Transmitter control in communication systems

• US 8,379,710 B2
• Filed: 03/10/2009
• Issued: 02/19/2013
• Est. Priority Date: 03/10/2009
• Status: Active Grant

• Current Assignee: Intel Corporation
• Original Assignee: Intel Corporation
• Inventors: Mezer, Amir, Ran, Adee
• Primary Examiner(s): PATEL, DHAVAL V
• Application Number:
  US12/381,282
• Publication Number:
  US 20100232492A1
• Time in Patent Office: 1,442 Days
• Field of Search: 375/232, 375/257, 375/229, 375/230, 375/231, 708/300, 708/819, 333/18
• US Class Current: 375/232
• CPC Class Codes: H04L 2025/03356 Baseband transmission
• CPC Class Codes: H04L 2025/03808 Transmission of equaliser coefficients
• CPC Class Codes: H04L 25/03343 Arrangements at the transmitter end
• CPC Class Codes: H04L 27/01 Equalisers baseband equalizers at the transmitter end H04L25/03343; in analogue transmission systems H04B3/04, H04B7/005

Abstract

Techniques are described to adaptively adjust the equalizer settings of each transmitter in a transmitter-receiver pair. The transmitter-receiver pair can be used at least with implementations that comply with 40GBASE-CR4 or 100GBASE-CR10. For implementations that comply with 40GBASE-CR4, equalizer settings of four transmitters may be independently established.

Claims

1. A method comprising:

receiving a first signal from a first lane;

determining first equalizer settings of a first transmitter of the first signal based in part on error properties of the first signal using clock and data recovery for the first signal and also based in part on control signals from the first transmitter determined using a first control channel decoder, wherein the first equalizer used by the first transmitter is in compliance with one or more of clauses 72.7.1.10 and 72.7.1.11 of IEEE Std 802.3ap-2007;

requesting adjustment of the first equalizer settings using a control channel in compliance with a 10GBASE-KR PMD control function defined in clause 72.6.10 of IEEE Std 802.3ap-2007;

receiving a second signal from a second lane;

determining second equalizer settings of a second transmitter of the second signal based in part on error properties of the second signal using clock and data recovery for the second signal and also based in part on control signals from the second transmitter determined using a second control channel decoder;

transmitting the first equalizer settings to a receiver associated with the first transmitter;

transmitting the second equalizer settings to a receiver associated with the second transmitter;

requesting to adjust settings applied by the first equalizer of the first transmitter;

requesting to adjust settings applied by the second equalizer of the second transmitter; and

forming a third signal by combining contents of the received first and second signals, wherein

the first equalizer settings are determined independently from the second equalizer settings;

the first transmitter transmits independently of the second transmitter;

an aggregate transmission rate of signals transmitted over the multiple lanes is approximately a number of lanes times a transmission rate specified in 10GBASE-KR of IEEE 802.3ap (2007) and

electrical characteristics of the first and second transmitters are in compliance with clause 72.7.1 of IEEE Std 802.3ap-2007.

2. The method of claim 1, wherein the receiving the first and second signals comprise receiving the first and second signals in compliance with electrical characteristics of clause 72.7.1 of IEEE Std 802.3ap-2007.

3. The method of claim 1, wherein the receiving the first and second signals comprise:

receiving the first and second signals over a conductive material, wherein the conductive material includes two differential pairs.

4. The method of claim 1, further comprising:

receiving an indication of whether the first equalizer settings were applied.

5. The method of claim 1, wherein transmitting equalizer settings of the first transmitter takes place after determination of a number of utilized transmit-receive pairs.

6. The method of claim 1, wherein each of the first and second lanes comprises a coaxial cable.

7. A system comprising:

a first transmitter comprising an equalizer, wherein the equalizer is in compliance with one or more of clauses 72.7.1.10 and 72.7.1.11 of IEEE Std 802.3ap-2007;

a second transmitter comprising an equalizer, wherein the equalizer is in compliance with one or more of clauses 72.7.1.10 and 72.7.1.11 of IEEE Std 802.3ap- 2007, wherein electrical characteristics of the first and second transmitters are in compliance with clause 72.7.1 of IEEE Std 802.3ap-2007;

a first receiver;

a second receiver;

logic to form a third signal by combining content from the first and second signals; and

at least two sets of differential conductors to communicatively couple the first transmitter to the first receiver and to communicatively couple the second transmitter to the second receiver, wherein each of the at least two sets of conductors are to provide signal transmission in accordance with 10GBASE-KR of IEEE Std 802.3ap-2007, wherein

the first receiver comprises;

logic to receive a first signal from the first transmitter;

clock and data recovery logic to determine error properties of the first signal,

control channel decoder to decode control signals from the first transmitter,

remote transmit adaptation engine to determine first equalizer settings of the equalizer of the first transmitter based in part on the error properties and the control signals, and

a transmit control logic to request to adjust the settings applied by the equalizer of the first transmitter, the transmit control logic comprising;

logic to request to adjust equalizer settings of the first transmitter using a first control channel in compliance with 10GBASE-KR PMD control function defined in clause 72.6.10 of IEEE Std 802.3ap-2007; and

the second receiver comprises;

logic to receive a second signal from the second transmitter;

logic to determine second equalizer settings of the second transmitter based in part on clock and data recovery of the second signal;

logic to request to adjust equalizer settings of the second transmitter using a second control channel in compliance with 10GBASE-KR PMD control function defined in clause 72.6.10 of IEEE Std 802.3ap-2007; and

an aggregate transmission rate of signals transmitted between transmitter-receiver pairs is approximately a number of transmitter-receiver pairs times a transmission rate specified in 10GBASE-KR of IEEE 802.3ap (2007).

8. The system of claim 7, wherein the second transmitter further comprises:

logic to transmit the first equalizer settings to the second receiver to request to adjust equalizer settings of the first transmitter.

9. The system of claim 8, wherein the first receiver comprises:

logic to receive an indication of whether the transmitted first equalizer settings were applied by the first transmitter.

10. The system of claim 7, wherein the equalizer of the first transmitter comprises a feed forward equalizer and wherein the first transmitter comprises:

a control channel encoder to encode control signals for transmission to the first receiver.

11. The system of claim 7, wherein the equalizer of the first transmitter comprises a finite impulse response filter.

12. The system of claim 7, wherein the equalizer of the first transmitter comprises a feed forward equalizer.

13. The system of claim 7, wherein the second transmitter includes a Continuous-Time Linear Equalizer (CTLE), finite impulse response filter, and digital infinite impulse response filter, and wherein the first transmitter is to request an equalizer used in the second transmitter.

14. The system of claim 7, wherein the remote transmit adaptation engine is to determine equalizer settings after determination of a number of utilized transmit-receive pairs.

15. The system of claim 7, wherein each of the first and second lanes comprises a coaxial cable.