Achievable Rates of Coordinated Multi-Point Transmission Schemes Under Imperfect CSI
This paper studies the performance limitations of adaptive Coordinated Multi-Point (CoMP) transmission schemes with imperfect Channel State Information (CSI) in LTE-Advanced systems. First, the achievable rates are derived for both Joint Processing (JP) and Coordinated BeamForming (CBF) modes considering the CSI assumptions of delay and channel errors, which shows JP mode is more robust to imperfect CSI while CBF mode loses spatial multiplexing gain in proportion to delay. Then a mode switching scheme is proposed based on average SNR and normalized Doppler frequency. Numerical results show that the CBF mode should not be activated when the delay is large enough.