Optically maximum A posteriori demodulator

Details Optically maximum A posteriori demodulator Optically maximum A posteriori demodulator

1990-11-01

1994-04-12

Kuntz, Curtis

Pulse or digital communications

Repeaters

Testing

375 80, 330252, H03D 300

Patent

active

053032691

ABSTRACT:
A system and method for optimal maximum a posteriori (MAP) demodulation. The present invention incorporates neural network technology, i.e., a Hopfield network, (1) to replace the function of the traditional, suboptimal phase-locked loop in an FM receiver and/or (2) to optimally estimate a discrete phase value using an expected value (obtained from the mean of the prior probability distribution of the phase) and statistical dependence between different phase values in a block of samples (described by the covariance matrix of the prior phase distribution). The definition of the Hopfield network includes particular bias currents, feedback weights and a sigmoid function for solving the nonlinear integral equation associated with optimal demodulation. The present invention also includes a signal classifier having a plurality of angled modulators for modeling different phase modulation processes.

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