scholarly journals Satellite-Assisted Cell-Free Massive MIMO Systems with Multi-Group Multicast

Sensors ◽  
2021 ◽  
Vol 21 (18) ◽  
pp. 6222
Author(s):  
Jiamin Li ◽  
Lingling Chen ◽  
Pengcheng Zhu ◽  
Dongming Wang ◽  
Xiaohu You
Keyword(s):  
Closed Form ◽  
Massive Mimo ◽  
Mimo Systems ◽  
Transmission Efficiency ◽  
Spectrum Efficiency ◽  
Achievable Rate ◽  
Zero Forcing ◽  
Channel State ◽  
Average System ◽  
Ratio Transmission

In this paper, we use satellite-assisted and multi-group multicast mechanisms to relieve ground traffic pressure and improve data transmission efficiency of cell-free massive MIMO systems. We propose to estimate channel state information (CSI) by common pilot scheme. Given the estimated CSI, we derive the closed-form expressions of achievable rate with maximum ratio transmission (MRT) and zero-forcing (ZF) precoding. The correctness of the closed-form expressions is verified through simulations. The results show that with the help of satellite and multicast, the average system spectrum efficiency (SE) can be significantly improved.

scholarly journals Performance Analysis of Linear Precoding in Downlink Based on Polynomial Expansion on Massive MIMO Systems

2021 ◽  
Vol 2062 (1) ◽  
pp. 012006
Author(s):  
Sammaiah Thurpati ◽  
Mahesh Mudavath ◽  
P. Muthuchidambaranathan
Keyword(s):  
Performance Analysis ◽  
Massive Mimo ◽  
Mimo Systems ◽  
Polynomial Expansion ◽  
Achievable Rate ◽  
Linear Precoding ◽  
Zero Forcing ◽  
Sum Rate ◽  
Ratio Transmission ◽  
Maximum Ratio Transmission

Abstract The performance of linear precoding schemes in downlink Massive MIMO systems is dealt with in this paper. Linear precoding schemes are incorporated with zero-forcing (ZF) and maximum ratio transmission (MRT), truncated polynomial expansion (TPE), regularized zero force (RZF) in Downlink massive MIMO systems. Massive MIMO downlink output is evaluated with linear precoding included. This paper expresses the performance of achievable sum-rate linear precoding with variable signal-to-noise (SNR) ratio and achievable sum rate and several transmitter-receiver antennas, such as imperfect CSI, less complex processing, and inter-user interference. The transmitter has complete state information on the channel. The information narrates how a signal propagates to the receiver from the transmitter and reflects, for example, the cumulative effect of distance scattering, fading, and power decay. They show that the performance analysis of two linear precoding techniques, i.e., Maximum Ratio Transmission (MRT) and Zero Forcing (ZF) for downlink mMIMO output network over a perfect chain. The results show the improved ZF precoding achievable sum rate compared to the MRT precoding schemes and compared the average achievable rate RZF and TPE.

scholarly journals Performance Analysis of Linear Precoding in Downlink Based on Polynomial Expansion on massive MIMO systems

2021 ◽  
Author(s):  
SAMMAIAH THURPATI ◽  
P Muthuchidambaranathan
Keyword(s):  
Performance Analysis ◽  
Massive Mimo ◽  
Mimo Systems ◽  
Cumulative Effect ◽  
Polynomial Expansion ◽  
Achievable Rate ◽  
Linear Precoding ◽  
Zero Forcing ◽  
Sum Rate ◽  
Ratio Transmission

Abstract The performance of linear precoding schemes in downlink Massive MIMO systems is dealt with in this paper. Linear precoding schemes are incorporated with zero forcing (ZF) and maximum ratio transmission (MRT), truncated polynomial expansion (TPE), regularized zero force (RZF) in Downlink massive MIMO systems. Massive MIMO downlink output is evaluated with linear precoding included. This paper expresses the performance of achievable sum rate linear precoding with variable signal-to-noise (SNR) ratio and achievable sum rate and several transmitter-receiver antennas, such as imperfect CSI, less complex processing and inter-user interference. The transmitter has complete state information on the channel. The information narrate how a signal propagates to the receiver from the transmitter and reflects, for example, the cumulative effect of distance scattering, fading, and power decay. They show that the performance analysis of two linear precoding techniques,i.e.Maximum Ratio Transmission (MRT) and Zero Forcing (ZF) for downlink mMIMO output network over a perfect chain. The results show the improved ZF precoding achievable sum rate compared to the MRT precoding schemes and also compared the average achievable rate RZF and TPE.

scholarly journals Interference Suppression in Heterogeneous Massive MIMO Systems with Imperfect CSI

2021 ◽  
Author(s):  
Rana Sedghi ◽  
masoumeh azghani
Keyword(s):  
Massive Mimo ◽  
Mimo Systems ◽  
Estimation Error ◽  
Interference Management ◽  
Small Cells ◽  
Channel Estimation Error ◽  
Zero Forcing ◽  
Channel State ◽  
Error Matrix ◽  
Mimo Networks

Abstract Interference management is of paramount importance in heterogeneous massive mimo networks (HetNet). In this paper, an algorithm has been suggested to suppress the interference in large-MIMO HetNets with imperfect channel state information(CSI). The proposed technique controls both the intra-tier and cross-tier interference of the macrocell as well as the small cells. The intra-tier interference of the macrocell as well as the cross-tier interference have been minimized under maximum transmission power and minimum signal to interference and noise ratio (SINR) constraint. The channel estimation error matrix has also been modeled using the joint sparsity property. The precoding algorithm is thus achieved through the application of semi-definite relaxation and block coordinate descent techniques. The intra-tier interference of the small cells are addressed with the aid of the zero forcing scheme. The proposed method has been validated through various simulations which confirm the superiority of the algorithm over its counterparts.

scholarly journals A New Method in Pilot Reuse Factor Selection in Spectrum Efficient Massive MIMO Systems

2019 ◽  
Vol 25 (6) ◽  
pp. 70-77 ◽  
Author(s):  
Osman Dikmen ◽  
Selman Kulac
Keyword(s):  
Massive Mimo ◽  
Mimo Systems ◽  
Wave Structure ◽  
Base Station ◽  
Spectrum Efficiency ◽  
Zero Forcing ◽  
Millimetre Wave ◽  
Maximum Ratio Combining ◽  
A Cell ◽  
Definition Of

Spectrum efficiency studies of Massive MIMO systems have continued and still have not been fully explored in the literature. Therefore, the spectrum efficiency definition of a particular user in a cell in a Massive MIMO network is expressed in this paper. In addition, the uplink spectrum efficiency expressions for the Rayleigh fading are included. The Monte Carlo simulations are performed to verify these expressions. Due to the expectation of reaching to a thousand antennas together with the millimetre wave structure in the next years, in this study, it is contributed to the literature by explaining how to select the pilot reuse factor. The realization of this contribution is based on Zero Forcing (ZF) and Maximum Ratio Combining (MRC) schemes. The results of this study are useful for optimal design conditions, such as the number of antennas on the base station and pilot reuse factor selection for the next generation networks in order to obtain spectrum efficiency in Massive MIMO systems.

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 Energy-Efficient Dual-Iteration Power Allocation for Two-Phase Relay System with Massive Antennas

2014 ◽  
Vol 2014 ◽  
pp. 1-8
Author(s):  
Long Zhao ◽  
Wei Xiang ◽  
Jie Mei ◽  
Hui Zhao ◽  
Hang Long ◽  
...  
Keyword(s):  
Power Allocation ◽  
Relay Node ◽  
Spectrum Efficiency ◽  
Amplify And Forward ◽  
Zero Forcing ◽  
Channel State ◽  
Relay System ◽  
Two Phase ◽  
Massive Antennas ◽  
Equal Power Allocation

This paper considers the scenario where multiple source nodes communicate with multiple destination nodes simultaneously with the aid of an amplify-and-forward relay equipped with massive antennas. In order to achieve optimal energy efficiency (EE) of the entire relay system, this paper investigates the power allocation problem for the multiple pairs of nodes at both the source nodes and the relay node, where the relay employs the backward and forward zero-forcing filters. Since the EE optimization problem cannot be solved analytically, we propose a two-phase power allocation method. Given power allocation of one phase, the optimal power allocation is derived for the other phase. Furthermore, two dual-iteration power allocation (DIPA) algorithms with performance approaching that of optimal EE are developed based on the instantaneous and statistic channel state information, respectively. Numerical results show that the proposed DIPA algorithms can greatly improve EE while guaranteeing spectrum efficiency (SE) when compared with the equal power allocation algorithm. Moreover, both algorithms suggest that deploying a rational number of antennas at the relay node and multiplexing a reasonable number of node pairs can improve on the EE and SE.

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