Adaptive channel estimation of OFDM systems using the cyclic prefix with an RLS based algorithm in mobile channels

Channel estimation is very important in wireless mobile orthogonal frequency division multiplexing (OFDM) systems. The channel estimation in slow fading and frequency-selective channels is performed using the cyclic prefix of the guard interval which is used to prevent intersymbol interference instead of using pilot sequences. By such a method, adaptive channel estimation is obtained without needing the use of pilot sequences which results in sacrificing channel efficiency. A recursive least squares (RLS) based adaptive algorithm for online channel estimation is the subject of our investigation. In order to test the algorithm, simulation studies are carried out using both the time-invariant and the Jake´s channel model to perform convergence performance studies.