Method for error correction in digitally encoded speech
First Claim
1. A progressive method of decoding a transmitted, digitally encoded speech signal and correcting errors introduced during transmission, the method comprising the following steps:
- (a) receiving said transmitted signal and providing therefrom a frame of data bits having at least a first block of information bits and an additionally coded version of said first block of information bits;
(b) computing a first error syndrome over said first block of information bits;
(c) if said first syndrome indicates no error present in said first block of bits, utilizing said bits for speech synthesis;
(d) if said first syndrome indicates error present in said first block of bits, computing a second error syndrome over said additionally coded version of said first block of bits;
(e) if said second syndrome indicates no error present in said additionally coded bits, utilizing said additionally coded bits for speech synthesis;
(f) if said second syndrome indicates error present in said additionally coded bits, combining said additionally coded bits with said first block of information bits for error correction;
(g) computing a third syndrome over the correct bits resulting from steps (e) or (f);
(h) if said thrid syndrome indicates no error present in said resultant bits, utilizing said resultant bits for speech synthesis.
1 Assignment
0 Petitions
Accused Products
Abstract
A system and method for error correction in communication systems for transmission of digitized speech signals. Sub-band coding is preferably applied to the input signal, and the sample information and the side information provided. An error detection code (EDC) is applied to at least a portion of the side information and an error correction code (ECC) is applied over the side information and the EDC. A second EDC is applied to the ECC. These information signals and error detection and correction codes are multiplexed with the protected portion of the side information and the error correction code separated by at least the sample information. Speech signals are thus transmitted and reconstituted with improved quality with a minimum data rate required.
54 Citations
13 Claims
-
1. A progressive method of decoding a transmitted, digitally encoded speech signal and correcting errors introduced during transmission, the method comprising the following steps:
-
(a) receiving said transmitted signal and providing therefrom a frame of data bits having at least a first block of information bits and an additionally coded version of said first block of information bits; (b) computing a first error syndrome over said first block of information bits; (c) if said first syndrome indicates no error present in said first block of bits, utilizing said bits for speech synthesis; (d) if said first syndrome indicates error present in said first block of bits, computing a second error syndrome over said additionally coded version of said first block of bits; (e) if said second syndrome indicates no error present in said additionally coded bits, utilizing said additionally coded bits for speech synthesis; (f) if said second syndrome indicates error present in said additionally coded bits, combining said additionally coded bits with said first block of information bits for error correction; (g) computing a third syndrome over the correct bits resulting from steps (e) or (f); (h) if said thrid syndrome indicates no error present in said resultant bits, utilizing said resultant bits for speech synthesis. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
-
-
11. A system for providing error correction for digitally encoded speech signals having sample information and side information and comprising:
-
first coding means for providing a first error detecting code for at least a portion of said side information; second coding means for providing an error correcting code for said portion of side information and said first error detecting code; third coding means for providing a second error detecting code for said error correcting code; and multiplexing means for combining said sample information, said side information, and said error detecting and correcting codes and outputting said combined signals to a channel for transmission. - View Dependent Claims (12, 13)
-
Specification