Massive MIMO Antenna Schemes
Due to the high expectations of 5G, cellular evolution is expediting. The ever-increasing demand for more data and improved efficiency is driving radio access technology to higher frequency bands (such as 3.5 or 6 GHz), which offers significantly more available bandwidth, and to smaller cells, operating at lower power and allowing network densification.
One revolutionary change is in the use of massive multiple- input / multiple-output (MIMO) antenna schemes, enabling spatial multiplexing and maximizing the reuse of scarce bandwidth. With massive MIMO beam forming, it becomes possible to move the network forward from the traditional point-to-multipoint paradigm to a real-time adaptive point-to-point link, with the base station tracking the user and steering its signal to them. Improved antenna gain overcomes path loss, enabling higher data rates per hertz compared with an isotropic signal at the same power.
All of this drives new requirements for the development and implementation of massive MIMO technology within the 5G ecosystem. There are implications for the tools required to simulate, design and test highly complex systems containing tens or hundreds of antennas and the associated communication pathways.
Massive MIMO Beam Forming Design and Verification Challenges
Massive MIMO is a network-side (base-station) spatial multiplexing technique designed to improve data rates per user. The calibration and verification of multi-channel beam forming antennas requires a thorough understanding of the underlying technology and the effective application of appropriate test methods.
The required number of measurement channels remains an open and important question. Typical massive MIMO designs will range from tens to hundreds of antennas, beam forming in azimuth and elevation. Traditional 2D antenna pattern measurements may not be good enough to validate overall system performance.
Co-simulation approach for the channel model with antenna 3-D patterns are important parts of the development process. The ability to correlate simulation with actual measurements gives confidence that the final design meets design goals and greatly accelerates time-to-market.
Massive MIMO is a powerful tool to improve data rates. As mentioned earlier, a co-simulation approach for the channel model with antenna 3-D patterns are important parts of the development process. In the past, antenna designer may not need to provide the 3-D antenna patterns to the network planning because of the simplicity of the system. However, for massive MIMO antenna use in 5G network, antenna designer may need to consider providing 3-D pattern data set for overall channel performance estimation.