METHODS AND APPARATUS FOR MODULATING LIGHT TO CONCURRENTLY CONVEY HIGH RATE DATA AND LOW RATE DATA

• US 20130287403A1
• Filed: 04/30/2012
• Published: 10/31/2013
• Est. Priority Date: 04/30/2012
• Status: Active Grant

• Current Assignee: Intel Corporation
• Original Assignee: Intel Corporation
• Inventors: Roberts, Richard D.
• Granted Patent: US 8,818,204 B2
• Time in Patent Office: Days
• US Class Current: 398/118
• CPC Class Codes: H04B 10/1143 Bidirectional transmission
• CPC Class Codes: H04B 10/516 Details of coding or modulation

Abstract

A light transmitter receives a low-rate data signal having a low data rate and a high-rate data signal having a high data rate that is greater than the low data rate. The transmitter includes a light source and a light modulator to modulate the light source based on logic levels of the high-rate data signal and logic levels of the low-rate data signal, to produce modulated light that concurrently conveys the logic levels of the low-rate data signal and the logic levels of the high-rate data signal.

Claims

1. An apparatus, comprising:

a light source; and

a light modulator to

receive a low-rate data signal having a low data rate and a high-rate data signal having a high data rate that is greater than the low data rate, and

modulate the light source based on logic levels of the high-rate data signal and logic levels of the low-rate data signal to produce modulated light that concurrently conveys the logic levels of the low-rate data signal and the logic levels of the high-rate data signal.

2. The apparatus of claim 1, wherein the light modulator includes an amplitude level generator to:

generate amplitude modulation levels at a modulation rate that is at least as high as the high data rate based on logic levels of the low-rate data signal and logic levels of the high-rate data signal; and

amplitude modulate the light source based on the amplitude modulation states.

3. The apparatus of claim 2, wherein the light modulator further comprises:

a low-rate encoder to encode the logic levels of the low-rate data signal into a low-rate encoded signal; and

a high-rate encoder to encode the logic levels of the high-rate data signal into a high-rate encoded signal,

wherein the amplitude level generator is implemented to generate the amplitude modulation levels based on logic levels of the low-rate encoded signal and corresponding logic levels of the high-rate encoded signal.

4. The apparatus of claim 3, wherein the low-rate encoder is implemented to encode the logic levels of the low-rate data signal as a frequency shift keying (FSK) signal having frequencies representing the logic levels of the low-rate data signal.

5. The apparatus of claim 4, wherein the FSK signal is a frequency shift ON-OFF keying (FSOOK) signal including

multiple ON-OFF waveform cycles at a first frequency to represent a logic zero of the low-rate data signal, and

multiple ON-OFF waveform cycles at a second frequency to represent a logic one of the low-rate data signal.

6. The apparatus of claim 3, wherein the high-rate encoder is implemented to encode the logic levels of the high-rate data signal as edge transitions in the high-rate encoded signal.

7. The apparatus of claim 6, wherein the high-rate encoder is implemented to Manchester encode the high-rate data signal.

8. The apparatus of claim 2, wherein the light modulator further comprises:

a low-rate encoder implemented to generate an FSK signal having frequencies representing the logic levels of the low-rate data signal; and

a high-rate encoder to encode the logic levels of the high-rate data signal into a high-rate encoded signal,

wherein the amplitude level generator is implemented to generate the amplitude modulation levels at the modulation rate as a combination of logic levels of the FSK signal with corresponding logic levels of the low-rate encoded signal.

9. A system, comprising:

a communication system to communicate with a network;

a processor to interface between the communication system and a user interface system;

a light transmitter, the light transmitter comprising;

a light source; and

a light modulator to

receive a low-rate data signal having a low data rate and a high-rate data signal having a high data rate that is greater than the low data rate, and

modulate the light source based on logic levels of the high-rate data signal and logic levels of the low-rate data signal to produce modulated light that concurrently conveys the logic levels of the low-rate data signal and the logic levels of the high-rate data signal; and

a housing,

wherein the processor, the communication system, and the light transmitter are positioned within the housing.

10. The system of claim 9, wherein:

the communication system includes a wireless communication system; and

the housing includes a mobile hand-held housing to house the communication system, the processor, the user interface system, and a battery.

11. The system of claim 9, wherein the light modulator includes an amplitude level generator to:

generate amplitude modulation levels at a modulation rate that is at least as high as the high data rate based on logic levels of the low-rate data signal and logic levels of the high-rate data signal; and

amplitude modulate the light source based on the amplitude modulation states.

12. The system of claim 11, wherein the light modulator further comprises:

a low-rate encoder to encode the logic levels of the low-rate data signal into a low-rate encoded signal; and

a high-rate encoder to encode the logic levels of the high-rate data signal into a high-rate encoded signal,

wherein the amplitude level generator is implemented to generate the amplitude modulation levels based on logic levels of the low-rate encoded signal and corresponding logic levels of the high-rate encoded signal.

13. A method, comprising:

receiving a low-rate data signal having a low data rate;

receiving a high-rate data signal having a high data rate that is greater than the low data rate; and

modulating a light source based on logic levels of the high-rate data signal and logic levels of the low-rate data signal to produce modulated light that concurrently conveys the logic levels of the low-rate data signal and the logic levels of the high-rate data signal.

14. The method of claim 13, wherein said modulating comprises:

generating amplitude modulation levels at a modulation rate that is at least as high as the high data rate based on logic levels of the low-rate data signal and corresponding logic levels of the high-rate data signal; and

amplitude modulating the light source based on the amplitude modulation levels.

15. The method of claim 14, wherein said generating further comprises:

encoding the logic levels of the low-rate data signal into a low-rate encoded signal;

encoding the logic levels of the high-rate data signal into a high-rate encoded signal; and

generating the amplitude modulation levels based on logic levels of the low-rate encoded signal and corresponding logic levels of the high-rate encoded signal.

16. The method of claim 15, wherein said encoding of the low-rate data signal comprises encoding the logic levels of the low-rate data signal as a frequency shift keying (FSK) signal having frequencies representing the logic levels of the low-rate data signal.

17. The method of claim 16, wherein the FSK signal is a frequency shift ON-OFF keying (FSOOK) signal including

multiple ON-OFF cycles at a first frequency to represent a logic zero of the low-rate data signal, and

multiple ON-OFF cycles at a second frequency to represent a logic one of the low-rate data signal.

18. The method of claim 15, wherein said encoding of the high-rate data signal comprises encoding the logic levels of the high-rate data signal as edge transitions in the high-rate encoded signal.

19. The method of claim 18, wherein said encoding of the high-rate signal further comprises Manchester encoding of the logic levels of the high-rate data signal.

20. The method of claim 14, wherein said generating includes:

encoding the logic levels of the low-rate data signal as frequencies of a frequency shift ON-OFF keying (FSOOK) signal;

encoding the logic levels of the high-rate data signal into a high-rate encoded signal; and

combining, at the modulation rate, logic levels of the FOOSK signal with corresponding logic levels of the low-rate encoded signal to produce the amplitude modulation levels.