Pilot Structure for High Data Rate in OFDM/OQAM-IOTA System

In this paper, we introduce a novel pilot structure for OFDM/OQAM system which has high spectral efficiency by isotropic orthogonal transform algorithm (IOTA) function. In contrast with classical OFDM/QAM transmission scheme, the OFDM/OQAM-IOTA system requires a specific pilot structure for channel estimation because side-lobe components of the IOTA function cause an intrinsic interference. In case of conventional pilot structure, successive signal cancellation and null insertion schemes are considered for minimizing the channel estimation error. These schemes, however, reduce overall data transmission rate, especially for frequent pilot transmission, and it results in decreased throughput. For improving the data rate, we propose an additional data transmission scheme based on signal cancellation and an efficient 2-dimensional pilot block. Analysis and simulation results verify that the proposed pilot structure exhibit not only higher data rate but also more reliable channel estimation performance than the conventional pilot structure.