Abstract: A method of suppressing generation of carrier leak in a transmitter and reducing deterioration of communication quality comprises the steps of outputting DC elements (I, Q) from a DSP gradually changing the voltage values, measuring a sum of the DC elements (.DELTA.I.sub.DC, .DELTA.Q.sub.DC) and DC elements (I, Q), storing the DC elements (I, Q), when the above sum is equal to a specified value (herein, 0 V), as DC elements -.DELTA.I.sub.DC, -.DELTA.Q.sub.DC for correction, and correcting the DC elements (I.sub.DC, Q.sub.DC) (DC elements obtained by amplifying DC elements for (I, Q) channels demodulated by a quadrature demodulator during transmission) using the DC elements (-.DELTA.I.sub.DC, -.DELTA.Q.sub.DC) for correction during transmission.

Abstract: A distributed constant type multiple-line circuit is described which comprises a dielectric block (60) having shield conductors (62,64) on its rear surface and all the peripheral side surfaces, a central conductor (1) extending in the block in the front-to-rear thickness direction at the central portion thereof, a first plurality of conductors (2-5) positioned around and parallel to the central conductor and inductively coupled therewith, and a second plurality of conductors (2'-5') positioned nearby and parallel to the first conductors and inductively coupled therewith, respectively. The length of the central conductor is equal to one quarter of the wavelength of the central frequency (f.sub.1) in a frequency band, and the rear end thereof is isolated with the shield conductor on the rear surface of the block. Each of the lengths of the first conductors is equal to one quarter of the wavelength of a predetermined frequency (f.sub.2 -f.sub.

Abstract: A select call receiver, such as a pager, is disclosed which comprises a canned message memory. The canned message memory has canned message memory storage locations that are linked to message tag identifiers. The pager recalls and displays canned messages upon receipt of message tag identifiers. In the first embodiment, the pager provides a programming mode wherein the user of the pager can remotely program canned messages into the pager by accessing a convention paging terminal and keying numeric data into a telephone keypad. The numeric data is converted to alphanumeric data according to a mnemonic entry scheme and stored in the pager's canned message memory. In a second embodiment, the message tag identifier is also remotely programmable by the user, allowing great flexibility in the definition of the message tag identifiers.

Abstract: A land mobile radio communication system has a plurality of cell sites, each of which typically has a plurality of repeaters. The over-the-air radio communications between the cell site repeaters and the mobile radios in the system include both a voice component and a data component. The data component is carried as low-frequency subaudible information. Communication channels are provided between the radio users at each site as well as between users at different sites and between mobile radio users and the public telephone network. Within a cell site, the transmitted and received communications are digitized and passed through serial buses in a time multiplex fashion. The digitized voice is transferred between time slots to provide the required switching function. The system includes operational software to provide direct inward dial telephone number recognition, automatic voice prompts for a user entering a new cell, call priority override, fraud control for radio fleets and a dynamic control channel.

Abstract: A scan receiving system comprising an antenna circuit, a radio-frequency reception circuit connected to the antenna circuit and for converting a received radio-frequency signal into an audio-frequency signal, an audio-frequency circuit connected to the radio-frequency reception circuit and for amplifying the audio-frequency signal supplied from the radio-frequency reception circuit, an input circuit for inputting a desired reception frequency, and a controller connected to the radio-frequency reception circuit, the audio-frequency circuit and the input circuit, the controller including a plurality of channel memories which are provided in one-to-one correspondence with a plurality of carrier frequency channels so that a plurality of desired reception frequencies inputted through the input circuit are programmed in the plurality of channel memories, the frequencies programmed in the plurality of channel memories being scanned in the order of frequency ascending or descending in accordance with a scan instructi

Abstract: A receiver is disclosed which includes an automatic display illumination capability. Upon the receipt of a signal, the display is illuminated until either an interval timer expires, or the signal goes away. In the preferred embodiment, a portable scanning receiver employs a liquid crystal display and an incandescent light. The automatic display capability can be enabled and disabled to a manual display illumination mode of operation. Benefits include improved ease of use in low ambient light conditions and improved battery life.

Abstract: A method and apparatus for secure, remote programming of a receiving device by instructions transmitted in data format, whereby previously stored messages may be selectively updated, capcodes may be reprogrammed, and the pager display may be activated or deactivated.

Abstract: As for an electric apparatus having a case formed of electro-magnetic wave passing-through material, in order to provide an electro-magnetic wave shielding structure being capable to effectively prevent the leakage therefrom of an electro-magnetic wave generated therein, an electro-magnetic wave reflecting layer, namely, a conductive layer is formed on an inner face of the case and further, on a surface of the conductive layer, a magnetically losing layer containing Mn--Mg--Zn group soft ferrite particles having 1 to 20 .mu.m average diameter by 70 to 90 weight % at a thickness exceeding 80 .mu.m is formed, so as to repeatedly absorb the inner generated undesired electro-magnetic wave therein through repeated reflection between the conductive layer and the absorbing layer.

Abstract: A cordless telephone system including a master phone connected to a telephone line and a slave phone executing communication via one of a plurality of radio channels switchable to said master phone, the master phone and slave phone each having a correlation detector for detecting a correlation value between a received signal and a reference spreading code series, a comparator for comparing the correlation valued detected by the comparator to a prespecified reference correlation value, and a control circuit continuing communication by switching a radio channel when it is determined that the correlation value is lower than the prespecified reference value.

Abstract: A satellite broadcast receiver capable of receiving audio SCPC signals is disclosed in which the receiver comprises an RF reception unit for receiving television signals and audio SCPC signals broadcast from a satellite, frequency converter for converting an RF output from said RF reception unit into an IF signal, separator for separating the output of said frequency converter into a television signal and an audio SCPC signal, a TV signal processing unit for receiving and processing a first output from the separator, an SCPC signal processing unit for receiving and processing a second output from the separator, and a selector for selecting any one of the outputs from the TV signal processing unit and said SCPC signal processing unit, thereby enabling selective reception of TV signals and audio SCPC signals broadcast from a satellite.

Abstract: A power supply switching apparatus for switching power supplies used to all electronic appliance such as a pager and a portable telephone is described. A battery pack includes a battery and is connectable to an external DC power supply. In the battery pack, a power supply connection detecting circuit detects whether or not the external DC power supply is connected to this battery pack, and a switching circuit switches the battery and the external DC power supply. In an appliance housing a voltage is detected by a voltage detecting circuit to judge whether the detected voltage corresponds to the voltage derived from the battery power supply, or the voltage derived from the external DC power supply, and another switching circuit switches the battery power supply and a power stabilizing circuit. Both of these battery pack and appliance housing constitute the power supply switching apparatus.

Abstract: An abnormal transmission stopping circuit for use in a transmitter including a base band signal processing circuit, an amplitude modulator which modulates the amplitude of a carrier signal in accordance with a base band signal, and a transmission amplifier which amplifies a signal modulated by the amplitude modulator. The stopping circuit includes an electric current detecting circuit which detects a power supply current to the transmission amplifier, and a comparator which generates and supplies a transmitting function stopping signal to the base band signal processing circuit when the detected power supply current exceeds a threshold value.

Abstract: A scanning technique that is preferential as to communication channels actually utilized in the past. A programmable queue is written with a communication channel identity code based on a predefined criteria, such as each time the channel is actually used. The preferential queue is scanned in association with all the remaining communication channel identity codes, thereby providing a weighting factor that is skewed toward the selection of channels that have experienced actual use. System identification codes utilized in a mobile radio complex are stored in the queue in accordance with a roaming function, and group identity codes are stored in the queue when scanning home channels of mobile radio systems to determine incoming calls.

Abstract: In portable terminal units each of which has a rechargeable battery and a data processing section, one terminal is used as both a terminal for charging the rechargeable battery and a terminal for connecting a data processing unit to an external data processing unit. First protective circuitry protects the data processing unit from a battery charging current and second protective circuitry eliminates loading of the rechargeable battery due to a data voltage and protects the external data processing unit from charging current for the chargeable battery.

Abstract: A method and apparatus for efficiently monitoring a plurality of radio channels in a data communication system in which mobile message receiving devices are programmed to receive messages on a plurality of channels by selecting a group of channels for scanning, based upon detection of signal activity in the radio channels.

Abstract: The present invention eliminates the need for non-audio communications performed between base units and handset units to identify the handset unit existing communication zones, and thereby reduces the consumption of handset unit batteries to extend the lives thereof. The cordless system telephone apparatus in accordance with the invention comprises a control unit connected to a public communication network through telephone lines, a plurality of base units connected to the control unit, and a plurality of handset units communicating with the base units by way of radio waves. In waiting states where the handset units are not in audio communication with the base units, the control unit does not carry out, through the communications with the base units, identifications or registrations of the communication zones in which the handset units exist. The switching of the base units for higher communication qualities is only conducted during audio communications.

Abstract: A method and apparatus for one-touch recall and dialing of stored telephone or billing account numbers using only the numeric and special keys of a standard 12-key keypad. Upon momentary actuation of a numeric or special key of a standard keypad, the data input is entered into a buffer or directly dialed into a telephone network. If, however, the actuated key is actuated for more than a predetermined amount of time, a previously stored sequence of numbers is retrieved from a memory address location corresponding to the actuated key and is automatically dialed.

Abstract: A port selection circuit in which a port selection section and a variable frequency filter are integrated on a substrate. The port selection circuit selectively connects any one of first to n-th ports to an (n+1)-th port and comprises first to n-th switches. Each of the switches includes one end connected to a corresponding one of the first to n-th ports and the other end connected to a common connecting point. When any one of the first to n-th ports is selected, a variable frequency filter connected between the common connecting point and the (n+1)-th port is set to a frequency characteristic for transmitting the frequency assigned to the selected port.

Abstract: A method of searching a specified band of frequencies for a plurality of active signal frequency in a scanning receiver is disclosed. In the preferred embodiment, a range of channel memory storage locations are specified and a controller in the scanning receiver repetitively scans the range of frequencies for active signal frequencies and stores a number corresponding to each active signal frequency in one of the storage locations. Upon filling all of the specified storage locations, the search and store operation is terminated.

Abstract: A portable telephone is disclosed which comprises a data memory having a plurality of data storage locations for storing telephone numbers used to initiate telephone calls as an auto-dialer function. An audio memory is also disclosed which comprises a plurality of audio storage location, each of which may be linked to one of the data storage locations. A controller with a key matrix for inputting commands and a display for displaying status is included such that commands can be entered that cause the controller to sequentially recall telephone numbers stored in the data memory and play back voice tags stored in the audio memory, that are linked with the data memory. A loud speaker is disclosed for playing back the audio tags at a loud volume. When a tag is heard that represents the desired call destination, that call is initiated.