Spectrally efficient transform domain communication system with quadrature cyclic code shift keying. Issue 4 (1st March 2013)

• Record Type: Journal Article
• Authors: Hu, Su; Bi, Guoan; Guan, Yong Liang; Li, Shaoqian
• Is Part Of: IET communications. Volume 7:Issue 4(2013)
• Page Start: 382
• Page End: 390
• Publication Date: 2013-03-01
• Subjects: AWGN channels -- cognitive radio -- cyclic codes -- interference (signal) -- overlay networks; spectrally efficient transform domain communication system -- quadrature cyclic code shift keying -- overlay cognitive radio communication system -- spectrum bin nulling -- adaptive waveform -- spectrum sensing output -- spectral efficiency -- efficient modulation scheme -- fundamental modulation waveform -- data‐bearing quadrature branch -- inter‐branch interference -- orthogonality analysis -- AWGN channels -- multipath fading channels; AWGN channels -- cognitive radio -- cyclic codes -- interference (signal) -- overlay networks; spectrally efficient transform domain communication system -- quadrature cyclic code shift keying -- overlay cognitive radio communication system -- spectrum bin nulling -- adaptive waveform -- spectrum sensing output -- spectral efficiency -- efficient modulation scheme -- fundamental modulation waveform -- data‐bearing quadrature branch -- inter‐branch interference -- orthogonality analysis -- AWGN channels -- multipath fading channels; Telecommunication systems -- Periodicals; Speech processing systems -- Periodicals; 621.38205
• DOI: 10.1049/iet-com.2012.0247
• Languages: English
• ISSNs: 1751-8628

Abstract

Abstract : Transform domain communication system (TDCS), as an overlay cognitive radio communication system, has been proposed to obtain a low probability of interception by using spectrum bin nulling to synthesise an adaptive waveform corresponding to the spectrum sensing output. However, its low spectral efficiency limits potential practical applications. In this study, an efficient modulation scheme, namely quadrature cyclic code shift keying (Q‐CCSK), is proposed for TDCSs by generating another fundamental modulation waveform as the data‐bearing quadrature branch. Although using Q‐CCSK doubles the spectral efficiency for TDCSs, the instinct inter‐branch interference arises from the added quadrature branch. Through the orthogonality analysis, it is proven that the two branches (in‐phase and quadrature‐ branches) are still satisfied the property of quasi‐orthogonality. Moreover, the performances of TDCSs employing Q‐CCSK in additive white Gaussian noise (AWGN) and multipath fading channels are discussed, respectively. Analytical and simulation results demonstrate that, compared with conventional schemes, the TDCS employing Q‐CCSK can double the spectral efficiency with comparable systematic performance.