In this paper, an efficient dual function radar-communication system is proposed to improve the system's resource utilization. In this work, we considered a scenario where the location of the communication receiver is known prior but the radar target is moving and its location is changing with time. Therefore, we proposed a closed-loop design that allows an adaptive selection of appropriate information embedding strategies during tracking operations. We used two strategies that utilize the amplitudes and/or phases of the transmitted radar waveforms toward the communication direction according to the position of the communication receiver during each scan. Hence, during each radar illumination, the system carries out a target-tracking task and simultaneously maintains the communication symbols transmission toward the intended communication direction. The simulation results verify the effective performance of the proposed approach in terms of target detection and tracking performance and angular bit error rate (BER). Furthermore, the proposed amplitude phase-shift keying signaling strategy can transmit different communication symbols to different users located within the sidelobe region and also provides a significant improvement in data rate transmission and BER performance compared with the existing sidelobe-based communication strategies.

Dynamic spectrum access (DSA) systems, commonly known as spectrum sharing, are considered one of the most promising paths for more efficient spectrum allocation. When talking about DSA, the most discussed topics revolve around particular technologies such as cognitive radios or particular solutions such as the advanced wireless services-3 initiative. However, in this work, we explore a less discussed approach for spectrum sharing: the Federal Communications Commission (FCC)’s experimental radio service (ERS). The ERS grants licenses for experimentation, market trials, and product development in Federal and/or non-Federal bands. Frequencies in these licenses are assigned on a shared basis and not for the exclusive use of any one licensee. Using FCC’s scraped information in the period between 2007 and 2016, we were able to gain a deeper understanding of the ERS. We find that the processing time (i.e., time to get a license) has been reduced from 100 days to an average of 23 days in 2016. Moreover, the assignation process of experimental licenses is characterized great flexibility in terms of the authorized technical and nontechnical characteristics. We also explored what is behind these 10 years of information.