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We present a novel angle based indoor localization approach which exploits the directivity property of the smart antenna array at both transmitter and receiver sides. In contrast to conventional AOA based localization approaches, our system combines using beam steering transmitting and receiving approach to mitigate the effect of indoor multipath propagation. By setting the receiver beamforming weights,...
Based on thorough analyses of adverse effects from nonlinear distortion caused by high power amplifiers (HPAs) with phase conversion in multiple-input multiple-output space-time block code (MIMO-STBC) systems, this work proposes a nonparametric phase estimation and compensation method for the received signal. Using the optimal feedforward blind estimation technique, the receive signal's rotated phase...
In this paper, we consider a millimeter wave (mmWave) multiple-input multiple-output (MIMO) communication system with hybrid beamforming architecture. To search the optimal beam pair, the beam sweeping algorithm is complex and time-consuming in the case of initial access and beam switching. With the aim of improving the robustness, we propose a novel beam management scheme to quickly determine the...
This paper researches on millimeter-wave (mm-wave) channel estimation based on interference cancellation (IC) and DOA (Direction of Angles) estimation in hybrid massive MIMO systems. According to the ray-tracing model, the mm-wave channel estimation problem can be solved by converting into the estimation of parameters including the angles of departure (AOD), the angles of arrival (AOA) and the path...
Spectral efficiency and capacity of Land Mobile Satellite (LMS) systems can be enhanced by using MIMO (Multiple Input Multiple Output). Polarization diversity is an efficient technique to realize MIMO in LMS communications. Polarization diversity employs different polarization to realize multiple independent propagation paths. Dual polarized antennas offer a space and cost effective alternative compared...
This work presents an embedded computing framework for the analysis and design of large scale algorithms utilized in the estimation of acoustic doubly dispersive, randomly time-variant, underwater communication channels. Channel estimation results are used, in turn, in the proposed framework for the development of efficient high performance algorithms, based on fast Fourier transformations, for the...
Multi-carrier (MC) multiple-input multiple-output (MIMO) radar offers an additional degree of freedom in the array optimization through the carrier frequencies. In this paper, we study the MC-MIMO array optimization with respect to the direction of arrival (DOA) estimation based on the Cramer-Rao bound (CRB). In particular, we choose the transmit and receive antenna positions as well as the carrier...
In this paper, we study the estimation of channel non-reciprocity in precoded time division duplexing based massive multiple-input multiple-output (MIMO) systems. The considered channel non-reciprocity model covers both the frequency-response and the mutual coupling mismatches between the transmitter and the receiver chains of a massive MIMO basestation (BS). Based on the assumed non-reciprocity model,...
Noncoherent multi-user detection schemes in combination with subspace projection were shown to be an attractive approach in multi-user massive MIMO systems. Up to now, the subspace projection has been performed via a singular value decomposition (SVD) of the receive matrix and nulling the non-signal dimensions. In this paper, we employ an alternative approach to the subspace estimation step, namely...
The fifth-generation (5G) wireless communication systems envision the deployment of massive multiple-input multiple-output (MIMO) technology for enhanced network coverage and capacity. With frequency division duplex (FDD) being the prominent mode of operation, addressing the challenges for massive MIMO systems in FDD is extremely important. One such challenge is the downlink channel estimation, which...
The problem of estimating parameters of switched affine systems with noisy input-output observations is considered. A subspace technique is proposed to exploit the observations' permutation structure, which transforms the problem of associating observations with subsystems into one of de-permutating a block diagonal matrix. Then a spectral clustering algorithm is presented to recover the block structure...
Multiple Input Multiple Output (MIMO) systems are one of the advanced modern technology in the field of the cellular mobile telecommunications. This is due to the fact that its using gives the possibility of increasing the information rate or noise performance of the system. Estimation of the Raleigh Fading channel and the signal impairments caused by the Direct-Conversion Receiver (DCR) with spatial...
The dawn of 5G requires significantly higher data rates, not only for the Radio Access Technology (RAT), but also for the transport network. Line-of-Sight MIMO links based on mmWave radios promise reaching ultra-high throughput with reasonably small antennas. mmWave links with optimally arranged antennas are one viable concept for spatial multiplexing, capable of potentially achieving Gb/s data rates...
A random-vector-based beamforming scheme for Millimeter-Wave (mm-Wave) MIMO systems with asymptotic optimal performance at low signal-to-noise ratio (SNR) is proposed in this paper. Through transmitting random vectors from transmitter (TX) to receiver (RX) then back to TX, the proposed scheme can obtain the estimation of channel auto-correlation with low complexity operations and then obtain the nearly...
In order to describe the highly scattered property of millimeter wave (mmWave) multiple-input multiple-output (MIMO) channels, the existing high resolution frequency domain space-alternating generalized expectation-maximization (FD-SAGE) algorithm is studied and extended to three-dimentional (3D) MIMO case by including the estimation of elevation angles. The signal model and estimation procedure are...
In this paper, we propose an iterative message passing receiver jointly performing channel, phase noise estimation and symbol detection for multi-input multi-output (MIMO) systems. The joint iterative receiver is designed using message passing techniques: general expectation maximization (GEM) and belief propagation (BP) on factor graphs. Therein, the nonlinear measurement function node and symbol...
The carrier frequency between 4.4 GHz to 4.6 GHz is a promising spectrum for 5G mobile communications. In this paper, the MIMO channels at 4.6 GHz are measured and analyzed with massive MIMO TDD prototype. The DoA in uplink and downlink channels are investigated, with which channel reciprocity is analyzed. The measured scenarios cover LOS, NLOS, and blockage channels in outdoor microcell environment...
In this paper, we consider the design of multi-users space-time modulation (MUSTM) for an uplink MIMO system with one base station equipped with the massive number of antennas and N single-antenna users, where it is assumed that only large scale channel coefficients are available at both the transmitter and the receiver. For such a system, a novel concept called uniquely factorable (UF) MUSTM is introduced...
PieceWise Affine (PWA) models are used to approximate general nonlinear dynamics with an arbitrary precision. PWA model can be employed for a constrained optimal controller synthesis, whereas the complexity of the controller is in a large part determined with a complexity of the model. Among the prominent methods for a PWA system identification is the clustering-based identification, which is originally...
In this paper, we investigate the prediction of mobile MIMO channels with varying multipath parameters. Based on the PAST algorithm, we propose a multidimensional adaptive ESPRIT approach for jointly tracking the evolution of the Doppler frequencies and spatial directions of arrival and departure of the propagation paths. Future states of the channel are predicted using the last estimate of the propagation...
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