Cognitive　radio　is　regarded　as　a　core　technology　to　support　wireless　information　systems.　Spectrum　sensing　is　one　of　the　key　steps　to　achieve　cognitive　radio　technology.　To　address　this　problem　in　the　presence　of　Alpha　stable　noise　in　wireless　communication　systems,　we　propose　a　nonparametric　autocorrelation　method,　which　takes　advantages　of　the　characteristics　of　signal　autocorrelation　and　noise　nonstationarity.　The　autocorrelated　signal　is　distinguished　from　Alpha　stable　noise.　As　a　result,　the　proposed　method　is　immune　from　noise　uncertainty.　Simulation　results　show　the　validity　of　the　proposed　method　under　Alpha　stable　noise,　for　example,　impulsive　noise　in　wireless　information　systems.