Effectiveness of Preamble Based Channel Estimation for OFDM/OQAM System

In this paper, we propose a modified preamble based channel estimation for the orthogonal frequency division multiplex/offset QAM (OFDM/OQAM). In present of multi-path effect, the inter symbol interference (ISI) always exists in the OFDM/OQAM system and the preamble based channel estimation for the conventional orthogonal frequency division multiplex with cyclic prefix (CP-OFDM) is not feasible any more. Considering the characteristic of the extended Gaussian function (EGF), we propose two modified preamble based channel estimation by adding guard symbols, which are located at both sides (method A) and the left side (method B) of preamble reference symbol. Compared with the CP-OFDM system, the proposed preamble based channel estimation achieves 2dB improvement. Meanwhile, method B remains the same BER performance with method A, but require less guard symbols. Therefore, method B is more feasible and effective preamble based channel estimation method for the practical OFDM/OQAM system.