Filter Bank

In signal processing, a filter bank is an array of band-pass filters that separates the input signal into multiple components, each one carrying a single frequency Sub-band of the original signal. One application of a filter bank is a graphic equalizer, which can attenuate the components differently and recombine them into a modified version of the original signal. The process of decomposition performed by the filter bank is called analysis (meaning analysis of the signal in terms of its components in each sub-band); the output of analysis is referred to as a subband signal with as many subbands as there are filters in the filter bank. The reconstruction process is called synthesis, meaning reconstitution of a complete signal resulting from the filtering process.

In digital signal processing, the term filter bank is also commonly applied to a bank of receivers. The difference is that receivers also down-convert the subbands to a low center frequency that can be re-sampled at a reduced rate. The same result can sometimes be achieved by undersampling the bandpass subbands.

Another application of filter banks is signal compression, when some frequencies are more important than others. After decomposition, the important frequencies can be coded with a fine resolution. Small differences at these frequencies are significant and a coding scheme that preserves these differences must be used. On the other hand, less important frequencies do not have to be exact. A coarser coding scheme can be used, even though some of the finer (but less important) details will be lost in the coding.

The vocoder uses a filter bank to determine the amplitude information of the subbands of a modulator signal (such as a voice) and uses them to control the amplitude of the subbands of a carrier signal (such as the output of a guitar or synthesizer), thus imposing the dynamic characteristics of the modulator on the carrier.

Read more about Filter BankFFT Filter Banks, Filter Banks As Time-frequency Distributions

Other articles related to "filter bank, filter, filter banks, bank":

MPEG-1 Audio Layer II - How The MP2 Format Works
... which means that compression takes place in the time domain with a low-delay filter bank producing 32 frequency domain components ... By comparison, MP3 is a transform audio encoder with hybrid filter bank, which means that compression takes place in the frequency domain after a hybrid (double) transformation ... The MP2 sub-band filter bank also provides an inherent "transient concealment" feature, due to the specific temporal masking effect of its mother filter ...
Lifting Scheme - Properties
... Every perfect reconstruction filter bank can be decomposed into lifting steps by the Euclidean algorithm ... That is, "lifting decomposable filter bank" and "perfect reconstruction filter bank" denotes the same ... Every two perfect reconstructable filter banks can be transformed into each other by a sequence of lifting steps ...
Modified Discrete Cosine Transform
... to the audio signal directly, but rather to the output of a 32-band polyphase quadrature filter (PQF) bank ... by an alias reduction formula to reduce the typical aliasing of the PQF filter bank ... Such a combination of a filter bank with an MDCT is called a hybrid filter bank or a subband MDCT ...
Computational Auditory Scene Analysis - System Architecture - Cochleagram
... Because of the frequency selectivity of the basilar membrane, a filter bank is used to model the membrane, with each filter associated with a specific point on the basilar membrane ... Since the hair cells produce spike patterns, each filter of the model should also produce a similar spike in the impulse response ... The use of a gammatone filter provides an impulse response as the product of a gamma function and a tone ...
Filter Banks As Time-frequency Distributions
... In time-frequency signal processing, a filter bank is a special quadratic time-frequency distribution (TFD) that represents the signal in a joint time-frequency domain ... The filter bank and the spectrogram are the two simplest ways of producing a quadratic TFD they are in essence similar as one (the spectrogram) is obtained by dividing the time-domain in slices ...

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