Combined spectral shaping codes and OFDM modulation for narrowband interference channels
- Ouahada, K., Ferreira, Hendrik C., Han Vinck, A. J., Snyders, A. J., Swart, Theo G.
- Authors: Ouahada, K. , Ferreira, Hendrik C. , Han Vinck, A. J. , Snyders, A. J. , Swart, Theo G.
- Date: 2008
- Subjects: Distance-preserving mappings , Spectral nulls codes , Spectral shaping codes , OFDM modulation , Narrowband interference
- Language: English
- Type: Article
- Identifier: http://hdl.handle.net/10210/21215 , uj:16126 , Citation: Ouahada, K. et al. 2008. Combined spectral shaping codes and OFDM modulation for narrowband interference channels. SAIEE Africa Research Journal, 99(1):11-17.
- Description: Abstract: Distance Preserving Mappings 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 with an Orthogonal Frequency Division Multiplexing modulation scheme is actually a tool to reduce Electromagnetic Compatibility Interference in selected subbands or to cancel the narrowband interference potentially caused by, amongst others, high frequency radio transmissions. Taking into consideration the fact that a narrowband noise source is almost similar to a modulated orthogonal frequency division multiplexing carrier, and also the periodicity of the nulls in our spectrum, we are able to cancel the narrowband signal and its sideband interferences without using traditional techniques of cancellation, which is based on filtering. Shaping our spectrum at the transmitter is a technique, which can be exploited at the receiver to suppress any narrowband signal interference, which is regarded as noise. We will present in this paper the technique of cancellation and the coding gain that can be obtained when comparing to the uncoded data.
- Full Text:
- Authors: Ouahada, K. , Ferreira, Hendrik C. , Han Vinck, A. J. , Snyders, A. J. , Swart, Theo G.
- Date: 2008
- Subjects: Distance-preserving mappings , Spectral nulls codes , Spectral shaping codes , OFDM modulation , Narrowband interference
- Language: English
- Type: Article
- Identifier: http://hdl.handle.net/10210/21215 , uj:16126 , Citation: Ouahada, K. et al. 2008. Combined spectral shaping codes and OFDM modulation for narrowband interference channels. SAIEE Africa Research Journal, 99(1):11-17.
- Description: Abstract: Distance Preserving Mappings 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 with an Orthogonal Frequency Division Multiplexing modulation scheme is actually a tool to reduce Electromagnetic Compatibility Interference in selected subbands or to cancel the narrowband interference potentially caused by, amongst others, high frequency radio transmissions. Taking into consideration the fact that a narrowband noise source is almost similar to a modulated orthogonal frequency division multiplexing carrier, and also the periodicity of the nulls in our spectrum, we are able to cancel the narrowband signal and its sideband interferences without using traditional techniques of cancellation, which is based on filtering. Shaping our spectrum at the transmitter is a technique, which can be exploited at the receiver to suppress any narrowband signal interference, which is regarded as noise. We will present in this paper the technique of cancellation and the coding gain that can be obtained when comparing to the uncoded data.
- Full Text:
Cancellation and error correction for narrowband interference with spectral nulls codes and OFDM modulation
- Ouahada, K., Ferreira, Hendrik C., Han Vinck, A. J., Snyders, A. J., Swart, Theo G.
- Authors: Ouahada, K. , Ferreira, Hendrik C. , Han Vinck, A. J. , Snyders, A. J. , Swart, Theo G.
- Date: 2007
- Subjects: Error-correcting codes (Information theory) , Spectral nulls codes
- Language: English
- Identifier: http://hdl.handle.net/10210/18135 , uj:15964 , Citation: Ouahada, K. et al. 2007. Cancellation and error correction for narrowband interference with spectral nulls codes and OFDM modulation. Proceedings of IEEE Africon, 26-28 September, 2007, Windhoek, Namibia.
- Description: Conference proceedings
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- Authors: Ouahada, K. , Ferreira, Hendrik C. , Han Vinck, A. J. , Snyders, A. J. , Swart, Theo G.
- Date: 2007
- Subjects: Error-correcting codes (Information theory) , Spectral nulls codes
- Language: English
- Identifier: http://hdl.handle.net/10210/18135 , uj:15964 , Citation: Ouahada, K. et al. 2007. Cancellation and error correction for narrowband interference with spectral nulls codes and OFDM modulation. Proceedings of IEEE Africon, 26-28 September, 2007, Windhoek, Namibia.
- Description: Conference proceedings
- Full Text:
Binary permutation sequences as subsets of Levenshtein codes and higher order spectral nulls codes
- Ouahada, Khmaies, Swart, Theo G., Ferreira, Hendrik C.
- Authors: Ouahada, Khmaies , Swart, Theo G. , Ferreira, Hendrik C.
- Date: 2006
- Subjects: Levenshtein codes , Spectral nulls codes , Binary permutation sequences
- Language: English
- Type: Conference proceedings
- Identifier: http://hdl.handle.net/10210/18858 , uj:16051 , Citation: Ouahada, K., Swart, T.G. & Ferreira, H.C. 2006. Binary permutation sequences as subsets of Levenshtein codes and higher order spectral nulls codes. Proceedings of IEEE Information Theory Workshop, Chengdu, 22-26 October, 2006, China, October.
- Description: Abstract: We obtain long binary sequences by concatenating the columns of (0,1)-matrices derived from permutation sequences. We then prove that these binary sequences are subsets of the Levenshtein codes, capable of correcting insertion/deletion errors and subsets of the higher order spectral nulls codes, with spectral nulls at certain frequencies.
- Full Text:
- Authors: Ouahada, Khmaies , Swart, Theo G. , Ferreira, Hendrik C.
- Date: 2006
- Subjects: Levenshtein codes , Spectral nulls codes , Binary permutation sequences
- Language: English
- Type: Conference proceedings
- Identifier: http://hdl.handle.net/10210/18858 , uj:16051 , Citation: Ouahada, K., Swart, T.G. & Ferreira, H.C. 2006. Binary permutation sequences as subsets of Levenshtein codes and higher order spectral nulls codes. Proceedings of IEEE Information Theory Workshop, Chengdu, 22-26 October, 2006, China, October.
- Description: Abstract: We obtain long binary sequences by concatenating the columns of (0,1)-matrices derived from permutation sequences. We then prove that these binary sequences are subsets of the Levenshtein codes, capable of correcting insertion/deletion errors and subsets of the higher order spectral nulls codes, with spectral nulls at certain frequencies.
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Error correction of frequency-selective fading channels with spectral nulls codes
- Ouahada, K., Ferreira, Hendrik C., Snyders, A. J., Han Vinck, A. J., Swart, Theo G.
- Authors: Ouahada, K. , Ferreira, Hendrik C. , Snyders, A. J. , Han Vinck, A. J. , Swart, Theo G.
- Date: 2007
- Subjects: Frequency-selective fading channels , Spectral nulls codes
- Language: English
- Type: Conference proceedings
- Identifier: http://hdl.handle.net/10210/18126 , uj:15962 , Citation: Ouahada, K. et al. 2007. Error correction of frequency-selective fading channels with spectral nulls codes. Proceedings of IEEE Africon, 26-28 September, 2007, Windhoek, Namibia.
- Description: Abstract: In this paper, we investigate a prior error correction technique for frequency selective fading channels. Spectral nulls codes with nulls at submultiple frequencies are used to avoid fades at the corresponding frequencies. Coincide the spectrum null at the corresponding fading frequency and playing with its wideness, will minimize the bit errors caused by the channel.
- Full Text:
- Authors: Ouahada, K. , Ferreira, Hendrik C. , Snyders, A. J. , Han Vinck, A. J. , Swart, Theo G.
- Date: 2007
- Subjects: Frequency-selective fading channels , Spectral nulls codes
- Language: English
- Type: Conference proceedings
- Identifier: http://hdl.handle.net/10210/18126 , uj:15962 , Citation: Ouahada, K. et al. 2007. Error correction of frequency-selective fading channels with spectral nulls codes. Proceedings of IEEE Africon, 26-28 September, 2007, Windhoek, Namibia.
- Description: Abstract: In this paper, we investigate a prior error correction technique for frequency selective fading channels. Spectral nulls codes with nulls at submultiple frequencies are used to avoid fades at the corresponding frequencies. Coincide the spectrum null at the corresponding fading frequency and playing with its wideness, will minimize the bit errors caused by the channel.
- Full Text:
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