Each of the user terminals combines the obtained data portions into the original data. Thus the data is efficiently downloaded to the plurality of user terminals.

Abstract: In a CSMA wireless LAN, a sector antenna power detectors detects the power received by antenna elements of a sector antenna. A reference power generator generates a reference power, and a comparator compares the detected power with the reference power. A controller unit, based on the comparison result, determines whether there is a hidden terminal station. If a hidden terminal station is determined to exist, the controller outputs control signals so as to direct the terminal station to increase the transmission power. The terminal station in turn will increase the transmission power in response to the control signals to widen the communication area.

Abstract: First, in a microcomputer of a communication terminal, data communication request is carried out. Next, a profile corresponding to contents of requested data is received from a communication control device. The microcomputer then selects one of communication systems based on the profile. The result of the selection is notified to the communication control device. Then, a transmission request signal is transmitted from the microcomputer. Thereafter, the data is received from the communication control device through the selected communication system. Thus, the download through the selected communication system is completed.

Abstract: A multiple-frequency common antenna has a first substrate sheet and a second substrate sheet respectively structured by an HIP consisting of a metal plate, small metal plates disposed in two dimensions and linear metal bars connecting these elements. The antenna restricts propagation of surface currents of the first and second frequency bands which are not overlapping with each other. An inverse L-shape antenna and a monopole antenna which are fed with a center conductor and an external conductor of the coaxial line respectively operate as the antenna on the first substrate sheet in the first frequency band and second frequency band. The second substrate sheet does not propagate the radiated wave of the monopole antenna, thereby avoiding unwanted re-radiation.

Abstract: A weight computation unit finds a weight used in a maximum ratio combining carried out on data sub-carrier signals for each user terminal. A direction vector computation unit finds direction vectors on the basis of the weight. A user separation weight computation unit finds a user separation vector on the basis of the direction vectors. A user separation combining unit uses the user separation vector to well separate a data sub-carrier signal transmitted by a predetermined terminal from data sub-carrier signals received from all terminals.

Abstract: Fragment data is generated with respect to a certain data aggregate that is one of a plurality of data aggregates using a coded matrix. The fragment data is capable of restoring the certain data aggregate based on the coded matrix when the fragment data is collected to a required count. The generated fragment data is provided with an identification code associated with the certain data aggregate restored by the fragment data. The fragment data having the identification code is transmitted to a transmission channel. Further, the same transmission channel can be used to transmit the multiple pieces of the fragment data corresponding to the multiple data aggregates. When a receiving party is previously notified of the identification code, it can receive the fragment data by distinguishing which fragment data should restore which data aggregate.

Abstract: In a gain control device for packet signal receiver, a variable gain amplifier amplifies an input signal with a gain corresponding to a control voltage applied thereto, and a power detector detects output power of the variable gain amplifier. A packet detection circuit detects a packet signal based on the detected output power. A control circuit outputs the control voltage variable with the detected output power, and the control voltage is provided for the amplifier. Thus high-speed gain control is performed immediately after the start of detection of the packet signal. When the elapsed time after the start of detection of the packet signal exceeds a predetermined time, a sample-hold circuit sample-and-holds the control voltage. This control voltage is provided for the amplifier up to the end of reception of the packet signal thereafter. Thus low-speed gain control is performed to provide stable power without distorting the signal wave.

Abstract: A compact package whose inner walls can be located near a radio frequency circuit without changing the characteristics of the radio frequency circuit has a planar circuit on the bottom of the package, which is enclosed with metal walls. A high impedance plate is formed in two dimensions on the metal plate of a lid. The high impedance plate has a dielectric sheet on which is formed a conductor sheet on which is formed a two-dimensional periodic array of right hexagonal metal patches. The high impedance plate blocks surface propagation of electromagnetic waves in a certain frequency band (band gap). The operating frequency of the planar circuit is set within the band gap, so that the lid and the planar circuit can be put close to each other with no change in the operation characteristics of the planar circuit.

Abstract: In a gain control device for packet signal receiver, a variable gain amplifier amplifies an input signal with a gain corresponding to a control voltage applied thereto, and a power detector detects output power of the variable gain amplifier. A packet detection circuit detects a packet signal based on the detected output power. A control circuit outputs the control voltage variable with the detected output power, and the control voltage is provided for the amplifier. Thus high-speed gain control is performed immediately after the start of detection of the packet signal. When the elapsed time after the start of detection of the packet signal exceeds a predetermined time, a sample-hold circuit sample-and-holds the control voltage. This control voltage is provided for the amplifier up to the end of reception of the packet signal thereafter. Thus low-speed gain control is performed to provide stable power without distorting the signal wave.

Abstract: A terminal has a radio device TD1 for connection by radio communication, a terminal router CR1, and terminal segment C.1. The radio device TD1 uses a temporary terminal address while being connected to the same base transceiver station segment B.x. In the terminal segment C.1, an application uses a constant terminal specific address. The terminal router CR1 informs a base transceiver station gateway, which relays the communication data and exchange the path information with the data relay devices on the Internet, of the path information that the data communication to the terminal specific address goes through the temporary terminal address.

Abstract: A weight computation unit finds a weight used in a maximum ratio combining carried out on data sub-carrier signals for each user terminal. A direction vector computation unit finds direction vectors on the basis of the weight. A user separation weight computation unit finds a user separation vector on the basis of the direction vectors. A user separation combining unit uses the user separation vector to well separate a data sub-carrier signal transmitted by a predetermined terminal from data sub-carrier signals received from all terminals.

Abstract: A user accesses a control server using a web-browsing function provided in a cell phone to select purchase data, and sends an identification number specifying an in-vehicle device to be downloaded with the data. The control server sends a one-time password to the cell phone. The user inputs the one-time password into the in-vehicle device. When the in-vehicle device gets into one of download cells, such as a rail station, the ID and the one-time password are sent to the control server through an access point. The control server conducts conformation that the received ID and the one-time password are identical to those sent and received previously. When being confirmed as being identical, the requested data is delivered to the in-vehicle device through the access point.

Abstract: An OFDM system transceiver for transmitting frequency dividing data in parallel includes antenna elements for receiving known reception and reception data signals. The FFTs transform the known reception signals and the reception data signals to obtain known reception sub-carrier signals and reception data sub-carrier signals. The estimator estimates propagation path estimating values of each of the reception data sub-carrier signals with respect to each of the known reception sub-carrier signals. The weight calculator calculates a maximum ratio composition weight to composite the reception data sub-carrier signals. The setting means sets a transmission weight based on the maximum ratio composition weight. The generator generates a transmission data signal by arranging transmission sub-carrier signals on the frequency axis. The multipliers multiply the transmission data signals by the transmission weight and output the multiplied resultant to the respective antenna elements.

Abstract: An adaptive receiver includes an adaptive array unit and an equalizer unit. In the adaptive array unit, receiving signals of an array antenna are demodulated, weighted by multiplying with a complex weight calculated by an adaptive arithmetic unit, and adaptively combined. In the equalizer unit, propagation path estimation values are calculated from the receiving signals by a propagation path estimating unit, weighted with the complex weight by a complex weight adjusting unit, and adaptively combined. The combined demodulation signal is divided by the combined propagation path estimation value. Thereby, not only the unwanted signal wave of low correlation but also the unwanted signal wave of high correlation can be controlled effectively using an adaptive array antenna.