A Power Control Method for Channel Non-Reciprocity Compensation in Hybrid Duplexing

This paper proposes a power control method for a hybrid duplexing scheme which has both time division duplex (TDD) and frequency division duplex (FDD) components. In the proposed method, the base station (BS) adaptively and continuously changes the transmission power for a mobile station (MS) whose transmission parameters have been scheduled by exploiting channel state information (CSI) obtained through channel reciprocity. The TDD component in hybrid duplexing makes it possible for the BS to exploit the channel reciprocity and the FDD component enables fast feed-back from MS to BS. By using the proposed power control method, the BS can quickly change the transmission power for a MS during a down-link (DL) frame. This counteracts the change in link condition due to MS mobility and/or burst interference (i.e. channel non-reciprocity problem). This allows the scheduling of BS made in the beginning of DL frame to be valid for the whole DL frame since the MS can experience almost constant link quality during a DL frame. Our simulation results show that the proposed power control method can significantly improve bit error rate (BER) performance