Next-generation 5G networks are expected to represent a revolutionary change in wireless communications. Furthermore, multiple-input, multiple-output (MIMO) technology is primed to play an important role in these networks. Test systems must therefore account for this key technology. In the new technical brief, “Insights on Evolving 5G MIMO Networks and Test Methods,” Vaunix Technology describes various MIMO implementations before discussing possible test solutions for these systems.
The technical brief begins by noting that the number of devices connected to the internet will exceed 20 billion in 2020, according to some predictions. Another point mentioned is how mobile phones are increasingly being used to connect to the internet. These points help to illustrate the need for better network performance, which is what 5G is expected to provide. These performance improvements include faster data rates, enhanced spectral efficiency, and lower latency.
MIMO technology is expected to be utilized to overcome the challenges associated with 5G. The document examines MIMO by first discussing small cells, with an explanation of hardwired and mesh-network small cells. Millimeter-wave and massive MIMO are also discussed. The latter allows for a significant increase in spectral efficiency, which is a major requirement of 5G.
Linear processing and precoding are the next topics. According to the document, the preferred method for linear processing involves time-division-duplex (TDD) systems that leverage channel reciprocity, which is a property that allows channel state estimation (CSI) to be estimated at the transmitter. Furthermore, precoding techniques represent another challenge for engineers involved with 5G system development.
MIMO test solutions are then discussed. MIMO testing often requires digital attenuation and RF switching functionality. The document points out the benefit of utilizing USB-powered portable test equipment to meet MIMO test challenges. It also points out that vendors should offer products with a variety of frequency ranges and performance levels. Other factors mentioned are graphical-user-interfaces (GUIs) that are easy to use and install, as well as the capability to operate multiple devices directly from a PC or self-powered USB hub.
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