Abstract
This study introduces a receiver architecture for dual-functional
communication and radar (RadCom) base-stations (BS), which exploits the
spatial diversity between the received radar and communication signals,
and performs interference cancellation (IC) to successfully separate
these signals. In the RadCom system under consideration, both
communication and radar systems employ orthogonal frequency-division
multiplexing (OFDM) waveforms with overlapping subcarriers. Employing
OFDM waveform allows the BS to simultaneously perform uplink channel
estimation on the narrow-band subcarriers to efficiently obtain full
channel state information (CSI) between the users (UEs) and the BS
antenna elements. The estimated CSI matrix is then utilized to acquire
uplink data streams from the UEs by suppressing the inter-user
interference and radar signals which arrive at the BS through unknown
channels. After acquiring the UEs’ data, radar signals are extracted
from the received complex baseband signals by performing interference
cancellation. The proposed method has been analyzed mathematically and
verified by simulations under various conditions including CSI mismatch
and high radar interference. The results show that 16QAM modulated
uplink is outstandingly robust against radar interference and that
having a large number of antennas significantly improves the performance
of both communication and radar subsystems, cooperatively. This study
shows that it is possible to distinguish radar and communication signals
by employing large-scale antenna arrays to successfully realize a RadCom
receiver for future communication networks