Wideband Collaborative Spectrum Sensing Using Massive MIMO Decision Fusion

Abstract

In this paper, in order to tackle major challenges of spectrum exploration & allocation in Cognitive Radio (CR) networks, we apply the general framework of Decision Fusion (DF) to wideband collaborative spectrum sensing based on Orthogonal Frequency Division Multiplexing (OFDM) reporting. At the transmitter side, we employ OFDM without Cyclic Prefix (CP) in order to improve overall bandwidth efficiency of the reporting phase in networks with high user density. On the other hand, at the receiver side (of the reporting channel) we device the Time-Reversal Widely Linear (TR-WL), Time-Reversal Maximal Ratio Combining (TR-MRC) and modified TR-MRC (TR-mMRC) rules for DF. The DF Center (DFC) is assumed to be equipped with a large antenna array, serving a number of unauthorized users competing for the spectrum, thereby resulting in a "virtual" massive Multiple-Input Multiple-Output (MIMO) channel. The effectiveness of the proposed TR-based rules in combating (a) inter-symbol and (b) inter-carrier interference over conventional (non-TR) counterparts is then examined, as a function of the Signal-to-Interference-plus-Noise Ratio (SINR).Closed-form performance, in terms of system false-alarm and detection probabilities, is derived for the formulated fusion rules. Finally, the impact of large-scale channel effects on the proposed fusion rules is also investigated, via Monte-Carlo simulations.

Performance Analysis of Channel Estimation in 5G millimeter-Wave-MIMO Heterogeneous Systems

“…The convergence and feasibilityissues will be explored in the improved wideband mm-Wave-MIMO CE CS-based approach involving the large grid sizes. The efficiency in compression sensing may be improved as a future research by a suitable algorithm [61].The decentralized MMSE estimation of a general correlated random vector in a mmWave -Ma-MIMO framework as a future research may be considered [63].The mmWave -based wideband collaborative spectrum sensing using a Decision Fusion Centre equipped with multiple receive antennasin case of Ma-MIMO and a 'virtual' Ma-MIMO based radio networks may perform in future for better sensing performance, in mitigating severe shadowing effects considerably, and in presence of correlated measurements [64].…”

LMMSE channel estimation for OFDM systems with channel correlation function selection

“…The expectation and variance of (ĥ k_Int −ĥ k ) have been derived. Hence, we get (ĥ k_Int −ĥ k ) ∼  (0, 2 MSE + 2 ). We denote the noise MSE of 1 and 2 as 2 1 and 2 2 , respectively, that is, 2 1 = 2 MSE1 + 2 and 2 2 = 2 MSE2 + 2 .…”

Internet of Things (IoT) Enabled Architecture for Social Distancing During Pandemic

“…Therefore, dynamic spectrum management as well as energy efficient and environment-aware design should be jointly considered Salvo Rossi et al, 2013. A framework combining distributed decision fusion at the IoT gateway and orthogonal frequency division multiplexing (OFDM) based collaborative wideband spectrum sensing, similar to the one proposed in Dey et al (2020a), can be used to address the above-mentioned challenges. In our proposed architecture, orthogonality of the multiple users/ handheld devices transmitting simultaneously can be exploited by employing a massive antenna array at the gateway.…”