## 1 Introduction
### Related Works
Authors of [15; 16], on the other hand, provide more practical appeal analyses of GLRT-based tests by assuming that each SU antenna may experience a different noise power level. Additionally, the work in [17] proposes a general multiantenna-based detector for spectrum sensing that outperforms other detectors such as AGM, MMED, GLRT, and GLRT-based detectors under calibrated and uncalibrated antennas with known noise power levels and uncalibrated antennas with unknown noise power levels. Studies in [15; 16; 17] highlight the importance of using multiple antennas in SUs for SS when information on PU signal, sensing channels, and/or noise power values may not be available, but they do not consider correlated received signals at the antenna arrays. It is worth remembering that signal correlation is common in multiantenna receivers, for example, due to the proximity between the antennas. Furthermore, as spatial diversity decreases as the correlation increases, one may expect that it causes performance degradation in a given communication environment.Even so, few works consider correlated received signals in multiantenna-CR-based SS analyses [18]. Additionally, authors in [19] affirm that multiantenna-CR-based SS analyses with correlated received signals and uncalibrated antennas are seldom adopted and statements in [17] lead to the same conclusion. The work in [20] considers GLRT and CFCPSC in centralized CSS with multiantenna-SUs under frequency-selective (FS) sensing channels, unequal signal and noise powers, where the noise power at the front-end of SUs varies independently over time, and different numbers of SUs and antennas per SU. FS channels follow the IEEE 802.22 standard [21; 22] for wireless regional area networks (WRANs), and authors consider GLRT with HD and soft decision fusion and CFCPSC in soft decision with total and partial data fusion. For GLRT, HD fusion adopted the fusion rules AND, OR, and MAJ, and soft decision fusion adopted SF and weighted sample fusion (WSF) and eigenvalue fusion (EF) and weighted eigenvalue fusion (WEF). Results in [20] show that CFCPSC outperforms all except weighted GLRT in soft decision SF under DN. However, one can notice that although this work provides several performance analyses of GLRT and CFCPSC in different circumstances and scenarios, it does not consider received signal correlations at the antenna arrays of SUs. The work in [23], on the other hand, provides performance analyses of GLRT and CFCPSC in multiantenna-SUs in centralized CSS under the same FS sensing channels in [20] with received signal correlations at the antenna arrays but does not consider unequal signal nor noise powers. Yet, the work in [23] only adopts non-weighted GLRT in soft decision SF, HD with the fusion rules AND, OR and MAJ, and CFCPSC in soft decision SF compared to the work in [20], but includes analyses of CFCPSC in HD, which is not included in [20]. The results in [23] show that GLRT outperforms CFCPSC in soft decision under correlated signals without DN, but HD CFCPSC achieves better detection performances than HD GLRT and CFCPSC with soft decision or HD is more robust to FS channels. Although the aforementioned works are enough to provide a basis for the study of this paper, one can notice that they are far from exhaustive. That is, one can find other studies involving performance analyses of multiantenna SUs for nCSS and CSS under calibrated and uncalibrated antennas, unequal signal powers and/or noise powers, or correlated received signals at the antenna arrays, especially in nCSS. However, very few works adopt combinations of these phenomena, and, to the best of our knowledge, there are no performance analyses of the CFCPSC in multiantenna-CR-based SS combining unequal signal powers and noise powers with correlated received signals at the antenna arrays yet.