Reinhard Feger, Clemens Pfeffer, Andreas Stelzer,
"A Frequency-Division MIMO FMCW Radar System Based on Delta?Sigma Modulated Transmitters"
, in Microwave Theory and Techniques, IEEE Transactions on, Vol. 62, Nummer 12, Seite(n) 3572-3581, 12-2014
Original Titel:
A Frequency-Division MIMO FMCW Radar System Based on Delta?Sigma Modulated Transmitters
Sprache des Titels:
Englisch
Original Kurzfassung:
In this paper, we present a hardware-efficient method, which allows to
implement multiple-input multiple-output (MIMO) radars with a separation
of the transmit (TX) signals in the frequency domain. The proposed
architecture uses binary phase-shift keying (BPSK) modulators within the
TX paths of a multi-channel frequency-modulated continuous-wave (FMCW)
radar. These BPSK modulators are driven by 1-bit sequences, which are
generated using Delta-Sigma-modulators to shift the quantization noise
towards high frequencies. Thus, neither multi-bit digital-to-analog
converters, nor vector modulators or phase shifters are required for the
proposed approach. Since the FMCW principle relies on the evaluation of
beat frequencies within a narrow frequency band, the shaped quantization
noise is outside the frequencies of interest and can thus be filtered
out. The chosen hardware setup is optimized for integration into
monolithic microwave integrated circuits (MMICs), which is demonstrated
by a prototype system based on 77-GHz chips. Several MMICs are combined
to realize a radar frontend with six TX and eight receive channels
resulting in 48 MIMO channels. A signal-processing approach is derived
and a method to reduce ambiguities is presented. Measurements
demonstrate a range resolution of 15 cm and a 3-dB beamwidth of 3° with
position standard deviations better than 1 mm. Furthermore, a
measurement example with a target placed outside the unambiguous range
of the radar shows an 8-dB power reduction of the unwanted signal from
the target at the ambiguous distance. This improvement is achieved by
choosing nonidentical frequency spacings for the TX signals.
Sprache der Kurzfassung:
Englisch
Journal:
Microwave Theory and Techniques, IEEE Transactions on
Forschungs-