With increasing demand on data rate for various mobile services, radio spectrum becomes over-crowded and scarce gradually. To overcome the difficulty, emerging cellular system tend to allow adjacent cells to access the same frequency bands. However, this spectrum allocation results in severe inter-cell interference (ICI). In the long term evolution-advanced (LTE-A) proposed by the third generation partnership project (3GPP), coordinated multi-point (CoMP) transmission and reception technique is employed to reduce ICI effectively and improve throughput of cell-edge devices through coordinated transmission among base station (BS) cross multiple cells. CoMP technique can be divided into two classes, namely join processing (CoMP-JP) and coordinated beamforming (CoMP-CBF). In CoMP-JP scheme, BSs jointly transmit signals to user equipment (UE) belong to multiple cells, which requires BSs to exchange data of all UEs and global channel state information (CSI). In CoMP-CBF scheme, each BS simply transmits data to the subscribed UE. Compared with the CoMP-JP scheme, the CoMP-CBF scheme simply needs exchange of global CSI, and demands much less backhaul loading. To pursue the trend of green communication, the thesis designs precoders at BSs to minimize aggregate power consumption over all BSs under the constraint that signal quality at each UE is guaranteed, In practice, channel information exists a certain degree of errors resulted from channel estimation or quantization. Thus, we also take imperfect CSI into account and propose a robust precoding design by considering the dynamic range of channel information errors. Through simulation results, it shows that this precoder design is able to guarantee the quality of UE’s signal and consumes the minimum transmission power.
Index Terms—coordinated multi-point transmission and reception(CoMP), precoder, beamforming, minimize total power, imperfect CSI.