Sequence estimation in narrowband interference via the expectation-maximization algorithm /
The inherent interference rejection qualities of ographics.
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| Format: | Thesis Book |
| Language: | English |
| Published: |
[Place of publication not identified] :
[publisher not identified] ;
1998.
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| Subjects: |
| Summary: | The inherent interference rejection qualities of ographics. Direct-sequence Spread-spectrum (DS-SS) systems have generated a great deal of interest and research in this area. Here we seek to improve upon the performance of DS-SS in an AWGN, narrowband interference environment by using the EM algorithm to generate a maximum likelihood sequence estimate. We see that for tone interference, the performance of this system essentially meets the coherent BPSK lower bound, and significantly outperforms DS- SS systems that use a notch filter. For a Gaussian random process interference model, we find that the performance of the EM algorithm is comparable to that obtained using two sided suppression filters for moderate SNR, and that the EM algorithm outperforms filtering methods for higher SNR. We also compare the EM results to those obtained from traditional maximum-likelihood sequence estimation and from optimal (bit-by-bit) filtering. |
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| Item Description: | "Major subject: Electrical Enginering". Vita. |
| Physical Description: | viii, 66 leaves : illustrations ; 28 cm. Issued also on microfiche from Lange Micrographics. |
| Bibliography: | Includes bibliographical references: pages 43-47. |