Single-carrier STBC Diversity Using CDP-CE And Linear Inter / Extrapolation in A Doubly Selective Fading Channel

Single-carrier (SC) space time block coded (STBC) diversity combined with frequency-domain equalization (FDE) can obtain the full spatial diversity gain and the frequency diversity gain. Assuming time division duplex (TDD) transmission, STBC diversity with receive FDE and that with transmit FDE are applied to the uplink and downlink respectively. Therefore, only the base station (BS) requires the channel state information (CSI) and the complexity problem of mobile terminal (MT) can be alleviated. However, our previous studies on SC-STBC diversity assumed the perfect CSI. In this paper, we examine the impact of imperfect CSI on SC-STBC diversity for TDD uplink and downlink transmissions in a doubly selective (time and frequency-selective) fading channel. BS estimates the channel by cyclic delay pilot channel estimation (CDP-CE) and linear inter/extra-polation to track the time varying channel. We show SC-STBC using CDP-CE and linear inter/extra-polation achieves a good bit error rate (BER) performance in a range of practical MT moving speed. Keywords—STBC, channel estimation, TDD