TH66089A - Chien lookup cells for decoders used to correct errors in digital communication systems. - Google Patents

Abstract

DC60 (14/03/46) This content describes the decoder and decoding method. Syndromes are calculated from the codeword in the syndrome generator; error polynomials are generated based on the syndromes in the error polynomial generator; error positions are determined from the error polynomials in the error position generator; error sizes are calculated from the error polynomials in the error size generator; and the codeword is corrected by the error-corrected codeword generator in response to error position and size. Furthermore, the message transmission scheme to the internal decoder blocks is described, where one or more components generate a non-working message to signal the processing capability corresponding to the next codeword. Finally, the use of paired Chien search blocks is described, where Chien search is used to find the number of errors corresponding to a given codeword, separate from the position and size calculations. The architecture of the Chien/Forney search cell with enhanced error correction is described here, using a Galois field adder to synchronize the codeword and error vectors, thereby reducing the delay and overhead associated with the error correction block (950), which is used in conjunction with LIFO registers. The decoder is described here, and the decoding method is described, where the syndrome is calculated from the codeword in the syndrome generator, the error polynomial is generated based on the syndrome in the error polynomial generator, the error position is determined from the error polynomial in the error position generator, the error size is calculated from the error polynomial in the error size generator, and the codeword is corrected by the error correction codeword generator in response to the error position and size. The schematic for sending messages to the decoder block is also described, where one or more components create A message indicating a non-working state is sent to send a signal to show the processing capability corresponding to the next codeword. It also describes the implementation of a paired Chien search block in which the Chien search is used to find the number of errors corresponding to a given codeword, separate from the calculation of the position and magnitude of the errors performed by the Chien/Forney block. The architecture of the enhanced Chien search cell is also described using a Galois field adder to synchronize the codeword and error vectors, thereby reducing the delay and overhead associated with the error correction block (950), which is used in conjunction with LIFO registers.

Claims (11)

1. In the codeword error correction decoder, the method for finding the single error position polynomial coefficient generated from a codeword in the cell corresponding to that single error position polynomial coefficient involves the following operations: - Receiving the error position polynomial coefficient corresponding to the codeword as input. - Multiplying the error position polynomial coefficient by the first clock cycle (corresponding to the codeword processing) by a negative exponent Galois field multiplier, where the negative exponent is a function of the number of steps (j) corresponding to the cell and the length of the codeword (N). This multiplication results in the cell's output. - Repeating this cell output N minus one clock cycle by a positive exponent Galois field multiplier, where the positive exponent is a function of the number of steps (j). 2. The method according to claim 1, where the cell is the Chien search cell of the Chien search block. 3. The method according to claim 1, where the cell is the Forney algorithm cell of the Forney algorithm block. 4. Method according to claim 1, where the cell is the Forney algorithm cell of the Chien/Forney block. 5. The method under Claim 1, whereby the decoder is the Reed-Solomon decoder. 6. In the code word error correction decoder, the method for finding the coefficient of the single error polynomial is calculated by extracting the values from a code word in a cell corresponding to that single error polynomial coefficient. The operation of this method is controlled by the parameters of the following equation: X1=(chemical formula) where i=0, X1=(chemical formula) where i=1...(N-1), where Xi is the i-th root of the error, t is less than the total number of coefficients corresponding to the error polynomial minus one, Aj is the j-th error polynomial coefficient, N is the length of the code word, (alpha) is a member of the Galois field, and j is the number of steps corresponding to the single error polynomial coefficient. 7. The device for determining the polynomial coefficient representing the single error position generated from the codeword in the cell corresponding to that single error position polynomial coefficient is integrated into the decoder used to detect the codeword error. This device consists of: - A path for receiving the polynomial coefficient representing the error position corresponding to the codeword. - A path for multiplying the polynomial coefficient representing the error position in the first clock cycle corresponding to the codeword processing by a multiplier of the Galois field with a negative exponent, where the negative exponent is a function of the number of steps (j) corresponding to that cell and the length of the codeword (N). Such multiplication will result in the output of the cell and - a path for repeatedly multiplying that cell output a number of times minus one clock cycle using a Galois field multiplier with a positive exponent, where that positive exponent is a function of the number of steps (j). 8. The set of devices pursuant to claim 7, where the cell is the Chien search cell of the Chien search block. 9. The set of devices pursuant to claim 7, where the cell is a Forney algorithm cell of a Forney algorithm block. 10. Method according to claim 7, where the cell is the Forney algorithm cell of the Chien/Forney block. 11. The method under claim 7, whereby the decoder is the Reed-Solomon decoder.