Pre-distortion based joint transmission

The joint transmission (JT) technique was mainly presented by Baier et al. (2000). JT used in the downlink channel does not require a training sequence in the downlink in theory. Moreover, the mobile station (MS) does not demand channel estimation. However, JT requires a huge dynamic range and good linearity of the power amplifier of the transmitter because of the high peak to average ratio of transmitted signals of JT. In this paper, a new scheme called pre-distortion based joint transmission is proposed. Two pre-distortion approaches are also presented. One is based on the pre-clip technique, the other on a pre-nonlinear power amplifier. Finally, simulation results show that the pre-distortion based JT scheme has better BER performance and the BER performance of pre-distortion based JT under nonideal power amplifier is better than that of JT under ideal power amplifier. This is to say, maybe it is not worth compensating the deep channel shading.