Abstract: A light transmitter-receiver apparatus for detecting a trouble occurring on a light transmission line and reducing a light output. In a light transmitter-receiver apparatus including a light transmitter section for converting a transmission electric signal into a light signal and sending it, and a light receiver section for converting a light input signal into a reception electric signal, there is provided an output control section including an abnormality detecting component for detecting an abnormality occurring in a reception electric signal and an output level adjusting component for adjusting the magnitude of an output level of the light transmitter section depending upon a detection state of the signal abnormality. Signal abnormality may be detected by a missing of a synchronizing signal contained in the reception electric signal or a signal error occurring in the reception electric signal.

Abstract: The present invention relates to a system for displaying a map in a display unit of a mobile terminal device such that the relationship between a moving direction of the mobile terminal device and a direction of the displayed map is easily understandable. When the system detects that the mobile terminal device exists in a particular region on a path, it sends map data of the region to the mobile terminal device. The mobile terminal device receives the map data and displays a map of the region such that the moving direction of the portable terminal device is aligned with a top of the map displayed in the display unit.

Abstract: A multiplexed signal provided by superimposing a control data signal and a control clock signal on a video signal is generated and transmitted through a predetermined transmitting path. The received multiplexed signal is separated into each signal included in the multiplexed signal on the signal receiving side. Further, synchronization of each bit constituting the control data signal and a clock pulse of the control clock signal is secured by delaying the control clock signal more than a signal delay time that is caused by superimposing/separating processing on the signal sending side and the signal receiving side.

Abstract: A video signal transmission system, wherein on the transmission side, digital video signals representing three primary colors is time-division-multiplexed for conversion into a video data train, a packet including the video data train and rate information for each period based on the period of the transmission clock signal, and the packet is sequentially transmitted in synchronism with a transmission clock signal as a transmission signal, while on the reception side, a reception clock signal is generated in synchronism with each bit of the transmission signal received through a cable, the rate information is detected from the packet in the transmission signal, a reproduction reference clock signal is generated, the video data train in the transmission signal is separated into data of each of three primary colors, and the separated data of each of three primary colors is output in synchronism with the reproduction reference clock signal as the digital video signal.

Abstract: A video signal transmission method for time-division multiplexing digital video signals representing three primary colors to convert into serial video data, and transmitting the serial video data in blocks. The serial video data has 3×M×N bits per block, where M denotes the number of bits per pixel, and N denotes the number of pixels. A transmission side system clock signal, which has a frequency higher than the frequency of a reference clock signal of the digital video signals, is generated, and each of the bits in the block is transmitted in synchronism with the transmission side system clock signal.

Abstract: A video signal transmission system which includes a transmitter and a receiver. The transmitter converts digital video signals into serial video data by time division multiplexing; generates header data in a cycle of a divided clock signal produced by dividing a reference clock signal of the digital video signals; and provides a transmission signal in synchronization with a transmitter system clock signal, the transmission signal including a train of blocks each including the header data and a predetermined amount of the serial video data in that order.

Abstract: A positioning apparatus and method for accurately determining a current position of a mobile station. The current position of the mobile station is determined utilizing radio waves arriving from a plurality of base stations installed in a communication area. For calculating a propagation range of a radio wave arriving from each base station, error correction processing is performed using a predetermined error correction coefficient previously calculated by measuring a radio wave propagation situation around each base station to estimate a propagation range of a direct wave within incoming radio waves. The current position of the mobile station is determined using the estimated propagation range and the positions of the respective base station.

Abstract: A mobile communication apparatus and method which extract surrounding base stations within a certain defined area centered at a present location of a mobile unit, carry out an arithmetic operation for obtaining a specified weighting coefficient with respect to each of the extracted surrounding base stations on the basis of a direction of each of the extracted surrounding base stations from the present location of the mobile unit and a traveling direction of the mobile unit carry out a further arithmetic operation for weighting a value of the electric field strength of a signal recieved from each of the surrounding base stations with the weighting coefficient of a corresponding surrounding base station to provide a weighted electric field strength of each of the extracted surrounding base station, and select the one base station from the extracted surrounding base stations depending on a value of the weighted electric field strength.

Abstract: When position measurement accuracy of the present position which the base station distance and position measurement part measures from radio waves coming from base stations is not good, a GPS distance and position measurement part measures the present position from radio waves coming from GPS satellites. When position measurement accuracy of the present position obtained by the GPS distance and position measurement part is not good, a position measurement accuracy analysis part compounds the present position obtained by the base station distance and position measurement part with the present position obtained by the GPS distance and position measurement part, and calculates a new position within a range of overlap between a position measurement error of the present position obtained by the base station distance and position measurement part and a position measurement error of the present position obtained by the GPS distance and position measurement part.

Abstract: A receiving device is provided with a DLL circuit of a reduced scale. An inverse spreading processing to ensure the synchronism with a received signal and a processing to inversely spread original data in the received signal are performed by a time-sharing operation using one inverse spreading circuit and one integrator. During a period in which synchronous data for detecting a slot duration included in the received signal is received, the synchronous data is alternately inversely spread by an early code and a late code and sample-hold circuits alternately sample and hold the integrated output. Further, based on the difference (error signal) between sample-hold signals, the early code, the late code and a reference code outputted from a code sequence generator are synchronized with the received signal.

Abstract: A modulating apparatus modulates data to be transmitted according to a predetermined modulating system and generates a modulated wave, so that an optical device is driven by the modulated wave and a light-modulated wave is transmitted. As a result, an optical data communication can be realized. Since the optical device has non-linearity, a cross modulated wave is generated by the modulation of the data. However, if a carrier frequency is chosen so that the cross modulated wave does not enter a frequency band for transmitting the data, the problem of the cross modulated wave can be removed and data transmission without distortion can be achieved. The cost can be low if an LED is utilized as the optical device. Also, high-speed data transmission is possible if a multi-value modulating system is utilized.

Abstract: A code error correcting circuit interleaves original data comprising a sequence of bit data having a length of p bits by arranging the bit data of the original data into a hypothetical matrix of I rows and J columns and then selecting the bit data positioned on the ith row along an order of the jth column. The circuit is provided with a memory unit having a plurality of memory areas each having a length of 2n bits; and a controller for storing the original data to be interleaved into the memory areas respectively. The bit data, which are indicated by a bit select data, stored in the memory unit are sequentially outputted along an order of the ith row and the jth column in the hypothetical matrix as the interleaved original data.

Abstract: A small sized digital Nyquist filter having a high processing speed is provided. A delay in a delay element in the digital Nyquist filter is synchronized with a symbol rate of an input signal, and filtering coefficients at respective taps in the filer are sequentially selected synchronously with a sampling clock in accordance with a predetermined procedure, thereby reducing the number of taps to 1/oversampling number.

Abstract: A small sized digital Nyquist filter having a high processing speed is provided. A delay in a delay element in the digital Nyquist filter is synchronized with a symbol rate of an input signal, and filtering coefficients at respective taps in the filer are sequentially selected synchronously with a sampling clock in accordance with a predetermined procedure, thereby reducing the number of taps to 1/oversampling number.

Abstract: A communication apparatus for communicating with one base station among a plurality of base stations is provided with a present position detecting device for detecting a present position of the communication apparatus and outputting present position information indicative of the detected present position. The communication apparatus is also provided with an identification information obtaining device for obtaining identification information of respective one of the base stations on the basis of the present position information outputted by the present position detecting device. The communication apparatus is further provided with a specifying device for specifying said one base station on the basis of the identification information obtained by the identification information obtaining device.

Abstract: A positioning apparatus and method for accurately determining a current position of a mobile station. The current position of the mobile station is determined utilizing radio waves arriving from a plurality of base stations installed in a communication area. For calculating a propagation range of a radio wave arriving from each base station, error correction processing is performed using a predetermined error correction coefficient previously calculated by measuring a radio wave propagation situation around each base station to estimate a propagation range of a direct wave within incoming radio waves. The current position of the mobile station is determined using the estimated propagation range and the positions of the respective base station.

Abstract: When position measurement accuracy of the present position which the base station distance and position measurement part measures from radio waves coming from base stations is not good, a GPS distance and position measurement part measures the present position from radio waves coming from GPS satellites. When position measurement accuracy of the present position obtained by the GPS distance and position measurement part is not good, a position measurement accuracy analysis part compounds the present position obtained by the base station distance and position measurement part with the present position obtained by the GPS distance and position measurement part, and calculates a new position within a range of overlap between a position measurement error of the present position obtained by the base station distance and position measurement part and a position measurement error of the present position obtained by the GPS distance and position measurement part.

Abstract: A system for collecting personal information concerning a customer by wireless communications between the customer's portable terminal and a store apparatus installed in a store. The terminal stores the customer's personal information, and sends the stored personal information to the store apparatus. The store apparatus discounts a price for the customer's purchased goods when it receives the personal information sent by the terminal, and stores the received personal information in a store device.

Abstract: The system stores information about a point card. When a user of the system goes out of his/her residence, the system finds a store at which the point card can be used. The system also determines whether the store is located within a predetermined distance from a current location of the user. The system informs the user of whether the point card has expired or not.

Abstract: A positioning apparatus for determining a present position of a mobile station by using radio waves coming from a plurality of base stations arranged within a communication area is provided. The positioning apparatus receives the radio waves coming from the plurality of base stations to generate reception signals corresponding to the respective radio waves, and determines propagation ranges of the radio waves coming from the respective base stations. The apparatus further derives propagation ranges of direct waves coming from the respective base stations from the determined propagation ranges. Then, the present position of the mobile station is determined by performing positioning operation using the derived propagation ranges of the direct waves.