Research And Application Of Interference Estimation And Interference Suppression Technology

Interference in wireless cellular systems has always been one of the main factors affecting performance, and Interference Rejection Combining(IRC) is an algorithm commonly used at the receivers to suppress interference.In recent years, research on the IRC algorithm had mainly focused on using pilot signals to estimate the statistical characteristics of interference,so as to suppress it. Because the number of pilots in a real system is often limited, it will lead to inaccuracy in the estimation of the interference statistics information, so there still are some limitations in these methods.In this paper, we have derived the IRC algorithm in detail, and prove that two forms of the algorithm which are based on spatial covariance matrix (SCM) of total signal and SCM of interference plus noise respectively, are equivalent. Since there are more received signals than pilots within the coherence time and coherence bandwidth of the system,estimation of the signals SCM will be more accurate than that of interference plus noise SCM. Therefore, in the practical use of IRC algorithm, the estimation of the statistical characteristics of interference plus noise can be substituted by the estimation of the total signal characteristics to achieve better anti-interference performance.In this paper, we have verified the effectiveness of the IRC algorithm for total signal SCM estimation in the block fading channel model, and compare the performance of two covariance estimation algorithms under the condition of variant pilot ratios. Finally, we have built the LTE-A simulation platform to verify the availability of the algorithm under different simulation conditions. The results show that the IRC algorithm based on the total signal SCM estimation is always better than the interference plus noise SCM estimation algorithm in both simple system and complicated environment.