Method for transmitting an analog data stream with prevention of secondary minima, and circuit arrangement

1. A method for transmitting an analog data stream, the method having the following steps:

a) receiving the analog data stream via a transmission channel in a data stream receiver;

b) converting the received analog data stream into a digital data stream by sampling the analog data stream with a sampling rate in an analog/digital converter;

c) decimating the digital data stream in a decimation device in order to provide a decimated digital data stream;

d) deriving a control signal from either the digital data stream or the decimated digital data stream according to a predeterminable adjustment of a switching device;

e) supplying the derived control signal to a coefficient determining device;

f) supplying a reference signal, input via a reference signal input device, to the coefficient determining device;

g) determining at least one coefficient of an equalizer by means of the coefficient determining device in dependence on the reference signal supplied and in dependence on the control signal supplied;

h) equalizing the decimated digital data stream in the time domain in the equalizer to which at least one determined coefficient has been applied, in order to provide an equalized decimated digital data stream;

i) transforming the decimated equalized digital data stream from the time domain into the frequency domain by means of a transformation device, in order to provide transformation signals which are defined in amount and phase;

j) correcting the transformation signals in a correction device in order to provide corrected transformation signals;

k) determining at least one amount signal and at least one phase signal from at least one corrected transformation signal in a determining device;

l) decoding the at least one amount signal determined in the determining device and the at least one phase signal in a decoding device in order to provide a decoded data stream; and

m) outputting the decoded data stream via a data output device.

2. The method as claimed in claim 1 , wherein a suitable control signal is selected by means of the switching device.

3. The method for transmitting an analog data stream as claimed in claim 1 , wherein the analog data stream is oversampled at a sampling rate.

4. The method for transmitting an analog data stream as claimed in claim 1 , wherein the decimated digital data stream is sampled at a predeterminable rate in the equalizer.

5. The method for transmitting an analog data stream as claimed in claim 1 , wherein the reference signal is provided for determining a channel transfer function of the transmission channel.

6. The method for transmitting an analog data stream as claimed in claim 1 , wherein a fast Fourier transformation is used for transforming the decimated equalized digital data stream from the time domain into the frequency domain.

7. The method for transmitting an analog data stream as claimed in claim 1 , wherein the transformation signals are weighted with an inverse channel transfer function of the transmission channel for correcting the transformation signals in a correction device in order to provide corrected transformation signals.

8. The method for transmitting an analog data stream as claimed in claim 1 , wherein a transformation signal pair formed of an amount signal and a phase signal is in each case provided during a determination of the at least one amount signal and of the at least one phase signal from at least one corrected transformation signal in a determining device.

9. A circuit arrangement for transmitting an analog data stream, comprising:

a) a transmission channel for transmitting the analog data stream from a data stream transmitter to a data stream receiver;

b) an analog/digital converter arranged in the data stream receiver for converting the received analog data stream into a digital data stream by sampling the analog data stream at a sampling rate;

c) a decimation device for decimating the digital data stream in order to provide a decimated digital data stream;

d) a switching device which provides either an information item from the digital data stream or an information item from the decimated digital data stream as a control signal in dependence on an externally predeterminable switching signal;

e) in dependence on the control signal applied, a coefficient determining device for determining equalization coefficients which is applied to an equalizer;

f) a reference signal input device for inputting a reference signal which is provided for the coefficient determining device in order to provide the coefficient determining device with information on the channel transfer function of the transmission channel;

g) an equalizer for equalizing the digital data stream in the time domain in order to provide an equalized digital data stream;

h) a transformation device for transforming the decimated equalized digital data stream from the time domain into the frequency domain in order to provide transformation signals which are defined by amount and phase;

i) a correction device for correcting the transformation signals in order to provide corrected transformation signals;

j) a determining device for determining at least one amount signal and at least one phase signal from at least one corrected transformation signal;

k) a decoding device for decoding the at least one amount signal and of the at least one phase signal determined in the determining device, in order to provide a decoded data stream; and

l) a data output device for outputting the decoded data stream.

10. The circuit arrangement for transmitting an analog data stream as claimed in claim 9 , wherein the equalizer exhibits a variable adjustable filter order.

11. The circuit arrangement for transmitting an analog data stream as claimed in claim 9 , wherein the equalizer is constructed as a frequency domain equalizer for correcting the transformation signals in a correction device in order to provide corrected transformation signals.