摘要:
A phase locked loop is disclosed and includes a frequency divider circuit with a settable division ratio in a feedback path. The division ratio is produced using a control circuit which, besides an input for supplying the integer and fractional components for the frequency division ratio which is to be set, includes an input for supplying a phase correction signal. To produce the phase correction signal, the phase locked loop further includes a phase correction apparatus. The phase correction signal preferably contains a signal component with an exponential profile, and is supplied to the control circuit for producing a frequency division ratio for the frequency divider circuit such that it compensates for a phase drift in the output signal from the voltage controlled oscillator in the phase locked loop.
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.
摘要:
A radio-frequency IC (3) for a mobile radio transmitter (1) has an analogue/digital converter unit (5) for digitizing baseband signals (AB), a recovery unit (6, 7, 8, 9, 10) for recovering determined data information (Rot, TxSymbPhase) on which the baseband signals (AB) are based, a digital/analogue converter unit (11) and a frequency converter unit for producing transmitted signals on the basis of the signals produced by the digital/analogue converter unit (11).
摘要:
One embodiment of the present invention relates to an adaptive filtering apparatus comprising first and second real valued adaptive filters, respectively configured to receive an adaptive filter input signal based upon a transmission signal in a transmission path. The first real valued adaptive filter is configured to operate a real valued adaptive filter algorithm on the input signal to estimate a first intermodulation noise component (e.g., an in-phase component) in a desired signal and to cancel the estimated noise. The second real valued adaptive filter is configured to operate a real valued adaptive filter algorithm on the input signal to estimate a second intermodulation noise component (e.g., a quadrature phase component) in the desired signal and to cancel the estimated noise. Accordingly, each filter operates a real valued adaptive algorithm to cancel a noise component, thereby removing complex cross terms between the components from the adaptive filtering process.
摘要:
A loop filter includes an input terminal, an output terminal, and a control terminal for a selection signal. At least one low pass filter is disposed between that input terminal and that output terminal. The loop filter is adapted to select a configuration out of a first configuration and at least one second configuration in response to the selection signal. In the first configuration, the loop filter comprises a non-integrating transfer characteristic in operation. In the second configuration, the loop filter comprises an integrating signal transfer characteristic in operation.
摘要:
A radio-frequency IC (3) for a mobile radio transmitter (1) has an analogue/digital converter unit (5) for digitizing baseband signals (AB), a recovery unit (6, 7, 8, 9, 10) for recovering determined data information (Rot, TxSymbPhase) on which the baseband signals (AB) are based, a digital/analogue converter unit (11) and a frequency converter unit for producing transmitted signals on the basis of the signals produced by the digital/analogue converter unit (11).
摘要:
A frequency-dividing circuit arrangement is disclosed that includes a divider chain having a plurality of frequency divider stages. The frequency dividers can be changed over between the division ratios 2 and 3. At least that frequency divider that is arranged on the output side of the divider chain has an additional through-switching input that makes it possible to switch through the input signal to the output of the divider stage without influencing the delay-time effects of the divider stage. The advantages of a cascaded 2/3 divider chain, such as a high cut-off frequency, a simple design and the ability to arbitrarily expand, are thus achieved without accepting a lower limit of the range of possible division values.
摘要:
The invention provides an interface apparatus for data recovery which supplies an analog signal (applied to the input and containing data in line with a coding) having a first component and a second component to a signal processor. From this, the signal processor produces a continuous, demodulated data stream. The data stream is supplied to a connected delay unit, whose output is designed to provide the stored data symbols and whose delay in provision can be set by a signal at a control input. The interface allows a digital modulator to be connected to an analog I/Q interface on a baseband unit.
摘要:
A phase-locked loop suitable for mobile radio communications and a method for operating the same is disclosed. One embodiment of the phase-locked loop comprises an oscillator, a counter, a comparator, and a delay arrangement. The counter comprises a first input connected to the oscillator, a second input connected to a reference frequency terminal, and an output. An input of the comparator is connected to the output of the counter and an output of the comparator to the oscillator. The delay arrangement is connected between the oscillator and the first input of the counter or between the reference frequency terminal and the second input of the counter. The delay arrangement delays an input signal sent to an input of the delay arrangement, as a function of a sequence signal and makes a delayed signal available at an output of the delay arrangement.
摘要:
A phase-locked loop suitable for mobile radio communications and a method for operating the same is disclosed. One embodiment of the phase-locked loop comprises an oscillator, a counter, a comparator, and a delay arrangement. The counter comprises a first input connected to the oscillator, a second input connected to a reference frequency terminal, and an output. An input of the comparator is connected to the output of the counter and an output of the comparator to the oscillator. The delay arrangement is connected between the oscillator and the first input of the counter or between the reference frequency terminal and the second input of the counter. The delay arrangement delays an input signal sent to an input of the delay arrangement, as a function of a sequence signal and makes a delayed signal available at an output of the delay arrangement.