Hello, friend.
It can be seen from the following points
(1) Number of antennas
Traditional TDD networks have two, four, or eight antennas. Massive MIMO refers to 64, 128, or 256 channels.
(2) Dimension of signal coverage
Traditional MIMO is called 2D-MIMO. For example, 8 antennas are used as an example. In actual coverage, signals can only move in the horizontal direction and remain unchanged in the vertical direction. In massive MIMO, signals are transmitted on a plane. Based on the horizontal dimension space of the signal, the vertical dimension space is used. The radiation of the signal is an electromagnetic beam. Therefore, massive MIMO is also referred to as 3D-MIMO.
1. High multiplexing gain and diversity gain: The spatial resolution of a large-scale MIMO system is significantly higher than that of an existing MIMO system. It can deeply mine spatial resources. In this way, multiple users in a coverage area of the base station simultaneously communicate with the base station on the same time-frequency resource by using a degree of spatial freedom provided by large-scale MIMO, thereby improving a multiplexing capability of a spectrum resource among the multiple users, and greatly improving spectral efficiency without increasing base station density and bandwidth.
2. High energy efficiency: A large-scale MIMO system may form narrower beams, which are concentrated in a smaller space area, thereby improving energy efficiency on a radio frequency transmission link between a base station and a UE, and reducing a transmit power loss of the base station. It is an important technology for building a future energy-efficient green broadband wireless communication system.
3. High spatial resolution: Large-scale MIMO systems have better robust performance. Because the number of antennas is much larger than the number of UEs, the system has a high degree of freedom in space, and the system has a strong anti-interference capability. When the number of base station antennas tends to be infinite, the negative effects such as additive white Gaussian noise and Rayleigh fading are negligible.
I wish I could help you.
Thank you.
