摘要:
A PLL circuit (1) is regulated by means of a digital modulation signal (28) at a first frequency, and is then regulated at a second frequency, by deactivation of the digital modulation signal (28). A difference signal (32), which is characteristic of the voltage change in a control signal (22) for the VCO (7) which is produced by deactivation of the digital modulation signal (28) is compared with an analog modulation signal (34). The analog modulation signal (34) is changed so as to correct any discrepancy determined during the comparison.
摘要:
The invention relates to an apparatus and a method for ascertaining and correcting the optimum sampling time for an oversampled input bit stream. This involves feeding the data bit blanked with the current sampling phase into the comparative sequence and using the data bit to ascertain a new, corrected sampling phase. This decision-based approach enables the sampling phase to be continuously corrected.
摘要:
The present invention provides a method for automatic identification of the clock frequency of a system clock (15) for the configuration of a peripheral device (12), having the following steps: generation of a secondary clock (16) at a predetermined clock frequency; application of the system clock (15) and of the secondary clock (16) to a host (10); application of the system clock (15) and of the secondary clock (16) to the peripheral device (12); determination of the clock frequency of the system clock (15) in the peripheral device (12) by means of the secondary clock (16); and configuration of the peripheral device (12) using the determined system clock (15).
摘要:
In the case of a trimming method for a PLL circuit operating based on the principle of a two-point modulation, the PLL circuit is locked without any modulation being impressed and then an analog and a digital modulation signal are impressed into the locked PLL circuit. A signal that is characteristic of the PLL control error is tapped from the PLL circuit, and the modulation swing in the analog modulation signal is changed such that the characteristic signal has the same value as before the analog and digital modulation signals were impressed.
摘要:
Apparatus (20) having two devices (21, 22) which can be connected to one another via an interface (23, 24), where the devices (21, 22) each have an activation unit which, upon receipt of a control signal at a control input, prompts the respective device (21, 22) to change over from a standby mode to an active mode, and where the control signal is transmitted by the respective other device (21, 22), and the control input in one device (21) is an interface connection and, in the other device (22), is located outside the interface (23, 24).
摘要:
A PLL circuit is tuned to a first frequency by using a first digital modulation signal and subsequently tuned to a second frequency by using a second digital modulation signal. A differential signal, that is a function of the change in voltage of a VCO control signal generated by the modulation signals, is compared with a comparison signal, that is characteristic of the analog modulation amplitude. Based on the comparison the analog modulation amplitude is changed to minimize or substantially eliminate a deviation between the signals.
摘要:
The present invention provides a two-point modulator arrangement with a PLL that can be operated at various reference frequencies. A modulation signal provided by a digital signal processor is supplied as an analog signal at the input of the oscillator in the PLL and as a digital modulation signal on a frequency divider. For the purpose of pulse shaping the digital modulation data, a digital filter is provided that is coupled to the control input of the frequency divider and, in line with the principle proposed, is operated at the same, constant clock frequency as the signal processor, regardless of the reference frequency. As a result, no resynchronization of the digital modulation data is necessary upstream of the digital filter.
摘要:
In a method for demodulating a CPFSK-modulated signal, the n−1-th substitute symbol an−1 which occurs in the linear approximation of the CPFSK is estimated in order to determine an n-th input data symbol dn on which the CPFSK modulation is based. The n−1-th substitute symbol an−1 is in this case estimated on the basis of the previously determined n−1-th input data symbol {circumflex over (d)}n−1.
摘要:
One embodiment of the present invention relates to a combined mixer filter circuit. The circuit includes a sampler, a plurality of filter branches, and a coefficient generator. The sampler is configured to provide a sampled signal by sampling a received signal at a specified rate. The plurality of filter branches has selectable filter coefficients. The plurality of filter branches are configured to receive the sampled signal and generate a mixed and filtered output signal without a separate mixer component. The coefficient generator is coupled to the plurality of filter branches. The coefficient generator is configured to assign filter coefficient values to the selectable filter coefficients to yield a selected mixing function for the mixed filtered output signal.
摘要:
The method is based on a signal interval (DB) which comprises a first part (ET) (which is modulated using a first modulation method (GFSK)) of the signal interval and a second part (which is modulated using a second modulation method (DMPSK)) of the signal interval. The channel parameters (c(i)) relating to the second part (which is modulated using the second modulation method) of the signal interval are determined using a received data signal (a(i); p(i)) from the first part (ET) of the signal interval (DB).