FIR Filter with FFT Notching for Wideband Signal Interference

The patent replaces traditional time-domain filtering approaches (DFT/mDFT filterbanks requiring complex processor operations) with a frequency-domain approach using FFT blocks. This substitution leverages the efficiency of FFT algorithms to achieve the same notching function with significantly reduced computational complexity and memory requirements, directly resolving the contradiction between achieving notching capability and maintaining low processor loading.

The patent implements dynamically adjustable frequency notches in the FFT domain that can be adaptively configured based on detected narrowband device frequencies. This dynamic approach allows the system to apply notching only where and when needed, rather than using fixed broad notching, thereby preserving the overall dynamic range of the power amplifier while still meeting interference reduction requirements.

The patent applies local quality modification by introducing frequency-specific notches only at the precise locations where narrowband devices operate, rather than applying broad-spectrum attenuation. This localized approach preserves the signal power and communication performance in all frequency regions except where interference occurs, thereby maintaining high output power while eliminating harmful interference to narrowband devices.