Attitude Estimation for In-Service Base Station Antenna Using Downlink Channel Fading Statistics

Abstract

A maximum-likelihood-estimation method is proposed for extracting the attitude of a sectoring base station (BS) antenna by using the received signal strengths observed by multiple user equipments (UEs) in this contribution. This method calculates the likelihood function of the antenna attitude derived by taking into account the multiscale fading statistics, that is, path loss, shadowing, and multipath fading. Depending on whether a calibration result of these fading statistics is available or not, the proposed method can be utilized in either calibration-based estimation (CBE) or calibration-free estimation (CFE) approaches. The performance of both methods is evaluated by Monte-Carlo simulations and real experiments. The results obtained demonstrate that the estimation accuracy of both CBE and CFE approaches increases when the percentage of UEs in the line-of-sight (LoS) condition among all available UEs increases and, moreover, the total number of UEs has no significant impact on the estimation accuracy. Furthermore, the CFE exhibits more robust performance than the CBE particularly in the case where the calibration results involve uncertainties.

Theoretical Analysis Method for Roll Motion of Popup Data Communication Beacons

“…According to the structural design requirements of PDCB, the height of the PDCB above the water surface is 145 mm or more (including 110 mm of the BDS module). Thus, calculating the roll angle and evaluating its effect on data transmission are crucial [11,12].…”