Equalization of MIMO-OFDM System under Time Varying Channel using ANFIS

摘要

Background/Objective: High speed reliable communication for wireless internet is the main challenge for all communication engineers. Methods: Multiple Input Multiple Output (MIMO) Orthogonal Frequency Division Multiplexing (OFDM) is one possible solution, which promises high data rates. But MIMO-OFDM degrades the system performance in terms of Bit Error Rate (BER), due to Inter Symbol Interference (ISI), problem associated with multipath effect of the time varying wireless channels. To improve the performance of the MIMO-OFDM system a channel equalization technique is incorporated at the receiver end. Findings: The effectiveness of soft-computing approach in dealing the problem of non linear time varying channel is investigated in this paper by designing an equalizer based on Adaptive Neuro Fuzzy Inference System (ANFIS). The proposed technique is compared with the already tested Neural Network based equalizer. Result shows that the proposed equalizer gives better BER. Application/Improvements: The proposed equalizer can be implemented in wireless Local Area Networks (LAN) or mobile networks. The performance can be further improves with the increase signal length as evident by the graphs 14-16.