One-Bit Spectrum Sensing for Cognitive Radio

TL;DR

This paper proposes a one-bit ADC-based spectrum sensing method for cognitive radio, deriving a Rao's test detector, analyzing its performance, and demonstrating its effectiveness with theoretical and simulation results.

Contribution

It introduces a novel one-bit spectrum sensing detector based on Rao's test, with theoretical analysis and performance comparison to high-precision ADC methods.

Findings

Performance loss of ~2 dB at low SNR compared to infinite-bit ADCs.

Approximately 2.47 times more samples needed to compensate for performance loss.

Efficiency of incoherent accumulation is the square root of coherent accumulation.

Abstract

Spectrum sensing in cognitive radio necessitates effective monitoring of wide bandwidths, which requires high-rate sampling. Traditional spectrum sensing methods employing high-precision analog-to-digital converters (ADCs) result in increased power consumption and expensive hardware costs. In this paper, we explore blind spectrum sensing utilizing one-bit ADCs. We derive a closed-form detector based on Rao's test and demonstrate its equivalence with the second-order eigenvalue-moment-ratio test. Furthermore, a near-exact distribution based on the moment-based method, and an approximate distribution in the low signal-to-noise ratio (SNR) regime with the use of the central limit theorem, are obtained. Theoretical analysis is then performed and our results show that the performance loss of the proposed detector is approximately $2$ dB ($\pi/2$) compared to detectors employing $\infty$-bit ADCs when SNR is low. This loss can be compensated for by using approximately $2.47$ ($\pi^2/4$) times more samples. In addition, we unveil that the efficiency of incoherent accumulation in one-bit detection is the square root of that of coherent accumulation. Simulation results corroborate the correctness of our theoretical calculations.