Huawei has said that it has successfully tested the beginnings of a unified air interface that it hopes will be able to meet 5G demands on throughput and spectral efficiency and enabling different use cases.
Huawei has a longstanding commitment to developing a “unified” air interface based on the Filtered OFDM waveform, Sparse Code Multiple Access and Polar code. Broken down, fOFDM allows for a more flexible use of the OFDM interface by “filtering” different sub-bands within the baseband, so that they can then be configured differently to each other. It’s a key proposal to solving the conundrum of being able to serve different use cases from within the same air interface.
SCMA allows for more connections per link by using more efficient coding designs. Polar code is a super new coding scheme.
Having conducted initial tests, Huawei said that fOFDM could provide 100% higher system throughput vs LTE (which uses plan old OFDM), and that SCMA could support 300% more uplink connections, and that Polar code increased gain compared to LTE’s Turbo coding scheme.
Huawei says it has also tested Multi-User MIMO (MU-MIMO) and full duplex radio. The MU-MIMO element supported up to 24 users, achieving 3.6Gbos average throughput across a cell on 100MHz bandwidth.
Full duplex, which relies on self-interference cancellation algorithms to allow send and receive in the same channel, achieved a 90% throughput gain, Huawei said.
The trials took place under the auspices of the IMT-2020 Promotion Group – which is essentially China’s umbrella research body for 5G, backed by a number of its operators and tech vendors.
Delivering an air interface specification that can meet 5G’s often competing demands is the first challenge for the industry, and there is not unanimity on which schemes will be deployed. The fOFDM waveform, for example, is less favoured by some than other candidates such as Filter bank multicarrier (FBMC) and Universal filtered multicarrier (UFMC).
Huawei will naturally be keen to prove the efficacy of its chosen candidate.