Tingjian Tian

5G Field Trials: OFDM-Based Waveforms and Mixed Numerologies

Service diversity is expected in the upcoming fifth-generation (5G) cellular networks, which poses great challenges to the underlying waveforms to accommodate heterogeneous service requirements in a flexible way. By dividing the bandwidth into several subbands, each having a different numerology, this paper reports a field trial in time division duplex downlink conducted on a configurable test bed in a real-world environment for the performance evaluations of orthogonal frequency-division multiplexing (OFDM)-based 5G waveform candidates, i.e., cyclically prefixed OFDM (CP-OFDM), windowing OFDM (W-OFDM), and filtered OFDM (f-OFDM), in the presence of mixed numerologies. Field trial results confirm the feasibility of mixed numerologies and reveal the impact of several important system parameters, e.g., guard bandwidth, data bandwidth, signal-to-noise ratio (SNR), and transmit power. The results also suggest that f-OFDM outperforms CP-OFDM and W-OFDM in terms of both the spectrum efficiency and robustness in a high SNR regime, and the gain increases with a higher inter-numerology out-of-band interference. In some specific scenarios, ideal spectrum utilization can be realized by f-OFDM which completely removes the guard band.

Large scale experimental trial of 5G mobile communication systems — TDD massive MIMO with linear and non-linear precoding schemes

Recently, NTT DOCOMO and Huawei conducted a large-scale experimental trial of key technologies for the 5th generation (5G) mobile systems. Downlink multi-user (MU) transmission with massive MIMO in the time-division duplex (TDD) mode is one of the technologies evaluated in this trial. With linear and non-linear downlink precoding schemes, we investigated the practical performance of MU massive MIMO systems under different numbers of users, user distributions, and different radio frequency channel calibration settings with up to 24 users deployed. When linear precoding is used, the cell spectrum efficiency reaches 39 bit/s/Hz, and it reaches 43 bit/s/Hz when non-linear precoding is used. In term of the cell throughput, up to 1.35 Gbps cell throughput was observed with a linear precoder and 100 MHz bandwidth; and 343 Mbps cell throughput was observed with a non-linear precoder and 20 MHz bandwidth. Based on these investigations, we verified the feasibility and performance of a TDD massive MIMO system for 5G mobile systems, and studied the impact of key factors on the system performance.

Introduction on IMT-2020 5G Trials in China

Ultrahigh data rate, massive connectivity, ultralow latency, and high reliability, as well as ultraflexible air interface design to support diversified usage scenarios, are the major targets of 5G radio access network design. To meet these targets, advanced new radio transmission technologies, including new waveform, new channel coding, non-orthogonal multiple access, as well as massive antenna techniques, have been proposed and studied worldwide in both academic and industries. Most of the gains claimed in the literature are from simulations or by small scale lab testing. Instead, this paper elaborates on the first hand results and analysis of the large-scale field trials carried out in China for a selection of key 5G technology components as well as some of their combinations, including filtered-orthogonal frequency division multiplexing (OFDM) (f-OFDM), polar code, sparse code multiple access, and massive multi-input multi-output (MIMO) for both uplink and downlink cellular networks. Testing results verify the feasibility and benefit of each technology contributing toward the diversified 5G targets, as well as the feasibility for these technologies to work jointly for higher spectrum efficiency, larger connectivity, and lower latency.

Trial Results of 5G New Air Interface Technologies

This paper presents field trial results of innovative air interface technologies: sparse code multiple access (SCMA), filtered orthogonal frequency division multiplexing (f-OFDM), and massive multiple-input multiple-output (MIMO). To confirm the improvement of the promising technologies, the counterparts in long term evolution (LTE) are selected as the comparison baseline. For each technology, detailed parameter configurations and deployment scenarios are addressed at first, then precise test procedures are described, finally, extensive analysis are provided to testify the high spectral efficiency, flexibility and system capacity introduced by the new technologies. According to the trial results, SCMA can achieve

5G Field Experimental Trial on Frequency Domain Multiplexing of Mixed Numerology

3

Large scale massive MIMO field trial for 5G mobile communications system

times connection number and throughput than SC-FDMA in uplink, and

Ultra-Low Latency for 5G - A Lab Trial.

90\%

Evaluation of Coverage and Mobility for URLLC via Outdoor Experimental Trials

throughput gains over OFDMA in downlink. Waveform f-OFDM is validated to support flexible resources allocation thus avoiding asynchronous transmission in both uplink and downlink. The large number of antennas in Massive MIMO accommodates more user and offers around

5G Experimental Trials for Ultra-Reliable and Low Latency Communications Using New Frame Structure

10

5G Field Experimental Trials on URLLC Using New Frame Structure

times throughput than single user scenario in downlink.