Power Spectra in Spacetime Noncommutative Inflation

String/M theory inspires an uncertainty relation between space and time which deviates from general relativity. It is possible to explore this deviation from cosmological observations, in particular from the CMB fluctuation spectrum. This paper extends some previous observations to more general inflation schemes, we find that the noncommutative spacetime effects always suppress the power spectrum, of both the scalar and tensor perturbations, and may provide a large enough running of the spectral index to fit the WMAP data in the inflation model.