| Abstrakt: |
Massive multiple‐input multiple output (MIMO) systems provide a promising technology for the next generation of wireless communication systems (5G). In the present research, a novel random access (RA) protocol is proposed based on the beamforming properties to admit as many user equipment (UE) as possible, enhance the system performance, and manage the limited number of orthogonal pilots simultaneously. First of all, the proposed RA protocol is studied theoretically to find out formulas for average number of users who will have access to the base station (BS). The result shows the same number of UEs can access the BS as conventional protocols such as multichannel RA solutions. However, in contrary to the conventional protocols, the proposed protocol guaranties that the UEs are located in separate locations, thus, the signal to interference ratio (SINR) of the admitted users are enhanced in multiuser MIMO data transmission phase. A series of enhancements are then proposed to save the orthogonal pilots and to increase the average admitted users significantly. It is shown that, using our novel protocols, we can almost admit as many users as the number of antennas in the BS, using only a fraction of orthogonal pilots needed in conventional protocols. [ABSTRACT FROM AUTHOR] |
Plný text