Question

Design and property of matched filter in digital communication

Answer 1

matched filter is obtained by correlating a known signal, or template, with an unknown signal to detect the presence of the template in the unknown signal.[1][2] This is equivalent to convolving the unknown signal with a conjugated time-reversed version of the template. The matched filter is the optimal linear filter for maximizing the signal-to-noise ratio (SNR) in the presence of additive stochastic noise.

Matched filters are commonly used in radar, in which a known signal is sent out, and the reflected signal is examined for common elements of the out-going signal. Pulse compression is an example of matched filtering. It is so called because impulse response is matched to input pulse signals. Two-dimensional matched filters are commonly used in image processing, e.g., to improve SNR for X-ray. Matched filtering is a demodulation technique with LTI (linear time invariant) filters to maximize SNR.[] It was originally also known as a North filter.

Answer 2

Answer:

Matched filter is a linear filter used to maximize the SNR at the output

Explanation:

• Matched filter is a linear filter used in digital communication to maximize the signal to noise ratio at the output.
• As it a linear filter, the impulse response is in time domain and where in frequency response, the signal sampled at the time very greater than the average power of the filter noise.
• It convolutes the noise signal throughout a conjugated time-reversed version.
• Hence, the output given by this filter is like the nonexistence of noise.
• They are applicable even for non-Gaussian noise.