Methods and circuits using frequency shift keying modulation to transfer data over transmission lines simultaneous with television signals

• US 6,189,148 B1
• Filed: 01/28/1999
• Issued: 02/13/2001
• Est. Priority Date: 01/28/1999
• Status: Expired due to Term

• Current Assignee: Christopher J. Schultheiss, Douglas G. Brown
• Original Assignee: Christopher J. Schultheiss, Douglas G. Brown
• Inventors: Monaco, Lawrence D., Clark, Jerry R., Cutler, Todd D., Schultheiss, Christopher J.
• Primary Examiner(s): Faile, Andrew
• Assistant Examiner(s): Srivastava, Vivek
• Application Number:
  US09/239,215
• Time in Patent Office: 747 Days
• Field of Search: H04/N.100, H04/N.111, 348/6, 348/8, 348/9, 348/12, 455/6.3, 455/3.1, 455/6.1, 455/5.1, 455/66, 375/303, 375/272, 375/334
• US Class Current: 725/78
• CPC Class Codes: H04N 21/454 Content or additional data filtering, e.g. blocking advertisements
• CPC Class Codes: H04N 7/106 for domestic distribution

Abstract

Data is transferred using frequency shift keying modulation in a frequency range that is not within a television signal frequency range used to conduct the television signal over the transmission line. Consequently, the present invention may allow the television signal and the data to be conducted on the same cabling. The frequency shift keying modulation is provided by generating a modulated data signal based on information included in the data. For example, the frequency shift keying modulation generates a modulated data signal at a first frequency when the data is equal to a logical 0 and at a second frequency when the data is equal to a logical 1.

Claims

1. A method of transferring data over a television signal transmission line comprising the step of transferring the data between a personal computer and a set top box over the television signal transmission line using frequency shift keying modulation in a frequency range that is not within a television signal frequency range to simultaneously conduct the television signal and the data over the television signal transmission line, wherein the step of transferring comprises the steps of:

converting an interface format data signal to an internal format data signal;

generating a modulated data signal at a frequency based on information included in the internal format data signal;

driving the modulated data signal to compensate for a characteristic impedance of the television signal transmission line to provide a buffered modulated data signal; and

setting a switch direction that electrically couples the buffered modulated data signal to the television signal transmission line.

2. The method of claim 1, wherein the step of transferring comprises the step of receiving the data from the television signal transmission line which simultaneously conducts a television signal.

3. The method of claim 1, wherein the step of transferring comprises the steps of:

generating a modulated data signal at a frequency that is based on information included in the data; and

transmitting the modulated data signal from the personal computer to the set top box over the television signal transmission line.

5. The method of claim 1, wherein the step of transferring comprises the step of transferring the data from a first device in a residence to a second device in the residence.

6. The method of claim 1, wherein the step of transferring comprises the step of transferring data over a coaxial cable.

4. A method of transferring data over a television signal transmission line comprising the step of transferring the data between a personal computer and a set top box over the television signal transmission line using frequency shift keying modulation in a frequency range that is not within a television signal frequency range to simultaneously conduct the television signal and the data over the television signal transmission line;

and

wherein the step of transferring comprises the step of receiving the data from the television signal transmission line which simultaneously conducts a television signal, wherein the step of receiving comprises the step of;

setting a switch direction that electrically couples the data from the television signal transmission line to provide a buffered modulated data signal;

receiving the buffered modulated data signal to compensate for a characteristic impedance of the television signal transmission line;

generating an internal format data signal from the buffered modulated data signal using frequency shift keying demodulation based on a frequency of the buffered modulated data signal; and

converting the internal format data signal to an interface format data signal.

7. A cable transfer interface circuit that transmits data from a data interface over a television signal transmission line during a transmit operation and that provides data from the television signal transmission line to the data interface during a receive operation, the cable transfer interface circuit comprising:

a converter that converts a first personal computer voltage level interface format data signal from the data interface to a transmit voltage level format data signal during the transmit operation;

a transmitter, responsive to the converter, that provides a transmit modulated data signal based on the transmit voltage level format data signal using frequency shift keying during the transmit operation in a frequency range that is not within a television signal frequency range used to conduct the television signal over the television signal transmission line;

a switch, responsive to the transmitter, that electrically couples the transmit modulated data signal to the television signal transmission line during the transmit operation;

wherein the switch electrically couples data from the television signal transmission line to provide a receive modulated data signal during the receive operation;

a receiver, responsive to the switch, that provides a receive voltage level format data signal based on the receive modulated data signal to the converter interface during the receive portion using frequency shift keying demodulation in the frequency range that is not within the television signal frequency range used to conduct the television signal over the television signal transmission line; and

wherein the converter converts the receive voltage level format data signal to a second personal computer voltage level interface format data signal during the receive operation.

8. The cable transfer interface circuit of claim 7, wherein the transmitter comprises:

a frequency shift keying modulator that generates a modulated data signal based on information included in the first personal computer interface format data signal; and

a transmit interface, responsive to the frequency shift keying modulator, that transmits the transmit modulated data signal over the television signal transmission line via the switch based on the modulated data signal, wherein the television signal transmission line has an impedance in a range between about 75 ohms and 25 ohms.

9. The cable transfer interface circuit of claim 7, wherein the receiver comprises

a receive interface that receives data from the television signal transmission line to provide a modulated data signal;

a frequency shift keying demodulator, responsive to the receive interface, that demodulates the modulated data signal to provide a demodulated data signal; and

a level shifter, responsive to the frequency shift keying demodulator, that shifts a voltage level of the demodulated data signal to provide the receive format data signal.

10. The cable transfer interface circuit of claim 7, wherein the television signal transmission line is a coaxial cable.

11. The cable transfer interface circuit of claim 7, wherein the transmitter is located in a building, and wherein data is transmitted over the television signal transmission line to a device in the building.

12. The cable transfer interface circuit of claim 7, wherein the frequency range is between about 800 KHz and 1 MHz.