Figures (12)  Tables (1)

    • Figure 1. 

      Block diagram of energy detection.

    • Figure 2. 

      Block diagram of entropy-based detector.

    • Figure 3. 

      System model for proposed two-stage spectrum sensing.

    • Figure 4. 

      Pd vs. SNR at Pf = 0.1 and α = 4 for CED and different types of entropy.

    • Figure 5. 

      ROC curve for CED and various types of entropy detection at SNR = -18 dB.

    • Figure 6. 

      CROC curve for CED and various types of entropy detection at SNR = -18 dB.

    • Figure 7. 

      Pd vs SNR curves for Renyi entropy detection at various numbers of bins.

    • Figure 8. 

      Pd vs SNR at Pf = 0.1 and α = 4 for CED and different types of entropy.

    • Figure 9. 

      ROC curve for proposed two-stage SS technique at SNR = -23 dB.

    • Figure 10. 

      CROC curve for proposed two-stage SS technique at SNR = -23 dB.

    • Figure 11. 

      ROC curve of proposed two-stage SS technique with the different number of samples.

    • Figure 12. 

      Performance comparison of the proposed two-stage SS technique at various values of false alarm probability.

    • Authors Year Title Techniques and concept covered Gaps or concept not covered
      G. Prieto et al. [10] 2019 Numerical analysis of histogram-based estimation techniques for entropy-based spectrum sensing Entropy-based detection is proposed for spectrum sensing. Several rules for determining the number of bins in histogram are evaluated. Those rules are as follows: square root rule, Scott rule, and Sturges rule This study focuses only on the Shannon entropy. It does not include other types of entropy such as Renyi, Kapur, and Tsallis entropy
      A. Fawzi et al. [3] 2020 Adaptive two-stage spectrum sensing model using energy detection and wavelet denoising for CR systems Two-stage spectrum sensing techniques are proposed by combining two well methods: ED and WD Even though it improves the performance of SS, the proposed technique is not robust to noise uncertainty at low SNR. Moreover, since WD is integrated with ED at low SNR, sensing time and computational complexity are very high
      A. D. Sahithi et al. [9] 2020 Analysis of energy detection spectrum sensing technique in cognitive radio Cooperative spectrum sensing using ED is used to overcome the problem of uncertainty occurred due to fading and hidden primary terminal This study does not focus on overcoming the problem of noise uncertainty
      F. Mashta et al. [17] 2021 An integrated parallel multistage spectrum sensing for cognitive radio Two-stage and three-stage detector for SS are discussed in detail Even though three-stage and two-stage spectrum sensing are performed, the overall performance of SS is not good at low SNR due to its sensitivity to noise uncertainty. Moreover, since the eigenvalue-based detector is used, the complexity of overall system increases
      ED and maximum eigenvalue detector with different smoothing factors are used

      Table 1. 

      A summary of some related work.