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Towards 5G: A study of the impact of antenna polarization on statistical channel modeling
Sustainable Engineering and Innovation
The millimetre wave (mmWave) is alleged as an important element invention to respond to the rapid increase in wireless demand for mobile traffic using its huge bandwidth. However, channel modeling remains difficult due to its high dependence on weather conditions and the positioning of the antenna for communication in direct visibility line-of-sight (LOS). Co-polarization and cross-polarization (X-pol) are two main events in the direction of the radiation element for wave transmission; where the wanted direction of wave transmission denotes the co-pol and the orthogonal propagation of the intended direction represents X-pol. This work investigates the effect of the polarization on a statistical channel modeling at 28 GHz, 38 GHz & 73 GHz mmWave channel using NYUSIM Model.
Performance of Multi –user MIMO system in the presence of Polarization diversity
Emp loying Dual Polarized antenna plays a vital role for the future generation MIMO systems due to its advantages such as space effectiveness and robustness. In this paper, we provide Outage probability of Multiuser Dual Polarized antenna in an uplink environ ment. Specifically, we provide the simu lation results of Outage Probability for different varying parameters such as an increase in a number of the user, noise variance, and Cross Polarization Discrimination. Th is parameter is investigated through Monte Carlo simu lation.
Statistical characterization of an urban dual-polarized MIMO LMS channel
International Journal of Satellite Communications and Networking, 2018
This paper presents a thorough statistical characterization of a dual-polarized multiple-input-multiple-output channel, based on a measurement campaign of 2 land mobile satellite link scenarios in urban environments. The received signal is decomposed into its large-scale and small-scale fading parts, which are separately evaluated and characterized. The large-scale fading can be well approximated by the Lognormal distribution, whereas the small-scale fading in line-of-sight condition can be characterized as a Rician channel with a strong direct component and high Kfactors. On the other hand, in nonline-of-sight cases, the fading can be approximated by Nakagami or Rician distribution with low K-factors. The cross-polar discrimination is found between 14.2 and 22.5 dB, whereas the cross-polar isolation is found between 12.8 and 21 dB, respectively. Finally, assessing the diversity performance, applying the maximal ratio combining technique, it is found that the left-hand circular polarized transmission outperforms the right-hand circular polarized transmission, providing gains up to 2.5 dB, especially in nonline-of-sight cases. The low-diversity gains indicate that beamforming would be preferable to be applied in the specific channel. KEYWORDS channel characterization, channel modeling, dual-polarized, multiple-input-multiple-output (MIMO) satellite measurements 1 | INTRODUCTION In the years to come, new narrowband satellite communication technologies will allow for direct connection of millions of Internet of Things (IoT) devices in a resource efficient way. The ultimate success of global IoT coverage will depend on the active support of satellite networks providing L-band and S-band services. Satellite technology serves as a key enabler to transform IoT connectivity across industries and geographical borders and has the potential to play a key role in cases where sensors and actuators are distributed over a very wide area as well as in remote areas not served by terrestrial access networks. Indeed, the use of the satellite is found to be of great importance in some applications of IoT, like smart grid, environmental monitoring, and emergency management, because satellite communications have unique merits such as large-scale coverage, superb ability to support emerging communications services, and cost effectiveness for broadcast/multicast connectivity. 1-3 Bringing wide-area connectivity for the IoT by using satellite technology is therefore an attractive solution to complement terrestrial networks, allowing densification and coverage extension in remote areas. 4 The proliferation of multiantenna technology and its adoption in terrestrial communication systems provided unprecedented capacity improvement and enhanced spectral efficiency. The applicability of multiple-input-multiple-output (MIMO) techniques is also an appealing solution in satellite communication systems with a very promising outlook. 5,6 Specifically, land mobile satellite (LMS) systems can take advantage of MIMO techniques and achieve substantially increased rates. The characterization of a MIMO LMS channel through a measurement
Los and Nlos channel capacities for MIMO polarization diversity
Proceedings of the 10th Wseas International Conference on Communications, 2006
As a result of the desired high-data transmission rate in the outdoor and indoor environment, an exploitation of multiple-input multiple output (MIMO) systems appears recently under the condition of rich scattering environments. The MIMO channel, correponding really to transmission capacity, is obviously characterized by antenna configuration and propagation environment. In this paper, we assume that all scatterers are uncorrelated, independent and identically distributed (i.i.d). In addition, we investigate the channel capacity of single, dual and triple polarized dipole antennas compared to omni-vertical and omnihorizontal antennas based on 2×2 and 3×3 MIMO systems for narrow transmission bandwidth. Moreover, the results of simulations illustrate that while the antenna correlation is eliminated by polarization diversity technique, the problems of cross-polar discrimination (XPD) and line of sight (LOS) can be also resolved.
2008 Wireless Telecomunications Symposium, 2008
We investigate the channel properties of a dualpolarized MIMO implementation in a mobile-tomobile line-of-sight (LOS) channel and characterize the channel's input/output cross-polarization discrimination (IOXPD) behavior. From experimental data involving transmissions with 14 MHz bandwidths, we find that the IOXPD is frequency selective and exhibits statistical decorrelation properties in both time and frequency. Short-term variations in the IOXPD are driven primarily by variations in the cross-polarization components. These components exhibit considerable fading and frequency selectivity relative to the copolarized LOS component. Typical XPD characterizations found in literature provide average co-to-cross polarization power ratios across the band, but these are inadequate to model the frequency selectivity and statistical behaviors of the IOXPD that would be needed in higher fidelity system input-output models. We propose a model to capture the frequency selectivity as well as the time and frequency decorrelation behavior of the IOXPD observed in the mobile-to-mobile LOS channel.
A CDL-Based Channel Model With Dual-Polarized Antennas for 5G MIMO Systems in Rural Remote Areas
IEEE Access, 2020
In the fifth-generation (5G) mobile networks, it is expected that users experience high throughputs with an ultra-low-latency network, while a massive number of devices are connected to the network. However, in remote rural areas, there is still a large number of people that do not have access to broadband Internet. To overcome this issue, a possible strategy is to exploit the excellent propagation conditions of very high frequency (VHF) and ultra-high frequency (UHF) bands by allowing secondary spectrum reuse in the TV white space (TVWS) channels. But for that, a reliable channel model is required to perform valid coverage and data rate prediction studies. In this paper, a channel model is proposed that takes into account large and small scale fading effects, as well as the particularities of such remote rural areas. The proposed model makes use of measurements along with the clustered delay line (CDL) profiles from 3rd Generation Partnership Project (3GPP). It is a simple model to implement and can be used to provide fast link and system-level simulations. Numerical and analytical results are provided to validate the proposed model and a data rate evaluation is carried out for single-input single-output (SISO) and multipleinput multiple-output (MIMO) configurations, as well as for single-polarized (SP) and dual-polarized (DP) antennas. INDEX TERMS Channel modeling, remote rural areas, CDL, MIMO and dual-polarized antennas.
Directional Random Scattering MIMO Channels: Entropy Analysis and Capacity Optimization
2006 IEEE International Conference on Communications, 2006
In this paper, we study the effect of directional random scattering on the capacity of multiple-input multiple-output (MIMO) systems. First, we use the spatial decomposition of the MIMO channel matrix to analyze the randomness (entropy) of directional scattering. The analysis shows that directional scatterers (with at least a null in the angular power spectrum) will no longer be random when the receiver observation radius is sufficiently large. Therefore, directional scattering limits the expected linear increase of MIMO capacity with increasing the number of antennas. Second, we consider the effect of receiver antenna arrangement (positions) on the capacity of MIMO systems. For any random scatterer with a given angular power spectrum, we show that it is possible to choose the receiver antenna arrangement with the optimum whitening of the MIMO channel matrix that, in turn, maximizes MIMO channel capacity. I. INTRODUCTION A. Motivation and Background The pioneering work of Telatar [1], and Foschini and Gans [2] predicted linear capacity enhancement in multiple-input multiple-output (MIMO) systems by increasing the number of transmitter/receiver antenna elements. However, this analysis assumes independent fading paths between the transmitter and receiver antenna elements. In practical systems, the assumption of independent fading may be violated due to insufficient antenna spacing and restricted/directional angular spread of scatterers [2]. The effect of fading correlation on MIMO capacity has been studied in the literature, where channel correlation is often decomposed into the transmitter/receiver correlation matrices [3]-[7]. A limitation of this approach is that the effects of random scattering environment and deterministic antenna configurations are intertwined in the correlation matrices [8]. This often hinders obtaining a generic insight into the effect of directional scattering on the capacity of MIMO systems and the possibility of MIMO capacity optimization by using the optimum antenna configuration. Accurate physical modeling of the MIMO channel matrix requires that the scattering characteristics of the wireless spatial channel be taken into account. In [9], Muller proposed the decomposition of the MIMO channel based on the random propagation from transmitter antennas to the scattering objects
Tri-orthogonal polarization diversity for 5G networks
Millimetre-waves offer the possibility of wide bandwidth and consequently high-data rate for wireless communications. For both uni-polarised and dual-polarised systems, signals sent over a link may suffer severe degradation because of antenna misalignment. Orientation robustness may be enhanced by the use of mutual orthogonality in three dimensions. Multiple-input multiple-output polarisation diversity offers a way of improving signal reception without the limitations associated with spatial diversity. Scattering effects often assist propagation through multipath. However, high-path loss is often considered to limit millimetre-wave propagation, thereby reducing any reception enhancement through scattering. We show that the inclusion of a third orthogonal dipole at a frequency of commercial interest provides antenna orientation robustness in this setting, as well as improved performance in a rich scattering environment, by means of a Ricean fading channel model.
Analyzing randomly placed multiple antennas for MIMO wireless communication
2012 IEEE 8th International Conference on Wireless and Mobile Computing, Networking and Communications (WiMob), 2012
We present an analytical approach for determining the signal-to-noise-ratio (SNR) of m multiple antennas in the line-of-sight case. The antennas are placed at random positions within a disc of given diameter d. We characterize the angular signal strength with three sectors: the main beam, the side beams and an area of white Gaussian noise. The SNR and the sector angles depend on d, m, and the wavelength λ. It turns out that for randomized antenna positions the analysis can be reduced to the analysis of a random geometric walk in two dimensions. The angle of the main beam is approximately λ/d with a SNR proportional to √ m. For the side beams the SNR is proportional to sinc(2αd/λ) where α denotes the angle deviating from the target. The range of the side beams is limited to an approximate angle of λ/d √ m. Beyond this angle we observe average white Gaussian noise.
Performance of MIMO systems based on dual-polarized antennas in urban microcellular environments
2004
Recent works have analyzed the potential performance of MIMO systems using dual-polarized antennas at both ends of the wireless link. These works assume Rayleigh and Ricean fading MIMO channel models. Here, we analyze the capacity of such systems in microcellular environments using a physical model of the MIMO channel. The use of a physical model permits us to analyze the impact of environmental parameters, like antennas location and orientation, on the system performance. As example, we present ergodic and outage capacity estimations in a specific urban environment from the predictions of a site-specific ray-tracing propagation tool.