Channel compensation with virtual pilot signal and time-frequency interferometry for MIMO-OFDM

Abstract

MIMO has been recognized as a promising way to provide high speed data transmission. However, since the number of pilot symbols is proportionally depending on the number of transmit antenna, the total transmission rate of MIMO would be degraded. To solve this problem, the channel estimation method using virtual pilot signal (VPS) with a few pilot signals has been proposed. However, since the conventional method identifies the channel state information (CSI) iteratively, the complexity is a seriously considerable work. Previously, we have proposed the time-frequency interferometry (TFI)-OFDM to achieve a superior BER performance with a small number of pilot symbols without any iterative channel estimation. However, the TFI method is still needed a large number of pilot signals. To mitigate the problem of the TFI method, in this paper, we propose a novel channel compensation method based on VPS and TFI for MIMO without increasing the system complexity. The proposed method has a low complexity with improving BER performance to compare with the conventional method. From the simulation results, the proposed method can achieve the improved BER performance of 1.5dB gain compared with the conventional method for 4 × 4 and 8 × 8 MIMO systems.