ZTE claims milestone with first pre-commercial test of distributed MIMO

Chinese vendor ZTE said it achieved a significant breakthrough in research on next-generation radio access networks by completing the first pre-commercial test of distributed multiple input and multiple output (D-MIMO) technology.

ZTE and an unnamed partner conducted a joint field test where they demonstrated an up-to-9 times increase in data rate at the cell edge through the use of D-MIMO technology based on ZTE's proprietary Cloud Radio solution. The outdoor part of the test covered single-user and multiple-user scenarios in an environment with multiple overlapping base stations and used commercially-available mobile device terminals.

ZTE says the Coherent-Joint Transmission technology used in its new D-MIMO system ensures full phase synchronization among base stations, so that the jointly transmitted signal is amplified to the maximum level as it arrives at the antenna of a user terminal, minimizing interference with other terminals. Compared with the legacy Non-Coherent-JT technology, Coherent-JT provides 3 dB of additional gain at the antenna of a target user terminal and forms null steering at the antennas of other user terminals to minimize signal interference, achieving multi-user joint transmission (MU-JT).

ZTE had been touting its work in pre-5g technology as well as R&D in 5G. Earlier this month, ZTE opened a new R&D center in Tokyo to further strengthen the company's research on 5G and other next-generation network technologies. That new opening means ZTE now operates 20 R&D centers in Asia, North America and Europe.

In July, ZTE announced it had signed a memorandum of understanding with Japan's SoftBank to collaborate on research and development on pre-5G technology. Under the MOU, the two companies agreed to cooperate on R&D, evaluation and verification of mobile communications solutions based on ZTE's Pre5G technology, including massive MIMO, which provides higher, farther and deeper coverage than traditional LTE technologies while lowering base station energy consumption.

ZTE's much bigger Chinese rival Huawei has been touting 4.5G and has said it would launch a commercial 4.5G network in 2016 featuring latency rates of around 10 milliseconds, peak downlink speeds of around 6 Gbps and the ability to support 100,000 connections within a single square kilometer.

ZTE claimed credit nearly a year ago for becoming the world's first company to complete pre-commercial field testing of multi-user and multi-stream transmission on a massive MIMO (multiple input multiple output) base station, claiming new records in single-carrier transmission capacity and spectral efficiency.

Using its proprietary multi-user/multi-stream spatial multiplexing technology, the company said it achieved peak data throughput that is more than three times that of traditional base stations and average data throughput that exceeds conventional systems by at least five times. The handsets that were used in that trial were based on existing 4G standards.

For more:
- see this Mobile World Live article
- see this press release

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