1. A VSB (Vestigial Sideband) demodulator configured to demodulate a VSB modulated signal including a plurality of fields each having a plurality of segments, the plurality of fields each having as one of the plurality of segments a field synchronization component containing a predetermined PN (Pseudo Noise) sequence, the plurality of segments each having a segment synchronization component having predetermined four symbols, the VSB demodulator comprising:
a channel estimation section configured to perform a convolution operation between the VSB modulated signal and the predetermined PN sequence, and generate a timing signal synchronous with the segment synchronization components of the VSB modulated signal according to results of the operation;
a phase variation detection section configured to detect a phase error in the VSB modulated signal in accordance with timing indicated by the timing signal, and output a detection signal corresponding to variation in the detected phase error; and
a waveform equalization section, including a filter, configured to update a coefficient of the filter and perform waveform equalization on the VSB modulated signal,
wherein the waveform equalization section increases a coefficient update gain for the filter when the detection signal indicates that the variation in the phase error is larger than a predetermined value.
2. The VSB demodulator of claim 1, wherein the phase variation detection section detects as the phase error a difference between in-phase components of second and third symbols of the symbols included in the segment synchronization component.
3. The VSB demodulator of claim 1, wherein the phase variation detection section detects the phase error by using the segment synchronization component of a segment other than the segment that is the field synchronization component.
4. The VSB demodulator of claim 1, wherein the channel estimation section further generates as the timing signal a signal which is synchronous with the segment synchronization components or a delayed signal of the VSB modulated signal.
5. A television receiver comprising:
a tuner section configured to receive a VSB modulated high-frequency signal, tune the received high-frequency signal, convert the tuned signal into a baseband signal, and output a resultant VSB modulated signal, the high-frequency signal having been VSB-modulated in such a manner that the high-frequency signal includes a plurality of fields each having a plurality of segments, and that the plurality of fields each include as one of the plurality of segments a field synchronization component containing a predetermined PN sequence, and that the plurality of segments each have a segment synchronization component having predetermined four symbols;
the VSB demodulator of claim 1 configured to demodulate the VSB modulated signal output from the tuner section; and
a back end section configured to decode results of demodulation performed by the VSB demodulator, and output a resultant videoaudio signal.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A device for the UV treatment of fluids flowing in a flow channel, comprising;
a plurality of UV emitters that are disposed in the flow channel;
at least one UV sensor adapted to monitor an operating state of the UV emitters;
at least one power supply means for supplying power to said UV emitters, wherein said at least one power supply means is configured to modulate an operating voltage, for individual ones of said emitters or groups of said emitters, that is supplied to said emitters during operation; and
at least one unit, connected with said at least one UV sensor, for monitoring said UV emitters, wherein said at least one unit is configured to evaluate a modulation contained in UV radiation emitted by said UV emitters.
2. A device according to claim 1, wherein said UV emitters are low-pressure mercury UV emitters.
3. A device according to claim 2, wherein said low-pressure UV emitters are amalgam-type emitters.
4. A device according to claim 1, wherein the operating voltage for each of said UV emitters is adapted to be modulated individually.
5. A device according to claim 1, wherein the modulation is an amplitude modulation.
6. A device according to claim 1, wherein evaluation of the modulation is adapted to be effected by means of a Fourier transformation.
7. A device according to claim 1, wherein said UV emitters are adapted to be switched off individually for purposes of calibration.
8. A method of operating a UV disinfection device provided with at least one UV emitter, including the steps of:
supplying at least one UV emitter with an operating voltage for a firing and continuous operation thereof;
modulating said operating voltage, an operating current, or an electrical power of at least one of said UV emitters;
detecting UV radiation emitted by said at least one UV emitter with a UV sensor that is adapted to temporally resolve the modulation;
evaluating a signal recorded by said UV sensor; and
checking whether the modulation in a signal given off by said UV sensor corresponds to a desired value.
9. A method according to claim 8, wherein said modulating step comprises carrying out modulation differently for each UV emitter.
10. A method according to claim 8, wherein during operation said UV emitters are operated in a substantially unmodulated manner, and wherein for checking an individual emitter, only such individual emitter is supplied with modulated operating voltage.
11. A method according to claim 10, wherein said modulating step is carried out successively for all of said UV emitters.
12. A method according to claim 10, wherein said modulating step is repeated cyclically.
13. A method according to claim 8, wherein for low-pressure mercury UV emitters, the operating voltage has a natural frequency in the range of from 20 kHz to 1 MHz, and wherein modulation of the operating voltage is in the form of amplitude modulation at frequencies of from 100 Hz to 100 kHz.
14. A method according to claim 8, wherein adjacent ones of said UV emitters may be combined into groups, wherein emitters of a given group may be jointly modulated at similar frequencies.
15. A method according to claim 14, wherein the emitters of a given group may be jointly modulated at frequencies that are adjacent in a frequency grid.