Generalized detector as a spectrum sensor in cognitive radio networks

In the present paper, a chip-level minimum mean-square-error (MMSE) decision-feedback equalizer for the downlink receiver of multicode wideband direct sequence code-division multiple access (DS-CDMA) wireless communication systems over frequency-selective channels is investigated. Firstly, the MMSE per sym-bol achievable by an optimal decision-feedback equalizer is derived, assuming that all interchip interference (ICI) of the desired user can be eliminated. The MMSE of the decision-feedback equalizer is always less than or at most equal to that of linear equalizers. When all the active codes belong to the desired user, the ideal deci-sion-feedback equalizer is able to eliminate multicode interference and approach the performance of the single-code case at high signal-to-noise ratio (SNR) range. Secondly, we apply the hypothesis-feedback equalizer or tentative-chip decision-feedback equalizer in the multicode scenario. The tentative-chip decision-feedback equ-alizer outperforms the chip-level linear equalizer and the decision-feedback equalizer that only feeds back the symbols already decided. The performance gain increases with SNR, but decreases with the number of active codes owned by the other users. When all the active codes are assigned to the desired user, the tentative-chip decision-feedback equalizer eliminates the multicode interference and achieves single-user performance at the high SNR, similarly, to the ideal decision-feedback equalizer. The asymptotic performance of the decision-feed-back equalizer is confirmed through the bit error rate (BER) simulation over various channels.

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Generalized Receiver Employment in Ultra-Wideband Systems: Performance Analysis

Tuzlukov

2022

International Journal of Applied Mathematics, Computational Science and Systems Engineering

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In the present paper, a performance analysis of an ultra-wideband (UWB) system based on the ge-neralized approach to signal processing in noise is discussed. The UWB system utilizes a new pulse design that made the performance analysis possible, since the new not only has a short duration to reduce collision, but is also spectrally compliant to the standards on UWB systems. We present the performance analysis of the UWB system constructed based on the generalized receiver processing different pulse shapes and with various num-bers of users. New simulation results on multiuser performance of the impulse radio are also presented.

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Generalized detector as a spectrum sensor in cognitive radio networks

Abstract: Abstract. The implementation of the generalized detector (GD)

Cited by 6 publications

References 29 publications

Performance analysis of the dynamic switch system based on user activity in cognitive radio network

Performance analysis of the dynamic switch system based on user activity in cognitive radio network

Generalized Receiver with Decision-Feedback Equalizer for Multicode Wideband DS-CDMA

Generalized Receiver Employment in Ultra-Wideband Systems: Performance Analysis

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