METHODS AND APPARATUSES FOR MINIMIZING CO-CHANNEL INTERFERENCE

• US 20090068953A1
• Filed: 10/30/2008
• Published: 03/12/2009
• Est. Priority Date: 04/12/2004
• Status: Active Grant

• Current Assignee: DTVG Licensing, Inc. (AT&T, Inc.)
• Original Assignee: The DIRECTV Group, Inc. (AT&T, Inc.)
• Inventors: Sun, Feng-Wen, Santoru, Joseph, Lee, Lin-Nan, Maitra, Shamik, Chen, Ernest C., Lin, Tung-Sheng, Lai, Dennis, Zhou, Guangcai, Von Ancken, Adam
• Granted Patent: US 8,571,480 B2
• Time in Patent Office: Days
• US Class Current: 455/63.100
• CPC Class Codes: H04B 7/18513 Transmission in a satellite or space-based system
• CPC Class Codes: H04B 7/1858 Arrangements for data transmission on the physical system, i.e. for data bit transmission between network components
• CPC Class Codes: H04N 21/2347 involving video stream encryption
• CPC Class Codes: H04N 21/4405 involving video stream decryption
• CPC Class Codes: H04N 21/6143 involving transmission via a satellite
• CPC Class Codes: H04N 5/211 Ghost signal cancellation H04N23/81 takes precedence
• CPC Class Codes: H04N 7/16 Analogue secrecy systems; Analogue subscription systems
• CPC Class Codes: H04N 7/163 by receiver means only
• CPC Class Codes: H04N 7/1675 Providing digital key or authorisation information for generation or regeneration of the scrambling sequence pseudo-random number generators in general G06F7/58
• CPC Class Codes: H04N 7/17318 Direct or substantially direct transmission and handling of requests

Abstract

Methods and apparatuses for minimizing co-channel interference in communications systems are disclosed. A method in accordance with the present invention comprises scrambling a first frame using a first scrambling code, attaching a first header to the first frame to create the first signal, scrambling a second frame using a second scrambling code, attaching a second header to the second frame to create the second signal, and transmitting the first signal and the second signal over different channels of the communication system.

Claims

1. A method for minimizing co-channel interference in a communication system having at least a first signal and a second signal, each signal transmitted on different channels within the communication system, comprising:

starting a first frame of the first signal;

starting a second frame of the second signal having an offset from the first frame; and

simultaneously transmitting the first signal and the second signal from a transmitter over different channels of the communication system.

2. The method of claim 1, wherein the offset is an offset in time.

3. The method of claim 2, wherein the offset is at least one symbol interval.

4. The method of claim 2, wherein the first frame comprises a first Start-Of-Frame (SOF) portion and the second frame contains a second SOF portion different than the first SOF portion.

5. The method of claim 4, wherein the first SOF portion and the second SOF portion are selected from a limited number of SOF portions.

6. The method of claim 4, wherein the first SOF portion is offset by at least one symbol interval from the second SOF portion.

7. The method of claim 6, wherein the first frame comprises a number of first pilot symbol blocks and the second frame comprises a number of second pilot symbol blocks.

8. The method of claim 7, wherein the first pilot symbol blocks are scrambled with the header.

9. The method of claim 2, further comprising:

transmitting information associated with the offset to a receiver within the communication system.

10. A computer-readable medium bearing instructions for minimizing co-channel interference in a communication system, said instruction, being arranged, upon execution, to cause one or more processors to perform the method of claim 1.

11. The method of claim 1, wherein the offset is an offset in frequency.

12. The method of claim 11, wherein the offset is at least one megahertz.

13. The method of claim 11, wherein the first frame comprises a first Start-Of-Frame (SOF) portion and the second frame contains a second SOF portion different than the first SOF portion.

14. The method of claim 13, wherein the first SOF portion and the second SOF portion are selected from a limited number of SOF portions.

15. The method of claim 13, wherein the first SOF portion is offset by at least one symbol interval from the second SOF portion.

16. The method of claim 15, wherein the first frame comprises a number of first pilot symbol blocks and the second frame comprises a number of second pilot symbol blocks.

17. The method of claim 16, wherein the first pilot symbol blocks are scrambled with the header.

18. The method of claim 11, further comprising:

transmitting information associated with the offset to a receiver within the communication system.