In this paper, exact performance analyses of the noncoherent ultra-wideband differential transmitted reference systems are evaluated in the correlated Nakagami-m fading channels via applying the characteristic function (CF) method, where the correlated channel model is derived from the bivariate Nakagami-m distribution. Moreover, the independent Nakagami-m fading channel is considered as a special case by contrast. Numerical results show that the CF method can be demonstrated a better prediction in comparison with the Gaussian approximation scheme, and the system performance can be improved by increasing the number of frames appropriately.