Transceiver and method of adjusting the TX signal of the transceiver for weakening EMI

Patent metadata

Field	Value
Publication number	US-10790873-B2
Application number	US-201816206541-A
Country	US
Kind code	B2
Filing date	Nov 30, 2018
Priority date	Dec 21, 2017
Publication date	Sep 29, 2020
Grant date	Sep 29, 2020

Abstract

The present application relates to a transceiver, TX/RX PHY, and a method of operating the TX/RX PHY arranged for bi-directional data communication of a node with a counterpart node connected to in a point-to-point network using differential mode signaling over a single twisted-pair cable. A TX adjustment component is arranged in a TX path of the TX/RX PHY and configured to adjust a TX data communication signal generated by the TX/RX PHY for transmittal to the counterpart node. The TX adjustment component is further configured to accept information about a common mode signal detected on the single twisted-pair cable and to adjust the TX data communication signal to at least weaken the common mode signal occurring at the counterpart node in response to transmitting the TX data communication signal.

First claim

The invention claimed is:

1. A transceiver arranged for bi-directional data communication of a node with a counterpart node connected in a point-to-point network using differential mode signaling over a single twisted-pair cable, the transceiver comprising:
a transmitted (TX) adjustment component arranged in a TX path of the transceiver and configured to
adjust a TX data communication signal generated by the transceiver for transmittal to the counterpart node,
accept information about a common mode signal detected on the single twisted-pair cable, and
adjust the TX data communication signal to at least weaken the common mode signal occurring at the counterpart node in response to transmitting the TX data communication signal, wherein the TX adjustment component comprises a cancellation signal generator configured to generate an inverse common mode cancellation signal, which is injected into the TX path of the transceiver, and the cancellation signal generator comprises a coefficient control component configured to estimate at least one frequency range in which the detected common mode signal exceeds a predefined threshold.

2. The transceiver of claim 1 , wherein the TX adjustment component further comprises at least one of:
a filter component configured to filter the TX data communication signal based on the information about a common mode signal; and
an amplitude adaptation component configured to adapt the amplitude of the TX data communication signal.

3. The transceiver of claim 2 , wherein the cancellation signal generator further comprises:
a conversion matrix component configured to determine matrix coefficients based on the at least one estimated frequency range and to configure the cancellation signal generator based on the determined matrix coefficients.

4. The transceiver of claim 2 , wherein the filter component further comprises:
a finite impulse response (FIR) filter component, wherein the coefficient control component is configured to determine filter coefficients based on the at least one estimated frequency range and to configure the FIR filter component based on the determined filter coefficients.

5. The transceiver of claim 2 , wherein the amplitude adaptation component further comprises:
a modulation control component,
a symbol modulation component, and
a signal scaler component, wherein the modulation control component is provided with several predefined modulation schemes and configured to
select a new modulation scheme out of the several predefined modulation schemes based on the information about the detected common mode signal, a number of symbols of the selected new modulation scheme is less than a number of symbols of a current modulation scheme, the symbol modulation component is configured to
apply the selected new modulation scheme for TX data communication of the transceiver with the counterpart node, and the signal scaler component is configured to
adjust an amplitude of analog signals carrying the TX data communication of the transceiver in accordance with a new maximum modulation amplitude being a function of the selected new modulation scheme.

6. The transceiver of claim 1 , further comprising:
a RX reporting component configured to:
receive the information about the detected common mode signal from the counterpart node and
provide, with a detection section, the information about the detected common mode signal to the TX adjustment component, and
detect, with the detection section, the common mode signal on the single twisted-pair cable.

7. The transceiver of claim 1 , wherein the information about the detected common mode signal comprises frequency transformed coefficients of the detected common mode signal.

8. A method of operating a transceiver arranged for bi-directional data communication of a node with a counterpart node connected in a point-to-point network using differential mode signaling over a single twisted-pair cable, wherein the method comprises:
accepting information about a common mode signal detected on the single twisted-pair cable;
adjusting a TX data communication signal generated by the transceiver for communication with the counterpart node to at least weaken the common mode signal occurring at the counterpart node in response to communication the TX data communication signal;
determining an estimated frequency range in which the common mode signal exceeds a predefined threshold;
determining finite impulse response (FIR) filter coefficients based on the estimated frequency range and the common mode signal.

9. The method of claim 8 , wherein the adjusting of the TX data communication signal comprises at least one of:
generating an inverse common mode cancellation signal and injecting the generated inverse common mode cancellation signal into the TX path of the transceiver;
filtering the TX data communication signal based on the information about a common mode signal; and
adapting the amplitude of the TX data communication signal in response to the information about a common mode signal.

10. The method of claim 9 , wherein the generating of the inverse common mode cancellation signal further comprises:
determining matrix coefficients based on the estimated frequency range and the information about the detected common mode signal; and
configuring an inverse mode conversion matrix using the matrix coefficients, wherein the inverse mode conversion matrix is used to generate the inverse common mode cancellation signal based on the TX data communication signal, and the inverse common mode cancellation signal is injected into the TX path of the transceiver.

11. The method of claim 9 , wherein the filtering of the TX data communication signal further comprises:
configuring a FIR filter using the FIR filter coefficients, wherein the FIR filter is provided in the TX path of the transceiver to weaken the TX data communication signal in the estimated frequency range.

12. The method of claim 9 , wherein adapting of the amplitude of the TX data communication signal further comprises:
selecting a new modulation scheme out of several predefined modulation schemes, wherein a number of symbols of the selected new modulation scheme is less than a number of symbols of a current modulation scheme;
applying the selected new modulation scheme by the transceiver for data communication with the counterpart node; and
scaling an analog signal carrying TX data communication of the transceiver in accordance with a maximum modulation amplitude, which is a function of the selected new modulation scheme.

13. The method of claim 12 , wherein the maximum modulation amplitude of the selected new modulation scheme is downscaled from a maximum modulation amplitude of the current modulation scheme by a factor corresponding to a ratio of the numbers of symbols of the current modulation scheme and the new modulation scheme.

14. The method of claim 12 , wherein the several predefined modulation schemes are distinct pulse amplitude modulation schemes.

Assignees

• Nxp Bv

Inventors

• Pandey Sujan
• Frambach Johannes Petrus Antonius

Classifications

• H04B3/28

  Reducing interference caused by currents induced in cable sheathing or armouring · CPC title

• H04B3/30

  Reducing interference caused by unbalanced currents in a normally balanced line · CPC title

• H04L1/0009

  by adapting the channel coding (H04L1/1812 takes precedence) · CPC title

• H04L27/02

  Amplitude-modulated carrier systems, e.g. using on-off keying; Single sideband or vestigial sideband modulation (H04L27/32 takes precedence) · CPC title

• H04B3/04 Primary

  Control of transmission; Equalising · CPC title