B-SSCT: A block sequential spectrum sensing scheme for cognitive radio

Recently, it has been shown that in comparison to the well-known energy detection scheme, the sequential shifted chi-square test (SSCT) is capable of delivering considerable reduction on the average sample number (ASN) while maintaining a comparable detection error performance for spectrum sensing. Nonetheless, SSCT needs to perform threshold comparisons on every received sample, which may be difficult or even infeasible in practice particularly when the sampling rate is high and/or the signal-to-noise ratio is low. This paper proposes an extension of SSCT, called block-wise SSCT (B-SSCT), to overcome this shortcoming. Numerical algorithms are applied to evaluate the false-alarm and miss-detection probabilities and the ASN of B-SSCT, in a recursive fashion. Simulation and numerical results show that compared to the original SSCT, B-SSCT is capable of achieving almost the same detection error performance with a significantly reduced number of threshold comparisons and a slightly increased ASN. An implementation example demonstrates potential practical feasibility of B-SSCT in a real environment.