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The estimation of symbol timing offset (STO) is an important issue for orthogonal frequency division multiplexing (OFDM) systems. In the literature, a variety of STO estimation methods have been proposed. In this paper, we propose a new blind STO estimation for OFDM systems with constant modulus (CM) constellation. The proposed estimator can estimate STO with only one OFDM symbol. Besides, a low complexity...
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...
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...
This paper presents a complete method for automatic and robust control configuration selection for linear systems which relies upon acquired process data under Gaussian noise excitation. The selection of the configuration is based on the estimation of the Interaction Measure named Participation Matrix. This estimation is derived with uncertainty bounds, which allows to determine online whether the...
In a multi-user millimeter (mm) wave communication system, we consider the problem of estimating the channel response between the central node (base station) and each of the user equipments (UE). We propose three different strategies: 1) Each UE estimates its channel separately, 2) Base station estimates all the UEs' channels jointly, and 3) Two stage process with estimation done at both UE and base...
In this paper, we propose a new technique for synchronization and channel estimation in M-QAM OFDM radio over fiber (RoF) system by using constant amplitude zero auto-correlation (CAZAC) sequence based training preamble. Delay and correlate method is used to identify the training sequence in the received signal vector and to correct the symbol timing offset. For an optimum demodulation of OFDM signal,...
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...
Channel estimation is one of the most important parts in current mobile communication systems. Among the huge contributions in channel estimation studies, the discrete Fourier transform (DFT)-based channel estimation has attracted lots of interests since it can not only be easily implemented but also have acceptable performance in practical systems. In this paper, we propose an improved DFT-based...
This paper proposes a channel estimation and equalization methods for a transmit diversity system of using time domain training sequence inserted orthogonal frequency division multiplexing (TS-OFDM) signal in higher time-varying fading channels. The salient feature of the proposed channel impulse response (CIR) estimation method for the transmit diversity system with a space frequency block coding...
A minimum mean square error estimation (MMSE) using a virtual pilot channel estimation scheme was proposed by our researchers for improving the error performance of the IEEE 802.11p. However, compared to the STA channel estimation scheme, the MMSE scheme cannot provide an acceptable error performance in a low SNR region. To alleviate this, we propose an adaptive channel estimation scheme, which selectively...
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...
This paper presents a vehicle positioning method based on joint estimation of time of arrival (TOA) and direction of arrival (DOA) with Vehicle-to-Roadside (V2R) communications. By analyzing the measured channel frequency response (CFR) between vehicles and the roadside unit (RU), the enhanced two-dimensional matrix pencil (2-D MP) algorithm is implemented to design the parameter estimator, which...
We consider tensor factorizations using a generative model and a Bayesian approach. We compute rigorously the mutual information, the Minimal Mean Square Error (MMSE), and unveil information-theoretic phase transitions. In addition, we study the performance of Approximate Message Passing (AMP) and show that it achieves the MMSE for a large set of parameters, and that factorization is algorithmically...
In this paper, we consider a problem of sampling a Wiener process, with samples forwarded to a remote estimator via a channel that consists of a queue with random delay. The estimator reconstructs a real-time estimate of the signal from causally received samples. Motivated by recent research on age-of-information, we study the optimal sampling strategy that minimizes the mean square estimation error...
One of the orthogonal frequency division multiplexing (OFDM) schemes is the Time Domain Synchronous OFDM (TDS-OFDM) scheme, in which, the guard intervals between consecutive OFDM symbols contain Pseudo Noise (PN) sequences which are known to the receiver and are used for channel estimation and synchronization. In this paper, a joint channel estimation algorithm is proposed for TDS-OFDM scheme, the...
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...
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