What is Massive MIMO?
what is mimo？MIMO (Multiple Input, Multiple Output) is a wireless communication technology that improves the capacity and efficiency of communication systems by using multiple transmitting and receiving antennas simultaneously over the same time and frequency resources. MIMO allows multiple data streams to be transmitted concurrently within the same spectrum, increasing system throughput, improving signal quality, and reducing interference. Massive MIMO is an extension of MIMO, a key technology in 5G that increases system capacity and spectrum efficiency by using a large number (typically hundreds or more) of antennas to simultaneously process more data streams.
Differences between MIMO and Massive MIMO
Traditional TDD networks typically use 2, 4, or 8 antennas, while Massive MIMO refers to systems with 64, 128, or 256 channels. Traditional MIMO is often referred to as 2D-MIMO, where, for example, with 8 antennas, the signal coverage can only move horizontally, with no vertical movement, causing the signal to radiate like a plane. In contrast, Massive MIMO introduces a vertical dimension to the spatial domain, utilizing both horizontal and vertical spatial resources, where the signal radiation pattern becomes an electromagnetic beam. This is why Massive MIMO is also referred to as 3D-MIMO.
Will 6G continue to use Massive MIMO?
The application and implementation of MIMO technology in 4G (LTE) and 5G (NR) differ significantly. In 4G LTE, the number of antennas used in MIMO systems is relatively small, typically 2x2 MIMO (2 transmitting and 2 receiving antennas) or 4x4 MIMO (4 transmitting and 4 receiving antennas). MIMO in 4G primarily aims to improve spectral efficiency and network capacity, especially in lower frequency bands (e.g., 700 MHz to 2.6 GHz).
In 5G, MIMO technology, particularly Massive MIMO, uses much larger antenna arrays, typically 64x64, 128x128, or even larger, with some systems supporting hundreds or thousands of antennas. 5G's MIMO technology uses more antennas to achieve higher spatial multiplexing, improve spectral efficiency, and better utilize spectrum in both the millimeter-wave (mmWave) band (24 GHz and above) and Sub-6 GHz bands.
6G (the sixth-generation mobile communication technology) is expected to continue using Massive MIMO technology, which is likely to be further optimized and developed. In 6G networks, Massive MIMO is expected to play an even more crucial role, as it can effectively enhance network capacity, increase spectrum efficiency, reduce interference, and improve signal quality and coverage.
6G will drive further advancements in communication technology, supporting higher frequency bands and potentially incorporating even more antennas and advanced beamforming techniques. Massive MIMO will play a central role in these advanced features, especially in the use of millimeter-wave and terahertz bands. With larger antenna arrays, Massive MIMO will support more parallel data streams, which is critical to meeting 6G's demands for high-speed data rates, massive connectivity, and ultra-low latency.
