The optimal solution of MIMO signal detection is a NP problem.Making use of the properties of quantum mechanics such as quantum parallelism and entanglement,Quantum Neural network(QNN) can solve this problem efficiently.This paper adopts method of Hopfield neural network to realize MIMO signals detection.Basic on mapping between detecting sequence Maximum a posteriori Probality(MAP) optimum reception likelihood function and energy function of Hopfield nerve net,we conformat a kind of quantum neural network MIMO singal detector.Computer simulation results show that the method has powerful property in bit error rate.
An analysis is made of the task of measuring and phase conjugation of the optical field against the background of noise in the case of a priori indeterminacy of the statistical properties of the received signal. Mode expansion of a useful signal is employed to show that the optimal algorithm may be realized in at least two variants: either on the basis of multichannel heterodyne reception and phase conjugation of the filtered signal at a radio frequency or with the aid of "physical" phase conjugation methods directly at an optical frequency. Expressions are obtained for estimating the quality of the measurements and phase conjugation. It is shown that practical realization of the latter variant of the optimal algorithm may result in a significant deterioration of the potential characteristics.