How the zero - phase filter without filtered signal truncation at the end can be implemented?

1. What is zero-phase filtering?
2. Why ideal filters Cannot be implemented?
3. Can the ideal filter be implemented practically?
4. What is zero-phase signal?

What is zero-phase filtering?

A filter has a zero-phase response if its frequency response is real-valued. A zero-phase filter must have an odd-number of samples in its support with the origin at the center. If the filter has real coefficients, then the impulse response must be symmetric about the origin, i.e. h(n) = h(-n).

Why ideal filters Cannot be implemented?

The reason is that their frequency responses include exactly flat passbands, exactly flat stopbands of zero gain, and zero width transition bands. These features make it impossible to realize such filters using either existing physical devices or finite-time computable algorithms...

Can the ideal filter be implemented practically?

Design of Digital Filters

An ideal filter is considered to have a specified, nonzero magnitude for one or more bands of frequencies and is considered to have zero magnitude for one or more bands of frequencies. On the other hand, practical implementation constraints require that a filter be causal.

What is zero-phase signal?

A zero-phase signal is thus a linear-phase signal for which the phase-slope is zero. As mentioned above (in §7.4.3), it would be more precise to say ``0-or-