Abstract:
A dual-radio communication apparatus has a first radio device, such as a Bluetooth radio, for use in a first frequency band, and a second radio device, such as a Globalstar satellite radio, for use in a second frequency band, which is proximate to the first frequency band. The communication apparatus also has a controller coupled to the first and second radio devices. The first radio device may comprise a frequency-hopping spread-spectrum transmitter. Moreover, the first radio device has a first operating mode employing a first frequency range. The first radio device also has a second operating mode employing a second frequency range, which is smaller than the first frequency range. The controller is adapted to set the first radio device in its second operating mode, when the second radio device is in operation, and otherwise set the first radio device in its first operating mode.
Abstract:
An entire radio transceiver can be completely integrated into one IC chip. In order to integrate the IF filters on the chip, a heterodyne architecture with a low IF is used. A single, directly modulated VCO is used for both up-conversion during transmission, and down-conversion during reception. Bond-wires are used as resonators in the oscillator tank for the VCO. A TDD scheme is used in the air interface to eliminate cross-talk or leakage. A Gaussian-shaped binary FSK modulation scheme is used to provide a number of other implementation advantages.
Abstract:
A demodulator circuit for demodulating a frequency modulated input, which includes a detector (14) that is operable to produce a demodulated signal from an incoming frequency modulated signal. A tuning circuit (19) is connected to the detector and operable to vary the frequency response characteristics of the detector. An auxiliary detector (25, 26) is connected to receive a reference frequency signal and to provide an auxiliary tuning signal to the detector on the basis of detection of the reference frequency signal.
Abstract:
An FM demodulator circuit includes a filter (10) and a detector (14) for receiving a frequency modulated input signal and for providing a demodulated output signal. A tuning circuit (19) is provided for tuning the frequency characteristics of the filter and of the detector. A DC offset estimator (18) is connected to the output of the detector to produce an offset signal representing the estimated DC offset of the demodulated output signal, and to provide the offset signal to the tuning circuit. The tuning circuit is operable to tune the frequency characteristics of the filter and detector in dependence upon the offset signal.
Abstract:
A demodulator circuit for demodulating a frequency modulated input signal includes a filter (12) for receiving an incoming input signal and for providing a filtered output signal, a detector (16) for receiving the filtered output signal, and for producing a demodulated output signal therefrom, a tuning circuit (18, 20) which is operable to introduce a test signal into the demodulator circuit in the absence of an incoming input signal, and to vary the frequency response characteristics of at least one of the filter and detector in response to the test signal.
Abstract:
An apparatus and method for transmitting packets having quality of service requirement wherein the quality of service requirements associated with the packets are received at an input, said quality of service parameters include at least one of delay, bandwidth, peak bandwidth and retransmission bandwidth. The received quality of service parameters are mapped to radio protocol parameters including at least one of a priority slot interval, a priority slot phase, a packet duration and modulation format for the radio channel. The packets are transmitted on a radio channel according to the mapped radio protocol parameters.
Abstract:
To enhance in-building location determination of an electronic device, described is a system and a method that uses a blip access point to transfer location assistance information to the electronic device. The location assistance information may contain a map of dummy beacons that serve as reference points (e.g., landmarks) from which the electronic device may determine its location relative to the map information.
Abstract:
Wireless communication terminals and methods are disclosed that determine acoustic ranging synchronized to RF communication signals. A communication terminal can include a RF transceiver, a microphone, and a controller. The controller synchronizes a clock in response to known timing characteristics of received RF communication signals. The controller determines an acoustic signal generation time relative to the RF communication signal synchronized clock at which the other communication terminal will generate an acoustic signal. The controller determines an acoustic signal receipt time relative to the RF signal synchronized clock when the acoustic signal from the other communication terminal is detected in the microphone signal. The controller further determines a propagation time of the acoustic signal from the other communication terminal to the microphone based on a difference between the acoustic signal generation time and the acoustic signal receipt time, and determines a range to the other communication terminal in response to the propagation time of the acoustic signal.
Abstract:
Packet transmissions between a base station and terminals are performed using half-duplex uplink and downlink transmission intervals with adaptive intra-interval packet retransmission and packet expansion. The uplink and downlink transmission intervals used for communication with a terminal may be offset commensurate with a degree of symmetry of information flow between the terminal and the base station. The offset between the uplink and downlink transmission intervals may be adaptively adjusted based on a type of information being communicated between terminals and the base station. For example, different offsets may be used for voice and data communications. In some embodiments of the present invention, uplink and downlink transmission intervals for communications with a terminal have substantially equal durations. For example, voice packet transmissions between the base station and the terminal may use uplink and downlink transmission intervals having substantially equal durations.
Abstract:
A method and control device for generating a transmit power level for a communication apparatus for operation in a wireless communication network having a network node. The control device comprises a controller adapted to generate a request message for requesting access to a communication channel, to be transmitted to the network node. The control device is also adapted to determine whether access to the communication channel has been granted in response to the request message. A transmit power control unit is adapted to generate a transmit power level for the communication apparatus in dependence of whether access to the communication channel has been granted.