查看文章

This paper presents parameter optimization of the multi taper spectrum estimation method (MTM) for 64-FFT based cognitive radio (CR) spectrum sensing. The design problem is formulated to determine the MTM parameters pair; the half time bandwidth product, and the number of tapers that maximize the performance at a fixed number of data samples. Maximum performance is defined by the highest probability of detection at a fixed false alarm probability. A Monte Carlo simulation is implemented to find the optimal parameters. The binary hypothesis test is developed to insure that the effect of choosing optimum MTM parameters is based upon performance evaluation. The whole band under sensing is divided into subbands, some contain primary user signal (PR), and the other does not. Consequentially, in addition to the variance of the estimate, the spectral leakage outside the PR subband is included in the performance evaluation. We found that the half time bandwidth product of 4 and 5 tapers gives the highest performance. We examined both MTM and periodogram (ie, energy detector) methods in Gaussian (AWGN) and Rayleigh flat fading environments. The CR system performance using the MTM technique outperforms the performance of the same system that uses periodogram in all the cases we examined.