Chinese equipment vendor Huawei completed the first phase of testing a supposed new 5G air interface as part of a series of field trials defined by the IMT-2020 5G Promotion Group.

Tests of outdoor macro cells, conducted last month in Chendu, China, showed that the air interface technology can effectively improve spectrum efficiency and meet the diverse service requirements for 5G defined by ITU-R, the company claimed.

Launched by China Academy of Information and Communication Technology (CAICT), the IMT-2020 5G Promotion Group aims to foster a joint effort to promote 5G technology evaluation and field testing among the global mobile industry and ecosystem to ensure successful commercial deployment by 2020. The group in January outlined its overall plan for 5G testing in China.

Huawei is a member of the group and has been collaborating with CAICT, China Mobile, China Unicom and China Telecom to explore air interface technologies to achieve the best spectral efficiency and massive links capabilities. Its efforts are focused on New Radio (NR) technology, which includes the optimised new air interface, full-duplex and massive MIMO technologies.

Defining the air interface
The 5G air interface technology has been implemented through three foundational technologies: filtered Orthogonal Frequency Division Multiplexing (F-OFDM), Sparse Code Multiple Access (SCMA) and Polar code to meet 5G requirements and performance targets.

Huawei said in a statement that F-OFDM technology is the basis for creating an ultra-flexible air interface to adaptively fit all 5G use-case scenarios defined by ITU-R with a single-radio technology platform. Test results showed it can provide 100 per cent higher system throughput compared with LTE in the presence of mixed service on the same carrier frequency with mixed radio numerologies.

SCMA will support massive connections and obtain higher system throughput simultaneously via the joint optimisation on sparse SCMA codebook design and multi-dimensional modulation. The test results showed SCMA can increase the uplink connection number by 300 per cent and at the same time increase the downlink system throughput up to 80 per cent.

Meanwhile, Polar code allocates information to the highly reliable data locations in the code structure to transmit useful user information and supports channel coding of any code rate with an appropriate code construction to fit any future service requirement. The test results showed that Polar code provided coding gain from 0.5dB to 2.0dB compared with Turbo code used in LTE system.