On channel estimation in DTMB standard using time domain PN sequences

In some OFDM systems, time domain CP (cyclic prefix) and scattered pilots are used for synchronization and channel estimation. While in novel OFDM broadcasting systems, such as China Digital Terrestrial Multimedia Broadcasting Standard (DTMB), PN sequences rather than cyclic prefixes are inserted as guard interval between N-point IFFT blocks, which are also used as training symbols. This paper proposed a frequency domain transform method for channel estimation in time domain PN based OFDM systems. With simulation results, comparing to LS-DFT method that using scattered pilots for channel estimation, it is shown that our proposed method can provide satisfactory performance in time domain PN based terrestrial television broadcasting standard.