Results and discussion: In this Section, we present some simulation results to demonstrate the performance of the proposed algorithm. The simulation environment is summarised as follows. The position measurement yk was generated according to eqn. 3 with xk+, =x , + v,T + ak72/2. The initial target position was x, = 10 OOO m and the initial velocity was v, = 150ds. The sampling period T was 0.1 s and the sample size L was 300. The target manoeuvre was set to occur from k = 151 to k = 200 with a, = 40m/s2. The size of the trimmed mean filter was 25 ( N = 12) and the M in eqn. 7 was 1. Two sets of measurement noise v, were generated the first was from a true mixture of two Gaussian distributions and the other was from the synthetic a n t model in [l]. Table 1. As we can see, the mean estimates for the proposed algorithm are very close to the true parameter values. Compared with the identification using the pure noise data, our method yields somewhat larger MSEs.Next we examine the results for identifying the synthetic glint noise record in Fig. 2. The same initial estimates were used and the results are listed in Table 2. From this Table, we see that the identified parameters using the measurements are similar to those using the pure glint data. Thus, we can conclude that the proposed algorithm is effective for online g h t identification. Introduction:The current growth of the personal wireless communications market is pushing operators of mobile radio networks to explore capacity-increasing techniques such as the use of microcells. Whereas the base station (BS) antennas used in conventional macrocells are usually situated at high elevations, the idea of microcells is to place the BS antenna below the average height of the surrounding buildings to confine the radiated power within a small coverage area, such that the same frequency channels can be re-used at short distances without introducing an unacceptable degree of inter-user interference. The efficient planning of microcells requires an accurate prediction of the electromagnetic field strength distribution. Various groups have been active in the development of so-called deterministic propagation models based on an accurate description of the buildings around the BS, and ray-tracing algorithms incorporating multiple reflection and diffraction [l -31. Although considerably better than their statistical counterparts, these models have been found to provide an unsatisfactory prediction accuracy in some situations [3]. In particular, it was shown in [3] that deterministic models treating the buildings as being opaque at UHF frequencies can seriously underestimate the field strength behind the first buildings surrounding the BS. Since the shielding of the BS antenna from its nearby environment is essential in the microcellular concept, it is of special interest to obtain a better understanding of the propagation phenomena responsible for this discrepancy.In the framework of a collaboration between EUT, KPN Research and Swisscom, an extensive measurement campaign ...
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DOI to the publisher's website. • The final author version and the galley proof are versions of the publication after peer review. • The final published version features the final layout of the paper including the volume, issue and page numbers. Link to publication General rights Copyright and moral rights for the publications made accessible in the public portal are retained by the authors and/or other copyright owners and it is a condition of accessing publications that users recognise and abide by the legal requirements associated with these rights. • Users may download and print one copy of any publication from the public portal for the purpose of private study or research. • You may not further distribute the material or use it for any profit-making activity or commercial gain • You may freely distribute the URL identifying the publication in the public portal. If the publication is distributed under the terms of Article 25fa of the Dutch Copyright Act, indicated by the "Taverne" license above, please follow below link for the End User Agreement:
For the design of ULPC systems that can compensate for different types of fading, the short-term frequency scaling factor of all types of fading is needed. Attention is focused on the short-term frequency scaling factor of clear-sky amplitude scintillation and amplitude scintillation occurring with rain attenuation simultaneously, often referred to as wet amplitude scintillation. It is shown that these factors are strongly variable: they depend on various meteorological parameters and on the aperture illumination efficiency of the receiving antenna. In addition, it is shown that amplitude scintillation can only be compensated partly by means of ULPC, owing to the limited correlation of amplitude scintillation measured on two radiowaves with different carrier frequencies propagating along the same path simultaneously. Furthermore, a new procedure is presented to separate rain attenuation and amplitude scintillation.
A conformal dielectric rod antenna array with operating frequency of 11.2 GHz is investigated, designed, and measured. This antenna array is combined with a single pole double throw radio frequency microelectromechanical systems (RF‐MEMS) switch to realize switched‐beam performance. Moreover, this antenna array exhibits uniform radiation performance for different scan angles with no grating lobes. The characterization and measurement of the antenna system have been performed. The measured radiation pattern of the antenna in the anechoic chamber is in good agreement with the simulated antenna pattern. The measured antenna with the RF‐MEMS switch has 13.5 dBi realized gain, −15 dB sidelobe level, 22° half‐power beamwidth, and 7.3% (fractional) bandwidth (or 800 MHz) at 11.2 GHz.
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