Receiving device, equalizer module and signal processing method

Abstract

This disclosure provides a receiving apparatus comprising: an equalizer for encoding a multi-order pulse amplitude modulated signal sample into an intermediate mapping symbol, wherein the LSB of the intermediate mapping symbol represents a positive or negative sign, and at least one MSB of the intermediate mapping symbol represents the absolute value of the signal amplitude; and a demapper for demapping the intermediate mapping symbol and outputting a restored encoded symbol.

Claims

1. A receiving device, comprising: an equalizer for encoding a multi-order pulse amplitude modulated signal sample into an intermediate mapping symbol, wherein, The intermediate mapping symbol has an LSB representing the positive or negative polarity of the signal sample, and at least one MSB representing the absolute value range of the amplitude of the signal sample; and a demapper for demapping the intermediate mapping symbol to output a restored coded symbol.

2. The receiving apparatus as claimed in claim 1, wherein the multi-order pulse amplitude modulation system is a fourth-order pulse amplitude modulation system.

3. The receiving device as described in claim 2, wherein, When the potential of the signal sample is greater than a first threshold, the intermediate mapping symbol is 11; when the potential of the signal sample is greater than a second threshold and less than the first threshold, the intermediate mapping symbol is 01; when the potential of the signal sample is greater than the third threshold and less than the second threshold, the intermediate mapping symbol is 00; and when the potential of the signal sample is less than the third threshold, the intermediate mapping symbol is 10.

4. The receiving apparatus as claimed in claim 2, wherein the demapping performed by the demapping unit comprises: outputting the restored encoding symbol as 11 when the intermediate mapping symbol is 11; outputting the restored encoding symbol as 10 when the intermediate mapping symbol is 01; outputting the restored encoding symbol as 01 when the intermediate mapping symbol is 00; and outputting the restored encoding symbol as 00 when the intermediate mapping symbol is 10.

5. The receiving device as claimed in claim 1, wherein, When the potential of the signal sample is greater than an intermediate reference value, the LSB of the intermediate mapped symbol is 1; and when the potential of the signal sample is less than the intermediate reference value, the LSB of the intermediate mapped symbol is 0.

6. The receiving device as claimed in claim 5, wherein, The at least one MSB of the intermediate mapping symbol represents the absolute value of the potential of the signal sample relative to the intermediate reference value.

7. The receiving apparatus as claimed in claim 1, wherein the equalizer is a decision feedback equalizer (DFE), the receiving apparatus further comprising: a continuous time linear equalizer (CTLE) coupled to the decision feedback equalizer; a deserializer for deserializing the restored encoded symbol; and a clock data recovery circuit coupled to the decision feedback equalizer, the demapping unit and the deserializer.

8. An equalizer module, comprising: a plurality of decision units for encoding a multi-order pulse amplitude modulated signal sample into an intermediate mapping symbol, wherein, The intermediate mapping symbol has an LSB representing the positive or negative polarity of the signal sample, and at least one MSB representing the absolute value range of the amplitude of the signal sample; and a demapper for demapping the intermediate mapping symbol to output a restored coded symbol.

9. The equalizer module as claimed in claim 8, wherein the multi-order pulse amplitude modulation system is a fourth-order pulse amplitude modulation system.

10. The equalizer module as described in claim 9, wherein, When the potential of the signal sample is greater than a first threshold, the intermediate mapping symbol is 11; when the potential of the signal sample is greater than a second threshold and less than the first threshold, the intermediate mapping symbol is 01; when the potential of the signal sample is greater than the third threshold and less than the second threshold, the intermediate mapping symbol is 00; and when the potential of the signal sample is less than the third threshold, the intermediate mapping symbol is 10.

11. The equalizer module as claimed in claim 9, wherein the demapping performed by the demapping includes: outputting the restored encoding symbol as 11 when the intermediate mapping symbol is 11; outputting the restored encoding symbol as 10 when the intermediate mapping symbol is 01; outputting the restored encoding symbol as 01 when the intermediate mapping symbol is 00; and outputting the restored encoding symbol as 00 when the intermediate mapping symbol is 10.

12. The equalizer module as described in claim 8, wherein, When the potential of the signal sample is greater than an intermediate reference value, the LSB of the intermediate mapped symbol is 1; and when the potential of the signal sample is less than the intermediate reference value, the LSB of the intermediate mapped symbol is 0.

13. The equalizer module as described in claim 12, wherein, The at least one MSB of the intermediate mapping symbol represents the absolute value of the potential of the signal sample relative to the intermediate reference value.

14. A signal processing method, comprising: encoding a multi-order pulse amplitude modulated signal sample into an intermediate mapping symbol, wherein, The LSB of the intermediate mapping symbol represents the positive or negative polarity of the signal sample, and at least one MSB of the intermediate mapping symbol represents the absolute value range of the amplitude of the signal sample; and the intermediate mapping symbol is demapped to output a restored coded symbol.

15. The method as described in claim 14, wherein the multi-order pulse amplitude modulation system is a fourth-order pulse amplitude modulation system.

16. The method as described in claim 15, wherein, When the potential of the signal sample is greater than a first threshold, the intermediate mapping symbol is 11; when the potential of the signal sample is greater than a second threshold and less than the first threshold, the intermediate mapping symbol is 01; when the potential of the signal sample is greater than the third threshold and less than the second threshold, the intermediate mapping symbol is 00; and when the potential of the signal sample is less than the third threshold, the intermediate mapping symbol is 10.

17. The method of claim 15, wherein the demapping comprises: outputting the decoded symbol as 11 when the intermediate mapping symbol is 11; outputting the decoded symbol as 10 when the intermediate mapping symbol is 01; outputting the decoded symbol as 01 when the intermediate mapping symbol is 00; and outputting the decoded symbol as 00 when the intermediate mapping symbol is 10.

18. The method as described in claim 14, wherein, When the potential of the signal sample is greater than an intermediate reference value, the LSB of the intermediate mapped symbol is 1; and when the potential of the signal sample is less than the intermediate reference value, the LSB of the intermediate mapped symbol is 0.

19. The method as described in claim 18, wherein, The at least one MSB of the intermediate mapping symbol represents the absolute value of the potential of the signal sample relative to the intermediate reference value.

20. The method of claim 14, wherein the encoding step is performed using a decision feedback equalizer (DFE), the method further comprising: processing the multi-stage pulse amplitude modulated signal sample with a continuous time linear equalizer (CTLE); and deserializing the restored encoded symbol.

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