SUN TRACKING METHOD

[[abstract]]本發明係有關於一種太陽光追蹤方法，係主要設有仰角步進馬達與方位角步進馬達之雙軸調整機制，以及依東、西、南、北四個方位及位於四個方位中間之太陽能電池感測器，藉此，透過太陽演算時間法，粗步進行仰角與方位角調整，再利用東、西、南、北四個方位設置之太陽能電池感測器，全面地追蹤太陽軌跡，而後利用中間所設之太陽能電池感測器準確地偵測太陽所在位置，繼而驅使仰角步進馬達與方位角步進馬達作細步之仰角與方位角的角度調整，據此，以準確追蹤太陽的位置，進而達到有效集收太陽光能，並提高發電效率等實質效益。[[abstract]]The present invention relates to a sun tracking method, which primarily uses a two-axis adjustment mechanism having elevation and azimuth stepping motors and a plurality of solar energy cell detecting devices set on the east, west, south and north positions and in the center of the four positions. Accordingly, with a sun formula, elevation and azimuth can be adjusted preliminarily and then the four solar energy cell detecting devices on the east, west, south and north positions may be used to track the sun orbit in its entirety. The solar energy cell detecting device set in the center may be used to detect the sun position accurately, so that the elevation and azimuth stepping motors can be driven to fine-tune the angles of the elevation and azimuth. Accordingly, the sun position can be tracked accurately to achieve the substantial beneficial results of collecting solar energy and promoting the efficiency for generation of electric power

OFDM無線通訊系統載波同步技術

[[abstract]]任何通訊系統的均須要達到同步(Synchronization)，包括載波與時間同步。通訊系統如果沒有同步的傳輸錯誤率會很高，使效率會很差。就如同在聽收音機時，調諧器(Tuner)的頻率如果有偏差時，會聽到許多雜音。因此同步(Synchronization)是任何通訊網路能正常運作的第一步！鎖相迴路(Phase Locked Loop，PLL)是傳統許多通訊接收機採用的同步電路與技術。例如許多高價的FM收音機均宣稱採用鎖相迴路PLL以提升接收機的靈敏度(Sensitivity)。但是從文獻中幾乎找不到有關使用鎖相迴路PLL結合OFDM載波同步的研判。 許多文獻上指出：僅1％的頻偏就會使信雜比(Signal-to-Noise Ratio，SNR)下降30dB。因此本專題將研究數個OFDM通訊系統的載波同步技術，我們也將研究將鎖相迴路(Phase Locked Loop)加入載波同步系統中，以提昇OFDM系統的穩定度與可用度