IS-95, an interim standard proposed for future digital personal communications systems, uses two levels of encoding of digital data for error control and compatibility with code-division multiple access (CDMA) transmission. The data is first convolutionally encoded and the resulting symbols are interleaved and then groups are encoded as orthogonal Walsh sequences. Decoding these two separate encodings is traditionally done in separate sequential steps. By combining the decoding and applying feedback of the final decision of the second level of decoding to the first level decoder it is possible to reduce the error rate of the decoder. Each Walsh sequence encodes six non-adjacent symbols of the convolutional code. The receiver computes an estimate of the probability that each of the sixty-four possible Walsh sequences has been sent, and uses this estimate as an estimate for each of the convolution symbols which specified the Walsh sequence. Since the convolution symbols are non-adjacent, it is likely that the actual value of some of the earlier symbols will have been determined by the final decoder before later symbols specifying the same Walsh sequence are used by the convolution decoder. The knowledge of the values of these symbols can be used to adjust the probability estimates for that Walsh sequence, improving the likelihood that future convolutional symbols will be correctly decoded. Specific metrics for estimating probabilities that each convolutional symbol was sent were tested with and without the proposed feedback, and error rates were estimated based on extensive computer simulations. It was found that applying feedback does improve error rates. Analytical methods were also applied to help explain the effects. / Graduation date: 1996

Thesis (M.E.)--University of Florida, 2001. / Title from first page of PDF file. Document formatted into pages; contains viii, 71 p.; also contains graphics. Vita. Includes bibliographical references (p. 69-70).

Thesis (Ph. D.)--Ohio State University, 2006. / Title from first page of PDF file. Includes bibliographical references (p. 148-154).

Thesis (Ph. D.)--University of Hong Kong, 2006. / Title proper from title frame. Also available in printed format.

Thesis (M.S.)--Worcester Polytechnic Institute. / Keywords: precision personnel locator; digital systems; embedded systems; waveform generation; data communication. Includes bibliographical references (leaves 108-110).

Thesis (MCIS - Computer and Information Sciences) -- AUT University, 2008. / Includes bibliographical references. Also held in print ( xi, 105 leaves : ill. ; 30 cm.) in the Archive at the City Campus (T 621.382 LOL)

Thesis (M.S.E.C.E.)--University of Delaware, 2009. / Principal faculty advisor: Leonard J. Cimini, Jr., Dept. of Electrical & Computer Engineering. Includes bibliographical references.

Thesis (Ph. D.)--University of Texas at Austin, 2001. / Vita. Includes bibliographical references. Available also from UMI/Dissertation Abstracts International.

Thesis (Ph. D.)--University of Texas at Austin, 2001. / Vita. Includes bibliographical references. Available also from UMI/Dissertation Abstracts International.

Thesis (Ph. D.)--University of Texas at Austin, 2000. / Vita. Includes bibliographical references (leaves 164-178). Available also in a digital version from Dissertation Abstracts.