3 results about "Discriminant" patented technology

The application relates to a digital phase discrimination method and an electronic device. The method comprises: acquiring an input signal sampled by a discrete sequence, and resampling the input signal to obtain a reconstructed waveform sequence; detecting a zero-crossing point of the reconstructed waveform sequence, and extracting sampling data of a plurality of continuous sampling points centered on the zero-crossing point; based on the sampling data, performing local waveform fitting on a middle sampling point in the plurality of continuous sampling points as an origin through a preset quadratic polynomial model to determine a zero-crossing time offset of the input signal, and performing effectiveness verification on the zero-crossing time offset based on a discriminant of the quadratic polynomial model; and outputting phase difference information between the input signal and a preset reference signal based on the verified zero-crossing time offset. The application can improve the digital phase discrimination accuracy.

The invention relates to methods and systems for operating a quantum computing device to sample from an approximate stationary distribution of a Markov chain P having n states, through the construction and execution of a quantum circuit, said method comprising the step of: Initialize an ancilla qubit to the ∣0> state and at least one qubit register in its initial state; Prepare an unitary matrix U, which encodes a discriminant D in block form, allowing polynomial transformations of its singular values or eigenvalues; Apply successively a single qubit gate on the ancilla qubit and the ancilla controlled unitary matrix U on the qubit registers creating a reflection about an approximation of the stationary distribution of the Markov Chain P; and Prepare an approximation of the sought coherent quantum state associated with the stationary distribution, preferably using quantum amplitude amplification

The invention discloses an impossible difference divider search method for an SKINNY128 algorithm, and the method combines difference set propagation with a Boolean satisfiability problem (SAT) modeling technology, and integrates a miss-in-the-middle idea. The method comprises the following steps of: firstly, simulating propagation of a differential set in a SKINNY128 round function with a probability 1 from the encryption direction and the decryption direction respectively, and recording all possible propagation modes; then, constructing a bit-oriented SAT constraint model based on a propagation mode; then, constraints are established for possible contradiction points in the middle round; and finally, searching an effective impossible differential divider by solving the SAT model, and taking the condition that the model has a solution as a judgment condition. According to the method, the defects that in the prior art, contradictory points cannot be positioned, and indirect contradictions cannot be processed are overcome, and an impossible difference divider with a longer round number of an SKINNY128 algorithm can be automatically and more comprehensively searched.