A review. Quantum detection theory is a reformulation, in quantum-mechanical terms, of statistical decision theory as applied to the detection of signals in random noise. Density operators take the place of the probability density functions of conventional statistics.The optimum procedure for chooeing between two hypotheses, and an approximate procedure valid at small s i nal-to-noise ratios and call threshold detection, a r e prersented. Quantum estimation theory seeks best estimators of parameters of a density operator. A quantum counter= part of the Crapdr-Rao inequality of conventional statirstics sets a lower bound to the mean-square e r r o r s of such estimates, present a r e p r a a r i l y to the detection and estimation of signals of optical Applications at I frequencies in the presence of thermal radiation.

No abstract

No abstract

No abstract

No abstract