Abstract: A modulator generates a modulation signal from an input signal. A serial-parallel converter generates a subcarrier modulation signal from the modulation signal. An inserter inserts a transmission-side data series, generated by multiplying a data series having an autocorrelation property by a predetermined series amplitude coefficient, in a signal for synthesis, generated by multiplying the subcarrier modulation signal by a predetermined signal amplitude coefficient, in such a way that elements in the signal for synthesis and elements in the transmission-side data series are alternately positioned, thereby generating first data. An IFFT unit performs an inverse fast Fourier transformation on the first data. A separator generates a baseband signal based on first half data of an operation result from the IFFT unit. A transmitter generates a transmission signal from the baseband signal, and transmits it to another apparatus via an antenna.

Abstract: There is provided a wireless communication system which causes a wireless terminal to select a relay device among plural relay devices connected together via a communication line when the wireless terminal attempts to communicate with another wireless terminal. The relay device has an information acquiring unit, a calling determining unit, and an information adding unit. The wireless terminal has an information analyzing unit which analyzes whether or not the own device is included in a communication counterparty of calling information when the calling information is included in communication information, a priority comparing unit which determines whether or not a priority level of the calling information is higher than that of a current communication when the own device is included, and a channel changing unit which changes a channel to that of another relay device of the calling information when the priority level of the calling information is higher.

Abstract: A modulator generates a modulation signal from an input signal. A serial-parallel converter generates a subcarrier modulation signal from the modulation signal. A first operator generates first data by multiplying a predetermined non-singular matrix by the subcarrier modulation signal. A second operator generates second data by multiplying a matrix calculated by multiplying a predetermined transformation matrix by the predetermined non-singular matrix by the subcarrier modulation signal, or multiplying the predetermined transformation matrix by the first data. A synthesizer generates a baseband signal from data obtained by adding the second data to the first data, or data obtained by subtracting the second data from the first data. A transmitter generates a transmission signal from the baseband signal, and transmits the transmission signal to another apparatus via an antenna.

Abstract: A modulator generates a modulation signal from an input signal by, and a serial-parallel converter generates a subcarrier modulation signal from the modulation signal. A shifter shifts a predetermined data series to generate a shift sequence. Two IFFT units perform an IFFT on data sent thereto to generate first data and second data. An operator generates baseband signals from at least one of the sum of the first data and the second data and the difference therebetween. The foregoing processing is repeated with a predetermined number of times to shift the predetermined data series being changed. A PAPR determiner sends the baseband signal matching with a predetermined reference for determining a transmission signal to a transmitter. The transmitter generates a transmission signal from the baseband signal, and transmits the transmission signal to another communication apparatus via an antenna.

Abstract: A modulator modulates an input signal by a predetermined modulation scheme to generate a modulation signal. A serial-parallel converter performs serial-parallel conversion of the modulation signal and assigns the modulation signal to subcarriers with frequency components orthogonal to each other, thereby generating a subcarrier modulation signal. A synthesizer generates a baseband signal from the subcarrier modulation signal based on a predetermined transformation matrix. The predetermined transformation matrix is a matrix which indicates inverse discrete Fourier transformation and is divided into a plurality of square matrices identical in the number of rows and the number of columns, and in which elements other than elements of a plurality of diagonally positioned square matrices are set to 0. A transmitter generates a transmission signal from the baseband signal, and transmits the transmission signal to another apparatus via an antenna.

Abstract: The present invention provides a gain control circuit for an FM receiver that can reduce a reproduced audio output according to the magnitude of the noise component of an intended signal included in a received signal. The gain control circuit of the present invention is constituted by a noise level measurement circuit 26 and a preamplifier 25. The noise level measurement circuit 26 measures a noise level in an audio signal Sa1 output from an FM detector 4 and outputs a control signal Sc corresponding to the noise level. The preamplifier 25 reduces an output according a value of the control signal Sc. With the gain control circuit of the present invention, the volume of the speaker is reduced as the noise component in the audio signal Sa1 increases due to a decrease in received electric field strength, and therefore discomfort caused by unpleasant noise can be reduced.

Abstract: At least two or more wireless communication apparatuses of the present invention are located adjacent or separately in a relatively confined area. The output portion of any one currently used wireless communication apparatus of the wireless communication apparatuses is connected to the input portion of each of the other standby wireless communication apparatus. While a radio signal is transmitted from the transmitter of the currently used wireless communication apparatus, a reception limit signal is transmitted from the output portion of the currently used apparatus to the respective input portion of each of the nearby standby apparatuses so that the reception ability of the receiver of the standby apparatus is effectively limited.

Abstract: A frame sync detecting circuit and FSK receiver sequentially derive a moving average value (?) from oversample values of a received word pattern, for given symbol periods, and a difference between the moving average value and an average value for the given symbol periods in a given sync word pattern is determined as DC offsets ?f. Subsequently, the DC offset ?f is subtracted from the received word pattern, and correlation processing with respect to the sync word pattern is performed to determine a correlation value (?). If the correlation value exceeds a predetermined threshold, it is determined that a sync word candidate has been received, and symbol values of the received word pattern after the DC offset correction are compared with respective symbol values of the sync word pattern. A sync word pattern detection is determined if errors in the symbols are within a given range.

Abstract: A user location monitoring unit of a data communication control apparatus monitors a message sent from a wireless device via a repeater. Upon detection of a change in the location of the wireless device, the user location monitoring unit updates the location information in the database and notifies via the Internet a management server of the location change. Upon receipt of the message via the Internet, a destination address confirming and correcting unit of the data communication control apparatus uses the user ID of a destination wireless device as a search keyword to search the database. In turn, the destination address confirming and correcting unit corrects the destination address of the message to the latest address of the pertinent user ID and outputs the corrected message to a received message forwarding unit.

Abstract: A monitor terminal transmits a monitor request command to monitor a repeater station designated by an operator to a monitor server via the Internet. The monitor server detects a monitor station located in the communication range of the designated repeater station from the content of the received monitor request command, and transmits a monitor instruction command to the detected monitor station via the Internet. The monitor station intercepts a radio signal during transmission from the repeater station to a radio communication device or vice versa. Upon reception of the monitor instruction command, the monitor station transmits the intercepted radio signal as monitor data to the monitor server. The monitor server transfers the monitor data to the monitor terminal. Upon reception of the monitor data transferred from the monitor server, the monitor terminal radio-transmits the received monitor data using a radio wave format receivable by the radio communication device.

Abstract: Circuit blocks and respectively convert high-voltage logic signals in which two logical values are expressed by a first signal potential and a second signal potential into low-voltage logic signals in which the two logical values are expressed by a third signal potential at least as large as the first signal potential and a fourth signal potential that is the third signal potential to which a positive voltage has been added and which is no greater than the second signal potential, and outputs the converted logic signals. The transistors in the circuit block are of the form of replacing the respective transistors of the circuit block with elements of opposite polarity, so that when the third signal potential is changed and operation of one of the circuit blocks and becomes difficult, the other operates normally. Consequently, stable level conversion can be accomplished.

Abstract: Provided are a clock regeneration circuit and a receiver, wherein difference values (V1, V2, V3) from an ideal value can be obtained for respective three sample data (T1, T2, T3) which are obtained by oversampling a 4-level FSK demodulated signal at a higher frequency than that of a symbol clock and in which sample data (T2) at a symbol point (P) is included at a median, and a sampling timing of the symbol point (P) is shifted toward a point where the sample data (T3) having a smaller difference value is obtained, by a time corresponding to the difference value (V2) at the symbol point. Thus, the clock regeneration circuit and the receiver are capable of regenerating a stable clock from multi-level modulated waves in a small calculation amount.

Abstract: A PLL circuit comprises a phase detector, a charge pump, a loop filter, a voltage-controlled oscillator (VCO), and two variable voltage sources. The phase detector and the charge pump each comprises low-voltage transistors, and operates with a fixed supply voltage VCC1 (e.g., 5 V) which is a potential difference applied from the variable voltage source of a power-supply voltage VL and the variable voltage source of a power-supply voltage VDC (=VL+VCC1). A tuning control signal VC generated by integrating an output current signal of the charge pump using the loop filter is input to the VCO having an input voltage range of the tuning control signal from 0 V to VCC2 (e.g., 16 V).

Abstract: A high frequency circuit includes an amplifier part that includes a plurality of amplifier circuits amplifying a high frequency signal and connected in parallel, that synthesizes outputs of the amplifier circuit and that supplies the outputs to an antenna; a controller that outputs a low power signal during a low power mode in which the amplifier part operates at low power; and an operation suppressing circuit that disables one of the plurality of amplifier circuits based on the low power signal.

Abstract: A microphone which does not need a hanger plate structure is provided. A conductive hanger knob is provided at the back of the rear case of a microphone case. The hanger knob has three layers of a conductive shaft part, an insulator part and a conductive bolt part in the named order from its center. The shaft part is electrically insulated from the bolt part. A notch that locks the bolt part of the hanger knob at a hanger surface is formed at a conductive hanger hook on which the microphone is hooked via the hanger knob. A support spring portion disposed at the back of the hanger surface urges the shaft part of the hanger knob locked at the notch in a direction of pushing the shaft part back toward the hanger surface. This provides electric conduction between the shaft part and the bolt part via the hanger hook.

Abstract: A user location monitoring unit of a data communication control apparatus monitors a message sent from a wireless device via a repeater. Upon detection of a change in the location of the wireless device, the user location monitoring unit updates the location information in the database and notifies via the Internet a management server of the location change. Upon receipt of the message via the Internet, a destination address confirming and correcting unit of the data communication control apparatus uses the user ID of a destination wireless device as a search keyword to search the database. In turn, the destination address confirming and correcting unit corrects the destination address of the message to the latest address of the pertinent user ID and outputs the corrected message to a received message forwarding unit.

Abstract: A drop detection part that detects drop of the device into the water, a light emitting body disposed in the housing, and a light-emission control circuit that makes the light emitting body emit light when the drop detection part detects the drop into the water are provided, and the rear face of the housing is made translucent, a lower part of a sealing member sealing the front housing and the rear housing is also made translucent, and a cover part covering the light emitting body is formed on this translucent part.

Abstract: A target identification device in a user object includes: a user information obtaining part and a target information obtaining part obtaining a position, a speed over ground and a course over ground of the user object and a target object; a processor that calculates a CPA distance and a TCPA with respect to the target object relative and the user object, based on the positions, the speeds over ground and the courses over ground of the user object and the target object. The processor replaces the course over ground of the user object with a direction toward the target object and calculates the CPA and the TCPA when the speed over ground of the user object is a low speed determination value or less.

Abstract: A preamble generating apparatus used for synchronization of a reception apparatus in an orthogonal frequency division multiplexing system and generating a preamble to be added to a beginning of data at a time of communication, receives preamble length identifying information and position specifying information, and generates a plurality of elements constituting a preamble according to a predetermined sequence based on those information. The preamble generating apparatus creates a preamble model, and generates a plurality of preambles by setting the generated elements at positions of elements in element deciding information included in the preamble model, the positions indicating elements in the preamble model which are to be used in data communication.

Abstract: A wireless communication apparatus is provided for selecting an optimum frequency even when radio wave conditions have changed. A wireless communication apparatus provided with a frequency selector for selecting an optimum frequency for establishing a link for mutually transmitting and receiving has a transceiver for transmitting radio waves to another wireless communication apparatus and receiving from the other wireless communication apparatus radio waves responding to those transmitted radio waves, a quality analyzer for analyzing communication quality indicating the condition of the link from the received radio waves, and a quality updater for updating the analyzed communication quality on the basis of time elapsed from when the radio waves were received. In addition, the frequency selector selects the optimum frequency on the basis of the updated communication quality.