A modified SPRT based cooperative spectrum sensing scheme in cognitive radio

In this paper, a modified sequential probability ratio test (SPRT) scheme, namely sequential energy detection (SED), is proposed for cooperative spectrum sensing to reduce the average number of required samples. In the scheme, the data samples are first grouped into data blocks and the sequential probability ratio test (SPRT) use the energies of the data blocks as the statistics variables. The resulting detection rule exhibits simplicity in implementation and in analysis and avoid the deterministic knowledge of primary signals. The detection performance in terms of average sample number (ASN) is evaluated theoretically. Numerical results are provided to verify the theoretical analysis.