Qualcomm and ZTE complete 5G-A interoperability tests of HPUE, SUL and waveform switching

Qualcomm Technologies and ZTE completed several 5G-A chip and system interoperability tests organized by the IMT-2020 (5G) Promotion Group, ithome.com reported on November 10, citing the group's WeChat account ithome.comithome.comithome.comOpen source ↗. The tests covered high-power user equipment (HPUE), supplementary uplink (SUL), layer-1 fast waveform switching and device-side beam prediction.

HPUE and supplementary uplink

In the FDD HPUE tests, a mobile test terminal based on the Qualcomm X105 modem and RF system was checked in n1 (2.1 GHz) and n28 (700 MHz) at power class PC2 (26 dBm). In TDD, the same platform was tested in n41 (2.6 GHz) and n78 (3.5 GHz) at PC1.5 (29 dBm). Higher transmit power is intended to improve uplink at the cell edge.

TDD SUL was tested in band A (n95, 2010–2025 MHz) and band F (n98, 1880–1920 MHz). The terminal stays connected to the main carrier and also sends data on a supplementary uplink carrier in lower-frequency spectrum.

Waveform switching and beam prediction

Layer-1 fast waveform switching, supported in 3GPP Release 18, lets the network switch between DFT-s-OFDM and CP-OFDM depending on channel conditions, with the switch indicated via DCI ithome.comithome.comithome.comOpen source ↗. DFT-s-OFDM has a lower peak-to-average power ratio and is used where coverage is limited; CP-OFDM is used where the connection is good.

In the beam-management test, the terminal operated in a ZTE base-station cell in n258 (25.5 GHz), using 12 wide beams as prediction input and 24 narrow beams as output. According to the report, reference-signal overhead and the terminal's measurement load for narrow beams dropped significantly while downlink data performance was maintained.