Optimization of Codes and Weighting Functions for Binary Phase-Coded FMCW MIMO Radars

Binary phase coding is a promising technique to realize multiple-input multiple-output radars. However, for the case of frequency-modulated continuous-wave radars, using well-known orthogonal codes for transmit (TX) signal separation in the receiver does not lead to optimal results. In this work, we therefore present a two-step optimization approach to determine binary sequences and filter weights that allow implementing TX signal separation by means of digital signal processing in the receiver. The presented technique is verified in simulations using modulation sequences with 32 chips. Despite the very short codes, a suppression of unwanted signal components better than 10 dB is achieved.