| 摘要 |
A finite impulse response filter performs an FFT on a signal, multiplies it by a transfer function in the frequency domain, and then performs an inverse FFT. The transfer function is dynamically computed in real-time by detecting signal energy in the frequency domain and turning off bins that contain the signal. The signal is delayed prior to turning off the bin in a FIFO memory by an amount equal to the time required to compute the transfer function. In this way, relatively fast changes in the interference environment can be tracked and rejected. For example, short duration narrow band interference signals in the presence of a wideband signal of interest, including direct sequence (DS) spread-spectrum signals in the presence of frequency hopped (FH) spread spectrum signals are rejected. The received signal quality of DS spread spectrum signals is improved.
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