Dual-function radar–communications: information transmission during FDA radar listening mode

Abstract

We investigate the frequency diverse array (FDA) for joint radar and communication systems. The basic idea is to use the transmitter/receiver modules of the radar system for communication purpose during listening mode as a secondary function. The radar will be performing its routine functions during the active mode as a primary function. An FDA at the transmitter side will be used to produce an orthogonal frequency division multiplexed signal, which is proposed for the communication system. The directivity of the radar antenna, FDA in this case, provides an additional advantage to mitigate the interferences other than the Direction of Interest (DoI). The proposed technique allows two beampatterns to be transmitted sequentially from the same FDA structure. Due to the communication signal transmission in the mainlobe of the second beampattern, the bit error rate achieved in the mainlobe is better than the existing techniques using the sidelobe transmission for communications. At the receiver, both incoming signals of radar and communication will share a different spatial angle. Simulation results indicate the novelty of the idea to suppress the interferences in terms of DoI. Furthermore, we analyzed the signal-to-interference ratio and Cramer–Rao lower bounds for angle and range estimation for the proposed technique.

Multi-user transmission for the joint radar communication systems based on amplitude phase shift keying modulation and waveform diversity

“…Figure 15(a) shows the transmit BP radiations corresponding to two BF weight vectors for the ASK-based communication schemes [13,14,40,41]. These BF vectors are designed to broadcast the SL level of either −40 or −30 dB, that is selected from 0 < L k ≤ ε max , (k = 1, 2), toward the communication receivers.…”

“…These BF vectors are designed to broadcast the SL level of either −40 or −30 dB, that is selected from 0 < L k ≤ ε max , (k = 1, 2), toward the communication receivers. During each radar pulse, the SL level remains identical at both communication units for the existing ASK-based communication schemes [13,14,40,41]. For the PSK-based communication schemes [15,25,42,43], two BF weight vectors are designed to have the same amplitude response but exhibit unique phase responses, uniformly distributed from 0 • to 360 • , at the communication receivers.…”

Low‐sidelobe waveform design for integrated radar‐communication systems based on frequency diversity array

“…Al‐Salehi A. et al. [25] embed the communication information only during the listening time by orthogonal frequency division multiplexing (OFDM) technology. However, the above methods do not consider the effect on radar detection performance.…”

“…Recently, several methods for the IRCS-FDA have been proposed [24,25]. Nusenu S. et al [24] embed the communication information by the spread sequence technique and adopted the time-domain orthogonal waveforms for distinction.…”

Throughput Enhancement for the Joint Radar-Communication Systems Based on Cognitive Closed-Loop Design

“…The authors in [31] utilized the degrees of freedom (DOFs) and developed radar waveforms that serve various functions simultaneously. In [32], the authors developed a method for throughput enhancement by exploiting the silent period (when the primary radar function is inactive) for information transmission. In this work, during each illumination, the detection and tracking of the moving target by the proposed DFRC system is assumed to be the primary function and simultaneously maintaining the information bits transmission towards the communication station as the secondary function.…”