MMSE adaptive array suppressing only multipath waves with delay times beyond the guard Interval for fixed reception in OFDM systems

摘要

It is known that OFDM transmission systems give better performance than single-carrier systems in a multi-path environment. However, the communication quality degrades rapidly when the delayed wave arrives beyond the guard interval. In order to solve this problem, various systems that try to suppress the undesired wave by using an adaptive array have been proposed. This paper considers fixed reception and investigates an MMSE adaptive array for OFDM that does not suppress waves arriving within the guard interval, only waves arriving beyond the guard interval. More precisely, the SMI optimization method is proposed in which a window function is used to extract only the wave components beyond the guard interval. In order to demonstrate the effectiveness of the proposed system, an evaluation is made by computer simulation. It is shown that the system operates well as an MMSE adaptive array in a fixed reception environment, exhibiting high suppression power for delayed waves beyond the guard interval.