OFDM Channel Estimation using a MMSE Estimator of a Comb-type System
Sonali .D.Sahu, A.B.Nandgaonkar
Abstract
Orthogonal frequency division multiplexing (OFDM) is a key technique for wireless communication because of its robustness for narrow band interference, frequency selective fading and spectral efficiency. Channel estimation and equalization in OFDM is necessary in order to nullify the effect of impairments induced by the frequency selective fading channel. Frequency domain comb type pilot assisted channel estimation has been implemented for the channel estimation purpose. Modified Minimum Mean Square Error (MMSE) estimator is considered for estimation of the channel at pilot subcarriers. The performance and complexity comparison is made between the modified MMSE and MMSE estimator for fast fading Rayleigh channel. Linear, Low Pass and spline cubic interpolation techniques have been used with the proposed modified MMSE estimator. The effect of increase in number of channel taps on the performance of both estimators has been studied.
Keyword
Co-channel interference, communication channels, data communication, digital communication, frequency division multiplexing, frequency domain analysis, time domain analysis, time-varying channels.