Synchronization Algorithm of 5G New Waveform Based on Index Modulation

Filtered orthogonal frequency division multiplexing (F-OFDM) is one of the core technologies of 5G. And the filtered orthogonal frequency division multiplexing with index modulation (F-OFDM-IM) can further reduce the effect of the carrier frequency offset (CFO) on the performance of the FOFDM system. But it cannot eliminate the CFO fundamentally and still has to complete the synchronization estimation. However, applying the existing synchronization algorithms directly to the F-OFDM-IM system has some disadvantages, such as inaccurate estimation, low spectrum efficiency, small estimation range. Thus, this paper proposes a new synchronization algorithm based on the F-OFDM-IM system. Firstly, a training sequence based on pseudo-noise (PN) sequence and zadoff-chu (ZC) sequence is proposed to complete sample timing offset (STO) estimation. Then, an improved CFO estimation method is proposed based on the traditional CP algorithm. This method divides the CP into three parts, then uses the part that is less affected by inter symbol interference (ISI) to complete the fractional frequency offset (FFO) estimation and the integer frequency offset (IFO) estimation in turn. Finally, the analysis and simulation results show that the proposed synchronization algorithm can further improve spectrum efficiency and estimation performance.