Decoding-Aided Parameter Estimation for Interference Cancellation and Suppression Receivers in LTE-Advanced Systems

Parameter estimation of interfering signals transmitted by neighboring cells has become one of the important signal processing problems for Long-Term Evolution Advanced (LTE-A) systems. Knowledge of the interfering signal parameters is required to improve the downlink performance in interference-limited scenarios by providing estimated parameters to non-linear interference cancellation and suppression receivers, such as maximum likelihood (ML) and symbol-level interference cancellation (SLIC). In this paper, we consider the problem of interfering signal parameter estimation (blind detection) in the presence of the useful signal with known parameters transmitted by the serving cell. To improve the performance of parameter estimation, soft cancellation of the serving signal after linear Minimum Mean Squared Error Interference Rejection Combining (MMSE-IRC) and turbo decoding is proposed. The parameters of the interfering signals such as precoding vectors, number of spatial layers and power boosting are estimated after soft compensation of the useful signal and are subsequently used in non-linear receivers to improve interference cancellation and suppression efficiency. The results show that such approach for parameter estimation provides performance for non-linear interference cancellation and suppression receivers close to the ideal system where interfering signal parameters are perfectly known.