MOBILE TERMINAL DEVICE, WIRELESS BASE STATION DEVICE, AND WIRELESS COMMUNICATION METHOD

摘要

Provided are a mobile terminal apparatus, a radio base station apparatus and a radio communication method capable of making the most of the effects of the MIMO technique and the CoMP technique, when employing both of the techniques. According to the radio communication method of the present invention, a mobile terminal apparatus estimates downlink channel states using respective reference signals included in downlink signals from plural cells; selects PMIs using a codebook based on the channel states; estimates a phase difference between the cells based on the selected PMIs or the channel states; and transmits information of the phase difference and the selected PMIs to radio base station apparatuses of the respective cells. A radio base station apparatus receives an uplink signal including a PMI and the information of the phase difference between the cells; multiplies a transmission signal by a precoding weight corresponding to the PMI; adjusts the phase difference between the cells with use of the information of the phase difference between the cells; and transmits the transmission signal to a radio base station apparatus of another cell by coordinated multi-point transmission.