“…Indeed, besides the non-IID noise, the radio frequency (RF) IQ imbalance [21], [22] can also lead to performance degradation for the spectrum sensing methods, which, however, is beyond the scope of this paper. Some approaches have been suggested for robust spectrum sensing in the literature, such as the GLRT test [23], independence test [24], Hadamard ratio test [25], [26], Gerschgorin disk test [27], locally most powerful invariant test (LMPIT) [28] and volume-based test approaches [29]. Being robust against the non-IID noise and derived in the GLRT paradigm, the Hadamard ratio approach [30]- [32] has received much attention in the community of spectrum sensing, such as [25], [26].…”