發送短信 : Accurate two-stage frequency offset estimation for coherent optical systems

  _____    _    _     _  __    ______    ______  
 / ____|| | || | ||  | |/ //  /_   _//  /_   _// 
/ //---`' | || | ||  | ' //    -| ||-   `-| |,-  
\ \\___   | \\_/ ||  | . \\    _| ||_     | ||   
 \_____||  \____//   |_|\_\\  /_____//    |_||   
  `----`    `---`    `-` --`  `-----`     `-`'