Effect Of Antenna Configuration Research Articles

Performance analysis of spatial modulation over generalized [formula omitted] fading distribution

In this paper, moment generating function (MGF) based mathematical expression is derived to compute bit error rate (BER) for spatial modulation (SM) system over generalized α−κ−μ fading channel distribution. The derivation exploits the MGF of the square of α−κ−μ fading distribution and Gauss Quadrature formulas to find a numerical solution of the intractable mathematical integrals. The Monte Carlo simulations are performed to analyze the BER curves of the SM system for M-quadrature amplitude modulation (QAM) signal over different values of α−κ−μ fading distribution. Besides, the effect of antenna configuration on the performance of the investigated system is also highlighted. Furthermore, the theoretical and simulated probability density function (PDF) curves for different values of α−κ−μ distribution are also drawn.

Effect of Antenna Configuration on MIMO-Based Access Points in a Short Tunnel With Infrastructure

Performance of MIMO technology is highly dependent on the surrounding propagation environment and antenna configuration. In order to benefit from MIMO technology inside underground mines with low angular spread, careful antenna design and deployment strategies are required. In this regard, we studied the effect of uniform-linear-array (ULA) configuration on the MIMO channel capacity inside a short underground service tunnel. With its extensive infrastructure, this tunnel represents a typical midsize underground-mine tunnel. We simulated and measured channel frequency response at 2.49 GHz for grids of transmitters and receivers in different parts of the tunnel while taking into account practical considerations for access point (AP) deployments. All the ULA configurations were deployed either close to the sidewalls or under the ceiling. Among them, two configurations, which show the best performance for AP communications, were identified. For these configurations, we found that interelement separation requires to be four times longer than in conventional indoor environment with rich multipath (i.e., $2\lambda$ ) to provide decorrelation among MIMO subchannels. We also found that infrastructure which has been neglected in previous studies, significantly degrades MIMO performance. Insightful results and guidelines for employing MIMO technology in underground mines can significantly benefit mining industry.

Effect of antenna configuration on power transfer efficiency for planar inductively coupled plasmas

Based on a transformer model for inductively cowpled plasmas (ICPs), the dependence of power coupling efficiency on Q value, plasma electron density and effective electron-atom collision frequency is analyzed. The effect of coil configuration on power coupling efficiency is studied using four types of coils (one-turn, two-turn, three-turn and four-turn planar concentric coils) experimentally. The results indicate that the inductive discharge depends on coil inductance while the coupling efficiency varies with the Q value and discharge conditions such as pressure and input power. The coupling efficiency increases with the increase of pressure and input power, which is in accordance with the transformer model. However, the prediction given in the model that an increase in coil Q value improves power coupling efficiency is only applicable for coils with the same inductance. The study on power coupling efficiency for single multi-turn coil has been applied as an experimental reference for a large-area, high density inductive discharge source using four parallel multi-turn coils.