Out-of-band power suppression for TDS-OFDM systems

In this paper, the out-of-band power suppression technique for the time domain synchronous orthogonal frequency division multiplexing (TDS-OFDM) system is proposed. The technique combines the time-domain windowing and training sequence (TS) redesigning, and could satisfy the spectral mask requirement for the digital television terrestrial broadcasting (DTTB) system without squared root raised cosine (SRRC) filter. An improved frame structure with overlapping between adjacent frames for the dual pseudo noise padded (DPNP) TDS-OFDM system is put forward to make the spectral efficiency undiminished. The simulation results show that the proposed method could lower the out-of-band power leakage by 6-10dB in the power spectrum density (PSD) compared to the conventional TDS-OFDM system without SRRC filter while achieving a similar spectrum shaping performance of conventional CP-OFDM. This technique will enhance the application of the TDS-OFDM in the broadband multimedia transmission areas.