Polarization-switched differential ternary phase-shift keying

Patent metadata

Field	Value
Publication number	US-9130679-B1
Application number	US-201213437502-A
Country	US
Kind code	B1
Filing date	Apr 2, 2012
Priority date	May 27, 2011
Publication date	Sep 8, 2015
Grant date	Sep 8, 2015

Abstract

Methods and systems for transmission and reception of ternary phase-shift keyed data that include mapping triplets of binary bits to pairs of ternary symbols, such that three bits of data are encoded across two symbols having three-point constellations; modulating the pairs of ternary symbols onto a carrier; and transmitting the modulated carrier across a transmission medium.

First claim

What is claimed is:

1. A method for transmitting ternary phase-shift keyed data, the method comprising:
mapping triplets of binary bits to pairs of ternary symbols, such that three bits of data are encoded across two symbols having three-point constellations;
modulating the pairs of ternary symbols onto a carrier;
transmitting the modulated carrier across a transmission medium; and
forming an alternating polarization optical carrier beam,

wherein said forming comprises:
modulating a series of pulses onto a laser beam;
removing every second pulse from the modulated beam;
splitting each pulses into two;
delaying one split pulse by one signal period;
rotating one split pulse's polarization; and
combining the split pulses to form a series of pulses having alternating polarization.

2. The method of claim 1 , further comprising chirping the pulses.

3. The method of claim 1 , further comprising encoding a binary bitstream according to a rate 8/9 code before performing said mapping.

4. A method for transmitting ternary phase-shift keyed data, the method comprising:
mapping triplets of binary bits to pairs of ternary symbols, such that three bits of data are encoded across two symbols having three-point constellations;
modulating the pairs of ternary symbols onto a carrier;
transmitting the modulated carrier across a transmission medium,

wherein modulating further comprises forming a ternary constellation by amplitude modulating two signal paths and phase modulating one of said signal paths, such that the two paths combine to form a four-point constellation having three points at a same amplitude that are centered at the origin and having one unused point at a higher amplitude than the other points.

5. A transmitter comprising:
an encoder configured to map triplets of binary bits to pairs of ternary symbols, such that three bits of data are encoded across two symbols having three-point constellations;
a modulator configured to modulate the pairs of ternary symbols onto a carrier for transmission across a transmission medium; and
a polarization switched pulse generator configured to form an alternating polarization optical carrier beam,

wherein said polarization switched pulse generator comprises:
a first amplitude modulator configured to modulate a series of pulses onto a laser beam;
a second amplitude modulator configured to remove every second pulse from the modulated beam;
a beam splitter configured to split each pulse into two pulse;
a delay module configured to delay one split pulse by one signal period;
a polarization rotator configured to rotate one split pulse's polarization; and
a beam combiner configured to combine the split pulses to form a series of pulses having alternating polarization.

6. The transmitter of claim 5 , further comprising a chirping module configured to chirp the pulses.

7. The transmitter of claim 5 , wherein the encoder is further configured to encode a binary bitstream according to a rate 8/9 code before performing said mapping.

8. A transmitter comprising:
an encoder configured to map triplets of binary bits to pairs of ternary symbols, such that three bits of data are encoded across two symbols having three-point constellations; and
a modulator configured to modulate the pairs of ternary symbols onto a carrier for transmission across a transmission medium,

wherein the modulator comprises two signal paths configured to form a ternary constellation, wherein each signal path comprises an amplitude modulator and one signal path comprises a phase modulator, such that the two paths combine to form a four-point constellation having three points at a same amplitude that are centered at the origin and having one unused point at a higher amplitude than the other points.

Assignees

• Ip Ezra
• Yaman Fatih
• Xu Lei
• Wang Ting
• Inada Yoshihisa
• Ogata Takaaki
• Aoki Yasuhiro
• Nec Lab America Inc
• Nec Corp

Inventors

• Ip Ezra
• Yaman Fatih
• Xu Lei
• Wang Ting
• Inada Yoshihisa
• Ogata Takaaki
• Aoki Yasuhiro

Classifications

• H04L27/20

  Modulator circuits; Transmitter circuits · CPC title

• H04B10/524 Primary

  Pulse modulation · CPC title

• H04B10/532 Primary

  Polarisation modulation · CPC title

• H04B10/556

  Digital modulation, e.g. differential phase shift keying [DPSK] or frequency shift keying [FSK] · CPC title

• H04L27/2075

  in which the data are represented by the change in carrier phase · CPC title