High Range Resolution at Reduced Sampling Rates in OFDM Systems Exploiting Pilot Aliasing

High range resolution (HRR) is critical for automotive radar where it is directly dependent on the available transmission bandwidth. However, HRR sensing for OFDM entails high sampling frequencies, which extends the system's complexity and requires costly receivers. In this letter, we present an approach for achieving HRR with a reduced sampling rate by exploiting pilots aliasing in OFDM systems. In particular, the pilots take a ladder shape in the time-frequency lattice such that under-sampling the received signal causes aliasing in the pilot symbols with zero-interference from the data. The proposed approach allows low-cost sensors to obtain the sensing information without losing the range-velocity resolution.