Systems and methods for improved data transmission in short-reach links

Patent metadata

Field	Value
Publication number	US-10958486-B2
Application number	US-201816127177-A
Country	US
Kind code	B2
Filing date	Sep 10, 2018
Priority date	Sep 8, 2017
Publication date	Mar 23, 2021
Grant date	Mar 23, 2021

Abstract

Systems and methods are provided for enabling lower-bandwidth hardware components to support higher data rates. In particular, aspects of the disclosed systems and methods use Raised Cosine pulse shaping in short-reach links to band limit the signal spectra and thereby enable existing, such lower-bandwidth components to support higher data rates.

First claim

What is claimed is:

1. A system comprising:
a transmitter comprising:
a symbol generator;
a pulse shaper;
a transmitter equalizer;
an electronic-to-optical converter;
a first processor; and
a first memory in communication with the first processor;

short-reach optical communication link; and
a receiver comprising:
an optical-to-electronic converter;
a low pass filter;
timing recoverer;
receiver equalizer;
a slicer;
a second processor; and
a second memory in communication with the second processor;

wherein the transmitter and receiver are in communication via the short-reach optical communication link;
wherein the first memory stores instructions that, when executed by the first processor, are configured to cause the transmitter to:
receive a first electronic signal;
convert the first electronic signal to data symbols with the symbol generator;
raised cosine pulse shape with the pulse shaper, based at least in part on anticipated transmitter property foreknowledge, the data symbols using pre-programmed values to provide raised cosine pulses with roll-off factor, between 0.05 and 0.3;
equalize, with the transmitter equalizer, using pre-programmed filtering based at least in part on the anticipated transmitter property foreknowledge, the pulse shaped data;
convert with the electronic-to-optical converter the equalized and raised cosine pulse shaped data into an optical signal; and
send, to the receiver, the optical signal via the short-reach optical communication link; and

wherein the second memory stores instructions that, when executed by the second processor, are configured to cause the receiver to:
receive the optical signal;
convert with the optical-to-electronic converter the optical signal into a second electronic signal;
filter with the low pass filter the second electronic signal to minimize out-of-band noise and maximize signal-to-noise ratio for the second electronic signal;
perform timing recovery with the timing recoverer on the second electronic signal;
equalize, with the receiver equalizer, using pre-programmed values based at least in part on anticipated receiver property foreknowledge, the second electronic signal;
slice with the slicer the equalized second electronic signal for calculation of a symbol error rate and to convert the second electronic signal into a plurality of bits for processing.

2. The system of claim 1 , wherein the transmitter comprises a directly modulated vertical-cavity surface-emitting laser.

3. The system of claim 2 , wherein the anticipated transmitter property foreknowledge comprises transmission response impairments relating to one or both of transmitter hardware bandwidth limitations and channel bandwidth limitations.

4. The system of claim 2 , wherein raised cosine pulse shaping the first electronic signal follows available frequency response.

5. The system of claim 1 , wherein the anticipated transmitter property foreknowledge comprises transmission response impairments relating to one or both of transmitter hardware limitations and channel limitations.

6. The system of claim 1 , wherein raised cosine pulse shaping the first electronic signal follows available frequency response.

7. The system of claim 1 , wherein the short-reach optical communication link comprises a multimode fiber.

8. The system of claim 1 , wherein the short-reach optical communication link comprises a single mode fiber.

9. The system of claim 1 , wherein timing recovery on the second electronic signal implements feedforward clock recovery.

10. The system of claim 1 , wherein equalizing the second electronic signal comprises equalizing at least one sample per symbol.

11. The system of claim 1 , wherein the transmitter and the receiver have a bandwidth of less than 50 GHz; and
wherein sending, by the transmitter, the optical signal via the short-reach optical communication link comprises sending, by the transmitter, the optical signal at a data rate of at least 100 Gbps via the short-reach optical communication link.

Assignees

• Georgia Tech Res Inst

Inventors

• Varughese Siddharth Jacob
• Lavrencik Joseph Justin
• Ralph Stephen E
• Thomas Varghese Antony

Classifications

• H04B10/6971 Primary

  using equalisation · CPC title

• H04L25/03343

  Arrangements at the transmitter end · CPC title

• H04B2210/254

  before the transmission line, i.e. pre-compensation · CPC title

• H04B10/58

  Compensation for non-linear transmitter output · CPC title

• H04L7/00

  Arrangements for synchronising receiver with transmitter {(synchronisation of generators of electric oscillations or pulses H03L7/00)} · CPC title