Digital Signal Processing

Swati S. Godbole ¹, Sanjay B. Pokle ²

Affiliations
1 Department of Electronics & Telecommunication, G.H. Raisoni College of Engineering, Nagpur, IN
2 Department of Electronics, Shree Ramdevbaba Kamla Nehru Engineering College, Nagpur, IN

Abstract

This Paper involves the study of the principles of Adaptive Noise Cancellation (ANC) and its Applications. Adaptive Noise Cancellation is an alternative technique of estimating signals corrupted by additive noise or interference. It needs two inputs - a primary input containing the corrupted signal and a reference input containing noise correlated in some unknown way with the primary noise. The reference input is adaptively filtered and subtracted from the primary input to obtain the signal estimate. Adaptive filtering before subtraction allows the treatment of inputs that are deterministic, stationary or time-variable. Noise cancellation is a common occurrence in todays telecommunication systems. Noise is unwanted signal that is disturbing especially in communication system. The main purpose of this paper is to eliminate noise that exists in input signal, which makes it difficult to understand. The signal interference caused by noise is distracting to both users and causes a reduction in the quality of the communication. This paper focuses on the use of adaptive filtering techniques to reduce this unwanted noise, thus increasing communication quality. Adaptive filters are a class of filters that iteratively alter their parameters in order to minimize a function of the difference between a desired target output and their output. In the case of adaptive noise cancellation in telecommunications, the optimal output is a noisy signal that accurately emulates the unwanted noise signal. This is then used to negate the noise in the return signal. The better the adaptive filter emulates this noise, the more successful the cancellation will be. Various applications of the ANC can be studied. Computer simulations for some cases are carried out using Matlab software and experimental results are presented that illustrate the usefulness of Adaptive Noise Canceling Technique. This paper examines various techniques and algorithms of adaptive filtering, employing discrete signal processing in MATLAB. Simulation was utilized by using MATLAB software to eliminate the noise. The strategies & design methodologies of of Adaptive Noise Canceller using the least mean square (LMS) algorithm is considered in this paper.

Keywords

The Signal Interference, Adaptive Filters.

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