ZTE introduced its first pre-5G concept at the LTE World Summit 2014 in Nice, France, today (2 July 2014). ZTE announced that under certain conditions some 5G technologies can provide a 5G-like user experience on 4G terminals without changing the air interface standards.
“With next-generation 5G technologies being deployed in 2020, there were industry concerns over what technologies will be used in the next six years,” said Dr Xiang Jiying, ZTE's CTO of wireless products. “To address this, ZTE proposes to apply some of the 5G technology on top of 4G to meet users' requirements.”
For example, with Massive MIMO the reference codes, such as the CSI-RS (channel state information reference signal) should be modified to support hundreds of antenna ports, and the terminals should also be modified for the feedback of hundreds of PMIs (Pre-coding Matrix Indicator).
However, in TDD (time division duplex) mode, the symmetry of uplink and downlink channels can be used for channel estimation. Although without feedback channels, the accuracy of channel estimation even exceeds the feedback result.
Another example is inter-site interference cancellation in UDNs (user densification network). The interference can be decreased effectively through ZTE's sophisticated 4G Cloud Radio architecture, such as its dynamic local mesh networks, and the R12 on/off technologies.
In addition, ZTE said it has invested heavily in the development of 4G vector processing chipsets, which have extensible software architecture and can meet pre-5G requirements by modifying software instruction sets rather than changing hardware.