Vlsi Technology, Inc.

Koninklijke Philips Corporation N.V.

Philips Semiconductors Inc.

Vsli Technology, Inc.

Philippe Gaglione

Satoshi Yoshida

Laurent Winckel

Patrick Feyfant

Varenka Martin

Oliver Weigelt

Denis Archambaud

Rita Lagomarsino

John Whittle

Bernard Ginetti

Laurent Souef

Bruno Bocaert

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.

Voice recording and playback mode using the G.726 half-rate within the personal handy phone system

The present invention provides methods of transmitting information within a personal handy-phone system wireless local loop and personal handy-phone system wireless local loops. One embodiment of a personal handy-phone system wireless local loop according to the present invention comprises: a base station; a repeater station configured to transmit a plurality of uplink radio signals to the base station and receive a plurality of downlink radio signals from the base station; and a portable station configured to transmit the downlink radio signals to the repeater station and receive the uplink radio signals from the repeater station.

Personal handy-phone system wireless local loops and methods of transmitting information within personal handy-phone systems

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.

Hardware PCH checking for personal handyphone system portable station

A method for remotely updating software code of personal handy phone system equipment. The present invention enables a remotely located control terminal to update stored software code within a distant portable station or cell station of the personal handy phone system. Specifically, by coupling a control terminal to the existing communication network of a personal handy phone system, the control terminal is able to communicate with portable stations and cell stations. To update the software code of a specific portable station or cell station, the control terminal first establishes communication with that particular device by sending an unique preparatory signal addressed to it. The addressed device receives the unique preparatory signal and checks the validity of it. If the addressed device determines the unique preparatory signal is valid, it transmits a unique verification signal addressed to the control terminal indicating that it is ready to receive the updated version of the software code. Once the control terminal receives the unique verification signal from the particular portable station or cell station, it proceeds to download an updated version of software code into the flash memory of that device.

Method for remotely updating software code for personal handy phone system equipment

A method and system that enables an automatic delay setting within a wireless local loop system. The present invention determines the transmission distance time delay existing between a base station and a personal station by employing the communication interface that is utilized between them. The main reason for determining the transmission time delay caused by large transmission distances (e.g., over 300 meters) existing between base stations and personal stations is to compensate for it. Once the transmission distance time delay is known, the personal station utilizes that value to compensate for it. Specifically, the present invention directs a base station to transmit a control signal to a personal station. The personal station receives the control signal and transmits a signal to the base station. The base station determines if it started to receive the signal from the personal station later than it expected the signal to arrive, assuming close proximity of the two stations. If the signal arrived when it was expected to arrive, the base station discontinues determining the transmission distance time delay. If the signal arrived later than expected, the base station calculates the time difference between the expected arrival time and the actual arrival of the signal. The time difference is equivalent to the transmission distance time delay. Once the time difference is determined, the base station then transmits it to the personal station. The personal station stores the transmission distance time delay value enabling it to compensate for it.

Wireless local loop automatic delay setting

The present invention provides methods of synchronization, personal handy-phone system stations, and phase lock loops. Synchronization of a personal handy-phone system station with a telecommunication network, and another communication station are provided. One method of synchronization comprises: providing a counter configured to generate a plurality of counter values; storing a first counter value; detecting a reference event; latching a second counter value responsive to the detecting of the reference event; comparing the first counter value and the second counter value to detect phase drift; and compensating for phase drift responsive to the comparing.

Methods of synchronizing a personal handy-phone system station and phase lock loops

A system for a direct digital down conversion of a 10.8 MHz intermediate frequency signal in the personal handy phone system. The present invention includes a system that enables a direct digital down conversion of a 10.8 MHz intermediate frequency signal into a digital baseband signal within cell stations and portable stations of the personal handy phone system. To perform this direct digital down conversion of a 10.8 MHz intermediate frequency signal, one embodiment of the present invention uses a hard limiter circuit, a sampler circuit and a digital down converter circuit. The hard limiter circuit of the present invention receives a 10.8 MHz intermediate frequency signal, utilized within cell stations and portable station of the personal handy phone system, and provides a threshold for it. The sampler circuit uses a 19.2 MHz oscillating clock signal to sample the intermediate frequency signal that is output from the hard limiter circuit. Due to spectral leakage, the 10.8 MHz intermediate frequency signal that was input into the sampler circuit is output as an 8.4 MHz intermediate frequency signal. The digital down converter circuit uses an 8.4 MHz signal to perform a digital down conversion of the 8.4 MHz intermediate frequency signal into a digital baseband signal. The present invention provides a system that utilizes only one digital down conversion stage to perform a direct digital down conversion of a 10.8 MHz intermediate frequency signal into a digital baseband signal.

Direct digital down conversion of a 10.8 MHz intermediate frequency

The present invention provides methods of analyzing a radio signal, including a personal handy-phone system radio signal. In accordance with a first aspect of the present invention, a method of analyzing a radio signal in a transceiver selectively coupled with a first antenna and a second antenna comprises: receiving a radio signal comprising a plurality of slots via the first antenna; first configuring the transceiver to receive via the first antenna; during the receiving of a selected slot, first determining a radio signal characteristic; following the first determining and during the receiving of the selected slot, second configuring the transceiver to receive via the second antenna; and following the second configuring and during the receiving of the selected slot, second determining a radio signal characteristic.

Methods of analyzing a radio signal and methods of analyzing a personal

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.

Slot by slot PS/CS switching apparatus within the personal handy phone

A circuit arrangement on a handset for monitoring changes in the system parameters of a personal handyphone system by hardware checking the broadcasting reception indication (BRI) pattern. The circuit arrangement includes a memory portion for storing the previous BRI pattern received at the circuit arrangement, and an interrupt generator for comparing the stored previous BRI pattern with a current BRI pattern and for generating an interrupt to activate the handset processor when the previous BRI pattern differs from the current BRI pattern.

Personal handyphone system hardware checking of broadcasting reception

Methods of synchronization, personal handy-phone system stations and

A system that enables a portable station of the personal handy phone system to support a conference call. The present invention provides this capability by empowering a portable station to communicate with up to four cell stations simultaneously enabling the user of the portable station to communicate with the users of four other telecommunication devices. Specifically, the present invention modifies the internal circuitry of a portable station to increase the number of receiving channel circuits to four and the transmitting channel circuits to four while adding a digital signal processor to mix the different received and outgoing voice signals. The increased number of receiving and transmitting channel circuits enables a portable station to utilize all the communication slots located within the frames of the radio communication interface of the personal handy phone system. Communication is time-multiplexed across these slots. The frames each have eight slots, four for receiving data and four for transmitting data. These eight slots enable a portable station implemented with the present invention to support communication with four cell stations simultaneously. To facilitate this type of communication, the slots located within the portable station frames operate in conjunction with the slots located within the cell station frames of the cell stations involved in the conference call thereby creating communication channels. The cell stations involved in the conference call each utilize different communication channels to communicate with the portable station implemented with the present invention.

Conference call on a personal handy phone system portable station

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.

Personal handyphone system hardware checking of SA-field

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.

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Mandelieu, France

Philippe Gaglione