scholarly journals Robust Hybrid Beam-Forming for Non-Orthogonal Multiple Access in Massive MIMO Downlink

Electronics ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 75
Author(s):  
Fahad Alraddady ◽  
Irfan Ahmed ◽  
Filmon Habtemicail
Keyword(s):  
Massive Mimo ◽  
Multiple Access ◽  
Beam Forming ◽  
Transmission Scheme ◽  
Zero Forcing ◽  
Hybrid Precoding ◽  
Hybrid Beam ◽  
Power Domain ◽  
Mimo Downlink ◽  
User Interference

This paper presents hybrid precoding for a non-orthogonal multiple access (NOMA) transmission scheme in a millimeter wave (mmWave) massive MIMO (mMIMO) downlink. In hybrid precoding, the analog precoder is obtained by the orthogonalization of the users’ channel vectors to minimize inter-beam interference. The digital precoder consists of a zero-forcing precoder to minimize inter-user interference. In order to break the barrier of one user per beam, we utilize the NOMA within the beam for power domain multiplexing among users. Simulation results show the proposed scheme’s efficacy compared to the state-of-the-art schemes and provide 1.48 times better sum-rate performance at 10 dB received SNR.

scholarly journals A New Cooperative and Distributed Antenna Structure in Massive MIMO-NOMA Based on mmWave Transmission Scheme

2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Pouria Salehi ◽  
Naser Parhizgar ◽  
Farshad Pesaran
Keyword(s):  
Massive Mimo ◽  
Multiple Access ◽  
High Energy ◽  
Base Stations ◽  
Spectrum Efficiency ◽  
High Rate ◽  
Transmission Scheme ◽  
Antenna Structure ◽  
Distributed Antenna ◽  
Sum Rate

In this paper, we propose a new massive multiple-input multiple-output (MIMO) nonorthogonal multiple access (NOMA) system with a cooperative and distributed antenna structure based on a millimeter-wave (mmWave) transmission system. We proposed this method to obtain high energy efficiency (EE) and spectrum efficiency (SE) by using the mmWave transmission scheme. In the proposed system, the user selects a few nearby base stations (BS) to create a virtual cell to own the serving BS antenna set. We concentrate on the mmWave massive MIMO-NOMA scheme. In this scheme, a large number of BS antennas and users by uniform distributions (UD) are considered in a specific area. Also, we combine our proposed method by interleaving division multiple access (IDMA) and utilize the IMDA benefits for high-rate applications. The proposed transmission scheme significantly improves the performance output in terms of SE, EE, sum rate, and log sum rate, according to our simulation results.

scholarly journals Low-Complexity Multi-User Parameterized Beamforming in Massive MIMO Systems

Electronics ◽  
2020 ◽  
Vol 9 (6) ◽  
pp. 882 ◽  
Author(s):  
Geon-Woong Jung ◽  
Yong-Hwan Lee
Keyword(s):  
Computer Simulation ◽  
Massive Mimo ◽  
Mimo Systems ◽  
Low Complexity ◽  
Beam Direction ◽  
Transmission Scheme ◽  
Zero Forcing ◽  
Combined Use ◽  
Ratio Transmission ◽  
Maximum Ratio Transmission

In this paper, we design a complexity-reduced transmission scheme in massive antenna environments. To reduce the implementation complexity for the generation of beam weight, we design a multi-user parameterized beamforming (MUPB) scheme that can control the beam direction using a single parameter with combined use of maximum ratio transmission and partial zero-forcing scheme that partially nulls out interference. We design the MUPB to maximize the signal-to-leakage plus noise ratio (SLNR). To further reduce the implementation complexity, we optimize the MUPB based on approximated SLNR instead of accurate SLNR. Finally, the performance of the proposed MUPB is verified by computer simulation.

scholarly journals Adaptive Regularized Zero-Forcing Beam Forming In Massive MIMO With Multi-Antenna Users

2021 ◽  
Author(s):  
Evgeny Bobrov ◽  
Boris Chinaev ◽  
Viktor Kuznetsov ◽  
Hao Lu ◽  
Dmitrii Minenkov ◽  
...  
Keyword(s):  
Open Source ◽  
Impulse Response ◽  
Open Source Software ◽  
Massive Mimo ◽  
Radio Channel ◽  
Channel Impulse Response ◽  
Beam Forming ◽  
Zero Forcing

We are testing the proposed approach in several scenarios generated using Quadriga - an open source software for generating realistic radio channel impulse response. <br>

scholarly journals Adaptive Regularized Zero-Forcing Beam Forming In Massive MIMO With Multi-Antenna Users

2021 ◽  
Author(s):  
Evgeny Bobrov ◽  
Boris Chinaev ◽  
Viktor Kuznetsov ◽  
Hao Lu ◽  
Dmitrii Minenkov ◽  
...  
Keyword(s):  
Open Source ◽  
Impulse Response ◽  
Open Source Software ◽  
Massive Mimo ◽  
Radio Channel ◽  
Channel Impulse Response ◽  
Beam Forming ◽  
Zero Forcing

We are testing the proposed approach in several scenarios generated using Quadriga - an open source software for generating realistic radio channel impulse response. <br>

scholarly journals Zero-Forcing Precoding in the Measured Massive MIMO Downlink: How Many Antennas Are Needed?

2019 ◽  
Vol 2019 ◽  
pp. 1-10 ◽  
Author(s):  
Zhe Zheng ◽  
Jianhua Zhang ◽  
Xiaoyong Wu ◽  
Danpu Liu ◽  
Lei Tian
Keyword(s):  
Massive Mimo ◽  
Mimo System ◽  
Signal To Noise Ratio ◽  
Base Station ◽  
Simple Expression ◽  
Mimo Channel ◽  
Channel Measurements ◽  
Zero Forcing ◽  
Theoretical Derivation ◽  
Mimo Downlink

In order to understand how many antennas are needed in a multiuser massive MIMO system, theoretical derivation and channel measurements are conducted; the effect of a finite number of base station (BS) antennas on the performance capability of Zero-forcing (ZF) precoding in a rich scattering channel is quantified. Through the theoretical analysis, the needed number of the transmit antennas for ZF precoder to achieve a certain percentage of the broadcast channel (BC) capacity will monotonically decrease with the increase of the transmit signal-to-noise ratio (SNR), and the lower bound of the needed transmit antennas is derived with a simple expression. Then the theoretical derivation is verified by simulation results, and the transmission performance is evaluated by channel measurements in urban microcell (UMi) scenario with frequencies of 3.5 and 6 GHz. From the measurement results, the ZF capability can be enhanced by improving the SNR and enlarging the antenna array spacing when the massive MIMO channel does not under a favorable propagation condition. Furthermore, because of the lower spatial correlation, the performance of ZF precoding at 6 GHz is closer to the theoretical derivation than 3.5 GHz.

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