Channel reliability factor estimation for LTE systems

This paper addresses the problem of turbo decoding in the presence of non-ideal knowledge of the channel parameters. A practical OFDM system employing an interpolation based channel estimator is considered and a scheme for deriving the corresponding channel reliability factor to be passed to the turbo decoder is presented. Simulations are carried out for a realistic multicarrier system operating in the framework of a Long Term Evolution air interface. Our results show that a performance gain can be achieved with a limited increase in complexity by estimating the channel reliability factor with the proposed method in contrast to a system that ignores the imperfections in the channel estimates.