The deployment of 5G is coincident with the virtualization of the network architecture. The benefits of virtualization—a nimble network that’s easy to upgrade and maintain—do not extend to the radio unit (RU). At some point, the virtual world has to meet the real world and, in the case of the cellular network, that’s at the RU.
The higher speed and improved energy efficiency of 5G have a lot to do with the deployment of massive MIMO RUs. Where legacy radios had two or four antennas, a massive MIMO radio may have 64. With these antennas, technologists can implement techniques such as beamforming and multi-user MIMO, which dramatically improve the spectral efficiency of the network.
Massive MIMO technology wouldn’t be possible without dramatic improvements in radio technology. Analog Devices, Inc. (ADI) has been deeply involved in the RU since the 2G days and has created some of the core technologies that make 5G possible. Radio channel density has increased by an order of magnitude in the last decade, and power per channel has fallen by an order of magnitude in the same period.
But it’s not just the chips. ADI views the RU system holistically and applies our expertise to minimize system cost, size, and weight at the system level. For example, the antenna filters in a massive MIMO RU may account for 30% to 40% of the volume of the box. We architect the system such that the filter’s complexity is reduced by up to 50% compared to competitive solutions.