In this paper, linear precoding for non-orthogonal space time block codes (STBC) is investigated. A theoretical model of spatial correlation with a Laplacian distribution of AOA is first derived. The design of the pre...
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ISBN:
(纸本)9781424411436
In this paper, linear precoding for non-orthogonal space time block codes (STBC) is investigated. A theoretical model of spatial correlation with a Laplacian distribution of AOA is first derived. The design of the precoder is based on the choice of the codeword error matrix according to a criterion. We propose here a new criterion based on the system outage probability to select the suitable codeword error matrix allowing to move rapidly from one diversity order to the next. Codeword selection points out the importance of the determinant and the eigenvalues of the error matrices. The proposed method is applied to the non-orthogonal optimal STBC : 2 x 2 Golden Code and 4 x 4 Perfect Code.
In this paper, we evaluate the performance of the digital beamsteering (DBS) precoder in multi-user multiple-input multiple-output (MIMO) systems operating at mmWave frequencies. This evaluation is done using a 3-D mm...
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ISBN:
(纸本)9781728136875
In this paper, we evaluate the performance of the digital beamsteering (DBS) precoder in multi-user multiple-input multiple-output (MIMO) systems operating at mmWave frequencies. This evaluation is done using a 3-D mmWave statistical channel model developed based on outdoor extensive measurement in New York city. The NYUSIM channel simulator generates 3-D realistic statistical temporal and spatial parameters. The DBS performance is evaluated in terms of capacity achieved as a function of the number of users and compared with two classical precoders, namely, zero forcing (ZF) and conjugate beamforming (CB). The base station is equipped with three different antenna array configurations: uniform linear array, uniform square array and uniform rectangular array. Simulation results show that DBS can be realistically considered as an attractive precoder for mmWave multi-user MIMO system with tens of antennas at the base station;trading-off performance, low implementation complexity and less overhead.
Multi-cell processing (MCP) is regarded as an effective way for interference mitigation in cellular networks. We propose a joint Base Station (BS) selection and linear precoding design algorithm for the downlink trans...
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ISBN:
(纸本)9781424468904
Multi-cell processing (MCP) is regarded as an effective way for interference mitigation in cellular networks. We propose a joint Base Station (BS) selection and linear precoding design algorithm for the downlink transmission in MCP enabled networks. The algorithm solves a regularized utility maximization problem to find a sparse solution for the precoding matrix. The BS selection is thus based on the sparsity pattern of the resulted precoding matrix. With the joint design, the proposed algorithm rigorously takes into account and optimizes the effect of BS selection on the overall system performance. The problem of total power minimization for target SINR, which can be cast as a Second Order Cone Program (SOCP) is used as an example for illustration. Simulation is performed to compare the proposed algorithm with the BS selection schemes in literature. It shows that our joint algorithm not only requires less power for target SINR, but also dramatically reduces the computational complexity.
In this paper mutual information maximizing linear precoding for MIMO transmission using finite signal alphabets and a parallel layer MIMO detection scheme is derived. The derivation exploits that the mutual informati...
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ISBN:
(纸本)9781424493326
In this paper mutual information maximizing linear precoding for MIMO transmission using finite signal alphabets and a parallel layer MIMO detection scheme is derived. The derivation exploits that the mutual information of the parallel detection scheme can be expressed in terms of the mutual information associated with optimal maximum likelihood detection. Results show that the large performance gap between parallel layer detection and maximum likelihood detection in ill conditioned channels can be substantially alleviated by optimal precoding.
Fast and continues development Wireless communication requires enhancement of capacity of system. To improve the capacity of system multiuser multiple inputs multiple outputs (MU-MIMO) is considered. It has ability sy...
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ISBN:
(纸本)9781538654729
Fast and continues development Wireless communication requires enhancement of capacity of system. To improve the capacity of system multiuser multiple inputs multiple outputs (MU-MIMO) is considered. It has ability system capacity improvement without additional bandwidth. In the implementation of MU-MIMO Multi User Interference (MUI) created and this interference degrade the system performance. Thus to minimize or suppress the interference, precoding technique used before signal transmission. Due to low complexity linear precoding preferred. For the massive system dimension, an appropriate precoding algorithm designing is difficult with less computing complexity and better error rate performance simultaneously over fading channels. This paper convey sum rate performance and bit error rate (BER) performance of linear precoding techniques above fading channels with assuming that the transmitter has perfect channel state information (CSI). To valuation of the bit error rate performance, different fading surroundings namely, Rician, Nakagami, and Rayleigh fading channel distributions offered.
The mobile WiMAX standard (802.16e) uses multiple-input multiple-output (MIMO) limited feedback linear precoding to exploit the channel state information at the transmitter. Although the performance of limited feedbac...
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ISBN:
(纸本)9781424425198
The mobile WiMAX standard (802.16e) uses multiple-input multiple-output (MIMO) limited feedback linear precoding to exploit the channel state information at the transmitter. Although the performance of limited feedback linear precoding in relation to traditional open-loop MIMO has been extensively studied in the literature, these studies commonly assume a zero-lag feedback channel. However, due to the mobile nature of the mobile station (MS), the channel feedback information at the base station (BS) is incorrect because of an inherent delay between the time the MS estimates the channel feedback information and the time it is used in the BS. This results in performance degradation compared to a zero-lag feedback channel. To date, few researchers have studied the impact of MS velocity and Doppler spread on the performance of limited feedback linear precoding. Simulation results show that the performance of the mobile WiMAX precoded system degrades significantly as the MS velocity increases. At a velocity of 3km/h the precoded system degrades by 0.1-0.2dB in terms of array gain. However, the performance drops considerably when the velocity exceeds 10 km/h. At high MS velocities (i.e., 120 km/h), the linear precoding technique fails to provide any benefits. In this high mobility case we show that a linear precoding MIMO system with more antennas experiences the same performance as an open-loop MIMO system with fewer antennas.
In this paper, several multi-user multiple-input multiple-output (MU-MIMO) linear precoding schemes with both perfect and imperfect channel state information (CSI) for downlink transmission are proposed. Compared to n...
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ISBN:
(纸本)9781424455379
In this paper, several multi-user multiple-input multiple-output (MU-MIMO) linear precoding schemes with both perfect and imperfect channel state information (CSI) for downlink transmission are proposed. Compared to nonlinear precoding schemes which need perfect CSI to achieve the channel capacity, we focus on systems which are restricted to use only linear precoding schemes due to complexity constraints and limited feedback. The limited feedback and some improvement technologies have also been introduced. The proposed MU-MIMO schemes extend the point-to-point single-user precoding to point-to-multipoint multi-user precoding.
Massive Multiple-Input Multiple-Output (MIMO) answers the exponentially increasing demand for comprehensive fixed broadband and broadcast wireless communication services. Massive MIMO is a pivotal technology in the 5G...
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The ergodic capacity of MIMO frequency-flat and -selective channels depends greatly on the eigenvalue distribution of spatial correlation matrices. Knowing the eigenstructure of correlation matrices at the transmitter...
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The ergodic capacity of MIMO frequency-flat and -selective channels depends greatly on the eigenvalue distribution of spatial correlation matrices. Knowing the eigenstructure of correlation matrices at the transmitter is very important to enhance the capacity of the system. This fact becomes of great importance in MIMO wireless systems where because of the fast changing nature of the underlying channel, full channel knowledge is difficult to obtain at the transmitter. In this paper, we first investigate the effect of eigenvalues distribution of spatial correlation matrices on the capacity of frequency-flat and -selective channels. Next, we introduce a practical scheme known as linear precoding that can enhance the ergodic capacity of the channel by changing the eigenstructure of the channel by applying a linear transformation. We derive the structures of precoders using eigenvalue decomposition and linear algebra techniques in both cases and show their similarities from an algebraic point of view. Simulations show the ability of this technique to change the eigenstructure of the channel, and hence enhance the ergodic capacity considerably. Copyright (c) 2007 *** and T. Le-Ngoc.
linear zero forcing (ZF) precoding can obtain near-optimal performance as the number of base station (BS) antennas increases, but involve complex matrix inversion calculations whose computational complexity is cubic w...
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linear zero forcing (ZF) precoding can obtain near-optimal performance as the number of base station (BS) antennas increases, but involve complex matrix inversion calculations whose computational complexity is cubic with respect to the number of user equips (UEs) in massive multiple-input multiple-output (MIMO) systems. In this paper, a low-complexity modified successive over-relaxation-based ZF (MSOR-ZF) linear precoding is proposed, in which complicated matrix inversion is directly avoided through the use of MSOR iteration. Moreover, to further increase the convergence rate, the proposed MSOR-ZF precoding exploits the diagonal dominant property of the matrix instead of the original zero vector solution to achieve a satisfactory performance with a reduced iteration number. The proposed precoding is superior in convergence rate and reduces the computational complexity by approximately one order of magnitude, which is indicated by theoretical analysis. Simulation results demonstrate that the proposed precoding can achieve better achievable sum-rate and bit-error-ratio (BER) performance than some existing iterative-based precoding schemes with lower complexity. (C) 2020 Elsevier Inc. All rights reserved.
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