Cognitive radio (CR) technology with dynamic spectrum management capabilities is widely advocated for utilizing effectively the unused spectrum resources. The main idea behind CR technology is to trigger secondary communications to utilize the unused spectral resources. However, CR technology heavily relies on spectrum sensing techniques which are applied to estimate the presence of primary user (PU) signals. This paper firstly focuses on novel analysis filter bank (AFB) and FFT-based cooperative spectrum sensing (CSS) techniques as conceptually and computationally simplified CSS methods based on subband energies to detect the spectral holes in the interesting part of the radio spectrum. To counteract the practical wireless channel effects, collaborative subband-based approaches of PU signal sensing are studied. CSS has the capability to relax the problems of both hidden nodes and fading multipath channels. FFT- and AFB-based receiver side sensing methods are applied for OFDM waveform and filter bank-based multicarrier (FBMC) waveform, respectively, the latter one as a candidate beyond-OFDM/beyond-5G scheme. Subband energies are then applied for enhanced energy detection (ED)-based CSS methods that are proposed in the context of wideband, multimode sensing. Our first case study focuses on sensing potential spectral gaps close to relatively strong primary users, considering also the effects of spectral regrowth due to power amplifier nonlinearities. The study shows that AFB-based CSS with FBMC waveform is able to improve the performance significantly. Our second case study considers a novel maximum–minimum energy detector (Max–Min ED)-based CSS. The proposed method is expected to effectively overcome the issue of noise uncertainty (NU) with remarkably lower implementation complexity compared to the existing methods. The developed algorithm with reduced complexity, enhanced detection performance, and improved reliability is presented as an attractive solution to counteract the practical wireless channel effects under low SNR. Closed-form analytic expressions are derived for the threshold and false alarm and detection probabilities considering frequency selective scenarios under NU. The validity of the novel expressions is justified through comparisons with respective results from computer simulations.

具有动态频谱管理功能的认知无线电（CR）技术被广泛提倡有效利用未使用的频谱资源。CR技术背后的主要思想是触发辅助通信以利用未使用的频谱资源。但是，CR技术严重依赖于频谱感知技术，该技术可用于估计主要用户（PU）信号的存在。本文首先着重研究新颖的分析滤波器组（AFB）和基于FFT的协作频谱感测（CSS）技术，这些技术在概念上和计算上都基于子带能量简化了CSS方法，以检测无线电频谱中有趣部分的频谱空洞。为了抵消实际的无线信道影响，研究了基于协作子带的PU信号感测方法。CSS具有缓解隐藏节点和衰落多路径通道的问题的能力。基于FFT和AFB的接收器侧检测方法分别应用于OFDM波形和基于滤波器组的多载波（FBMC）波形，后者是一种超越OFDM / beyond-5G方案的候选方案。然后，将子带能量应用于基于宽带多模式传感的环境中提出的基于增强能量检测（ED）的CSS方法。我们的第一个案例研究着重于感测接近相对较强的主要用户的潜在频谱间隙，同时还考虑了功率放大器非线性引起的频谱再生长的影响。研究表明，具有FBMC波形的基于AFB的CSS能够显着提高性能。我们的第二个案例研究考虑了基于新颖的最大-最小能量检测器（Max-Min ED）的CSS。与现有方法相比，该方法有望以较低的实现复杂性有效地克服噪声不确定性（NU）问题。所开发的算法具有降低的复杂度，增强的检测性能和改进的可靠性，是一种有吸引力的解决方案，可以抵消低SNR下的实际无线信道效应。考虑到NU下的频率选择场景，得出了阈值和虚警和检测概率的闭式解析表达式。通过与计算机模拟的相应结果进行比较，可以证明新颖表达的有效性。所开发的算法具有降低的复杂度，增强的检测性能和改进的可靠性，是一种有吸引力的解决方案，可以抵消低SNR下的实际无线信道效应。考虑到NU下的频率选择场景，得出了阈值和虚警和检测概率的闭式解析表达式。通过与计算机模拟的相应结果进行比较，可以证明新颖表达的有效性。所开发的算法具有降低的复杂度，增强的检测性能和改进的可靠性，是一种有吸引力的解决方案，可以抵消低SNR下的实际无线信道效应。考虑到NU下的频率选择场景，得出了阈值和虚警和检测概率的闭式解析表达式。通过与计算机模拟的相应结果进行比较，可以证明新颖表达的有效性。