Power line communication system

• US 20030133473A1
• Filed: 08/02/2002
• Published: 07/17/2003
• Est. Priority Date: 08/04/2001
• Status: Abandoned Application

• Current Assignee: Arkados Incorporated (Iota Communications, Inc.)
• Original Assignee: Arkados Incorporated (Iota Communications, Inc.)
• Inventors: Walvis, Dick J., Logvinov, Oleg, Manis, Constantine N., Ebert, Brion J.
• Application Number:
  US10/211,759
• Publication Number:
  US 20030133473A1
• Time in Patent Office: Days
• US Class Current: 370/480
• CPC Class Codes: H04B 2203/5416 by adding signals to the wave form of the power source
• CPC Class Codes: H04B 3/542 the information being in digital form
• CPC Class Codes: H04L 5/06 the signals being represented by different frequencies combined with time-division multiplexing H04L5/26

Abstract

Power line communication method and apparatus in which data modulated radio frequency carriers from two different sources are transmitted by the power line, the range of frequencies of the carriers from one source partially overlapping the range of frequencies of the carriers from the other source, and in which carriers of the one source are shifted to frequencies other than the overlapping frequencies when carriers at the overlapping frequencies and from the other source are present on the line. Optionally, the data signal sampling rate can be changed to simplify signal filtering requirements.

Claims

1. Apparatus for generating and transmitting over a transmission medium a plurality of radio frequency carriers modulated with data signals, the carriers having frequencies in two different, separated frequency ranges, one range higher than the other range, receiving apparatus for receiving and demodulating the carriers transmitted over the transmission medium and having a detector responsive to radio frequency carriers with a frequency intermediate said frequency ranges and a selector coupled to the detector and to the transmitting apparatus for enabling the generation of a plurality of modulated radio frequency carriers having frequencies in one of the two different frequency ranges.

2. Apparatus as set forth in claim 1, wherein the one of the two different frequency ranges is the higher frequency range.

3. Apparatus as set forth in claim 2, wherein the transmission medium is a power line.

4. Apparatus as set forth in claim 3, wherein the power line has interconnected segments and the intermediate carriers are supplied to one segment and the generating and transmitting apparatus and the receiving apparatus are coupled to a different segment.

5. Apparatus as set forth in claim 1, wherein the apparatus for generating and transmitting comprises first means for sampling data signals at a first rate, second means coupled to the first means for providing data signals sampled at a second rate higher than the first rate carrier generating means for generating a plurality of carriers having frequencies different from the sampling rate, modulating mean coupled to the second means and to the carrier generating means for modulating the plurality of carriers with the data signals sampled at the second rate.

6. Apparatus as set forth in claim 5, wherein the receiving apparatus comprises receiving means for receiving the plurality of carriers modulated with the data signals sampled at the second rate, frequency converting means coupled to the receiving means for increasing the frequency of the received carriers and decimating means coupled to the frequency converting means for converting the signals at the output of the frequency converting means to data signals sampled at the first rate.

7. A transmitter having a radio frequency carrier generator for generating a plurality of radio frequency carriers to be transmitted over a transmission medium, the carriers having frequencies in a first range, a modulator coupled to the generator for modulating the carriers with data signals, a mapper coupled to the modulator for selecting the carriers to be modulated dependent on the presence of electrical signals supplied to the transmission medium by another transmitter and having frequencies in a second range which overlaps, but is not coextensive with, said first range, said mapper changing the frequencies of the carriers in said first range which overlap the frequencies of the electrical signals in the second range to different frequencies.

8. A transmitter as set forth in claim 7, wherein the different frequencies are higher frequencies.

9. A transmitter as set forth in claim 8, wherein the lower end of the second range overlaps the upper end of the fast range and the higher frequencies are at the upper end of the second range.

10. Apparatus for generating and transmitting over a transmission medium a plurality of radio frequency carrier modulated with data signals comprising first means for sampling data signals at a first rate, second means coupled to the first means for providing data signals sampled at a second rate higher than the first rate, carrier generating means for generating a plurality of carriers having frequencies different from the sampling rate, modulating means coupled to the second means and to the carrier generating means for modulating the plurality of carriers with the data signals sampled at the second rate.

11. Receiving apparatus comprising receiving means for receiving a plurality of carriers modulated with the data signals sampled at a first rate, frequency converting means coupled to the receiving means for increasing the frequency of the received carriers and decimating means coupled to the frequency converting means for converting the signals at the output of the frequency converting means to data signals sampled at a second rate lower than said first rate.

12. In a power line communication system in which data modulated radio frequency carriers from two different sources are transmitted by the power line, the range of frequencies of the carriers from one source partially overlapping the range of frequencies of the carriers from the other source, the method of reducing interference between the carriers from the one source and the carriers from the other source which comprises:

monitoring the power line at the one source to determine the presence or absence of carriers at overlapping frequencies from the other source; and

when the presence of carriers at overlapping frequencies from the other source are detected shifting the frequencies of the carriers from the one source which overlap the frequencies of the carriers of the other source to frequencies other than the overlapping frequencies.

13. The method as set forth in claim 12, wherein the upper end of the range of carrier frequencies of the one source overlaps the lower end of the range of carrier frequencies of the other source.

14. The method as set forth in claim 13, wherein the frequencies of the carriers in the upper end of the range of frequencies of the carrier frequencies of the one source are shifted to higher frequencies.

15. The method as set forth in claim 14, wherein the higher frequencies are in the range of frequencies of the carriers of the other source.