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Evaporation duct has strong impacts on the performance of marine radar and communication systems. Evaporation duct channel is a promising channel for marine high capacity data transmission. Wave propagation models and evaporation duct models are well studied, and statistical features of duct channel has been observed. However, the work on the physical model of small-scale characteristics of evaporation...
Massive multiuser multi-input multi-output (MU-MIMO) system adopting large amount of antennas is a promising technique to improve spectral efficiency and energy efficiency for next generation wireless communication systems. In practice, the channels composed of pairs of transmit and receive antennas are often correlated and computational complexity is one of the critical concern in implementation...
By combining the polarized modulation and the spatial modulation technique, dual-polarized spatial modulation (DPSM) has been recently proposed for MIMO transmission to improve the spectral efficiency and reduce the space occupancy. The performance of DPSM over correlated Rayleigh and Rice fading channels has been studied, showing that DPSM technique outperforms uni-polarized SM technique. For a general...
The channel factors during signal propagation from the satellite to moving user terminal (UT) is comprehensively analyzed. Then an algorithm is presented to model dual-polarized MIMO LMS channel, which investigates almost all channel factors including temporal and polarization correlation, line-of-sight (LOS) shadowing, multipath effect, cross-polar discrimination (XPD) of antennas, cross-polar coupling...
In this paper, an antenna grouping assisted spatial modulation scheme is proposed for massive MIMO systems. Massive multiple-input-multiple-output (MIMO) systems are capable of offering abundant spatial capacity by deploying hundreds of antennas at the base station (BS). Spatial modulation (SM) is one of the key technologies in exploiting spatial capacity, which maps the information bits to the active...
Nowadays the Massive MIMO system is one of the keys for obtaining high quality and reliability of data transmission. One of the main characteristics influencing the MIMO system performance is the channel (system) correlation matrix (CM). The proposed research assumes an exponential-type banded CM structure, which is bridging the gap between fully correlated and uncorrelated/weakly correlated (tridiagonal...
In this paper, we describe a modified signal design for Multistream Spatial Modulation (MSM). The fundamental idea behind MSM is to activate multiple antennas and transmit complex symbols along with active antenna indices. Here, a modified MSM technique explicitly designed to combat the effect of spatial correlation in realistic channel scenarios is proposed. In this MSM scheme, two antennas are made...
We consider the problem of covariance estimation with projected or missing data, and in particular the application to spatial channel covariance estimation in a multi-user Massive MIMO wireless communication system with arbitrary (possibly time-varying and/or non-orthogonal) pilot sequences. We introduce batch and online estimators based on the expectation-maximization (EM) approach, and provide sufficient...
Exponentially increasing demands for higher data rates and quality of service cannot be satisfied by delivering more power as higher power levels may reduce Signal-to-Interference-plus-Noise Ratio (SINR) with negative impact on overall system performances. Simultaneously, the continuous shrinking in transistors size for denser circuits integration, following Moore's law, will be constrained by the...
This paper considers a multi-user multiple-input multiple-output (MU-MIMO) visible light communication (VLC) interference channel. The multi-user interference (MUI) can be successfully eliminated with the perfect knowledge of channel state information (CSI). However, the perfect information may not be available at transmitter, which will lead to severe interference and consequently degrade the system...
Massive Multiple-Input Multiple-Output (MIMO) communications uses a large number of antennas at the base station to increase the data rate and user density in future wireless systems. For simulation, it has become common practice to use i.i.d. complex Gaussian matrix entries to obtain an average MIMO channel behavior. More refined models have been devised and proposed to standardization bodies; yet,...
Massive multiple-input multiple-output (MIMO) systems can achieve high data rates due to the large number of antennas at the base station when it serves a small number of users. However, deploying massive MIMO in current mobile networks faces a lot of practical issues such as limited physical space and power consumption. Packing large number of antennas in a limited physical space makes spatial correlation...
This paper discusses the channel capacity of mobile terminal MIMO antenna focusing on correlation coefficient, radiation efficiency, body effect and propagation model. To find the dominant factor enhancing channel capacity, resistance loaded two-dipole array is examined in terms of correlation and efficiency. A smart phone model with two small folded inverted F-shaped antennas is also used to examine...
Multiple input multiple output (MIMO) processing is impractical when optical channels have to be switched directly to different locations. This paper tries to solve this problem by exploiting a mode forming remote switch network using multimode fiber to optically route only the desired channel to the desired destination while maintaining data security.
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...
Coordinated multi-point transmission can provide high spectral efficiency for cellular systems. However, along with the increment in the amount of data, backhaul gradually becomes the bottleneck in terms of system performance and cost. In this paper, the backhaul delay is mainly focused in coordinated cellular networks and a hybrid channel prediction (HCP) algorithm is proposed. This algorithm combines...
The sum rate performance of distributed multiple-input multiple-output (D-MIMO) systems with Zero-Forcing (ZF) receivers over semi-correlated K fading channels involves special functions, which hinders us to further manipulations. To solve this issue, we derive the closed-form expressions of the achievable sum rate by using moment matching method, which is achieved by using a Gamma distribution to...
In this paper, we analyze uplink sum rate of multiple-input multiple-output (MIMO) systems with maximum-ratio combining (MRC) receivers. To be practical, receive correlation and different powers of users are assumed. Two novel approximate results on sum rate are derived in closed form. Based on the results, we also obtain the asymptotic results on sum rate when the number of base station antenna (M)...
In this paper, three-dimensional (3D) regular-shaped geometry-based stochastic model (RS-GBSM) is developed for wideband multiple-input multiple- output (MIMO) high speed railway communication system under non-isotropic scattering condition. Correlations of the proposed model in space, time and frequency are studied. Numerical result shows that the simulation model fits the reference model well.
This paper presents field experiments on the downlink throughput performance of a 5G centimeter wave radio access system employing higher rank MIMO in a shopping mall environment and a long corridor environment. The shopping mall has complex reflection paths within its non-line-of-sight areas. The long corridor environment exhibits line-of-sight propagation with many reflection paths. The results...
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