Circuit and method for optical bit interleaving in a passive optical network using multi-level signals

Patent metadata

Field	Value
Publication number	US-9538266-B2
Application number	US-201514642165-A
Country	US
Kind code	B2
Filing date	Mar 9, 2015
Priority date	Mar 9, 2015
Publication date	Jan 3, 2017
Grant date	Jan 3, 2017

Abstract

An optical line terminal transmitter front-end, an optical network terminal receiver front-end and a bit-interleaved passive optical network (BIPON). In one embodiment, the transmitter front-end includes: (1) a bit interleaver configured to group and interleave a plurality of user bit-streams to yield a combined single bit-stream, (2) an encoder coupled to the bit interleaver and configured to encode multiple bits of the single bit-stream into a multi-level code corresponding to a 2 m -level multi-level signal and (3) a multi-level modulator coupled to the encoder and configured to modulate the multi-level code into the 2 m -level multi-level signal.

First claim

What is claimed is:

1. An optical line terminal transmitter front-end, comprising:
a bit interleaver configured to group and interleave a plurality of user bit-streams to yield a combined single bit-stream;
a 1:m serial-to-parallel converter coupled to said bit interleaver and configured to convert said single bit-stream into a parallel data stream of m width;
an encoder coupled to said 1:m serial-to-parallel converter and configured to encode multiple bits of said parallel data stream into a multi-level code corresponding to a 2 m -level multi-level signal; and
a multi-level modulator coupled to said encoder and configured to modulate said multi-level code into said 2 m -level multi-level signal.

2. The transmitter front-end as recited in claim 1 wherein said encoder is a balanced Gray coder.

3. The transmitter front-end as recited in claim 1 further comprising an adaptive control configured to introduce predistortion into said 2 m -level multi-level signal.

4. The transmitter front-end as recited in claim 3 wherein said adaptive control is further configured to receive feedback from at least one optical network terminal and base said predistortion thereupon.

5. The transmitter front-end as recited in claim 1 wherein said bit interleaver is configured to group and interleave said plurality of user bit-streams according to a predetermined rate according to a bandwidth allocation.

6. The transmitter front-end as recited in claim 1 further comprising an electrical-to-optical modulator coupled to said multi-level modulator.

7. The transmitter front-end as recited in claim 1 wherein said 2 m -level multi-level signals are pulse-amplitude modulation signals.

8. An optical network terminal receiver front-end, comprising:
a clock-and-data recovery circuit/demultiplexer configured to receive bit-interleaved 2 m -level multi-level signals and recover a clock signal and multi-level codes therefrom, said multi-level codes being part of a data packet having a header and a payload;
a multi-level bit detector coupled to said clock-and-data recovery circuit/demultiplexer and configured to detect bits from said multi-level codes in said header; and
a bit-interleaved passive optical network header processor coupled to said multi-level bit detector and configured to determine, based on said bits, a subsampling rate, phase and bit position for said clock-and-data recovery circuit/demultiplexer to select for recovery ones of said multi-level codes in said payload.

9. The receiver front-end as recited in claim 8 further comprising a distortion/dispersion compensation (EDC) module coupled between said clock-and-data recovery circuit/demultiplexer and said multi-level bit detector and configured to introduce predistortion into said multi-level codes based on said subsampling rate, phase and bit position.

10. The receiver front-end as recited in claim 8 wherein said bit-interleaved passive optical network header processor is further configured to provide said subsampling rate, phase and bit position to said multi-level bit detector.

11. The receiver front-end as recited in claim 8 wherein said multi-level bit detector comprises M parallel voltage threshold detectors, M being a smallest integer at least equaling 2 m /m, and at least one combinatorial logic gate.

12. The receiver front-end as recited in claim 8 wherein said 2 m -level multi-level signals are pulse-amplitude modulation signals.

13. The receiver front-end as recited in claim 8 further comprising an optical-to-electrical modulator coupled to said clock-and-data recovery circuit/demultiplexer.

14. A bit-interleaved passive optical network, comprising:
an optical line terminal transmitter front-end configured to group and interleave a plurality of user bit-streams to yield a combined single bit-stream, encode multiple bits of said single bit-stream into a multi-level code corresponding to a 2 m -level multi-level signal and modulate said multi-level code into said 2 m -level multi-level signal;
an optical transmission medium; and
a plurality of optical network terminal receiver front-ends, each of said optical network terminal receiver front-ends configured to receive said 2 m -level multi-level signals from said optical line terminal transmitter front-end via said optical transmission medium, recover a clock signal and multi-level codes therefrom, said multi-level codes being part of a data packet having a header and a payload, detect bits from said multi-level codes in said header and determine, based on said bits, a subsampling rate, phase and bit position for said clock-and-data recovery circuit/demultiplexer to select for recovery ones of said multi-level codes in said payload.

15. The bit-interleaved passive optical network as recited in claim 14 wherein said optical line terminal transmitter front-end is further configured to introduce predistortion into said 2 m -level multi-level signal based on feedback from at least one of said plurality of optical network terminal receiver front-ends.

16. The bit-interleaved passive optical network as recited in claim 14 wherein said optical line terminal transmitter front-end is further configured to group and interleave said plurality of user bit-streams according to a predetermined rate according to a bandwidth allocation.

17. The bit-interleaved passive optical network as recited in claim 14 wherein said each of said optical network terminal receiver front-ends is further configured to introduce predistortion into said multi-level codes based on said subsampling rate, phase and bit position.

18. The bit-interleaved passive optical network as recited in claim 14 wherein said optical line terminal transmitter front-end comprises a balanced Gray coder.

19. The bit-interleaved passive optical network as recited in claim 14 wherein said 2 m -level multi-level signals are pulse-amplitude modulation signals.

Assignees

• Alcatel Lucent Usa Inc
• Alcatel Lucent

Inventors

• Chow Hungkei
• Houtsma Vincent E
• Van Veen Doutje T

Classifications

• H04B10/25891

  Transmission components (H04B10/40 takes precedence) · CPC title

• H04B10/541

  Digital intensity or amplitude modulation · CPC title

• H04Q11/0067 Primary

  Provisions for optical access or distribution networks, e.g. Gigabit Ethernet Passive Optical Network (GE-PON), ATM-based Passive Optical Network (A-PON), PON-Ring · CPC title

• H04Q11/0071

  Provisions for the electrical-optical layer interface · CPC title

• H04B10/25137

  using pulse shaping at the transmitter, e.g. pre-chirping or dispersion supported transmission [DST] · CPC title