MIMO-OFDM channel estimation with complex and bipolar NRZ encoded pilots

This paper presents a pilot based channel estimation method forMIMO-OFDM systems, and also presents generation of full orthogonal pilots from local orthogonal pilots, the combination of MIMO with OFDM is used to increase the bit rate as well as capacity.The existing channel estimation methods uses more OFDM periods (STBC) and gives high MSE(conventional pilots).The proposed channel estimation method uses Bipolar NRZ encoder for existing local orthogonal pilots and also new complex pilots are proposed with these techniques has complexity reduced. With this bipolar NRZ encoded local orthogonal pilots we can obtain the optimal MSE which is 25% of conventional pilot method MSE and it effectively utilizes OFDM periods compared to STBC pilot method. Experimental results show that the proposed method achieves higher accuracy and gives better performance.