Occurrence of partial discharges (PD) is one of the basic criteria of high voltage devices insulation evaluation. Precise PD source location is crucial for undertaking maintenance of mentioned equipment. This paper co...
详细信息
ISBN:
(纸本)9781479966134
Occurrence of partial discharges (PD) is one of the basic criteria of high voltage devices insulation evaluation. Precise PD source location is crucial for undertaking maintenance of mentioned equipment. This paper concerns the issue of partial discharges sources location using phased rectangulararrays technique and high-resolution direction of arrival estimation technology. In addition to the theoretical assumptions of both techniques, the simulation result, in which an uniform rectangular array (URA) was used for registration of the electromagnetic signals generated by defects in power transformer insulation system, were shown. To estimate the Direction of Arrival (DOA) of electromagnetic signals, that propagate from the discharge-generating defect to the transducer array installed on transformer tank, Minimum Variance Distortionless Response (MVDR) algorithm was chosen. The location of defect was determined using two intersecting lines defined by the DOAs from two URAs. With the ability to locate multisource discharges (even at very low signal to noise ratio - SNR), the adopted solution has advantages over conventional techniques.
As an important part of the space-air-ground-sea integrated communication networks, unmanned aerial vehicles (UAVs) and unmanned surface vehicles (USVs) have recently garnered considerable attention. In this paper, we...
详细信息
The concept of an intelligent reflecting surface (IRS) has recently emerged as a promising solution for improving the coverage and energy/spectral efficiency of future wireless communication systems. However, as the n...
详细信息
The concept of an intelligent reflecting surface (IRS) has recently emerged as a promising solution for improving the coverage and energy/spectral efficiency of future wireless communication systems. However, as the number of reflecting elements in an IRS increase, the beam training protocol in IRS-assisted millimeter-wave (mmWave) cellular systems requires a large beam training time because it needs to find the best beam pairs for the link between the base station (BS) and the IRS, as well as the link between the IRS and the mobile station (MS). In this paper, a fast beam training technique for IRS-assisted mmWave cellular systems with a uniform rectangular array is proposed for detecting the best beam pairs of BS-IRS and IRS-MS links simultaneously. Two different types of beam training signals (BTSs) are proposed to distinguish simultaneously transmitted beams from the BSs in multi-cell multi-beam environments: the Zadoff-Chu sequence based BTS (ZC-BTS) and m-sequence based BTS (m-BTS). The correlation properties of ZC-BTSs and m-BTSs are analyzed in multi-cell multi-beam environments. In addition, the effect of symbol time offset on the ZC-BTS and m-BTS is analyzed. Finally, simulation results reveal that the proposed technique can significantly reduce the beam training time for IRS-assisted mmWave cellular systems.
The performance of the conventional adaptive beamformer undergoes degradation in the presence of the mutual coupling between the neighbouring elements. To eliminate the sensitivity for the MC, the dummy elements are f...
详细信息
The performance of the conventional adaptive beamformer undergoes degradation in the presence of the mutual coupling between the neighbouring elements. To eliminate the sensitivity for the MC, the dummy elements are fixed around the array. Here, the authors demonstrate the optimal layers of auxiliary elements for uniform rectangular array (URA) in the case of the specific MC model and give the concrete theoretical proof. The corresponding derivation proves that only one layer of auxiliary elements is needed to tackle with the MC effect, and the output SINR and beampattern are improved by means of the proposed method for URA. Finally, the simulation results have shown the effectiveness of authors' method.
暂无评论