Modeling and Performance Analysis for Movable Antenna Enabled Wireless Communications

In this paper, we propose a novel antenna architecture called movable antenna (MA) to improve the performance of wireless communication systems. Different from conventional fixed-position antennas (FPAs), the MAs with the capability of flexible movement can be deployed at positions with more favorable channel conditions to achieve higher spatial diversity gains. To characterize the general multi-path channel in a given region, a field-response based channel model is developed under the far-field condition. In the deterministic channel case, we show the periodic behavior of the multi-path channel gain in a given spatial field, which can be exploited for analyzing the maximum channel gain of the MA. In the case of stochastic channels, the expected value of an upper bound on the maximum channel gain of the MA in the receive region is derived for different numbers of channel paths. Moreover, our results reveal that higher performance gains by the MA over the FPA can be acquired when the number of channel paths increases due to more pronounced small-scale fading effects in the spatial domain. Simulation results demonstrate that the MA system can reap considerable performance gains over the conventional FPA, and even achieve comparable performance to the single-input multiple-output beamforming system.