A multiple input multiple output (MIMO) communication system having a terminal and a base station. The terminal may calculate channel direction information and channel quality information in a zero-forcing mode based on expected different user interference. The terminal may also calculate channel direction information and channel quality information in a per user unitary rate control (PU2RC) mode by reusing the channel direction information and the channel quality information in the zero-forcing mode. The base station may design a preceding vector based on feedback information from the terminal.