If the transmitter knows the downlink channel state information (CSI) perfectly, ZF-precoding can achieve almost the system capacity when the number of users is large. On the other hand, wth limited channel statusstate information at the transmitter (CSIT) the performance of ZF-precoding decrease depending on the accuracy of CSIT. ZF-precoding requires the significant feedback overhead with respect to signal-to-noise-ratio (SNR) so as to achieve the full multiplexing gain<ref name="Jindal_ZF">{{cite journal|author=N. Jindal|title=MIMO Broadcast Channels with Finite Rate Feedback|journal=IEEE Trans. Information Theory.|pages=5045–5059|volume=52|number=11|date=Nov. 2006|doi=10.1109/TIT.2006.883550}}</ref>. Inaccurate CSIT results in the significant throughput loss because of residual multiuser interferences. Multiuser interferences are remained since those can not be nulled with beams generated by imperfect CSIT.
