Experiments on an ISAR-Communication System Using Continuous Phase Modulation and Mismatched Filtering

Due to the congestion of the electromagnetic spectrum, the need for spectral allocation has been tremendous in recent times. Should they have the ability to share their bandwidth, radar and communications systems could collaborate in order to alleviate the frequency spectrum. A possible way to create a joint radar-communication system is the use of communication codes to simultaneously transmit information and perform radar missions. In this paper, continuous phase frequency-shift keying codes are transmitted in an ISAR framework with the objective of creating radar images. Using such codes requires sidelobe mitigation, which is achieved via mismatched filtering. A civil aircraft is illuminated and imaged, and a comparison between the communication codes and the classical chirp case is provided. The communication code shows a more uniform sidelobe level than the chirp case, and they have the flexibility of performing communication tasks by transmitting information.