Delay and doppler shift estimation for non-constant envelope modulation in OFDM radar system

U. K. Singh, V. Bhatia, A. K. Mishra

Research output: Chapter in Book/Report/Conference proceedingConference Proceeding (Non-Journal item)

Abstract

Estimation of delay and Doppler shift is one of the main applications of radar systems. Particularly in orthogonal frequency division multiplex (OFDM) radar system for estimation of delay and Doppler shift, maximum likelihood (ML) estimator with constant envelope modulation technique is commonly used. However, such estimator does not perform well at low signal to noise ratio (SNR). In this paper, we propose a technique to enhance the SNR threshold of the ML estimator. Instead of using constant envelope modulation technique, we propose to use non-constant envelope modulation technique such as quadrature amplitude modulation (QAM). To reduce the SNR threshold, modulation order of QAM is used as a tuning parameter. To validate correctness of the proposed methodology Cramer-Rao lower bounds for the variance of delay and the Doppler shift are derived. We demonstrate significant improvement in SNR threshold of the estimator through an extensive simulation study. Further, performance improvements of the ML estimator with the proposed technique over conventional matched filter estimator is illustrated.

Original languageEnglish
Title of host publicationIET Conference Publications
PublisherInstitution of Engineering and Technology
Number of pages5
EditionCP728
ISBN (Electronic)9781785614217, 9781785615030, 9781785616624, 9781785616723, 9781785616990, 9781785617072
ISBN (Print)9781785615078, 9781785615153
DOIs
Publication statusPublished - 28 May 2018
Externally publishedYes
Event2017 International Conference on Radar Systems, Radar 2017 - Belfast, United Kingdom of Great Britain and Northern Ireland
Duration: 23 Oct 201726 Oct 2017

Publication series

NameIET Conference Publications
NumberCP728
Volume2017

Conference

Conference2017 International Conference on Radar Systems, Radar 2017
Country/TerritoryUnited Kingdom of Great Britain and Northern Ireland
CityBelfast
Period23 Oct 201726 Oct 2017

Keywords

  • CRLB
  • Delay
  • Doppler shift
  • ML
  • OFDM radar

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