Spread spectrum modulation over an asymmetric ethernet link

Patent metadata

Field	Value
Publication number	US-12388488-B1
Application number	US-202217954387-A
Country	US
Kind code	B1
Filing date	Sep 28, 2022
Priority date	Sep 29, 2021
Publication date	Aug 12, 2025
Grant date	Aug 12, 2025

Abstract

An automotive Ethernet physical-layer (PHY) transceiver includes an Analog Front End (AFE) and a digital processor. The AFE is coupled via a full-duplex Ethernet link to a peer transceiver. The AFE is configured to receive from the peer transceiver, over the full-duplex Ethernet link, an analog Ethernet signal conveying data symbols, at a reception data rate that is lower than a transmission data rate used in transmitting data from the PHY transceiver to the peer transceiver, the Ethernet signal being modulated by a spreading sequence having a Spreading Factor including a ratio between a spreading chip-rate and the reception data rate, and to convert the received analog Ethernet signal into a digital signal. The digital processor is configured to de-spread the digital signal using the spreading sequence to recover the data symbols.

First claim

The invention claimed is:

1. An automotive Ethernet physical-layer (PHY) transceiver, comprising:
an Analog Front End (AFE) coupled via a full-duplex Ethernet link to a peer transceiver, the AFE configured to:
receive from the peer transceiver, over the full-duplex Ethernet link, an analog Ethernet signal conveying data symbols, at a reception data rate that is lower than a transmission data rate used in transmitting data from the PHY transceiver to the peer transceiver, the Ethernet signal being modulated by a spreading sequence having a Spreading Factor comprising a ratio between a spreading chip-rate and the reception data rate; and
convert the received analog Ethernet signal into a digital signal; and

a digital processor, configured to:
de-spread the digital signal using the spreading sequence to recover the data symbols.

2. The automotive Ethernet PHY transceiver according to claim 1 , wherein, during a link-training phase, the digital processor is configured to monitor reception conditions affecting the Ethernet signal, and to negotiate with the peer transceiver the Spreading Factor selected from among multiple candidate Spreading Factor values, based at least on the monitored reception conditions.

3. The automotive Ethernet PHY transceiver according to claim 2 , wherein the digital processor is configured to determine the candidate Spreading Factor values based on the monitored reception conditions and on one or more of a maximal bandwidth requirement and a power consumption requirement.

4. The automotive Ethernet PHY transceiver according to claim 1 , wherein the digital processor is configured to evaluate a criterion for triggering modification of the Spreading Factor, and in response to detecting that the criterion is met, determine a modified Spreading Factor, and inform the peer transceiver of the modified Spreading Factor.

5. The automotive Ethernet PHY transceiver according to claim 4 , wherein the digital processor is configured to measure a reception quality or a predicted reception quality of the Ethernet signal, and to determine that the criterion for triggering Spreading Factor modification is met when the reception quality or the predicted reception quality varies by an amount larger than a specified reception quality amount.

6. The automotive Ethernet PHY transceiver according to claim 5 , wherein the digital processor is configured to, in response to detecting that the reception quality or the predicted reception quality has increased by more than the specified amount, select the modified Spreading Factor value smaller than the Spreading Factor.

7. The automotive Ethernet PHY transceiver according to claim 5 , wherein the digital processor is configured to, in response to detecting that the reception quality or the predicted reception quality has degraded by more than the specified amount, select a modified Spreading Factor value larger than the Spreading Factor.

8. The automotive Ethernet PHY transceiver according to claim 4 , wherein the digital processor is configured to determine the modified Spreading Factor by modifying the chip-rate associated with the Spreading Factor, and further associate the modified Spreading Factor with a modified spreading sequence in accordance with the modified chip-rate.

9. The automotive Ethernet PHY transceiver according to claim 4 , wherein the digital processor is configured to determine the modified Spreading Factor by modifying the reception data rate of the data symbols.

10. The automotive Ethernet PHY transceiver according to claim 9 , wherein the digital processor is configured to specify a maximal chip-rate supported, and to determine the modified Spreading Factor by modifying the reception data rate, when the chip-rate associated with the Spreading Factor has reached the maximal chip-rate supported.

11. The automotive Ethernet PHY transceiver according to claim 4 , wherein the digital processor is configured to coordinate with the peer transceiver a time for starting application of the modified Spreading Factor in sending subsequent data symbols from the peer transceiver to the automotive Ethernet PHY transceiver.

12. A method for data communication, comprising:
in an automotive Ethernet physical-layer (PHY) transceiver coupled via a full-duplex Ethernet link to a peer transceiver,
receiving from the peer transceiver, over the full-duplex Ethernet link, an analog Ethernet signal conveying data symbols, at a reception data rate that is lower than a transmission data rate used in transmitting data from the PHY transceiver to the peer transceiver, the Ethernet signal being modulated by a spreading sequence having a Spreading Factor comprising a ratio between a spreading chip-rate and the reception data rate, and converting the received analog Ethernet signal into a digital signal; and
de-spreading the digital signal using the spreading sequence to recover the data symbols.

13. The method according to claim 12 , comprising, during a link-training phase monitoring reception conditions affecting the Ethernet signal, negotiating with the peer transceiver the Spreading Factor selected among multiple candidate Spreading Factor values, based at least on the reception conditions.

14. The method according to claim 13 , wherein determining the candidate Spreading Factor values comprises determining the candidate Spreading Factor values based on the reception conditions and on one or more of a maximal bandwidth requirement and a power consumption requirement.

15. The method according to claim 12 , comprising evaluating a criterion for triggering modification of the Spreading Factor, and in response to detecting that the criterion is met, determining a modified Spreading Factor, and informing the peer transceiver of the modified Spreading Factor.

16. The method according to claim 15 , determining that the criterion is met comprises measuring a reception quality or a predicted reception quality of the Ethernet signal, and determining that the criterion for triggering Spreading Factor modification is met when the reception quality or the predicted reception quality varies by an amount larger than a specified reception quality amount.

17. The method according to claim 16 , comprising, in response to detecting that the reception quality or the predicted reception quality has increased by more than the specified amount, selecting the modified Spreading Factor value smaller than the Spreading Factor.

18. The method according to claim 16 , in response to detecting that the reception quality or the predicted reception quality has degraded by more than the specified amount, selecting a modified Spreading Factor value larger than the Spreading Factor.

19. The method according to claim 15 , wherein determining the modified Spreading Factor comprises modifying the chip-rate associated with the Spreading Factor, and further associate the modified Spreading Factor with a modified spreading sequence in accordance with the modified chip-rate.

20. The method according to claim 15 , wherein determining the modified Spreading Factor comprises modifying the reception data rate of the data symbols.

21. The method according to claim 20 , wherein determining the modified Spreading Factor comprises specifying a maximal chip-rate supported, and determining the modified Spreading Factor by modifying the reception data rate, when the chip-rate associated with the Spreading Factor has reached the maximal chip-rate supported.

22. The method according to claim 1

Assignees

• Marvell Asia Pte Ltd

Inventors

• Shen David
• Razavi Majomard Seid Alireza
• Chu William

Classifications

• H04B1/707 Primary

  using direct sequence modulation · CPC title

• H04L5/14

  Two-way operation using the same type of signal, i.e. duplex · CPC title

• H04J13/0044 Primary

  OVSF [orthogonal variable spreading factor] · CPC title