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dc.contributor.advisorPace, Phillip E.
dc.contributor.advisorJenn, David C.
dc.contributor.authorPaepolshiri, Nattaphum
dc.date.accessioned2012-03-14T17:45:40Z
dc.date.available2012-03-14T17:45:40Z
dc.date.issued1998-03-01
dc.identifier.urihttp://hdl.handle.net/10945/5517
dc.description.abstractPolyphase continuous waveform (CW) radar systems often use the popular Frank code and P4 code due to their linear time-frequency characteristics as well as their low periodic ambiguity sidelobes. The phase relationship of the Frank code corresponds to a sawtooth folding waveform. The phase relationship of the P4 code is symmetrical with a parabolic distribution. The radar system's unambiguous target detection range is limited by the number of subcodes within the code period (code length). Increasing the code length to extend the unambiguous range results in a larger range-Doppler correlation matrix processor in the receiver, a longer compression time and an increase in the receiver's bulk memory requirements. In addition, the entire code period may not be returned from the target due to a limited time-on-target resulting in significant correlation loss. To significantly extend the unambiguous range beyond a single code period, this thesis explores the relationship between the polyphase codes (Frank and P4) and the number theoretic transforms (NTT) where the residues exhibit the same distribution as the polyphase values. The unambiguous range is extended from the number of subcodes within a single code period to the dynamic range of the transform without requiring a large increase in correlation processing. The dynamic range of a NTT is defined as the greatest length of combined phase sequences that contain no ambiguities or repeated paired terms. By transmitting N 2 coprime code periods, the unambiguous range can be extended by considering the paired values from each sequence. A new Frank phase code formulation is derived as a function of the residue number system (RNS) where each residue corresponds to a phase value within the code period (modulus) sequence. Based on the symmetrical distribution of the P4 code, a new phase code expression is derived using both the symmetrical number system (SNS) and the robust symmetrical number system (RSNS). Here each phase value within the code period corresponds to a symmetrical residue. MATLAB simulations are used to verify the new expressions for the RNS, SNS and RSNS phase codes. Implementation considerations of the new approach are also addressed.en_US
dc.description.urihttp://archive.org/details/extendingunambig109455517
dc.format.extentxx, 109 p. ;en_US
dc.publisherMonterey, California. Naval Postgraduate Schoolen_US
dc.rightsThis publication is a work of the U.S. Government as defined in Title 17, United States Code, Section 101. Copyright protection is not available for this work in the United States.en_US
dc.subject.lcshElectrical engineeringen_US
dc.subject.lcshRadaren_US
dc.titleExtending the unambiguous range of CW polyphase radar systems using number theoretic transformsen_US
dc.typeThesisen_US
dc.contributor.corporateNaval Postgraduate School (U.S.).
dc.contributor.departmentElectrical and Computer Engineering
dc.contributor.departmentInformation Sciences (IS)
dc.identifier.oclc760085901
etd.thesisdegree.nameM.S.en_US
etd.thesisdegree.levelMastersen_US
etd.thesisdegree.disciplineElectronic Warfare Systems Engineering and M.S. in Electrical Engineeringen_US
etd.thesisdegree.grantorNaval Postgraduate Schoolen_US
etd.verifiednoen_US
dc.description.distributionstatementApproved for public release; distribution is unlimited.


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