4x4 MIMO is sweeping the world and 64 antennas Massive MIMO is starting to deploy by the thousand. Huawei also offers a middle ground: Eight antennas. They work with ordinary phones that only have two antennas. That's a big advantage since phones with four antennas are just hitting the market and won't be common for several years.
The eight antenna improvement over 2x2 is "almost double" according to Zarrar Khan, CTO of Kuwait VIVA, a rapidly growing telco controlled by Saudi Telecom. It offers significantly more capacity than 4x4 rigs. In comparison, Huawei reports 4x4 testing by MTN, the South African giant, improves downlink improvement of 74% and uplink 39%.
Important caveat: MIMO results are drastically different depending on the terrain.
Take any MIMO performance figure with a tablespoon of salt. The receiver tells apart MIMO signals by how they bounce off walls and obstacles slightly differently. The results are best with just the right conditions. Vendors have an incentive to choose the most favorable.
Viva uses Huawei's new 3DB AAU, an eight transmit, eight receive (8T8R) system in a way similar to massive MIMO (Transmission Mode 9/ TM9) The additional antennas focus the beam where the demand is greatest. Khan likes the result. "It gave us a capacity boost of about almost 100%. In terms of throughput of each customer, it has effectively gone up by more than 85%.Our total cost ownership has gone down by 40% with 8T8R. Instead of deploying expensive sites, we are upgrading the existing sites with 8T8R AAU.” (Quote and illustration from Huawei presentation.)
Networks needing capacity now can choose between more antennas (MIMO,) more cell sites (small cell,) and more spectrum (Carrier Aggregation.) Until recently, using multiple bands of spectrum was the most popular. With self-organizing networks now working well, small cells are becoming popular. With new four antenna phones (Qualcomm 835,) most tower cells are becoming common. Eight to sixty-four antenna MIMO is now part of the mix.
Everyone has a different opinion on which is best, which varies based on the circumstances.
Here's the pr. Monday, 1 February 2016 KSA 12:23 - GMT 09:23
Huawei and Qualcomm successfully conduct the first announced comprehensive test of LTE TM9 with 8x2 MIMO
[Shanghai, China, Feb 16, 2017] Huawei and Qualcomm Technologies, Inc., a subsidiary of Qualcomm Incorporated, completed the first announced 8-port 8x2 MIMO test based on LTE transmission mode (TM) 9 in 4.5G interoperability testing. The test used Huawei's unique 3DB AAU (8T8R) solution and the Qualcomm Snapdragon™ X16 LTE modem. Through MU-MIMO, several Snapdragon X16 LTE modem mobile test devices received the same 20MHz spectrum with each of them reaching a peak rate of 188.3Mbps. The tests demonstrate successful innovation in LTE-FDD with multi-antenna technology.
TM9- capable terminals can feedback user-level information to base stations, which will help to form the user dedicated beam. With this dedicated beam, the signal strength will be enhanced and the interference between users will be reduced. While many existing smartphones support TM9 with 4x2 MIMO, TM9 with 8x2 MU-MIMO beamforming provides additional capacity gains. In this joint test, 8x2 MU-MIMO generated a narrower and more focused energy beam, allowing for less interference among users. This greatly improves the multiplexing of spectrum resources, and provides a better user experience.
Huawei's unique 3DB AAU (8T8R) solution is commercially available and is proven to provide nearly 100% capacity improvement based on TM4 LTE smartphones compared with 2T2R. With the maturity of the TM9 terminal industry, the capacity and user experience can be further enhanced.
Bob Cai Mengbo, President of FDD LTE Product Line at Huawei, said, "With 3GPP evolution of multi-antenna technology, 4.5G spectrum efficiency will be further improved. And we look forward to continued cooperation with Qualcomm Technologies to jointly promote the maturity of the TM9, which can greatly help operators improve spectrum more effectively and better serve the end user.”
Francesco Grilli, vice president, product management, Qualcomm Technologies, Inc. says, "The comprehensive test of TM9 demonstrates the benefits of 8x2 MIMO in enhancing user experience and shows Huawei’s and Qualcomm Technologies’ efforts in bringing TM9 to the industry. TM9 8x2 MIMO is another important feature in the X16 Gigabit LTE modem from Qualcomm Technologies. Qualcomm Technologies is looking forward to working with Huawei in commercialization of this feature”.
Important caveat: MIMO results are drastically different depending on the terrain. Take any figure with a tablespoon-full of salt. The signals bounce off walls and obstacles slightly differently, allowing the receiver to tell them apart.