Demonstrations of “5G” wireless technology generally use microwave spectrum at 24 GHz or higher and massive base station antenna arrays that can create and modify the precise pattern needed to communicate with a device either over a direct path or by reflection. ZTE is applying some of the same principles used in 5G to create its “Pre-5G” solution. A key difference is that ZTE's technology will use 4G handsets. ZTE announced recently that it successfully completed pre-commercial field testing of the world's first pre-5G 3D/Massive MIMO base station in partnership with China Mobile.
The base station used a 64-port/128 antenna array. ZTE's high-performance vector processor system on chip (SoC) chipset provides much higher beam forming gain than previous systems, enhancing coverage for tall buildings improving indoor reception.
CTO of ZTE's Wireless Division, Dr. Xiang Jiying, said that, “As the number of antennas is ten times more, 3D/Massive MIMO had appeared to be a distant pipe-dream. However, the test indicates that we are taking a big step forward to realize the new technology using 4G handsets. This is a result of a number of innovations, and is in line with the pre5G concept previously proposed by ZTE. We will continue to deliver Pre5G features to offer 5G-like experience before 5G standardization.”
The technology helps telecom operators maximize use of existing sites and spectrum resources. ZTE said simulations show its 3D/Massive MIMO system can increase throughput by four to six times.
Huang Yuhong, vice president of the China Mobile Research Institute, said, “The pre-commercial field test of ZTE 3D/Massive MIMO was impressive and exceeded our expectations. This will definitely accelerate the pace of qualification and commercial deployment, and reinforce the advantages of TDD technology. China Mobile will continue to strengthen our partnership with ZTE in the development of 3D/Massive MIMO and other 5G technologies.”
I was unable to find any details on the field tests, but based on information released at ZTE's announcement of its pre-5G technology this summer it appears the system works best with LTE TDD (time-division duplex) as widely used in China. In TDD LTE, the same frequency band is used for uplink and downlink to the base station. This allows the 3D/Massive MIMO system to calculate the path (channel response) to the receiver, allowing it to optimize the antenna pattern used to communicate with it. In FDD (frequency-division duplex) LTE, as widely used in the United States, separate frequency bands are used for the uplink and downlink data. While the system may work with FDD, the user device would have to send real-time channel data on the signal it was receiving from the base station back to the base station, increasing its complexity and reducing its uplink data capacity.
See wwwen.ZTE.com.cn for additional information on ZTE and its technologies.