Manuscript received June 3;
1987;
revised September4;
1987. This work was supported in part by the Air Force Ofice of Scientific Research under Grant F49620-84-K-0139;
by the Joint Services Electronic Program under Grant N00014-K-0327;
and by the Wright-Patterson Air Force Base Avionics Laboratory under Contract F33615-86-C-1126. The work of K. J. Weingarten was supported in part by a Newport Research Award. The work of M. J. W. Rodwell was supported in part by an IBM Pre-Doctoral Fellowship. The authors are with the Edward L. Ginzton Laboratory;
Stanford University;
Stanford;
CA 94305. IEEE Log Number 87 1785 I;