Methods and systems for multi-level beacon tone modulation of an optical data signal
Methods for systems are described for communicating an optical data signal. An example method may comprise receiving a data signal comprising a first level indicative of an upper end of a power range of the data signal and a second level indicative of a lower end of the power range of the data signal. The example method may comprise modulating the data signal to generate a modulated data signal. The modulated data signal may comprise the first level modulated with a first beacon tone and the second level modulated with a second beacon tone. The second level may be modulated in phase with the first level. The method may comprise transmitting an optical signal comprising the modulated data signal.
1. A method comprising:
receiving a data signal comprising a first level indicative of an upper end of a power range of the data signal and a second level indicative of a lower end of the power range of the data signal;
modulating the data signal to generate a modulated data signal, wherein the modulated data signal comprises the first level modulated with a first beacon tone and the second level modulated with a second beacon tone, and wherein the second level is modulated in phase with the first level; and
transmitting an optical signal comprising the modulated data signal.
2. The method of claim 1 , wherein the first level of the data signal is separated from the second level of the data signal by a fixed direct current voltage bias.
3. The method of claim 1 , wherein transmitting the optical signal comprises transmitting the optical signal in free space.
4. The method of claim 1 , wherein the first beacon tone and the second beacon tone are the same.
5. The method of claim 1 , further comprising applying pulse amplitude modulation to one or more of the data signal, the modulated data signal, or the optical signal.
6. The method of claim 1 , wherein a total power level of the optical signal remains constant while an amplitude of one or more of the first beacon tone or the second beacon tone varies.
7. The method of claim 1 , wherein a swing of the optical signal remains constant while an amplitude of one or more of the first beacon tone or the second beacon tone varies.
8. A device comprising:
a modulator configured to:
receive a data signal comprising a first level indicative of an upper end of a power range of the data signal and a second level indicative of a lower end of the power range of the data signal; and
modulate the data signal to generate a modulated data signal, wherein the modulated data signal comprises the first level modulated with a first beacon tone and the second level modulated with a second beacon tone, and wherein the second level is modulated in phase with the first level; and
an optical terminal configured to transmit an optical signal comprising the modulated data signal.
9. The device of claim 8 , wherein the first level of the data signal is separated from the second level of the data signal by a fixed direct current voltage bias.
10. The device of claim 8 , wherein the optical terminal being configured to transmit the optical signal comprises the optical terminal being configured to transmit the optical signal in free space.
11. The device of claim 8 , wherein the first beacon tone and the second beacon tone are the same.
12. The device of claim 8 , wherein the modulator is further configured to apply pulse amplitude modulation to one or more of the data signal, the modulated data signal, or the optical signal.
13. The device of claim 8 , wherein a total power level of the optical signal remains constant while an amplitude of one or more of the first beacon tone or the second beacon tone varies.
14. The device of claim 8 , wherein a swing of the optical signal remains constant while an amplitude one or more of the first beacon tone or the second beacon tone varies.
15. A system comprising:
an optical transmitter configured to:
receive a data signal comprising a first level indicative of an upper end of a power range of the data signal and a second level indicative of a lower end of the power range of the data signal;
modulate the data signal to generate a modulated data signal, wherein the modulated data signal comprises the first level modulated with a first beacon tone and the second level modulated with a second beacon tone, and wherein the second level is modulated in phase with the first level; and
transmit an optical signal comprising the modulated data signal; and
an optical receiver configured to:
receive the optical signal, and
filter one or more of the first beacon tone or the second beacon tone from the optical signal.
16. The system of claim 15 , wherein the optical receiver is configured to filter one or more of the first beacon tone or the second beacon tone from the optical signal by using a high pass filter.
17. The system of claim 15 , wherein the first beacon tone and the second beacon tone are the same.
18. The system of claim 15 , wherein the optical transmitter is further configured to apply pulse amplitude modulation to one or more of the data signal, the modulated data signal, or the optical signal.
19. The system of claim 15 , wherein a total power level of the optical signal remains constant while an amplitude of one or more of the first beacon tone or the second beacon tone varies.
20. The system of claim 15 , wherein a swing of the optical signal remains constant while an amplitude of one or more of the first beacon tone or the second beacon tone varies.