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Fifth-generation (5G) new radio (NR) deployments are being rolled out in both the C–band (3.3 - 5.0 GHz) and millimeter-wave (mmWave) band (24.5 - 29.5 GHz). For outdoor scenarios, the C–band is expected to provide wide area coverage and throughput uniformity, whereas the mmWave band is expected to provide ultra-high throughput to dedicated areas within the C-band coverage. Due to the differences in the frequency bands, both systems are expected to be designed with different transmit and receive parameters, naturally resulting in performance variations proportional to the chosen parameters. Unlike many previous works, this paper presents measurement evaluations in central Auckland, New Zealand, from a precommercial deployment of a single-user, single-cell 5G-NR system operating in both bands. The net throughput, coverage reliability, and channel rank are analyzed across the two bands with baseband and analog beamforming. Our results show that the C-band coverage is considerably better than mmWave, with a consistently higher channel rank. Furthermore, the spatial stationarity region (SSR) for the azimuth angles-of-departure (AODs) is characterized, and a model derived from the measured beam identities is presented. The SSR of azimuth AODs is seen to closely follow a gamma distribution.
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Millimetre wave coarse beamforming using outband sub‐6 GHz reconfigurable antennas
Abstract Low latency beamforming using phased antenna arrays is the key for practical deployment of envisioned millimetre wave (mmWave) Gbps mobile networks. This work aims towards reducing the overhead of the exhaustive sector‐level sweep phase of the analog beamforming adopted in the IEEE 802.11ad standard. This work is the first to propose the use of reconfigurable antenna single RF chain in the sub‐6 GHz new radio (NR) band to aid codebook‐based beam selection in the mmWave band of the NR. We exploit the congruence between the spatial propagation signatures of signals at both mmWave and sub‐6 GHz frequencies to reduce the beam search space. The simulation results show a significant reduction in mmWave beam search overhead up to on average and with an average gain loss of 3dB.
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- PAR ID:
- 10368814
- Publisher / Repository:
- DOI PREFIX: 10.1049
- Date Published:
- Journal Name:
- IET Communications
- Volume:
- 15
- Issue:
- 19
- ISSN:
- 1751-8628
- Format(s):
- Medium: X Size: p. 2448-2460
- Size(s):
- p. 2448-2460
- Sponsoring Org:
- National Science Foundation
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