We report a new concept involving an adap-tive mixture of different sets of permutation codes (PC... more We report a new concept involving an adap-tive mixture of different sets of permutation codes (PC) in a single DPSK-OFDM modulation scheme. Since this scheme is robust and the algorithms involved are simple , it is a good candidate for implementation for OFDM-based power line communication (PLC) systems. By using a special and easy concept called Hamming distance profile, as a comparison tool, we are able to showcase the strength of the new PC scheme over other schemes reported in literature, in handling the incessant noise types associated with PLC channels. This prediction tool is also useful for selecting an efficient PC codebook out of a number of similar ones.
Permutation coding (PC) has been known to be effective in combating power line channel impairment... more Permutation coding (PC) has been known to be effective in combating power line channel impairments, when used in concatenation with other channel coding schemes like convolutional or Reed Solomon (RS) codes, using FSK, PSK or DPSK as the modulator. We hereby report the development of a modified DPSK modulator, called differential quinary PSK (DQuiPSK), with only 5 constellations, to improve the performance of permutation coded DPSK-OFDM modulation for power line communication (PLC) purposes. This combination is, therefore, termed an RS-PC-DQuiPSK-OFDM scheme, with RS being used as an outer code. To implement this over power line, universal software radio peripherals, which are software defined radio hardware, originally designed for radio communications, were used together with narrowband coupling circuits, to interface with the power line. Simulations and practical implementation results show the strength and competitive performance of our scheme over the conventional convolutional coded D8PSK-OFDM scheme specified in the narrowband PLC standard.
Distance Preserving Mappings (DPM) is a relatively new technique finding its way to a wide use in... more Distance Preserving Mappings (DPM) is a relatively new technique finding its way to a wide use in the coding field. New codes mapping convolutional code outputs onto spectral nulls codewords have the purpose of generating a code with a certain spectrum specification and error correction capabilities, which can be exploited by the Viterbi decoder. Combining this class of new codes
2009 IEEE International Symposium on Information Theory, 2009
Balancing of q-ary sequences, using a generalization of Knuth's efficient parallel balancing... more Balancing of q-ary sequences, using a generalization of Knuth's efficient parallel balancing scheme, is considered. It is shown that the new general scheme is as simple as the original binary scheme, which lends itself to parallel decoding of the balanced sequences.
Theory and Applications for Narrowband and Broadband Communications over Power Lines, 2010
ABSTRACT Digital transmission is at the core of any communications system, including Power Line C... more ABSTRACT Digital transmission is at the core of any communications system, including Power Line Communications (PLC) systems. This chapter distinguishes between modulation and coding for the two classes of PLC systems, namely narrowband and broadband PLC systems. It presents a selection of modulation and coding techniques for each class. The chapter addresses modulation and coding for narrowband PLC systems. It discusses some fundamentals, permutation trellis codes-a combined coding and describes modulation scheme utilizing Frequency Shift Keying (FSK) and convolutional codes. The chapter covers both accepted modulation and coding schemes for broadband systems, as well as some more recent results. For broadband systems, the two important modulation contenders which have previously been considered include spread spectrum and multicarrier techniques. The chapter presents the latest major and arguably most powerful class of codes from information theory, namely Low-Density Parity-Check (LDPC) codes, and shows how these may be adapted for PLC. carrier transmission on power lines; frequency shift keying; modulation; parity check codes
Proceedings of the 1999 IEEE Information Theory and Communications Workshop (Cat. No. 99EX253), 1999
In this paper, new results on multiple symbol insertion and/or deletion correcting codes are pres... more In this paper, new results on multiple symbol insertion and/or deletion correcting codes are presented. Firstly, new relationships between codebook properties and the symbol insertion and/or deletion correcting ability of a codebook are established. Secondly, new results on the upper bound of symbol insertion and/or deletion correcting codebook cardinalities are presented
We report a new concept involving an adap-tive mixture of different sets of permutation codes (PC... more We report a new concept involving an adap-tive mixture of different sets of permutation codes (PC) in a single DPSK-OFDM modulation scheme. Since this scheme is robust and the algorithms involved are simple , it is a good candidate for implementation for OFDM-based power line communication (PLC) systems. By using a special and easy concept called Hamming distance profile, as a comparison tool, we are able to showcase the strength of the new PC scheme over other schemes reported in literature, in handling the incessant noise types associated with PLC channels. This prediction tool is also useful for selecting an efficient PC codebook out of a number of similar ones.
Permutation coding (PC) has been known to be effective in combating power line channel impairment... more Permutation coding (PC) has been known to be effective in combating power line channel impairments, when used in concatenation with other channel coding schemes like convolutional or Reed Solomon (RS) codes, using FSK, PSK or DPSK as the modulator. We hereby report the development of a modified DPSK modulator, called differential quinary PSK (DQuiPSK), with only 5 constellations, to improve the performance of permutation coded DPSK-OFDM modulation for power line communication (PLC) purposes. This combination is, therefore, termed an RS-PC-DQuiPSK-OFDM scheme, with RS being used as an outer code. To implement this over power line, universal software radio peripherals, which are software defined radio hardware, originally designed for radio communications, were used together with narrowband coupling circuits, to interface with the power line. Simulations and practical implementation results show the strength and competitive performance of our scheme over the conventional convolutional coded D8PSK-OFDM scheme specified in the narrowband PLC standard.
Distance Preserving Mappings (DPM) is a relatively new technique finding its way to a wide use in... more Distance Preserving Mappings (DPM) is a relatively new technique finding its way to a wide use in the coding field. New codes mapping convolutional code outputs onto spectral nulls codewords have the purpose of generating a code with a certain spectrum specification and error correction capabilities, which can be exploited by the Viterbi decoder. Combining this class of new codes
2009 IEEE International Symposium on Information Theory, 2009
Balancing of q-ary sequences, using a generalization of Knuth's efficient parallel balancing... more Balancing of q-ary sequences, using a generalization of Knuth's efficient parallel balancing scheme, is considered. It is shown that the new general scheme is as simple as the original binary scheme, which lends itself to parallel decoding of the balanced sequences.
Theory and Applications for Narrowband and Broadband Communications over Power Lines, 2010
ABSTRACT Digital transmission is at the core of any communications system, including Power Line C... more ABSTRACT Digital transmission is at the core of any communications system, including Power Line Communications (PLC) systems. This chapter distinguishes between modulation and coding for the two classes of PLC systems, namely narrowband and broadband PLC systems. It presents a selection of modulation and coding techniques for each class. The chapter addresses modulation and coding for narrowband PLC systems. It discusses some fundamentals, permutation trellis codes-a combined coding and describes modulation scheme utilizing Frequency Shift Keying (FSK) and convolutional codes. The chapter covers both accepted modulation and coding schemes for broadband systems, as well as some more recent results. For broadband systems, the two important modulation contenders which have previously been considered include spread spectrum and multicarrier techniques. The chapter presents the latest major and arguably most powerful class of codes from information theory, namely Low-Density Parity-Check (LDPC) codes, and shows how these may be adapted for PLC. carrier transmission on power lines; frequency shift keying; modulation; parity check codes
Proceedings of the 1999 IEEE Information Theory and Communications Workshop (Cat. No. 99EX253), 1999
In this paper, new results on multiple symbol insertion and/or deletion correcting codes are pres... more In this paper, new results on multiple symbol insertion and/or deletion correcting codes are presented. Firstly, new relationships between codebook properties and the symbol insertion and/or deletion correcting ability of a codebook are established. Secondly, new results on the upper bound of symbol insertion and/or deletion correcting codebook cardinalities are presented
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Papers by Theo Swart
convolutional or Reed Solomon (RS) codes, using FSK, PSK or
DPSK as the modulator. We hereby report the development of
a modified DPSK modulator, called differential quinary PSK
(DQuiPSK), with only 5 constellations, to improve the performance of permutation coded DPSK-OFDM modulation for power line communication (PLC) purposes. This combination is, therefore, termed an RS-PC-DQuiPSK-OFDM scheme, with RS being used as an outer code. To implement this over power line, universal software radio peripherals, which are software defined radio hardware, originally designed for radio communications, were used together with narrowband coupling circuits, to interface with the power line. Simulations and practical implementation results show the strength and competitive performance of our scheme over the conventional convolutional coded D8PSK-OFDM scheme specified in the narrowband PLC standard.
convolutional or Reed Solomon (RS) codes, using FSK, PSK or
DPSK as the modulator. We hereby report the development of
a modified DPSK modulator, called differential quinary PSK
(DQuiPSK), with only 5 constellations, to improve the performance of permutation coded DPSK-OFDM modulation for power line communication (PLC) purposes. This combination is, therefore, termed an RS-PC-DQuiPSK-OFDM scheme, with RS being used as an outer code. To implement this over power line, universal software radio peripherals, which are software defined radio hardware, originally designed for radio communications, were used together with narrowband coupling circuits, to interface with the power line. Simulations and practical implementation results show the strength and competitive performance of our scheme over the conventional convolutional coded D8PSK-OFDM scheme specified in the narrowband PLC standard.