| 1. |
- Chung, Min Keun, et al.
(författare)
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LuMaMi28 : Real-Time Millimeter-Wave Multi-User MIMO Systems with Antenna Selection
- 2023
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Ingår i: IEEE Transactions on Wireless Communications. - 1536-1276. ; 22:11, s. 7944-7960
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Tidskriftsartikel (refereegranskat)abstract
- This paper presents LuMaMi28, a real-time 28GHz multi-user (MU) multiple-input multiple-output (MIMO) testbed. In this testbed, the base station has 16 transceiver chains with a fully-digital beamforming architecture (with different pre-coding algorithms) and simultaneously supports multiple user equipments (UEs) with spatial multiplexing. The UEs are equipped with a beam-switchable antenna array for real-time antenna selection where the one with the highest channel magnitude, out of four pre-defined beams, is selected. For the beam-switchable antenna array, we consider two kinds of UE antennas, with different beam-width and different peak-gain. Based on this testbed, we provide measurement results for millimeter-wave (mmWave) MU-MIMO performance in different real-life scenarios with static and mobile UEs. We explore the potential benefit of the mmWave MU-MIMO systems with antenna selection based on measured channel data, and discuss the performance results through real-time measurements.
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| 2. |
- Chung, Min Keun, et al.
(författare)
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Millimeter-Wave Massive MIMO Testbed with Hybrid Beamforming
- 2020
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Ingår i: Conference Record of the 54th Asilomar Conference on Signals, Systems and Computers, ACSSC 2020. - 1058-6393. - 9780738131269 ; 2020-November, s. 309-313
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Konferensbidrag (refereegranskat)abstract
- Massive multiple-input multiple-out (MIMO) technology is vital in millimeter-wave (mmWave) bands to obtain large array gains. However, there are practical challenges, such as high hardware cost and power consumption in such systems. A promising solution to these problems is to adopt a hybrid beamforming architecture. This architecture has a much lower number of transceiver (TRx) chains than the total antenna number, resulting in cost- and energy-efficient systems. In this paper, we present a real-time mmWave (28GHz) massive MIMO testbed with hybrid beamforming. This testbed has a 64-antenna/16-TRx unit for beam-selection, which can be expanded to larger array sizes in a modular way. For testing everything from baseband processing algorithms to scheduling and beam-selection in real propagation environments, we extend the capability of an existing 100-antenna/100-TRx massive MIMO testbed (below 6GHz), built upon software-defined radio technology, to a flexible mmWave massive MIMO system.
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| 3. |
- Gunnarsson, Sara, et al.
(författare)
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MmWave Massive MIMO in Real Propagation Environment : Performance Evaluation Using LuMaMi28GHz
- 2021
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Ingår i: 55th Asilomar Conference on Signals, Systems and Computers, ACSSC 2021. - 9781665458283 ; , s. 80-84
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Konferensbidrag (refereegranskat)abstract
- This paper presents measurement and analysis results for millimeter-wave (mmWave) massive multiple-input multiple-output (MIMO) performance in different real-life scenarios with moderate user equipment (UE) mobility. For the measurement campaign, the developed massive MIMO testbed operating at 28GHz called LuMaMi28GHz is employed. In this testbed, the base station has 16 transceiver chains with a fully digital beamforming architecture (with different pre-coding algorithms) and simultaneously supports multiple users with spatial multiplexing. The UEs are equipped with a beam-switchable antenna array for real-time antenna selection where the one with the highest channel magnitude, out of four pre-defined beams, is selected. We explore the potential benefit and features of mmWave massive MIMO systems with antenna selection based on both measured (and recorded) channel data and real-time system performance evaluation.
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| 4. |
- Wernehag, Johan, et al.
(författare)
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A 30dBm PA for MTC Communication in 65nm CMOS Technology
- 2016
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Ingår i: 2016 IEEE 7th Latin American Symposium on Circuits & Systems (LASCAS). - 9781467378352 ; , s. 147-150
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Konferensbidrag (refereegranskat)abstract
- In this paper the feasibility of using a fully integrated 65nm CMOS PA in future machine-type communication standards has been investigated. The integrated PA investigated shows a linear output power in VSWR 2:1 of minimum 24dBm. A VSWR of 2:1 with an associated 3.1dB front-end insertion loss corresponds to a VSWR of 5:1 at the antenna, which is a conservative number. The PAE at 1dB compression point is close to 40% for VSWR 1:1. Taking margin for modulation peak-to-average ratio of 5dB, the PAE at compression point -5dB is 31% at 2100MHz and 24% at 2600MHz. To show the possibility of multi-band operation the PA is centered at 2100MHz and then retuned to 2600MHz, indicating feasibility of a single high band PA. The gain of the two-stage PA is 27dB at 2100MHz and 24dB at 2600MHz. All simulated with a 3.3V output stage supply.
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| 5. |
- Ying, Zhinong, et al.
(författare)
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Antenna Designs for a Milimeter Wave Massive MIMO Testbed with Hybrid Beamforming
- 2021
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Ingår i: 2021 IEEE International Symposium on Antennas and Propagation and North American Radio Science Meeting : APS/URSI 2021 - Proceedings - APS/URSI 2021 - Proceedings. - 9781728146706 ; , s. 1241-1242
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Konferensbidrag (refereegranskat)abstract
- Massive multiple-input multiple-out (MIMO) technology and mm wave are important technologies in 5G/6G to enhance the spectrum efficiency and system capacity. However, it has a lot of challenges in mm wave range, such as high hardware cost and power consumption in such systems. Hybrid beamforming is an interesting solution with less number of RF transvers than antennas. In this paper, we will present antenna designs for a 28GHz hybrid beam forming massive MIMO system with 64 antennas and 16 RF transvers.
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