Modelling and mitigation of specular multipath interference in a dual-frequency phase comparison FMCW radar system

Schonken, Willem Petrus Francois (2017-03)

Thesis (DEng)--Stellenbosch University, 2017.

Thesis

ENGLISH ABSTRACT: Digital signal processing technology has improved greatly over the last two decades. Increased processing power, cheaper memory and higher sampling rates have enabled the application of Frequency-Modulated Continuous Wave (FMCW) radar to a myriad of new areas. FMCW offers a number of advantages, such as continuous coverage and low peak output power, making it an attractive technology for industrial and automotive applications. Expansion into new application environments and the use of new signal processing algorithms have created a need for new multipath interference models. This study aims to fulfil that need through rigorous mathematical modelling of both the physical multipath environment and the two-dimensional Fast Fourier Transform (FFT) signal processing method, in the context of a Dual-Frequency Phase- Comparison FMCW radar sensor. It will be shown that specular reflections can have a profound effect on the amplitude and the phase of an FMCW radar’s base-band received signals. The multipath phase error interacts with the signal processing method, resulting in new and interesting effects. Furthermore, new mitigation methods will be proposed and critically evaluated by means of simulated and real-world measurements.

AFRIKAANSE OPSOMMING: Digitale seinverwerkingstegnologie het baie verbeter oor die laaste twee dekades. Toenames in verwerkerkapasiteit, goedkoper geheue en hoër monstertempo’s maak dit moontlik om Frekwensie- Gemoduleerde Kontinuegolf (FGKG) radar in verskeie nuwe toepassings te gebruik. FGKG bied ´n aantal voordele, soos ononderbroke dekking en lae piek-uittreedrywing, wat dit ´n aanloklike tegnologie maak vir industriële en motorvoertuig-toepassings. Die uitbreiding van FGKG na nuwe toepassingsareas, asook die gebruik van nuwe seinverwerkingsalgoritmes, skep ´n behoefte aan nuwe multipad-steuringsmodelle. Die doel van hierdie studie is om aan daardie behoefte te voldoen deur middel van deeglike wiskundige modellering van beide die fisiese omgewing, asook die twee-dimensionele Vinnige Fourier Transform (VFT) seinverwerkingsmetode, binne die konteks van ´n Dubbelfrekwensie-Fasevergelykende FGKGradarsensor. Daar sal gewys word dat spekulêre weerkaatsings ´n diepgaande uitwerking kan hê op die amplitude en fase van ´n FGKG-radar se basisband-ontvangde seine. Daar is ´n wisselwerking tussen die multipad-fasefout en die seinverwerkingsmetode, wat nuwe en interessante nagevolge het. Verder sal daar ook nuwe foutverminderingsmaatreëls voorgestel word, wat krities geëvalueer sal word aan die hand van simulasiedata en regtewêreld-meetings.

Please refer to this item in SUNScholar by using the following persistent URL: http://hdl.handle.net/10019.1/101131
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