摘要:
In a frequency generating system, a triple/single local-oscillator concept for receiving and transmitting in the lower frequency band, transmitting in the upper frequency band, and receiving in the upper frequency band is used for a dual-band transceiver so that a single band-switched VCO can be used as local oscillator for setting the frequency in all four possible operating cases. The system can be used, for example, in highly integrated dual-band mobile parts for GSM 900/1800 mobile radio.
摘要:
Offset voltage compensation in baseband in a radio receiver path is achieved by control and programming signals which are required in any case to set the desired states in the circuit module. For this purpose a sequencer is started which is integrated on the module and provides additional control signals that are defined in time, without any additional computation power being required from a separate baseband processor. The offset voltage compensation can be used in receiver and transceiver chips for portable mobile radios, for example for GSM or PCN/PCS.
摘要:
In a digital phase-frequency detector with anti-backlash pulses, which prevent the mapping of very short correction pulses occurring on the basis of small phase differences by use of an AND logic circuit controlling the RESET of two flip flop circuits, a waste time is shortened by reducing a duration of the RESET pulse. The integrable phase-frequency detector according to the invention can be used in fast digital phase-locked control loops, for example for tuners, frequency synthesizers in the field of mobile radio.
摘要:
A method for searching for a radio cell is provided comprising determining, for each of a plurality of frequencies, a reception strength value indicating the reception strength within a first bandwidth around the frequency, wherein the first bandwidth is smaller than a second bandwidth with which a radio cell to be searched is operated; determining, based on the determined reception strength values, a spectral position for a radio cell at which a cell search is to be carried out; and carrying out a cell search at the determined spectral position.
摘要:
The present application relates to embodiments of methods and a device for digital modulation. In a first embodiment of the method, the following steps are executed: determining a polarity of the signal, providing an inverted carrier signal, providing an inverted signal by an inversion of the polarity of at least one portion of the signal, mixing the signal with the carrier signal when the signal has the first polarity, and mixing the inverted signal with the inverted carrier signal when the signal has the second polarity.
摘要:
A method for searching for a radio cell is provided comprising determining, for each of a plurality of frequencies, a reception strength value indicating the reception strength within a first bandwidth around the frequency, wherein the first bandwidth is smaller than a second bandwidth with which a radio cell to be searched is operated; determining, based on the determined reception strength values, a spectral position for a radio cell at which a cell search is to be carried out; and carrying out a cell search at the determined spectral position.
摘要:
Some embodiments of the present disclosure relate to multiband receivers that include at least one divider unit having a divisor that is other-than-two. For example, in some embodiments the divisor is an odd integer (e.g., three). Such divisors allow oscillators for respective receiver subunits in a multi-band receiver to have frequencies that are sufficiently different from one another so as to limit cross-talk interference there between, even when the receiver subunits are concurrently receiving data on adjacent channels. To facilitate this other-than-two divisor, a phase error compensation block is often used to compensate for the effects of using the other-than-two divisor.
摘要:
The invention is related to a data frame, particularly to a data frame configured to be received and processed by an RF-transceiver and a data frame structure. The invention is also related to a method for controlling an RF-transceiver.
摘要:
The invention relates to a polar transmission apparatus having a polar transformer for transformation of a baseband signal to an amplitude signal and a phase signal. The apparatus includes a frequency synthesizer for production of a radio-frequency signal from the phase signal, having a modulator for amplitude modulation of the radio-frequency signal. The modulation is selectively carried out either by a mixer mixing the radio-frequency signal with the amplitude signal or by an amplifier amplifying the radio-frequency signal and modulating the gain with the amplitude signal.
摘要:
A two-point modulator arrangement is specified, said arrangement being developed with respect to conventional two-point modulators to the effect that the high-pass coupling-in point of the modulator that comprises a phase locked loop is formed by an expanded loop filter. In accordance with the present principle, the expanded loop filter comprises a coupling-in element, at which the modulation signal is combined with the output signal of a phase comparator. A voltage-controlled oscillator having only one tuning input can thus advantageously be used.