This study investigates the benefits of waveform selection by exploiting multiple illuminators of opportunity (IO) in hybrid radar systems consisting of multi-band receivers which can utilise active radar transmitters and broadcasting signals for bistatic radar sensing. As a performance metric, Cramér-Rao lower bounds (CRLBs) on velocity and range estimations are considered. Considering that TV and radio broadcasting stations usually emit high power signals, they are suitable for passive sensing as IOs. Therefore, FM radio, Digital Video Broadcasting-Terrestrial (DVB-T) and Digital Audio Broadcasting (DAB) transmitters are considered for passive radar operations while also having an active radar transmitter in the multistatic radar network. Multistatic radar networks comprising receivers, transmitter and IOs transmitting the aforementioned waveforms are modelled and optimum selection of bistatic pairs are studied based on CRLBs on range and velocity estimations. Two different multistatic radar network scenarios are simulated and the results are evaluated to analyse the estimation accuracy of active and passive bistatic pairs in the network. The results show that multi-band multistatic radar network provides better range and velocity estimations and may also mitigate the adverse effects of jamming by exploiting broadcasting waveforms compared to a radar network which only considers radar transmitters for sensing.

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