Delay-spread estimation using cyclic-prefix in wireless OFDM systems

A novel cyclic-prefix based delay-spread estimation technique for wireless OFDM systems is proposed. The technique uses change of gradient of a correlation function as the strategy to detect delayed arrival paths. Estimation of the symbol timing and frequency synchronization information is also inherent in the technique. The proposed technique can be computationally efficiently implemented using the Viterbi search algorithm. Numerical results demonstrate the accuracy of the technique in estimating the relative timing (delay) and magnitude (power) of delayed paths in a multipath environment. The delay-spread information provided by the proposed technique can be adaptively used to improve the accuracy of the frequency domain channel response interpolation process in OFDM systems.