Direct-Position-Determination Based on Mixed-Bit Signal in Distributed Radar Systems

This letter addresses the problem of direct position determination (DPD) for a distributed radar system with stringent bandwidth/power budgets. The DPD methods usually require transmitting infinite-bit signals to the fusion center (FC), which occupies large transmission bandwidth and hardware resource. To alleviate this shortcoming, we derive a Rao-test-based method for mixed-bit signal (mixed-bit Rao test, MBRT) by adopting mixed analog-to-digital converters (ADCs) to achieve detection and localization simultaneously. Moreover, a closed-form expression of the Cramér-Rao lower bound (CRLB) for the mixed-ADC architecture is derived. Simulation results demonstrate that the MBRT outperforms the pure low-resolution ADC architecture and provides comparable performance with the pure infinite-resolution ADC topology.