Inter-symbol interference suppression scheme employing periodic signals in network MIMO-OFDM systems

This paper proposes an inter-symbol interference (ISI) suppression scheme employing periodic signals for network MIMO-OFDM systems. Network MIMO-OFDM suffers from the ISI due to long time difference of arrival (TDOA) among the users especially in large cells. In the proposed scheme, the periodic signals generated by only the even-numbered sub-carriers is adopted for suppressing the ISI and the appropriate transmission mode is chosen between the traditional non-periodic and periodic signals based on the theoretical BER obtained by means of correlation operation. The proposed approach makes the most of the useful properties that a certain ISI-affected user does not interfere at all with the other users, which enables us to make the counter-measure individually. The effectiveness of the proposed method is demonstrated in comparison with the traditional non-periodic transmission by means of computer simulations.