Sidelobe Reduction in Non-Contiguous OFDM-Based Cognitive Radio Systems Using a Generalized Sidelobe Canceller
In orthogonal frequency division multiplexing (OFDM), sidelobes of the modulated subcarriers cause high out-of-band (OOB) radiation, resulting in interference to licensed and un-licensed users in a cognitive radio system environment. In this work, we present a novel technique based on a generalized...
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| Format: | Article |
| Language: | English |
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MDPI AG
2015-10-01
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| Series: | Applied Sciences |
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| Online Access: | http://www.mdpi.com/2076-3417/5/4/894 |
| _version_ | 1818388722142412800 |
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| author | Atif Elahi Ijaz Mansoor Qureshi Zafar Ullah Khan Fawad Zaman |
| author_facet | Atif Elahi Ijaz Mansoor Qureshi Zafar Ullah Khan Fawad Zaman |
| author_sort | Atif Elahi |
| collection | DOAJ |
| description | In orthogonal frequency division multiplexing (OFDM), sidelobes of the modulated subcarriers cause high out-of-band (OOB) radiation, resulting in interference to licensed and un-licensed users in a cognitive radio system environment. In this work, we present a novel technique based on a generalized sidelobe canceller (GSC) for the reduction of sidelobes. The upper branch of the GSC consists of a weight vector designed by multiple constraints to preserve the desired portion of the input signal. The lower branch has a blocking matrix that blocks the desired portion and preserves the undesired portion (the sidelobes) of the input signal, followed by an adaptive weight vector. The adaptive weight vector adjusts the amplitudes of the undesired portion (the sidelobes) so that when the signal from the lower branch is subtracted from the signal from the upper branch, it results in cancellation of the sidelobes of the input signal. The effectiveness and strength of the proposed technique are verified through extensive simulations. The proposed technique produces competitive results in terms of sidelobe reduction as compared to existing techniques. |
| first_indexed | 2024-12-14T04:30:21Z |
| format | Article |
| id | doaj.art-c28c8df3b0744c6c83693622b08eaf9c |
| institution | Directory Open Access Journal |
| issn | 2076-3417 |
| language | English |
| last_indexed | 2024-12-14T04:30:21Z |
| publishDate | 2015-10-01 |
| publisher | MDPI AG |
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| series | Applied Sciences |
| spelling | doaj.art-c28c8df3b0744c6c83693622b08eaf9c2022-12-21T23:17:05ZengMDPI AGApplied Sciences2076-34172015-10-015489490910.3390/app5040894app5040894Sidelobe Reduction in Non-Contiguous OFDM-Based Cognitive Radio Systems Using a Generalized Sidelobe CancellerAtif Elahi0Ijaz Mansoor Qureshi1Zafar Ullah Khan2Fawad Zaman3Department of Electronic Engineering, International Islamic University, Sector H-10, Islamabad 44000, PakistanDepartment of Electrical Engineering, Air University, Sector E-9, Islamabad 44000, PakistanDepartment of Electronic Engineering, International Islamic University, Sector H-10, Islamabad 44000, PakistanDepartment of Electrical Engineering, COMSATS Institute of Information Technology, Attock Campus, Attock 43600, PakistanIn orthogonal frequency division multiplexing (OFDM), sidelobes of the modulated subcarriers cause high out-of-band (OOB) radiation, resulting in interference to licensed and un-licensed users in a cognitive radio system environment. In this work, we present a novel technique based on a generalized sidelobe canceller (GSC) for the reduction of sidelobes. The upper branch of the GSC consists of a weight vector designed by multiple constraints to preserve the desired portion of the input signal. The lower branch has a blocking matrix that blocks the desired portion and preserves the undesired portion (the sidelobes) of the input signal, followed by an adaptive weight vector. The adaptive weight vector adjusts the amplitudes of the undesired portion (the sidelobes) so that when the signal from the lower branch is subtracted from the signal from the upper branch, it results in cancellation of the sidelobes of the input signal. The effectiveness and strength of the proposed technique are verified through extensive simulations. The proposed technique produces competitive results in terms of sidelobe reduction as compared to existing techniques.http://www.mdpi.com/2076-3417/5/4/894cognitive radioorthogonal frequency division multiplexinggeneralized sidelobe canceller |
| spellingShingle | Atif Elahi Ijaz Mansoor Qureshi Zafar Ullah Khan Fawad Zaman Sidelobe Reduction in Non-Contiguous OFDM-Based Cognitive Radio Systems Using a Generalized Sidelobe Canceller Applied Sciences cognitive radio orthogonal frequency division multiplexing generalized sidelobe canceller |
| title | Sidelobe Reduction in Non-Contiguous OFDM-Based Cognitive Radio Systems Using a Generalized Sidelobe Canceller |
| title_full | Sidelobe Reduction in Non-Contiguous OFDM-Based Cognitive Radio Systems Using a Generalized Sidelobe Canceller |
| title_fullStr | Sidelobe Reduction in Non-Contiguous OFDM-Based Cognitive Radio Systems Using a Generalized Sidelobe Canceller |
| title_full_unstemmed | Sidelobe Reduction in Non-Contiguous OFDM-Based Cognitive Radio Systems Using a Generalized Sidelobe Canceller |
| title_short | Sidelobe Reduction in Non-Contiguous OFDM-Based Cognitive Radio Systems Using a Generalized Sidelobe Canceller |
| title_sort | sidelobe reduction in non contiguous ofdm based cognitive radio systems using a generalized sidelobe canceller |
| topic | cognitive radio orthogonal frequency division multiplexing generalized sidelobe canceller |
| url | http://www.mdpi.com/2076-3417/5/4/894 |
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