UMD Theses and Dissertations

Permanent URI for this collectionhttp://hdl.handle.net/1903/3

New submissions to the thesis/dissertation collections are added automatically as they are received from the Graduate School. Currently, the Graduate School deposits all theses and dissertations from a given semester after the official graduation date. This means that there may be up to a 4 month delay in the appearance of a given thesis/dissertation in DRUM.

More information is available at Theses and Dissertations at University of Maryland Libraries.

Browse

Search Results

Now showing 1 - 1 of 1
  • Thumbnail Image
    Item
    Sigma-Delta Quantization: Number Theoretic Aspects of Refining Quantization Error
    (2006-07-18) Tangboondouangjit, Aram; Benedetto, John J.; Mathematics; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)
    The linear reconstruction phase of analog-to-digital (A/D) conversion in signal processing is analyzed in quantizing finite frame expansions for R^d. The specific setting is a K-level first order Sigma-Delta quantization with step size delta. Based on basic analysis, the d-dimensional Euclidean 2-norm of quantization error of Sigma-Delta quantization with input of elements in R^d decays like O(1/N) as the frame size N approaches infinity; while the L-infinity norm of quantization error of Sigma-Delta quantization with input of bandlimited functions decays like O(T) as the sampling ratio T approaches zero. It has been, however, observed via numerical simulation that, with input of bandlimited functions, the mean square error norm of quantization error seems to decay like O(T^(3/2)) as T approaches zero. Since the frame size N can be taken to correspond to the reciprocal of the sampling ratio T, this belief suggests that the corresponding behavior of quantization error, namely O(1/N^(3/2)), holds in the setting of finite frame expansions in R^d as well. A number theoretic technique involving uniform distribution of sequences of real numbers and approximation of exponential sums is introduced to derive a better quantization error than O(1/N) as N tends to infinity. This estimate is signal dependent.