transmit diversity scheme for tds-ofdm system over the time selective fading channel
Transmit diversity is an attractive technology in broadcasting environment. When it is applied in Chinese Digital Terrestrial Television Broadcasting (DTTB) system, the training sequences (TS) from the different transmit antennas for channel estimation and synchronization will interfere with each other. In order to overcome the problem, two methods are proposed in which the orthogonal TS is designed based on pseudo noise (PN) sequences. One method holds good compatibility with the existing network and the other one obtains good performance under time selective channel. The corresponding channel estimation method is also presented and analyzed in this paper. Simulations show that the proposed schemes can effectively estimate the channel state information and achieve great diversity gain, even more than 3.5dB under fast fading channels. Moreover they can both work well in some cases where the system with single antenna can't work.
transmit diversity tds-ofdm space time block code training sequences group