Method to decode a data string

• US 7,802,173 B2
• Filed: 03/10/2004
• Issued: 09/21/2010
• Est. Priority Date: 04/17/2003
• Status: Active Grant

• Current Assignee: InterDigital Madison Patent Holdings (InterDigital, Inc.)
• Original Assignee: Thomson Licensing (Vantiva SA)
• Inventors: Chia, Song Yong, Chan, Choon Meng, Choo, Hin Soon
• Primary Examiner(s): RIZK, SAMIR WADIE
• Application Number:
  US10/553,699
• Publication Number:
  US 20070100819A1
• Time in Patent Office: 2,386 Days
• Field of Search: 714/819, 704/500, 340/539.1, 340/286.02, 348/461, 348/473, 455/404.1, 455/404.2, 725/23
• US Class Current: 714/819
• CPC Class Codes: G08B 27/008 with transmission via TV or radio broadcast
• CPC Class Codes: H04L 1/08 by repeating transmission, e.g. Verdan system H04L1/1858 and H04L1/189 take precedence

Abstract

The invention relates to decode data transmitted via US National Weather Service NOAA Weather Radio (NWR) transmitters or any other data transmitted in a comparable way. According to the invention a method to decode a received data string comprises the steps of locating a predefined significant part of the data string, disregarding an insignificant part of the data string, and further checking only the located significant part of the data string. Decoding according to the proposed algorithm is very reliable.

Claims

1. Method to decode a received data string in a processing device, said data string being part of a message containing non-data elements and data string elements of varying length, comprising the steps of:

locating a predefined subset of the data string, said subset consisting of data string elements considered as most significant; and

checking agreement of only said subset of repeated data string elements.

2. Method according to claim 1, comprising the steps of:

determining the length of said data string;

pinpointing predetermined data positions using said length;

removing data from said data string starting from a position determined by said length.

3. Method according to claim 2, wherein the determining step consists in locating a predetermined sequence in said data string.

4. Method according to claim 1, further comprising the steps of:

comparing, byte by byte, different data strings assumed to contain identical data;

taking as correct data those bytes for which said comparison gives the result “

identical”

.

5. Method according to claim 1, further comprising the steps of:

locating a predefined important segment as significant part of the data strings remaining after the previous step;

disregarding the data locations that do not belong to said important segment; and

further checking only the important segments.

6. Method according to claim 1 comprising the further step of:

searching for meaningful data in case that no correct data can be determined.

7. Method according to claim 1 comprising the further step of:

searching for a predefined header code block; and

attaching a header code block at the start of the received data string if no such header code block is found in the preceding step.

8. Method according to claim 1 comprising the further step of:

checking for a predetermined set of symbols at a predetermined location of the data string; and

inserting to or removing from the data string symbols so as to shift the predetermined location if the check of the previous step did locate them at a different position.

9. Device for performing a method according to claim 1.

10. Broadcast receiver being equipped with a device according to claim 9 or being provided for performing the method.