bandstopby

Bandstopby is a term used in signal processing to refer to a class of adaptive bandstop filtering techniques designed to suppress a targeted frequency band while preserving the rest of the signal. The concept is not part of standard DSP nomenclature; it appears in informal discussions, experimental software, and some educational materials as a descriptive label for a family of filters that dynamically adjust the stopband in response to input data.

In typical formulations, bandstopby combines a conventional bandstop or notch filter with a real-time adaptation loop. The adaptation analyzes the instantaneous spectrum or energy within the target band and modifies filter coefficients to deepen or widen the stopband as needed. This allows suppression of dominant interference that varies over time, such as moving hum or transient noise, while maintaining signal integrity elsewhere.

Applications include audio restoration, studio noise suppression, wireless communications, and biomedical signal processing. Compared with fixed bandstop filters, bandstopby offers improved flexibility and selectivity but introduces complexity, potential instability, and processing delay due to the adaptation loop. Performance depends on the adaptation algorithm, the base filter, and the convergence criteria.

Relation to other concepts: It is related to adaptive filtering, notch filtering, and spectral subtraction, and can be implemented with IIR or FIR structures. Some sources emphasize bandstopby as a practical design pattern rather than a formal standard, leading to diverse implementations.