Sampling method for use with bursty communication channels

• US 20020199153A1
• Filed: 06/22/2001
• Published: 12/26/2002
• Est. Priority Date: 06/22/2001
• Status: Abandoned Application

• Current Assignee: Lockheed Martin Corporation (Martin Marietta Corporation)
• Original Assignee: Lockheed Martin Corporation (Martin Marietta Corporation)
• Inventors: Fall, Thomas G.
• Application Number:
  US09/887,888
• Publication Number:
  US 20020199153A1
• Time in Patent Office: Days
• US Class Current: 714/781
• CPC Class Codes: H03M 13/00 Coding, decoding or code conversion, for error detection or error correction; Coding theory basic assumptions; Coding bounds; Error probability evaluation methods; Channel models; Simulation or testing of codes error detection or error correction for analogue/digital, digital/analogue or code conversion H03M1/00 – H03M11/00; specially adapted for digital computers G06F11/08; for information storage based on relative movement between record carrier and transducer G11B, e.g. G11B20/18; for static stores G11C

Abstract

An error correction method wherein an incoming data stream is divided into symbols. The divided data stream is sampled in threads, with samples taken at fixed time intervals. The fixed time intervals are slightly longer than the time interval of the bursts of data. A correction symbol is thus mixed with symbols of the divided data stream that have a fixed time separation. This generates an error corrected data stream. In a second embodiment, the same correction symbol is inserted in more than one thread. The threads are selected so that they partially overlap. Thus, a noise burst on the channel that overwhelms one of the threads will be within the limits of another one of the threads. The symbols that overlap may be determined using the overlapping symbols of the threads that are not overwhelmed, thus allowing the remainder of the non-overlapped threads to be determined.

Claims

1. An error correction method for use with a noisy communication channel, said method comprising the steps of:

dividing a data stream into symbols;

sampling the divided data stream in threads, wherein samples are taken at fixed 5 time intervals;

inserting a correction symbol into the data stream to mix the correction symbol with data symbols that have a fixed time separation;

transmitting the data stream;

receiving the transmitted data stream;

performing error detection and correction computations on the data and error correction symbols; and

outputting an error corrected data stream.

2. The method of claim 1 wherein the bursty communication channel comprises a satellite communication link.

3. The method of claim 1 wherein the bursty communication channel comprises a scratched compact disk.

4. The method of claim 1 wherein the incoming data stream comprises symbols in the form of bits.

5. The method of claim 1 wherein the incoming data stream comprises symbols in the form of bytes.

6. The method of claim 1 wherein the incoming data stream comprises symbols in the form of words.

7. The method of claim 1 wherein samples are taken at fixed time intervals that are longer than the time interval of the bursts of data.

8. The method of claim 1 wherein the step of performing error detection and correction comprises performing cyclic redundancy check error correction.

9. The method of claim 1 wherein the step of inserting a correction symbol into the data stream comprises the step of inserting the same correction symbol is in more than one thread.

10. An error correction method for use with a noisy communication channel, said method comprising the steps of:

copying each data symbol that is to be transmitted onto a register;

placing each data symbol onto a transmit output buffer in a predetermined position, wherein positions between each data symbol are filled with error correcting symbols calculated after a register gets filled;

transmitting a symbol transmission stream from the transmit output buffer;

receiving the transmitted transmission stream;

placing data and error correction symbols from the symbol transmission stream on predetermined registers;

performing error detection and correction computations on the data and error correction symbols;

placing the corrected data symbols on a receive output buffer in their correct positions; and

outputting an error corrected data stream from the receive output buffer.

11. The method of claim 10 wherein the bursty communication channel comprises a satellite communication link.

12. The method of claim 10 wherein the bursty communication channel comprises a scratched compact disk.

13. The method of claim 10 wherein the incoming data stream comprises symbols in the form of bits.

14. The method of claim 10 wherein the incoming data stream comprises symbols in the form of bytes.

15. The method of claim 10 wherein the incoming data stream comprises symbols in the form of words.

16. The method of claim 10 wherein samples are taken at fixed time intervals that are longer than the time interval of the bursts of data.

17. The method of claim 10 wherein the step of performing error detection and correction comprises performing cyclic redundancy check error correction.

18. The method of claim 10 wherein the step of inserting a correction symbol into the data stream comprises the step of inserting the same correction symbol is in more than one thread.