Multipath Separation and Parameter Estimation by Single RIS Antenna in Fading Channel

Channel identification and measurement accuracywill greatly affect wireless communication performance. Thebroadcasting of electromagnetic waves will produce multipath,and its superposition will lead to fading. If the multipath canbe separated and the phase of each path can be adjustedseparately, better signal transmission and reception strategiescan be designed to weaken or eliminate fading and improvesignal transmission performance. In this paper, we first analyzethe multipath structure of the wireless channel, then utilize thedynamic isomeric characteristics of the reconfigurable intelligentsurface (RIS) antenna, also called dynamic metamaterial antenna(DMA), to form differentiated patterns, and rapidly sampleswithin a period of single pilot symbol, so that a group ofmultipath signals are projected on multiple patterns and pathscan be separated and measured. We simulated and evaluated the normalized mean square error of the parameter estimates, including angle of arrival and path gain of channels underdifferent conditions. The results demonstrate that even single1-bi coding RIS antenna can achieve well multipath separationand parameter estimation effects