Method and apparatus for estimating channel length in wired communication system

1. A method for estimating a length of a channel in a wired communication system, comprising:

receiving a plurality of signals transmitted continuously via the channel;

determining a relation between a signal and at least one previous signal in the plurality of signals, to generate a decision result; and

determining the length of the channel according to the decision result;

wherein the step of determining the relation between the signal and the at least one previous signal in the plurality of signals to generate the decision result comprises utilizing an autoregressive model to describe the signal with the at least one signal, and outputting a corresponding autocorrelation function of the autoregressive model as the decision result.

2. The method of claim 1 , wherein the step of determining the length of the channel according to the decision result comprises comparing the decision result with a plurality of predefined experimental results to determine the length of the channel.

3. An electronic device for estimating a length of a channel in a wired communication system, comprising:

a reception terminal, for receiving a plurality of signals transmitted continuously via the channel;

a first decision unit, for determining a relation between a signal and at least one previous signal in the plurality of signals, to generate a decision result; and

a second decision unit, for determining the length of the channel according to the decision result;

wherein the first decision unit utilizes an autoregressive model to describe the signal with the at least one signal, and outputs a corresponding autocorrelation function of the autoregressive model as the decision result.

4. The electronic device of claim 3 , wherein the second decision unit compares the decision result with a plurality of predefined experimental results to determine the length of the channel.

5. A method for processing received signals in a wired communication system, comprising:

receiving a plurality of analog signals transmitted continuously via a channel;

performing a low-pass filtering operation on the plurality of analog signals, to generate a plurality of low-pass analog signals;

converting the plurality of low-pass analog signals into a plurality of digital signals;

determining a relation between a digital signal and at least one previous digital signal in the plurality of digital signals, to generate a decision result;

determining a length of the channel according to the decision result; and

determining to utilize the low-pass filtering operation or a band-pass filtering operation to process analog signals received after the plurality of analog signals according to the length of the channel.

6. The method of claim 5 , wherein the step of determining the relation between the digital signal and the at least one previous digital signal in the plurality of digital signals to generate the decision result comprises utilizing an autoregressive model to describe the digital signal with the at least one digital signal, and outputting a corresponding autocorrelation function of the autoregressive model as the decision result.

7. The method of claim 5 , wherein the step of determining the length of the channel according to the decision result comprises comparing the decision result with a plurality of predefined experimental results to determine the length of the channel.

8. A reception device in a wired communication system comprising:

a reception terminal, for receiving a plurality of analog signals transmitted continuously via a channel;

a filter module, for performing a low-pass filtering operation or a band-pass filtering operation on the plurality of analog signals according to a control signal, to output a plurality of low-pass analog signals or a plurality of band-pass analog signals;

an analog to digital converter (ADC), for converting analog signals outputted by the filter module into a plurality of digital signals; and

a channel length estimation module, coupled to the ADC, comprising:

a first decision unit, for determining a relation between a digital signal and at least one previous digital signal in the plurality of digital signals, to generate a decision result;

a second decision unit, for determining a length of the channel according to the decision result; and

a control signal generator, for outputting the control signal according to the length of the channel, so as to determine to utilize the low-pass filtering operation or the band-pass filtering operation to process following analog signals.

9. The reception device of claim 8 , wherein the first decision unit utilizes an autoregressive model to describe the digital signal with the at least one digital signal, and outputs a corresponding autocorrelation function of the autoregressive model as the decision result.

10. The reception device of claim 8 , wherein the second decision unit compares the decision result with a plurality of predefined experimental results to determine the length of the channel.

11. The reception device of claim 8 , wherein the filter module comprises:

a low-pass filter, for performing the low-pass filtering operation on the plurality of analog signals, so as to generate the plurality of low-pass analog signals;

a high-pass filter, for performing a high pass filtering operation on the plurality of low-pass analog signals, so as to perform the band-pass filtering operation on the plurality of analog signals, and generate the plurality of band-pass analog signals; and

a multiplexer, coupled to the low-pass filter, the high-pass filter and the ADC, for outputting the plurality of low-pass analog signals or the plurality of band-pass analog signals according to the control signal.

12. The reception device of claim 8 , wherein the control signal generator controls the filter module to output the plurality of low-pass analog signals via the control signal before the second decision unit determines the length of the channel.

13. The reception device of claim 8 , wherein the control signal generator controls the filter module to output the plurality of band-pass analog signals via the control signal when the length of the channel, determined by the second decision unit, is greater than a predefined value.