An integrated circuit device includes a digitally controlled oscillator (DCO), two charge-sharing capacitors, two charge-sharing switches, two pre-charge switches, and two DACs. The DCO has a first inverter and a second inverter. A first charge-sharing capacitor has a first terminal coupled to an input terminal of the first inverter through a first charge-sharing switch. A first DAC has an output terminal coupled to the first terminal of the first charge-sharing capacitor through a first pre-charge switch. A second charge-sharing capacitor has a first terminal coupled to an input terminal or an output terminal of the second inverter through a second charge-sharing switch. A second DAC has an output terminal coupled to the first terminal of the second charge-sharing capacitor through a second pre-charge switch.

A signal conversion from an input signal to an output signal where the filter used is factorized so that the conversion comprises determining 1) only a first factor at each sampling time of the input signal, where this first factor is independent on the sampling times of the output signal, and 2) only a second factor at each sampling time of the output signal, where this second factor is independent of the sampling times of the input signal. This reduces the computational load for this conversion. In addition, for most filters, the factors may be calculated recursively further increasing the computational load and also reducing the storage requirements. This allows for instantaneous changes in the sampling rates or non-uniform sampling rates with low computational requirements and low memory usage.

A digital filter circuit for filtering at least two input signals having different signal data rates is described. The digital filter circuit includes an input multiplexer sub-circuit, a digital filter, and an output multiplexer sub-circuit. The digital filter is connected to the input multiplexer sub-circuit downstream of the input multiplexer sub-circuit. The digital filter is connected to the output multiplexer sub-circuit upstream of the output multiplexer sub-circuit. The input multiplexer sub-circuit is configured to receive the at least two input signals having different signal data rates. The input multiplexer sub-circuit is configured to selectively forward the at least two input signals to the digital filter. The digital filter is configured to filter the at least two input signals, thereby obtaining at least two filtered input signals. The output multiplexer sub-circuit is configured to selectively output the at least two filtered input signals. Further, a measurement instrument and a signal processing method are described.

A digital filter circuit for filtering at least two input signals having different signal data rates is described. The digital filter circuit includes an input multiplexer sub-circuit, a digital filter, and an output multiplexer sub-circuit. The digital filter is connected to the input multiplexer sub-circuit downstream of the input multiplexer sub-circuit. The digital filter is connected to the output multiplexer sub-circuit upstream of the output multiplexer sub-circuit. The input multiplexer sub-circuit is configured to receive the at least two input signals having different signal data rates. The input multiplexer sub-circuit is configured to selectively forward the at least two input signals to the digital filter. The digital filter is configured to filter the at least two input signals, thereby obtaining at least two filtered input signals. The output multiplexer sub-circuit is configured to selectively output the at least two filtered input signals. Further, a measurement instrument and a signal processing method are described.

Filter circuitry is constituted by transversal filters which are connected in parallel to each other. The transversal filters change amplitude and a phase of an input digital signal X.sub.in[n.Math.T.sub.s] and output different digital signals X.sub.1[n.Math.T.sub.s], X.sub.2[n.Math.T.sub.s], and X.sub.3[n.Math.T.sub.s] as respective resulting digital signals whose amplitude and phase have been changed. A phase frequency computer computes a phase θ.sub.X[n.Math.T.sub.s] and a frequency f.sub.X[n.Math.T.sub.s] of the input digital signal X.sub.in[n.Math.T.sub.s] by performing phase computation and frequency computation using the digital signals X.sub.1[n.Math.T.sub.s], X.sub.2[n.Math.T.sub.s], and X.sub.3[n.Math.T.sub.s] output by the transversal filters.

Filter circuitry is constituted by transversal filters which are connected in parallel to each other. The transversal filters change amplitude and a phase of an input digital signal X.sub.in[n.Math.T.sub.s] and output different digital signals X.sub.1[n.Math.T.sub.s], X.sub.2[n.Math.T.sub.s], and X.sub.3[n.Math.T.sub.s] as respective resulting digital signals whose amplitude and phase have been changed. A phase frequency computer computes a phase θ.sub.X[n.Math.T.sub.s] and a frequency f.sub.X[n.Math.T.sub.s] of the input digital signal X.sub.in[n.Math.T.sub.s] by performing phase computation and frequency computation using the digital signals X.sub.1[n.Math.T.sub.s], X.sub.2[n.Math.T.sub.s], and X.sub.3[n.Math.T.sub.s] output by the transversal filters.

Systems and methods for interrogating sensing systems utilising bursts of samples. Bursts of samples correspond to optical pulses returning from optical sensors, where pulses are spaced at a period significantly longer than the pulse width, giving irregular sample spacing. The interrogation system and method processes the irregular busts of samples to recover phase information from received signals.

Provided is a digital filter circuit in which a filter coefficient can be easily changed, for which circuit scale and power consumption can be reduced, and which carries out digital filter processing in a frequency domain. This digital filter circuit includes: a separating circuit for separating a first complex number signal, of a frequency domain that was subjected to Fourier transform, into a real number portion and an imaginary number portion; a filter coefficient generating circuit for generating a first frequency domain filter coefficient from a first input filter coefficient and a third input filter coefficient, and for generating a second frequency domain filter coefficient from a second input filter coefficient and the third input filter coefficient; a first filter that filters the separated real number portion using the first frequency domain filter coefficient; a second filter that filters the separated imaginary number portion using the second frequency domain filter coefficient; and a combining circuit for combining the output from the two filters.

There is provided mechanisms for enabling linearization of a non-linear electronic device. A method is performed by a linearizer device. The method comprises receiving an input signal destined to be input to the non-linear electronic device. Input-output characteristics of the non-linear electronic device is represented by a model. The model is defined by a mathematical expression, and wherein input-output characteristics of the linearizer device is given by the linearization function. The linearization function is determined by applying a function recursion to the mathematical expression of the model. The method comprises obtaining an output signal by subjecting the input signal to the linearization function. The method comprises providing the output signal, instead of the input signal, as input to the non-linear electronic device, thereby enabling linearization of the non-linear electronic device.

There is provided mechanisms for enabling linearization of a non-linear electronic device. A method is performed by a linearizer device. The method comprises receiving an input signal destined to be input to the non-linear electronic device. Input-output characteristics of the non-linear electronic device is represented by a model. The model is defined by a mathematical expression, and wherein input-output characteristics of the linearizer device is given by the linearization function. The linearization function is determined by applying a function recursion to the mathematical expression of the model. The method comprises obtaining an output signal by subjecting the input signal to the linearization function. The method comprises providing the output signal, instead of the input signal, as input to the non-linear electronic device, thereby enabling linearization of the non-linear electronic device.