Document Type


Publication Date

March 2010

Patent Number



In accordance with the present invention, a method and apparatus for estimating the noise and interference over the transmission band for OFDM systems are provided. Noise variance and signal-to-noise ratio (SNR) are important parameters for adaptive orthogonal frequency division multiplexing (OFDM) systems since they serve as a standard measure of signal quality. Conventional algorithms assume that the noise statistics remain constant over the OFDM frequency band, and thereby average the instantaneous noise samples to get a single estimate. In reality, noise is often made up of white Gaussian noise along with correlated colored noise that affects the OFDM spectrum unevenly. Provided is an adaptive windowing technique to estimate the noise power that takes into account the variation of the noise statistics across the OFDM sub-carrier index as well as across OFDM symbols. The proposed method provides many local estimates, allowing tracking of the variation of the noise statistics in frequency and time. A mean-squared-error (MSE) expression in order to choose the optimal window dimensions for averaging in time and frequency is derived.

Application Number



University of South Florida

Filing Date


Primary/U.S. Class