OFDM Chirp Waveform Design Based on Subchirp Bandwidth Overlap and Segmented Transmitting for Low Correlation...

Area of Science:

• Radar Systems Engineering
• Signal Processing
• Waveform Design

Background:

• Orthogonal frequency division multiplexing (OFDM) chirp waveforms possess desirable characteristics for multiple-input multiple-output (MIMO) radar, including high range resolution, Doppler tolerance, and constant modulus properties.
• Conventional OFDM chirp signals suffer from high autocorrelation sidelobe peaks (ASP) and cross-correlation peaks (CP), which degrade MIMO radar detection performance.
• Effective detection in MIMO radar systems critically depends on minimizing correlation sidelobe peaks.

Purpose of the Study:

• To investigate the autocorrelation function structure of OFDM chirp signals.
• To propose a novel scheme for reducing ASP and CP in OFDM chirp signals for improved MIMO radar detection.
• To validate the proposed signal design through simulations and performance comparisons.

Main Methods:

• Designed OFDM chirp signals by selecting a suitable subchirp bandwidth and implementing a segmented transmit-receive mode to reduce ASP.
• Determined an appropriate interval between chirp rates of different signals to minimize CP.
• Conducted simulations to verify the effectiveness of the proposed methods in reducing ASP and CP.

Main Results:

• The proposed methods successfully reduced both autocorrelation sidelobe peaks (ASP) and cross-correlation peaks (CP) in OFDM chirp signals.
• Simulations demonstrated superior correlation performance compared to recent related studies.
• The designed signals exhibited good detection performance in MIMO radar detection scenarios, as shown by multiple signal detection and range image simulations.

Conclusions:

• The developed scheme effectively reduces sidelobe peaks in OFDM chirp signals, addressing a key limitation for MIMO radar applications.
• The designed OFDM chirp signals offer enhanced correlation properties, leading to improved detection capabilities in MIMO radar systems.
• This research contributes a practical solution for optimizing OFDM chirp waveforms in MIMO radar for better overall system performance.