摘要:
A circuit arrangement on a handset for checking paging information transmitted in a personal handyphone system. The circuit arrangement includes a memory portion for storing the identification numbers of the handset and the cell station from which the handset receives calls, and an interrupt generator for comparing transmitted identification numbers of a called handset and a cell station with the stored identification numbers of the handset and the cell station and for generating an interrupt when the stored identification number of the handset matches the transmitted identification number of the called handset and the stored identification number of the cell station matches the transmitted identification number of the cell station.
摘要:
Voice recording and playback mode using the G.726 half-rate within the personal handy phone system (PHS). When a portable station within the PHS operates as a voice recorder (e.g., functioning as an answering machine), a cost effective system in accordance with the present invention is adapted to compress and store received voice/sound signals in order to increase the usage of limited memory resources provided within the portable station. The present invention also enables previously compressed and stored voice/sound signals to be decompressed and played back in various portable station playback modes. Specifically, the portable station receives a voice/sound signal in a full rate (e.g., 32 kilobits-per-second) 4-bit adaptive differential pulse code modulation (ADPCM) data format in compliance with the International Telecommunication Union (ITU) recommendation G.726. The present invention compresses this received voice/sound signal to a half rate (16 kilobit-per-second) 2-bit ADPCM data format in compliance with the ITU recommendation G.726 in order to increase the usage of the limited memory resources provided within the portable station. During a playback mode of the portable station, the present invention decompresses the previously compressed and stored voice/sound signal to facilitate its playback.
摘要:
A method and system that enables a wireless repeater within the personal handy phone system to switch the communication mode of each slot within its communication interface. Specifically, the repeater is able to function as a cell station while communicating with a portable station and function as a portable station while communicating with a cell station. For instance, when the repeater communicates with a cell station, it switches the communication mode of a desired slot within its communication interface into portable station communication mode. Conversely, when the repeater communicates with a portable station, it switches a desired slot within its communication interface into cell station communication mode. Since a repeater implemented with the present invention is able to switch the communication mode of each slot within its communication interface, the amount of internal circuitry required within the repeater is significantly reduced. Specifically, the internal circuitry implemented within an embodiment of a wireless repeater in accordance with the present invention includes a radio circuit and a baseband circuit. The present invention enables the significantly reduced internal circuitry of the repeater to perform the dual function of communicating with cell stations and portable stations using a single communication interface. As a result of significantly reducing the internal circuitry of the repeater, it is less expensive to manufacture and requires less power to operate.
摘要:
A circuit arrangement for hardware checking the validity of data transmitted in a SA-field within the traffic channel of the personal handyphone system. The circuit arrangement includes a receiver for receiving control information corresponding to a SA-field, and an interrupt generator for generating an interrupt to activate the handset processor when the control information indicates the SA-field is the beginning of a series of SA-fields containing valid data.
摘要:
A key handling circuit for a switching matrix having row and column conductors includes bidirectional drives for the row conductors and the column conductors. The row drive and the column drive are in a low conductive condition except when a relevant key switch is activated. The row drive provides a current input for the column drive in one phase of operation and the column drive provides a current input for a row drive in a second phase of operation.
摘要:
A hardware timing system for a cellular telephone comprises a master counter and a slave counter. The slave counter controls timing window generators in synchronism with the time frame of the local base station. The phases of timing frames of other base stations are monitored using the master counter.
摘要:
A digital to analog converter (DAC) offset autocalibration system in a digital synthesizer integrated circuit. The present invention includes a DAC coupled to a filter. The input of the DAC accepts digital values for conversion to an analog signal. The output of the DAC is coupled to the input of the filter. The filter smoothes the analog signal received from the DAC. A switch is coupled to the filter output to receive the analog signal. A comparator is coupled to the switch. The input of the comparator receives the analog signal from the filter output via the switch. An autocalibration control circuit is coupled to the output of the comparator, to the switch, and to the DAC. The autocalibration control circuit is adapted to input a value to the DAC in order to determine an offset correction from the output of the comparator and adjust the analog signal using the offset correction.