M Tech Dissertations

Permanent URI for this collectionhttp://ir.daiict.ac.in/handle/123456789/3

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Subject: search.filters.subject.Digital signal processing

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    Transmultiplexer design using different filters
    (Dhirubhai Ambani Institute of Information and Communication Technology, 2010) Shiyani, Bhavin R.; Chakka, Vijaykumar
    Transmultiplexer is one of the applications of Filter banks, which is used to transmit many signals simultaneously through a single channel and so that to separate at receiving end. Design of transmultiplexer using prototype filters (low pass filters and band pass filters) has been studied and analysed with respect to complexity. Transmultiplexer design using complexity efficient polyphase structure has been studied and analysed in this thesis. In this thesis, different complexity efficient structures better than polyphase using CIC based structure, multistage CIC based structure, two stage CIC based decimator and multistage CIC based structure with compensator have been proposed. Performances of proposed structures are analysed (analysis of pass-band fluctuation, stop-band attenuation of each filter in transmultiplexer) in MATLAB environment with different classes of input like speech and image. This thesis also considers complexity of proposed structures.
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    Nonuniform sampling and its reconstruction methodologies
    (Dhirubhai Ambani Institute of Information and Communication Technology, 2008) Bhawsar, Vishal; Chakka, Vijaykumar
    Alias-free DSP (DASP) is a methodology of processing signals digitally inside bandwidth that are wider than the famous nyquist limit of half of the sampling frequency. This topic has benefited from a strong research revival during the past few years. DASP is facilitated by suitable combination of non-uniform sampling and appropriate processing algorithms. In this thesis different stretegies to perform nonuniform sampling and its spectrum analysis are studied. We examine the problem of reconstructing a signal from non-uniform samples. A polynomial interpolation based reconstuction techniques are presented. Its performance are compared with the other previous papers on reconstruction technique on the basis of MSE criteria and Complexity of algorithm.
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    Design of a low power, high speed MAC unit
    (Dhirubhai Ambani Institute of Information and Communication Technology, 2006) Mohanty, Swaprakash; Nagchoudhuri, Dipankar
    MAC operation is the main computational kernel in any digital signal processing architectures. MAC consumes nearly 2/3 portion of total power dissipated in a DSP block. This thesis deals with the design of a low power, high-speed MAC unit using custom based approach. Power-delay product (PDP) is taken as a design metric for this thesis. To meet the objective the first step is to design low power and speed efficient sub-blocks of a MAC unit such as Full Adder, register, multiplexer etc. Five different types of MAC units are designed. They are MAC unit using modified Booth’s algorithm, MAC unit using carry save principle, MAC unit using bypass principle and reconfigurable MAC unit. A performance analysis is drawn among these architectures. MAC unit is implemented using both conventional full adders as well as using a low power, high-speed full adder architecture. Layout of MAC unit architectures are done using Magic tool (0.25µm technology as well as 0.18 µm technology). Power & timing analysis are done using LTSpice & Irsim tool. After simulation it is concluded that MAC unit designed using bypass principle and reconfigurable MAC unit are suitable for low power DSP applications.