4 results about "Digital filter design" patented technology

This invention discloses a method for non-integer multiple sampling rate transformation based on a digital matched filter. The method includes the following steps: calculating the phase adjustment value related to the non-integer multiple sampling rate transformation based on the input-output sampling frequency relationship; determining the phase adjustment accuracy based on the input-output sampling frequency relationship; designing a digital filter based on the phase adjustment accuracy to obtain the digital matched filter impulse response value; and using the phase adjustment value as an index of the digital matched filter impulse response value to perform matched filtering calculations, thereby realizing the non-integer multiple sampling rate transformation. This invention significantly reduces the complexity of digital filter design, saves development time and costs, and offers high flexibility and effectiveness for systems requiring fractional multiple transformation and matched filters in communication systems.

The present application relates to a kind of FIR digital filter design method for intermediate frequency sampling, according to the theoretical range of bandpass sampling theorem to give sampling frequency;According to the frequency spectrum position relationship of signal after sampling, mirror frequency and its periodic continuation component, determine the initial value of optimal sampling frequency;FIR digital filter design is carried out, and the filter order, single-side roll-off bandwidth, out-of-band rejection ratio are obtained;Whether the number of FPGA multiplier required by filtering operation can be satisfied is evaluated;Expand signal bandwidth, re-evaluate whether the signal after expanding bandwidth meets the requirement of bandpass sampling theorem, if necessary, adjust the out-of-band rejection ratio parameter, cutoff frequency parameter, redesign FIR digital filter, to reduce single-side roll-off bandwidth, until the requirement is met, iteration optimal sampling frequency;Carry out digital filtering trial.The present application can give the optimal FIR digital filter design within the limit of theoretical requirement and engineering non-ideal dual constraints.

The application discloses a constrained total least log hyperbolic cosine adaptive filter and belongs to the field of digital filter design. The adaptive filter is established by linear constraint conditions and a log hyperbolic cosine function, and a total least square method is introduced. The linear constraint makes the adaptive filter better meet the actual environment, the log hyperbolic cosine function is minimized to improve the robustness and convergence speed of the algorithm, and the total least square method is used to effectively solve the performance decline problem of the algorithm when the input signal is polluted by noise. The constrained total least log hyperbolic cosine adaptive filter can be applied to electronic and communication systems in which the input and output signals are interfered by noise.

This invention provides a method and system for designing reconfigurable digital filters based on neural networks, relating to the field of neural network technology. First, a target filter response description containing desired frequency response curve information and time-domain response constraint information is received. This description is then input into a pre-trained reconfigurable filter neural network for direct structural parameter mapping, generating a filter structure description, including filter coefficient parameters and topological connection information. Next, filter response simulation verification is performed based on this filter structure description to calculate the actual filter response description, which is then compared with the target description to generate an error description. Finally, the internal parameters of the neural network are adaptively adjusted and optimized based on the error description, ensuring that the error between the actual response and the target response meets a preset standard. This invention enables rapid, flexible, and accurate design of digital filters, adapting to diverse needs and improving design efficiency.