G. Castagnoli, J. Ganz, and P. Graber, "Optimum cyclic redundancycheck codes with 16-bit redundancy," IEEE Trans. Commun., vol. 38, pp. 111--114, Jan. 1990.  Home/Search   Document Not in Database   Summary   Related Articles   Check

....a factor of per decoded bit. In order to easily search for other likely trellis paths if necessary, some additional storage is required over the normal Viterbi algorithm. Each candidate trellis path is checked by computing a 16 b CRC. The CRC polynomial was selected from those listed in [13] and [14] based on the number of information bits in a packet. For example, with 200 information bits in a packet, the selected CRC polynomial was . III. EXPERIMENTAL RESULTS The system was tested on two 512 512 images, the standard Lena and Goldhill images from the University of Southern California ....

G. Castagnoli, J. Ganz, and P. Graber, "Optimum cyclic redundancycheck codes with 16-bit redundancy," IEEE Trans. Commun., vol. 38, pp. 111--114, Jan. 1990.

....For the packets of length 200 bits and a convolutional code with memory 6, the resulting memory requirement is about 40 Kbytes, which is reasonable for an image application. Each candidate trellis path is checked by computing a 16 bit CRC. The CRC polynomial was selected from those listed in [50] and [51] based on the number of information bits in a packet. For example, with 200 information bits in a packet the selected CRC polynomial was X 16 X 14 X 12 X 11 X 8 X 5 X 4 X 2 1. Computing the check bits is very simple, 24 only requiring bit shift and XOR ....

G. Castagnoli, J. Ganz, and P. Graber, "Optimum cyclic redundancy-check codes with 16-bit redundancy," IEEE Transactions on Communications, vol. 38, no. 1, Jan. 1990, pp. 111--114.

....Alternatively, if used in conjunction with a retransmission scheme, the CRC code ensures that retransmissions are limited to those blocks known to be in error. The 16 bit CRC polynomial used for all simulation results is g(x) x 16 x 15 x 14 x 12 x 11 x 8 x 5 x 4 x 2 1 [8]. We wish to limit the bit stream expansion caused by LVA encoding to 10 . Using a convolutional code with = 4 memory units, and a (216, 200) CRC code results in 220 bits fed to convolutional encoder for every 200 information bits resulting in a 10 expansion as required. After channel coding, ....

G. Castagnoli, J. Ganz, P. Graber, "Optimum Cyclic Redundancy-Check Codes with 16-Bit Redundancy," IEEE Trans. Comm, Vol. 38, pp. 111-114, Jan. 1990.

....flush the memory of the encoder thus incurring another slight overhead penalty. For example, consider a concatenated coding system consisting of an inner convolutional code with rate R = 1 2 , constraint length K = 3 and (7; 5) 8 octal generating polynomial, and a (216; 200) 16 bit CRC outer code [10]. Thus 200 input bits are supplied to the outer CRC code which generates 216 output bits. The LVA requires that the ending state of the encoder is known so K Gamma 1 = 2 extra input symbols are supplied to the inner code to flush the memory. Thus blocks of 216 bits plus two memory flush bits are ....

G. Castagnoli, J. Ganz, P. Graber, "Optimum Cyclic Redundancy-Check Codes with 16-Bit Redundancy," IEEE Trans. Comm, Vol. 38, pp. 111-114, Jan. 1990.

....coder is illustrated in Fig. 4) where the gray block represents a segment of the channel encoded bit stream. We first partition the 3 D SPIHT bit stream into equal length segments, with each segment being of length N (bits) Each segment is then passed through a cyclic redundancy code (CRC) [17, 18] parity checker to generate c = 16 parity bits. In a CRC, binary sequences are associated with polynomials and codewords are selected such that the associated codeword polynomials v(x) of N c bits segments are the multiples of a certain polynomial g(x) called the generator polynomial. For this ....

....such that the associated codeword polynomials v(x) of N c bits segments are the multiples of a certain polynomial g(x) called the generator polynomial. For this work, we pick the CRC generator polynomial g(x) x 16 x 14 x 12 x 11 x 8 x 5 x 4 x 2 1 from the list in [18], which corresponds to the binary sequence of (10101100100110101) Next, m bits, where m is the memory size of the convolutional coder, are padded at the end of each N c bits segment to flush the memory of the RCPC coder. Hence, each N bits of the 3 D SPIHT bit stream is transformed into N c ....

G. Castagnoli, J. Ganz, and P. Graber, "Optimum Cyclic Redundancy-Check Codes with 16-Bit", IEEE Transactions on Communications, vol. 38, pp. 111--114, January 1990.

.... Gamma1 =K per decoded bit. In order to easily search for other likely trellis paths if necessary, some additional storage is required over the normal Viterbi algorithm. Each candidate trellis path is checked by computing a 16 bit CRC. The CRC polynomial was selected from those listed in [13] and [14] based on the number of information bits in a packet. For example, with 200 information bits in a packet the selected CRC polynomial was X 16 X 14 X 12 X 11 X 8 X 5 X 4 X 2 1. 3 Experimental Results The system was tested on two 512x512 images, the standard Lena and ....

G. Castagnoli, J. Ganz, and P. Graber, "Optimum cyclic redundancy-check codes with 16-bit redundancy," IEEE Trans. Comm., vol. 38, pp. 111--114, Jan. 1990.

....the packets of length 200 bits and a convolutional code with memory 6, the resulting memory requirement is about 40 Kbytes which is reasonable for an image application. Each candidate trellis path is checked by computing a 16 bit CRC. The CRC polynomial was selected from those listed in [19] and [20] based on the number of information bits in a packet. For example, with 200 information bits in a packet the selected CRC polynomial was X 16 X 14 X 12 X 11 X 8 X 5 X 4 X 2 1. Computing the check bits is very simple, only requiring bit shift and xor operations, and ....

G. Castagnoli, J. Ganz, and P. Graber, "Optimum cyclic redundancy-check codes with 16-bit redundancy," IEEE Transactions on Communications, vol. 38, pp. 111--114, Jan. 1990.

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