Pre-equalization technique for interference cancellation in the UMTS-TDD downlink channel

This paper proposes a technique aiming to simplify the mobile terminals by transferring as much as possible the complex operations to the base station. A pre-equalization technique is proposed for the downlink channel of UMTS TDD, which allows the use of simpler receiver schemes in the mobile unit. After the mathematical background, simulation results obtained in typical scenarios, using statistical channel models, are presented to demonstrate the performance of the proposed method. Several levels of correlation between the propagation channels that can be considered to exist between the different base station antenna array elements and the desired mobile unit were considered. The results have shown that that significant performance gains can be achieved in high multiple access interference (MAI) environments.