Abstract: There is provided a cordless telephone which can be connected to any one of digital exchanges of different protocols. A main unit of the cordless telephone is provided with a memory for storing a table for collating control data (first control data) defined by the protocol of a digital exchange to be connected and control data (second control data) inherent to the cordless telephone. The main unit also includes a protocol converting circuit 4 for conversion between the first control data and the second control data. If the cordless telephone is to be connected to another digital exchange structured in a different protocol, a protocol circuit 4 corresponding to the protocol of the digital exchange is used. Transfer of conversation between the cordless telephone and a fixed telephone can also be realized by providing a data distributing and combining circuit.

Abstract: A method for facilitating the placement of emergency calls from a wireless telephone within a cellular, or other wireless, communication system is disclosed herein. A wireless telephone is configured to receive from a base station a local emergency number associated with the service area of the base station. During operation of the wireless telephone, each number dialed or otherwise entered in by a user is compared to the local emergency number. If the dialed number matches the local emergency number, an emergency call is initiated by the wireless telephone; otherwise, the wireless telephone initiates a standard telephone call in response to entry of the dialed number. The user interface of the wireless telephone may optionally provide an indication upon the placement of an emergency call.

Abstract: The diversity antenna circuit comprises a first antenna for receiving a vertical plane of polarization of an electric wave, a second antenna for receiving a horizontal plane of polarization thereof, a receiving means for detecting the electric field strength of a received signal, a first matching means for matching the first antenna to the receiving means, a second matching means for matching the second antenna to the receiving means, a first transfer means, a second transfer means, a first switching means, a second switching means, and a switching control means for connecting one of the first and second antennas to the receiving means and separating another one from the receiving means according to ON/OFF control of the first and second switching means based on received electric field strength.

Abstract: A radio communication system in which each frame having an imbalanced transmission speed is time-divided to a low speed transmission area and to a high speed transmission area according to a specified ratio in the time domain. An upload signal as a first-directional signal and a download signal as a second-directional signal are allocated to the low speed transmission area and to the high speed transmission area respectively. In a case where a high speed transmission request is issued from a personal station (PS) to a base station (BS), the order of the upload signal and that of the download signal is exchanged in the time domain within one frame, so that the download signal and the upload signal are allocated to the low speed transmission area and the high speed transmission area respectively.

Abstract: In an flash memory which is an IC memory, a playback time proportional to a period of time when a rewind key is continuously pressed down, or a playback time proportional to a period of time when the rewind key is continuously pressed down while time-stamp information is played back, and a message is read out and played back from a message address at a destination for playback corresponding to the playback time. With this feature, a message address at a destination for playback can be changed according to a period of playback time corresponding to a period of time when the rewind key is continuously pressed down.

Abstract: A cordless telephone set having a base unit and handset units and enabling communications using a channel selected from a plurality of channels. The cordless telephone set comprises apparatus for storing a specified number of channels selected by the telephone apparatus and storing historical channel use data. Whether or not a channel is unused is determined and channels used with high frequency with the data stored in the first storage are changed to those used with low frequency according to the historical use data. Channels that are stored are progressively specified prior to a start of call and a specified channel is selected, if it is determined that the channel is an unused one.

Abstract: A system for compensating for reference frequency drift in a communications system. The inventive system includes a frequency source for providing a reference frequency. An error determination circuit determines if the reference frequency is within a predetermined range of a desired reference frequency and provides an error signal in response thereto. A frequency correction circuit steps the reference frequency up and/or down by a predetermined amount in response to the error signal until the reference frequency is within the predetermined range of the desired reference frequency. In a specific embodiment, the predetermined amount is twice the short-term capture range of the reference frequency which corresponds to approximately four parts per million. The predetermined range is the short-term capture range or two parts per million. The predetermined range is dependent upon the reference frequency band in which the receiver can successfully receive and decode the receive signal.

Abstract: The present invention allows efficient data compression when the contents of the control fields of packets are the same. An identity flag is substituted for a control field when the control field of an already-transmitted packet signal is identical to the control field of a packet signal which is to be newly transmitted. When non-identical, a non-identity flag is inserted to the control field. Thus, by using a larger number of small data format when identical control fields are transmitted consecutively, the data length of the control fields can be shortened.

Abstract: The present invention provides a portable individual calling device which performs no indication on the LCD indicator as a measure for preventing decrease in signal-receiving sensitiveness due to CPU noises, wherein the non-indication time period is shortened. For this purpose, the portable individual calling device comprises a receiving unit for receiving a radio signal which contains a selective calling number and message information, an LCD indicator for indicating message information, an address detecting unit for detecting whether the received signal contains its personal selective calling number, and a controlling unit for reading out message information from the received signal in correspondence with the detection of its personal selective calling number and for subjecting such information to data processing.

Abstract: A cordless telephone set with a handset to be placed on a charger for a secondary battery to be charged wherein the handset has a concave section on its junction surface with the charger and also has a terminal provided on a side wall of the concave section and projecting from the side wall, the charger has a convex power supply terminal on its junction surface with the handset, and the projecting terminal on the side all of the concave section of the handset is engaged in a side wall of the convex power supply terminal of the charger for electric connection.

Abstract: A method and device for error-correcting a plurality of bits transmitted over RF channels in a cellular communication system are provided. The present invention applies principles of majority voting to error-correct a plurality of bits in a message word simultaneously. Further, the present invention applies its error-correction capability to virtually any number of repeat transmissions over forward and reverse control/voice channels. Following synchronization of the transmit and receive stations, a message word having n-bits is transmitted repeatedly. The repeat bits are separated and analyzed whereafter the true logical state of the original n-bits is determined. The originally transmitted message word is then reconstructed based upon the determined true logical state of the n-bits.

Abstract: A method and apparatus for continuously calibrating the modulation sensitivity of a voltage controlled oscillator (VCO) within a modulator of a transmitter. In accordance with the present invention, the transmitter is coupled to the receiver in order to loop back the transmit signal. The present invention includes a baseband signal generator which generates a reference baseband signal of known amplitude during periods when no other baseband information is being applied to the transmitter by the user. A Signal and Reference Comparison Circuit (SRCC) receives the output from the demodulator and determines whether the VCO within the transmitter has the proper modulation sensitivity. If the modulation sensitivity of the VCO is not within a desired range, then a signal generated by the SRCC is applied to a baseband level control circuit to adjust the level of the baseband signal that is applied to the VCO.

Abstract: The present invention includes a method for generating a GMSK modulating signal from a serial digital data bit stream whereby the GMSK modulating signal modulates a carrier frequency signal associated with a GMSK transmitter of a digital communications system. Specifically, the method includes converting each set of m consecutive data bits of the bit stream into a parallel symbol, whereby there are 2.sup.m possible symbols. Each symbol is generally defined as (B.sub.-(m-1). . . B.sub.0), where B.sub.0 is the current data bit and B.sub.-(m-1) is the mth previous data bit with respect to B.sub.0. Next, a corresponding phase advance is assigned to each of the 2.sup.m symbols, each phase advance being substantially equivalent to a percent phase advance contributed by the m consecutive data bits of each symbol. Also, four corresponding accumulated phases are assigned to each of the 2.sup.m symbols, each accumulated phase being derived from a multiple of 90 degrees.

Abstract: A light-emitting element is supported by hooking claw sections at tip sections of a pair of supporting arm sections onto a top surface of the flange section, and a lower section of a basic body of the light-emitting element is pressed by a tip section of an elastic member to energize the light-emitting section upward. The light-emitting section raised upward by the elastic member is positionally restricted by hooking claw sections of a pair of supporting arm sections on a flange section, thus height of the light-emitting element on a substrate being maintained at a constant level.

Abstract: A data collection system in which, in communications between each of terminal units and a data collector through a power line, the data collector subjects a polling signal generated by a polling generating circuit to spread spectrum modulation by a spreading section, and superimposes the spread signal on the power line, while each of the terminal units subjects the incoming spread signal thereto superimposed on the power line to de-spread spectrum demodulation and recognizes it, and superimposes the data subjected to spread spectrum modulation on the power line after a certain period of time different from that in other terminal unit has passed. The data collector collects the data obtained by subjecting spread signals successively coming thereinto each by being superimposed on the power line to de-spread spectrum demodulation according to the polling.

Abstract: A system for networking dispatch-type of communications. A plurality of radio cells are coupled to a centralized hub controller via the public switched telephone network. The radio cells are networked together via the hub controller using one or more telephone voice lines and a respective data line for providing communications between each radio cell and the hub controller. Data packets are transferred between the radio cells and the hub controller on the data lines to set up a path for the dispatch communications on the telephone voice lines. The hub controller carries out a trunking function of the telephone voice lines so that the number of voice lines are minimized, while yet preventing blocking of dispatch communications.

Abstract: In a case where error correction code interleaved in the transmitting side and deinterleaved in the receiving side is subjected to decoding processing, a control circuit determines whether a result of decoding for each word is acceptable or not according to decoding acceptable/unacceptable data for each word stored in a decoding acceptable/unacceptable data memory, and subjects a correction object word not decoded to redecoding processing by controlling an error position estimating circuit and correcting data for the correction object word with an estimated error locator based on error position data for a forward word as well as a backward word from the correction object word.

Abstract: A circuit for grounding a signal at a first frequency and at a second frequency. The circuit includes a first capacitor and an inductor in series and a second capacitor in parallel with the first capacitor and inductor. The first capacitor is series resonant at the first frequency and the second capacitor is series resonant at the second frequency. The inductance of the inductor is selected so the combination of the packaging inductance of the first capacitor and the inductor parallel resonants with the second capacitor at a frequency lower than the second frequency and higher than the first frequency, where the second frequency is greater than the first frequency. The grounding circuit may be used to provide a second input to a balanced RF mixer where the RF mixer receives a RF signal at the second frequency at a first input and generates an IF signal at the first frequency.

Abstract: A novel narrow-band communication apparatus comprises a digital signal processor for demodulating the output from a receiving section and outputting a modulation signal for an audio input, an electric field strength detector section for detecting electric field strength in the output from the receiving section, an indicator for indicating whether the narrow-band communication apparatus is in a receiving mode or in a transmission mode, and a power controller for controlling supply of power to, or an operating state of specified portions of, the narrow-band communication apparatus according to the output from the electric field strength detector as well as from the indicator.

Abstract: A method for determining the best time to sample data bits of a data bit stream of a received information signal in a digital communication system includes the steps of determining the current derivative of a respective sample of the information signal, weighting the sample by a predetermined amount, determining an accumulated derivative value for the same sample number of a previous symbol of the information signal, weighting the previous accumulated derivative value by another predetermined amount, summing the two weighted values together and assigning this accumulated derivative value to the respective sample. The method further includes the step of comparing the accumulated derivative values of a predetermined number of consecutive samples to determine which sample has the greatest accumulated derivative value. The sample having the greatest accumulated derivative value substantially corresponds to the beginning of a symbol.