On channel estimation and equalization in TDS-OFDM based terrestrial HDTV broadcasting system

In TDS-OFDM (time-domain synchronous orthogonal frequency division multiplexing) systems, pseudonoise (PN) sequences rather than cyclic prefixes are inserted as guard interval, between consecutive inverse discrete Fourier transformed (IDFT) symbol blocks. Since the PN sequences can also be used as training symbols, such system can provide higher spectrum efficiency. However, due to non-cyclic property of the signal, the simple channel estimation and equalization techniques for conventional cyclic prefixed OFDM (CP-OFDM) can not be applied to TDS-OFDM. In this paper, we propose a channel estimation and equalization method for TDS-OFDM. Channel estimation depends on time domain correlation and iterative interference cancellation techniques, while equalization is based on tail cancellation and cyclic restoration algorithm (TCCR). It is shown that our proposed method can provide satisfactory performance in TDS-OFDM based terrestrial high-definition television (HDTV) broadcasting system.