EFFICIENCY ANALYSIS AND FORECAST OF THE USE OF THE MASSIVE MIMO SYSTEM

Abstract

Today’s goal in cellular network is having high-speed mobile data in any dense urban area. The forecast of the latter is that it will only get more and current cellular base stations not able to continuously increase the transmit/receiving data speeds. Massive MIMO is currently the most compelling sub-6 GHz physical-layer technology for future wireless access. The main concept is to use large antenna arrays at the base stations to simultaneously serve many autonomous terminals. The key concept is to equip BSs with arrays of many antennas, which are used to serve many terminals simultaneously, at the same time-frequency resource. In the article, the word “massive” refers to the number of antennae and not the physical size, where the antenna arrays have attractive form factors: in the 2 GHz band, a half-wavelength-spaced rectangular array with 200 dual-polarized elements is about 1.5 x 0.75 meters large. In the article it is shown how Massive MIMO operates in time division duplex mode and the downlink beamforming exploits the uplink-downlink interaction of radio propagation. Specifically, the BS array uses channel estimates obtained from uplink pilots transmitted by the terminals to learn the channel in both directions. This makes Massive MIMO entirely scalable with respect to the number of base station antennas. BSs in Massive MIMO operate autonomously, with no sharing of payload data or channel state information with other cells. The rich and unique propagation signatures of the terminals are exploited with smart processing at the array to achieve superior capacity. The article presents the analysis, benefits of the massive MIMO system and forecast usage.