Characteristics of codebooks used with permutation code trees
- Heymann, R., Swart, Theo G., Ferreira, Hendrik C.
- Authors: Heymann, R. , Swart, Theo G. , Ferreira, Hendrik C.
- Date: 2010
- Subjects: Powerline communications , Permutation codes
- Language: English
- Type: Conference proceedings
- Identifier: http://hdl.handle.net/10210/21341 , uj:16142 , Citation: Heymann, R., Swart, T.G. & Ferreira, H.C. 2010. Characteristics of codebooks used with permutation code trees. Proceedings of Workshop on Power Line Communications and its Applications in Networking and Smart Grid, 22-24 September, 2010, Boppard, Germany.
- Description: Abstract: Permutation codes are used in powerline communications (PLC), together with M-FSK modulation, to combat errors introduced by the channel. It has been proposed that permutation code trees can be used to detect and correct substitution and synchronization errors. This is a fast and simple decoding algorithm with an error correction capability of one error per codeword. However, not all codebooks are suitable to be used with permutation code trees. An investigation is proposed to determine the codebook characteristics which make it suitable for use with permutation code trees.
- Full Text: false
- Authors: Heymann, R. , Swart, Theo G. , Ferreira, Hendrik C.
- Date: 2010
- Subjects: Powerline communications , Permutation codes
- Language: English
- Type: Conference proceedings
- Identifier: http://hdl.handle.net/10210/21341 , uj:16142 , Citation: Heymann, R., Swart, T.G. & Ferreira, H.C. 2010. Characteristics of codebooks used with permutation code trees. Proceedings of Workshop on Power Line Communications and its Applications in Networking and Smart Grid, 22-24 September, 2010, Boppard, Germany.
- Description: Abstract: Permutation codes are used in powerline communications (PLC), together with M-FSK modulation, to combat errors introduced by the channel. It has been proposed that permutation code trees can be used to detect and correct substitution and synchronization errors. This is a fast and simple decoding algorithm with an error correction capability of one error per codeword. However, not all codebooks are suitable to be used with permutation code trees. An investigation is proposed to determine the codebook characteristics which make it suitable for use with permutation code trees.
- Full Text: false
Synchronization using insertion/deletion correcting permutation codes
- Cheng, Ling, Swart, Theo G., Ferreira, Hendrik C.
- Authors: Cheng, Ling , Swart, Theo G. , Ferreira, Hendrik C.
- Date: 2008
- Subjects: Synchronization , Permutation codes
- Language: English
- Type: Conference proceedings
- Identifier: http://hdl.handle.net/10210/18690 , uj:16031 , Citation: Cheng, L., Swart, T.G. & Ferreira, H.C. 2008. Synchronization using insertion/deletion correcting permutation codes. Proceedings of the IEEE International Symposium on Power Line Communications and its Applications, 2-4 April, 2008, Jeju City, Jeju Island, South Korea.
- Description: Abstract: In this paper, we present a fast synchronization coding scheme, which uses single insertion/deletion error correcting permutation codes. A possible application to M-ary FSK for the CENELEC A band power-line communications (PLC) is considered. Compared to conventional timing recovery schemes, no redundancies for preamble sequences and no processing delays from decision devices are needed.
- Full Text:
- Authors: Cheng, Ling , Swart, Theo G. , Ferreira, Hendrik C.
- Date: 2008
- Subjects: Synchronization , Permutation codes
- Language: English
- Type: Conference proceedings
- Identifier: http://hdl.handle.net/10210/18690 , uj:16031 , Citation: Cheng, L., Swart, T.G. & Ferreira, H.C. 2008. Synchronization using insertion/deletion correcting permutation codes. Proceedings of the IEEE International Symposium on Power Line Communications and its Applications, 2-4 April, 2008, Jeju City, Jeju Island, South Korea.
- Description: Abstract: In this paper, we present a fast synchronization coding scheme, which uses single insertion/deletion error correcting permutation codes. A possible application to M-ary FSK for the CENELEC A band power-line communications (PLC) is considered. Compared to conventional timing recovery schemes, no redundancies for preamble sequences and no processing delays from decision devices are needed.
- Full Text:
Re-synchronization of permutation codes with Viterbi-like decoding
- Cheng, Ling, Swart, Theo G., Ferreira, Hendrik C.
- Authors: Cheng, Ling , Swart, Theo G. , Ferreira, Hendrik C.
- Date: 2009
- Subjects: Synchronization , Permutation codes , Decoding
- Language: English
- Type: Conference proceedings
- Identifier: http://hdl.handle.net/10210/18809 , uj:16045 , ISBN: 978-1-4244-3790-0 , Citation: Cheng, L., Swart, T.G. & Ferreira, H.C. 2009. Re-synchronization of permutation codes with Viterbi-like decoding. Proceedings of the IEEE International Symposium on Power Line Communications and its Applications, 29 March - 1 April, 2009, Dresden, Germany.
- Description: Abstract: In this paper, we present a fast re-synchronization algorithm for permutation coded sequences. The new algorithm combines the dynamic algorithm and a Viterbi-like decoding algorithm for trellis codes. The new algorithm has a polynomial time complexity O(N), where N denotes the length of the sequence. A possible application to M-ary FSK for the CENELEC A band power-line communications (PLC) is considered.
- Full Text:
- Authors: Cheng, Ling , Swart, Theo G. , Ferreira, Hendrik C.
- Date: 2009
- Subjects: Synchronization , Permutation codes , Decoding
- Language: English
- Type: Conference proceedings
- Identifier: http://hdl.handle.net/10210/18809 , uj:16045 , ISBN: 978-1-4244-3790-0 , Citation: Cheng, L., Swart, T.G. & Ferreira, H.C. 2009. Re-synchronization of permutation codes with Viterbi-like decoding. Proceedings of the IEEE International Symposium on Power Line Communications and its Applications, 29 March - 1 April, 2009, Dresden, Germany.
- Description: Abstract: In this paper, we present a fast re-synchronization algorithm for permutation coded sequences. The new algorithm combines the dynamic algorithm and a Viterbi-like decoding algorithm for trellis codes. The new algorithm has a polynomial time complexity O(N), where N denotes the length of the sequence. A possible application to M-ary FSK for the CENELEC A band power-line communications (PLC) is considered.
- Full Text:
Binary permutation sequences as subsets of Levenshtein codes, spectral null codes, run-length limited codes and constant weight codes
- Ouahada, Khmaies, Swart, Theo G., Ferreira, Hendrik C., Cheng, Ling
- Authors: Ouahada, Khmaies , Swart, Theo G. , Ferreira, Hendrik C. , Cheng, Ling
- Date: 2008
- Subjects: Permutation codes , Insertion/deletion correcting codes , Constant weight codes , Spectral null codes , Run-length limited codes
- Language: English
- Type: Article
- Identifier: http://hdl.handle.net/10210/18337 , uj:15986 , Citation: Ouahada, K. et al. 2008. Binary permutation sequences as subsets of Levenshtein codes, spectral null codes, run-length limited codes and constant weight codes. Designs, Codes and Cryptography, 48(2): 141-154. DOI: 10.1007s10623-007-9161-7. , DOI: 10.1007s10623-007-9161-7.
- Description: Abstract: We investigate binary sequences which can be obtained by concatenating the columns of (0,1)-matrices derived from permutation sequences. We then prove that these binary sequences are subsets of a surprisingly diverse ensemble of codes, namely the Levenshtein codes, capable of correcting insertion/deletion errors; spectral null codes, with spectral nulls at certain frequencies; as well as being subsets of run-length limited codes, Nyquist null codes and constant weight codes.
- Full Text:
- Authors: Ouahada, Khmaies , Swart, Theo G. , Ferreira, Hendrik C. , Cheng, Ling
- Date: 2008
- Subjects: Permutation codes , Insertion/deletion correcting codes , Constant weight codes , Spectral null codes , Run-length limited codes
- Language: English
- Type: Article
- Identifier: http://hdl.handle.net/10210/18337 , uj:15986 , Citation: Ouahada, K. et al. 2008. Binary permutation sequences as subsets of Levenshtein codes, spectral null codes, run-length limited codes and constant weight codes. Designs, Codes and Cryptography, 48(2): 141-154. DOI: 10.1007s10623-007-9161-7. , DOI: 10.1007s10623-007-9161-7.
- Description: Abstract: We investigate binary sequences which can be obtained by concatenating the columns of (0,1)-matrices derived from permutation sequences. We then prove that these binary sequences are subsets of a surprisingly diverse ensemble of codes, namely the Levenshtein codes, capable of correcting insertion/deletion errors; spectral null codes, with spectral nulls at certain frequencies; as well as being subsets of run-length limited codes, Nyquist null codes and constant weight codes.
- Full Text:
The effect of Hamming distances on permutation codes for multiuser communication in the power line communications channel
- Shongwe, Thokozani, Speidel, Ulrich, Swart, Theo G., Ferreira, Hendrik C.
- Authors: Shongwe, Thokozani , Speidel, Ulrich , Swart, Theo G. , Ferreira, Hendrik C.
- Date: 2011
- Subjects: Multiuser communication system , Permutation codes , Permutation sequences , Hamming distances , Power line communications
- Type: Article
- Identifier: uj:4742 , ISSN 978-1-61284-992-8 , http://hdl.handle.net/10210/11728
- Description: We partition permutation sequences into groups to form permutation codes for multiuser communication. Each group becomes a codebook for each user in a multiuser communication system. We present simulation results for the performance of different partitions of permutation codes for multiuser communication, where the codes are to be used in channels with background noise and jamming, such as the Power Line Communications (PLC) channel. With the help of the simulation results, we show that by partitioning codebooks according to distance properties we can affect the performance of the codes. The permutation codes have codewords of length M with symbols taken from an alphabet whose cardinality is M, where M is any integer. Each symbol may be seen as representing one out of the M frequencies in an M-ary Frequency Shift keying modulation scheme, for example. Each user has a codebook of cardinality greater or equal to M and there can be a maximum of M - 1 users communicating at the same time through a multiple access OR channel.
- Full Text:
- Authors: Shongwe, Thokozani , Speidel, Ulrich , Swart, Theo G. , Ferreira, Hendrik C.
- Date: 2011
- Subjects: Multiuser communication system , Permutation codes , Permutation sequences , Hamming distances , Power line communications
- Type: Article
- Identifier: uj:4742 , ISSN 978-1-61284-992-8 , http://hdl.handle.net/10210/11728
- Description: We partition permutation sequences into groups to form permutation codes for multiuser communication. Each group becomes a codebook for each user in a multiuser communication system. We present simulation results for the performance of different partitions of permutation codes for multiuser communication, where the codes are to be used in channels with background noise and jamming, such as the Power Line Communications (PLC) channel. With the help of the simulation results, we show that by partitioning codebooks according to distance properties we can affect the performance of the codes. The permutation codes have codewords of length M with symbols taken from an alphabet whose cardinality is M, where M is any integer. Each symbol may be seen as representing one out of the M frequencies in an M-ary Frequency Shift keying modulation scheme, for example. Each user has a codebook of cardinality greater or equal to M and there can be a maximum of M - 1 users communicating at the same time through a multiple access OR channel.
- Full Text:
Correcting adjacent errors using permutation code trees
- Heymann, R., Swart, Theo G., Ferreira, Hendrik C.
- Authors: Heymann, R. , Swart, Theo G. , Ferreira, Hendrik C.
- Date: 2011
- Subjects: Error-correcting codes (Information theory) , Permutation codes
- Language: English
- Type: Conference proceedings
- Identifier: http://hdl.handle.net/10210/18278 , uj:15979 , ISBN: 978-1-61284-993-5 , Citation: Heymann, R., Swart, T.G. & Ferreira, H.C. 2011. Correcting adjacent errors using permutation code trees. Proceedings IEEE Africon, 13-15 September, 2011, Livingstone, Zambia.
- Description: Abcstact: Permutation codes are M-ary codes which can be used, in combination with M-ary FSK, to correct errors in Power Line Communications (PLC). It has been shown in [1] that permutation code trees can be used to correct a single substitution or synchronization error per codeword, without the use of markers. In this paper, we show that, due to the structure of the permutation code tree, adjacent errors can also be corrected if the codebook is adapted.
- Full Text:
- Authors: Heymann, R. , Swart, Theo G. , Ferreira, Hendrik C.
- Date: 2011
- Subjects: Error-correcting codes (Information theory) , Permutation codes
- Language: English
- Type: Conference proceedings
- Identifier: http://hdl.handle.net/10210/18278 , uj:15979 , ISBN: 978-1-61284-993-5 , Citation: Heymann, R., Swart, T.G. & Ferreira, H.C. 2011. Correcting adjacent errors using permutation code trees. Proceedings IEEE Africon, 13-15 September, 2011, Livingstone, Zambia.
- Description: Abcstact: Permutation codes are M-ary codes which can be used, in combination with M-ary FSK, to correct errors in Power Line Communications (PLC). It has been shown in [1] that permutation code trees can be used to correct a single substitution or synchronization error per codeword, without the use of markers. In this paper, we show that, due to the structure of the permutation code tree, adjacent errors can also be corrected if the codebook is adapted.
- Full Text:
Decoding distance-preserving permutation codes for power-line communications
- Swart, Theo G., Ferreira, Hendrik C.
- Authors: Swart, Theo G. , Ferreira, Hendrik C.
- Date: 2007
- Subjects: Distance-preserving , Permutation codes , Power-line communications
- Language: English
- Type: Conference proceedings
- Identifier: http://hdl.handle.net/10210/17971 , uj:15943 , Citation: Swart, T.G. & Ferreira, H.C. 2007. Decoding distance-preserving permutation codes for power-line communications. Proceedings of IEEE Africon, 26-28 September, 2007, Windhoek, Namibia.
- Description: Abstract: A new decoding method is presented for permutation codes obtained from distance-preserving mapping algorithms, used in conjunction with M-ary FSK for use on powerline channels. The new approach makes it possible for the permutation code to be used as an inner code with any other error correction code used as an outer code. The memory and number of computations necessary for this method is lower than when using a minimum distance decoding method.
- Full Text:
- Authors: Swart, Theo G. , Ferreira, Hendrik C.
- Date: 2007
- Subjects: Distance-preserving , Permutation codes , Power-line communications
- Language: English
- Type: Conference proceedings
- Identifier: http://hdl.handle.net/10210/17971 , uj:15943 , Citation: Swart, T.G. & Ferreira, H.C. 2007. Decoding distance-preserving permutation codes for power-line communications. Proceedings of IEEE Africon, 26-28 September, 2007, Windhoek, Namibia.
- Description: Abstract: A new decoding method is presented for permutation codes obtained from distance-preserving mapping algorithms, used in conjunction with M-ary FSK for use on powerline channels. The new approach makes it possible for the permutation code to be used as an inner code with any other error correction code used as an outer code. The memory and number of computations necessary for this method is lower than when using a minimum distance decoding method.
- Full Text:
Combined permutation codes for synchronization
- Heymann, R., Ferreira, Hendrik C., Swart, Theo G.
- Authors: Heymann, R. , Ferreira, Hendrik C. , Swart, Theo G.
- Date: 2012
- Subjects: Permutation codes , Synchronization
- Language: English
- Type: Conference proceedings
- Identifier: http://hdl.handle.net/10210/18495 , uj:16006 , Citation: Heymann, R., Ferreira, H.C. & Swart, T.G. 2012. Combined permutation codes for synchronization. Proceedings of the International Symposium on Information Theory and Its Applications, 28-31 October, 2012, Honolulu, Hawaii, USA.
- Description: Abstract: A combined code is a code that combines two or more characteristics of other codes. A construction is presented in this paper of permutation codes that are self-synchronizing and able to correct a number of deletion errors per codeword, thus a combined permutation code. Synchronization errors, modelled as deletion(s) and/or insertion(s) of bits or symbols, can be catastrophic if not detected and corrected. Some classes of codes have been proposed that are synchronizable, i.e. they can be used to regain synchronization although the error leading to the loss of synchronization is not corrected. Typically, different classes of codes are needed to correct deletion and/or insertion errors after codeword boundaries have been detected. The codebooks presented in this paper consist of codewords divided into segments. By imposing restrictions on the segments, the codewords are synchronizable. One deletion error can be detected and corrected per segment.
- Full Text:
- Authors: Heymann, R. , Ferreira, Hendrik C. , Swart, Theo G.
- Date: 2012
- Subjects: Permutation codes , Synchronization
- Language: English
- Type: Conference proceedings
- Identifier: http://hdl.handle.net/10210/18495 , uj:16006 , Citation: Heymann, R., Ferreira, H.C. & Swart, T.G. 2012. Combined permutation codes for synchronization. Proceedings of the International Symposium on Information Theory and Its Applications, 28-31 October, 2012, Honolulu, Hawaii, USA.
- Description: Abstract: A combined code is a code that combines two or more characteristics of other codes. A construction is presented in this paper of permutation codes that are self-synchronizing and able to correct a number of deletion errors per codeword, thus a combined permutation code. Synchronization errors, modelled as deletion(s) and/or insertion(s) of bits or symbols, can be catastrophic if not detected and corrected. Some classes of codes have been proposed that are synchronizable, i.e. they can be used to regain synchronization although the error leading to the loss of synchronization is not corrected. Typically, different classes of codes are needed to correct deletion and/or insertion errors after codeword boundaries have been detected. The codebooks presented in this paper consist of codewords divided into segments. By imposing restrictions on the segments, the codewords are synchronizable. One deletion error can be detected and corrected per segment.
- Full Text:
Convolutional code search for optimum permutation trellis codes using M-ary FSK
- Swart, Theo G., Han Vinck, A. J., Ferreira, Hendrik C.
- Authors: Swart, Theo G. , Han Vinck, A. J. , Ferreira, Hendrik C.
- Date: 2007
- Subjects: Channel coding , Permutation codes , Frequency-shift keying , Interference suppression
- Language: English
- Type: Conference proceedings
- Identifier: http://hdl.handle.net/10210/18537 , uj:16011 , Citation: Swart, T.G., Vinck, A.J.H. & Ferreira, H.C. 2007. Convolutional code search for optimum permutation trellis codes using M-ary FSK. Proceedings of the IEEE International Symposium on Power Line Communications and its Applications, 26-28 March, 2007.
- Description: Abstract: Permutation trellis codes combined with M-ary FSK are considered with the aim of combating additive noise, impulse noise and permanent frequency disturbances. New permutation trellis codes are presented that were found by exhaustive computer search, considering the free distance and the distance spectrum of the codes. Until now the best binary convolutional codes were considered to be the best candidates to use in mappings for trellis codes, however the results will show that this is not always the case. Simulation results are also presented, showing that in most cases the new permutation trellis codes are performing better than the previous codes, although the gains attained are small.
- Full Text:
- Authors: Swart, Theo G. , Han Vinck, A. J. , Ferreira, Hendrik C.
- Date: 2007
- Subjects: Channel coding , Permutation codes , Frequency-shift keying , Interference suppression
- Language: English
- Type: Conference proceedings
- Identifier: http://hdl.handle.net/10210/18537 , uj:16011 , Citation: Swart, T.G., Vinck, A.J.H. & Ferreira, H.C. 2007. Convolutional code search for optimum permutation trellis codes using M-ary FSK. Proceedings of the IEEE International Symposium on Power Line Communications and its Applications, 26-28 March, 2007.
- Description: Abstract: Permutation trellis codes combined with M-ary FSK are considered with the aim of combating additive noise, impulse noise and permanent frequency disturbances. New permutation trellis codes are presented that were found by exhaustive computer search, considering the free distance and the distance spectrum of the codes. Until now the best binary convolutional codes were considered to be the best candidates to use in mappings for trellis codes, however the results will show that this is not always the case. Simulation results are also presented, showing that in most cases the new permutation trellis codes are performing better than the previous codes, although the gains attained are small.
- Full Text:
Decoding distance-preserving permutation codes for power-line communications
- Swart, Theo G., Ferreira, Hendrik C.
- Authors: Swart, Theo G. , Ferreira, Hendrik C.
- Date: 2007
- Subjects: Power-line communications , Permutation codes , Decoding methods
- Language: English
- Type: Conference paper
- Identifier: http://hdl.handle.net/10210/165801 , uj:15452 , T. G. Swart and H. C. Ferreira, "Decoding distance-preserving permutation codes for power-line communications," in Proceedings of IEEE Africon, Windhoek, Namibia, September 26-28, 2007, published on CD (6 pages).
- Description: A new decoding method is presented for permutation codes obtained from distance-preserving mapping algorithms, used in conjunction with M-ary FSK for use on powerline channels. The new approach makes it possible for the permutation code to be used as an inner code with any other error correction code used as an outer code. The memory and number of computations necessary for this method is lower than when using a minimum distance decoding method.
- Full Text:
- Authors: Swart, Theo G. , Ferreira, Hendrik C.
- Date: 2007
- Subjects: Power-line communications , Permutation codes , Decoding methods
- Language: English
- Type: Conference paper
- Identifier: http://hdl.handle.net/10210/165801 , uj:15452 , T. G. Swart and H. C. Ferreira, "Decoding distance-preserving permutation codes for power-line communications," in Proceedings of IEEE Africon, Windhoek, Namibia, September 26-28, 2007, published on CD (6 pages).
- Description: A new decoding method is presented for permutation codes obtained from distance-preserving mapping algorithms, used in conjunction with M-ary FSK for use on powerline channels. The new approach makes it possible for the permutation code to be used as an inner code with any other error correction code used as an outer code. The memory and number of computations necessary for this method is lower than when using a minimum distance decoding method.
- Full Text:
Concatenated permutation block codes based on set partitioning for substitution and deletion error-control
- Heymann, Reolyn, Weber, Jos H., Swart, Theo G., Ferreira, Hendrik C.
- Authors: Heymann, Reolyn , Weber, Jos H. , Swart, Theo G. , Ferreira, Hendrik C.
- Date: 2013
- Subjects: Binary data , Permutation codes
- Type: Article
- Identifier: uj:4853 , http://hdl.handle.net/10210/12520
- Description: A new class of permutation codes is presented where, instead of considering one permutation as a codeword, codewords consist of a sequence of permutations. The advantage of using permutations, i.e. their favourable symbol diversity properties, is preserved. Additionally, using sequences of permutations as codewords, code rates close to the optimum rate can be achieved. Firstly, the complete set of permutations is divided into subsets by using set partitioning. Binary data is then mapped to permutations from these subsets. These permutations, together with a parity permutation, will form the codeword. Two constructions will be presented: one capable of detecting and correcting substitution errors and the other capable of detecting and correcting either substitution or deletion errors.
- Full Text:
- Authors: Heymann, Reolyn , Weber, Jos H. , Swart, Theo G. , Ferreira, Hendrik C.
- Date: 2013
- Subjects: Binary data , Permutation codes
- Type: Article
- Identifier: uj:4853 , http://hdl.handle.net/10210/12520
- Description: A new class of permutation codes is presented where, instead of considering one permutation as a codeword, codewords consist of a sequence of permutations. The advantage of using permutations, i.e. their favourable symbol diversity properties, is preserved. Additionally, using sequences of permutations as codewords, code rates close to the optimum rate can be achieved. Firstly, the complete set of permutations is divided into subsets by using set partitioning. Binary data is then mapped to permutations from these subsets. These permutations, together with a parity permutation, will form the codeword. Two constructions will be presented: one capable of detecting and correcting substitution errors and the other capable of detecting and correcting either substitution or deletion errors.
- Full Text:
- «
- ‹
- 1
- ›
- »