Efficient ethernet multi-mode coding and modulation for twisted-pair

• US 10,644,834 B1
• Filed: 07/31/2018
• Issued: 05/05/2020
• Est. Priority Date: 08/08/2017
• Status: Active Grant

• Current Assignee: Marvell Asia Pte Limited (Marvell Technology Group Limited)
• Original Assignee: Marvell International Limited (Marvell Technology Group Limited)
• Inventors: McClellan, Brett Anthony, Leung, Ming-Tak, Wu, Xing
• Primary Examiner(s): Tabone, Jr., John J
• Application Number:
  US16/050,082
• Time in Patent Office: 644 Days
• Field of Search: 714760, 714752, 714784, 714786, 714821, 714712, 375295, 375316
• CPC Class Codes: H03M 13/1515 Reed-Solomon codes
• CPC Class Codes: H03M 13/6306 Error control coding in combination with Automatic Repeat reQuest [ARQ] and diversity transmission, e.g. coding schemes for the multiple transmission of the same information or the transmission of incremental redundancy H03M13/3761, H03M13/3769 and H03M13/635 take precedence
• CPC Class Codes: H04L 1/0009 by adapting the channel coding H04L1/1812 takes precedence
• CPC Class Codes: H04L 1/0041 Arrangements at the transmitter end
• CPC Class Codes: H04L 1/0045 Arrangements at the receiver end
• CPC Class Codes: H04L 1/0057 Block codes H04L1/0061, H04L1/0064 take precedence
• CPC Class Codes: H04L 1/0078 Avoidance of errors by organising the transmitted data in a format specifically designed to deal with errors, e.g. location forward error control, e.g. FEC, CRC H04L1/004; adaptive formatting H04L1/0006; mappings H04L27/00
• CPC Class Codes: H04L 69/323 in the physical layer [OSI layer 1]

Abstract

A method for communication, including, in a Physical Layer (PHY) transceiver, selecting a transmission bitrate from a plurality of transmission bitrates, for transmitting over a media interface bits received from an external device. The received bits are processed by generating, using a framing and encoding scheme that depends on at least the selected transmission bitrate, frames having a common frame length among the framing and encoding schemes. The frames are encoded to produce code words of a predefined Forward Error Correction Code (FEC) code, using a single FEC encoder that accepts a number of bits for encoding equal to the frame length. Sub-units of the code words are mapped into symbols using one of at least two mapping schemes that employ different voltage amplitude levels to define a transmission symbol, the mapping scheme being selected according to the selected transmission bitrate. The symbols are transmitted over the media interface.

Claims

1. A method for communication, comprising:

in a Physical Layer (PHY) transceiver, selecting a transmission bitrate from a plurality of predefined transmission bitrates that respectively differ one from another, for transmitting over a media interface a plurality of bits received for transmission from a device external to the PHY transceiver;

processing the received bits, by generating, using a framing and encoding scheme that is dependent on at least the selected transmission bitrate, one or more frames having a predefined frame length that is common among framing and encoding schemes for transmitting the received bits at the predefined transmission bitrates;

encoding the bits of the one or more frames, so as to produce one or more respective code words of a predefined Forward Error Correction Code (FEC) code, using a single FEC encoder that accepts a number of bits for encoding equal to the predefined frame length, wherein the single FEC encoder is reused among the framing and encoding schemes for transmitting the received bits at one of the predefined plurality of transmission bitrates;

mapping sub-units of the code words into transmission symbols for transmitting over the media interface using one of at least two different mapping schemes that respectively employ different voltage amplitude levels to define a transmission symbol, the mapping scheme being selected according to the selected transmission bitrate; and

transmitting the transmission symbols over the media interface.

2. The method according to claim 1, wherein processing the received bits comprises processing the received bits using a first framing and encoding scheme when the selected transmission bitrate is a lowest transmission bitrate among the plurality of transmission bitrates, and using a second framing and encoding scheme, that is different from the first framing and encoding scheme, when the selected transmission bitrate is higher than the lowest transmission bitrate, wherein the first framing and encoding scheme is specified in a 1000BASE-T1 standard for 1 Gbs Ethernet communication over a twisted-pair link.

3. The method according to claim 1, wherein selecting the transmission bitrate comprises selecting a transmission bitrate other than a lowest transmission bitrate among the plurality of transmission bitrates, and comprising establishing a link with a peer link partner by performing a link training process specified for the lowest transmission bitrate.

4. The method according to claim 1, wherein mapping the sub-units comprises mapping 3-bit units into 3-level PAM symbols when the selected transmission bitrate is a lowest transmission bitrate among the plurality of transmission bitrates, and into 8-level PAM symbols when the selected transmission bitrate is higher than the lowest transmission bitrate.

5. The method according to claim 1, further comprising receiving the received bits in single-byte units when the selected transmission bitrate is a lowest transmission bitrate among the plurality of transmission bitrates, and in four-byte units when the selected transmission bitrate is higher than the lowest transmission bitrate.

6. The method according to claim 1, wherein processing the received bits comprises packing a predefined number of the received bits in the frames to match a baud rate derived from a common Ethernet reference clock signal.

7. The method according to claim 1, wherein generating each of the one or more frames, when the selected transmission bitrate is higher than the lowest transmission bitrate, comprises encoding eight-byte groups of the received bits into respective sub-frames having a predefined length, and aggregating a predefined number of the sub-frames and an extension part to match the predefined frame length.

8. An apparatus, comprising:

an interface configured to receive bits for transmission over a media interface, wherein the bits are received from a device external to the apparatus at a transmission bitrate selected from a plurality of predefined transmission bitrates that respectively differ from one another;

a single Forward Error Correction Code (FEC) encoder that produces code words of a predefined FEC code, wherein the FEC encoder is reused for any transmission bitrate selected from the plurality of the predefined transmission bitrates, and accepts a number of bits for encoding equal to a predefined frame length;

a mapper/modulator, configured to;

process the received bits, by generating, using a framing and encoding scheme that is dependent on at least the selected transmission bitrate, one or more frames having a predefined frame length that is common among framing and encoding schemes for transmitting the received bits at the predefined transmission bitrates;

encode the bits of the one or more frames using the FEC encoder, so as to produce one or more respective code words of the predefined FEC code;

map sub-units of the code words into transmission symbols for transmitting over the media interface using one of at least two different mapping schemes that respectively employ different voltage amplitude levels to define a transmission symbol, the mapping scheme being selected according to the selected transmission bitrate;

transmit the transmission symbols over the media interface; and

a processor, configured to select the transmission bitrate from the plurality of the predefined transmission bitrates, and to configure the FEC encoder and the mapper/modulator with the selected transmission bitrate.

9. The apparatus according to claim 8, wherein the mapper/modulator is configured to process the received bits using a first framing and encoding scheme when the selected transmission bitrate is a lowest transmission bitrate among the plurality of transmission bitrates, and using a second framing and encoding scheme that is different from the first framing and encoding scheme, when the selected transmission bitrate is higher than the lowest transmission bitrate, wherein the first framing and encoding scheme is specified in a 1000BASE-T1 standard for 1 Gbs Ethernet communication over a twisted-pair link.

10. The apparatus according to claim 8, wherein the processor is configured to select a transmission bitrate other than a lowest transmission bitrate among the plurality of transmission bitrates, and to establish a link with a peer link partner by performing a link training process specified for the lowest transmission bitrate.

11. The apparatus according to claim 8, wherein the mapper/modulator is configured to map the sub-units by mapping 3-bit units into 3-level PAM symbols when the selected transmission bitrate is a lowest transmission bitrate among the plurality of transmission bitrates, and into 8-level PAM symbols when the selected transmission bitrate is higher than the lowest transmission bitrate.

12. The apparatus according to claim 8, wherein the interface is configured to receive the bits in single-byte units when the selected transmission bitrate is a lowest transmission bitrate among the plurality of transmission bitrates, and in four-byte units when the selected transmission bitrate is higher than the lowest transmission bitrate.

13. The apparatus according to claim 8, wherein the mapper/modulator is configured to process the received bits by packing a predefined number of the received bits in the frames to match a baud rate derived from a common Ethernet reference clock signal.

14. The apparatus according to claim 8, wherein the mapper/modulator is configured to generate each of the one or more frames, when the selected transmission bitrate is higher than the lowest transmission bitrate, by encoding eight-byte groups of the received bits into respective sub-frames having a predefined length, and aggregating a predefined number of the sub-frames and an extension part to match the predefined frame length.

15. A method for communication, comprising:

in a Physical Layer (PHY) transceiver, selecting a transmission bitrate, from among a plurality of predefined transmission bitrates that respectively include a 1 Gbps bitrate and one or more of a 2.5 Gbps, 5 Gbps and 10 Gbps transmission bitrate, for transmitting over a media interface a plurality of bits received for transmission from a device external to the PHY transceiver;

processing the received bits and additional bits to generate one or more frames having a predefined frame length, using a framing and encoding scheme that for the 1 Gbps transmission bitrate processes the received bits and the additional bits according to a 1000BASE-T1 mode of transmission;

encoding the bits of the one or more frames, using a Forward Error Correction (FEC) code encoder for transmission according to the 1000BASE-T1 mode of transmission, to produce a plurality of code words of a respective FEC code;

selectively mapping sub-units of the code words into transmission symbols according to (i) a 3-level PAM modulation scheme for transmitting the received bits over the media interface at the 1 Gbps transmission bitrate according to 1000BASE-T1 mode, or (ii) according to a higher level PAM modulation scheme for transmitting the received bits over the media interface at a transmission bitrate that is higher than the 1 Gbps transmission bitrate; and

transmitting the transmission symbols over the media interface according to the selected mapping.

16. The method according to claim 15, wherein selecting the transmission bitrate comprises selecting a transmission bitrate higher than 1 Gbps, and wherein processing the received bits comprises processing the received bits using a framing and encoding scheme that is different from the framing and encoding scheme specified for the 1000BASE-T1 mode of transmission, and that is dependent on the selected transmission bitrate.

17. The method according to claim 15, wherein the FEC code encoder comprises a Reed Solomon (RS) encoder that is reused among the plurality of transmission bitrates, wherein the RS encoder accepts for encoding a frame having the predefined frame length, independently from the selected transmission bitrate.

18. The method according to claim 15, wherein the higher level PAM modulation scheme maps 3-bit units of the code words into 8-level PAM symbols.

19. An apparatus for communication, comprising:

a processor, configured to select a transmission bitrate, from among a plurality of predefined transmission bitrates that respectively include a 1 Gbps bitrate and one or more of a 2.5 Gbps, 5 Gbps and 10 Gbps transmission bitrate;

an interface configured to receive from a device external to the apparatus a plurality of bits for transmission over a media interface; and

a mapper/modulator, configured to;

process the received bits and additional bits to generate one or more frames having a predefined frame length, using a framing and encoding scheme that for the 1 Gbps transmission bitrate processes the received bits and the additional bits according to a 1000BASE-T1 mode of transmission;

encode the bits of the one or more frames, using a Forward Error Correction (FEC) code encoder for transmission according to the 1000BASE-T1 mode of transmission, to produce a plurality of code words of a respective FEC code;

selectively map sub-units of the code words into transmission symbols according to (i) a 3-level PAM modulation scheme for transmitting the received bits over the media interface at the 1 Gbps transmission bitrate according to 1000BASE-T1 mode, or (ii) according to a higher level PAM modulation scheme for transmitting the received bits over the media interface at a transmission bitrate that is higher than the 1 Gbps transmission bitrate; and

transmit the transmission symbols over the media interface according to the selected mapping.

20. The apparatus according to claim 19, wherein the processor is configured to select the transmission bitrate by selecting a transmission bitrate higher than 1 Gbps, and wherein the mapper/modulator is configured to process the received bits using a framing and encoding scheme that is different from the framing and encoding scheme specified for the 1000BASE-T1 mode of transmission, and that is dependent on the selected transmission bitrate.

21. The apparatus according to claim 19, wherein the FEC code encoder comprises a Reed Solomon (RS) encoder that is reused among the plurality of transmission bitrates, wherein the mapper/modulator is configured to provide the RS encoder with a frame having the predefined frame length, independently from the selected transmission bitrate.

22. The apparatus according to claim 19, wherein the higher level PAM modulation scheme maps 3-bit units of the code words into 8-level PAM symbols.