Angular power distribution and mean effective gain of mobile antenna in different propagation environments

Abstract

We measured the elevation angle distribution and cross-polarization power ratio of the incident power at the mobile station in different radio propagation environments at 2.15-GHz frequency. A novel measurement technique was utilized, based on a wide-band channel sounder and a spherical dual-polarized antenna array at the receiver. Data were collected over 9 km of continuous measurement routes, both indoor and outdoor. Our results show that in non-line-of-sight situations, the power distribution in elevation has a shape of a double-sided exponential function, with different slopes on the negative and positive sides of the peak. The slopes and the peak elevation angle depend on the environment and base-station antenna height. The cross-polarization power ratio varied within 6.6 and 11.4 dB, being lowest for indoor and highest for urban microcell environments. We applied the experimental data for analysis of the mean effective gain (MEG) of several mobile handset antenna configurations, with and without the user's head. The obtained MEG values varied from approximately 5 dBi in free space to less than 11 dBi beside the head model. These values are considerably lower than what is typically used in system specifications. The result shows that considering only the maximum gain or total efficiency of the antenna is not enough to describe its performance in practical operating conditions. For most antennas, the environment type has little effect on the MEG, but clear differences exist between antennas. The effect of the user's head on the MEG depends on the antenna type and on which side of the head the user holds the handset. Index Terms-Angular power distribution, mean effective gain, mobile antenna, polarization, radio channel sounding. I. INTRODUCTION T HE gain of a mobile handset antenna is a critical parameter in cellular network design. Due to the large variety of mobile phones used in networks, it is very important that their antenna performance be able to be evaluated reliably. The traditional definition of antenna gain is not adequate for evaluating Manuscript

Centralized modeling of the communication space for spectral awareness in cognitive radio networks

“…For a mobile receiver antenna orientation is usually random. Considering only the maximum gain of an antenna is not enough to characterise its performance in practical operating conditions [17]. Measurements are needed to determine the mean effective gain of a test antenna.…”

“…Measurements are needed to determine the mean effective gain of a test antenna. The mean effective gain is defined as the ratio of the mean signal levels at the test antenna and a reference antenna [17,18]. In [17] is the lognormal variation of the received signal amplitude in a area where path loss is constant.…”

A compact dual-band dual-port diversity antenna for LTE

“…The environment depends strongly on the arrival angles distribution and on XPD. The most common distributions proven by measurements are Gaussian and Laplacian distributions [6]. Thus, we consider different distributions in elevation, while in azimuth plane the distribution will be uniform, as demonstrated by the two main measurement campaigns in the literature [6], [8].…”

“…Each environment is characterized by typical values of XPD, mean angle of incident wave distribution (θ i ) and standard deviation of wave distribution (σ). These values were deduced from several measurements [6], [7], [8] for different environments: isotropic, indoor, and outdoor. The isotropic environment is defined by XPD=0 dB, p θ (Ω)=p φ (Ω)=1, the indoor environment by XPD=1 dB, θ i = 20°, σ =30° and the outdoor environment by XPD=5 dB, θ i = 10°, σ =15°.…”

“…It can be seen that the ratio of MEG 1 , determined at port 1, over MEG 2 , determined at port 2, is almost equal to 1, which satisfied equal contribution of the two monopoles to receive the same quantity of power. This is due to the fact that the proposed structure is completely symmetric and that the Gaussian and Laplacian angular distributions are taken only along the elevation as presented in [6]. Finally, the efficiency of the diversity is usually presented in terms of diversity gain (DG).…”