Spectrum sharing is an elegant solution to the problem of spectrum scarcity. A novel advanced approach is developed in this study to enable power-controlled cellular networks coexist with primary rotating radars. A canonical scenario is considered where a single cellular BS interferes with single rotating radar. A new mathematical model is also developed using log-normal approximations to capture the aggregate interference from multiple power-controlled cellular systems. The cellular system transmits at high power for over 83.3% of time due to the slow radar antenna rotation and narrow main beam width. Our numerical results show that the power control drastically reduces the required separation distances between the two systems. The log-normal approximation gives results which virtually match the results of our simulation.

In this paper, we study spectral coexistence between rotating radar and power-controlled cellular networks in radar bands. For two systems to spectrally coexist, they must be able to operate effectively without causing harmful electromagnetic interference to each other. Very short radar-cellular system separation distances are required during 83.3% of time due to the narrow main beam width of the rotational radar antenna. We propose a spatio-temporal analytical approach with adaptive base station (BS) power control for adjacent spectrum sharing between the two systems. We develop a new model for the aggregate interference from power-controlled cellular BSs using log-normal approximation. The cellular system is allowed to transmit at high power when the radar antenna's main beam is pointing elsewhere from it. On the other hand, the cellular system reduces its transmit power only for a short period when the radar directional antenna main beam is pointing toward it. We use the degradation of the radar signal-to-interference plus noise ratio and cellular outage probability as our performance metrics. Numerical results show that power control of cellular BS highly reduces separation distance between the BS and radar, while yielding marginal degradation of outage performance. In addition, the mathematical results given by the log-normal approximation closely follow our simulated results. Detail system level assessments and investigations are presented to comprehensively understand secondary access to this band opportunistically.