0630 GMT - The U.S. dollar trades steady in early European trade as investors await the Kansas City Federal Reserve's annual Jackson Hole meeting, starting Thursday. Fed Chairman Kevin Warsh is due to speak Friday. Investors are waiting to see whether Warsh provides a better understanding of what the Fed's thinking of monetary policy is, although expectations are low in a new era where forward guidance has been dropped. The DXY index, which measures the dollar's value against a basket of currencies, is unchanged at 99.145.