Coexistence Performance of GAA Use Cases using LTE-TDD Technologies in 3.5GHz CBRS Spectrum

The Citizens Broadband Radio Service (CBRS) is a novel shared spectrum licensing regime in the range 3550-3700 MHz for wireless broadband that allows two tiers of broadband users to occupy spectrum on the secondary basis to the first primary tier composed by radar and fixed satellite services. The CBRS Alliance is an industry association developing standards for coexistence between LTE-TDD systems operating within the CBRS. The Alliance seeks to introduce a logical coordination entity known as a Coexistence Manager (CxM), that will manage efficient channel allocation among General Authorized Access (GAA) LTE users forming the third tier [1]. We evaluate the GAA coexistence performance of LTE-TDD networks and provide insights on the performance gain of potential channel allocation solutions in CxM. System simulations modeling a 3D city environment show that a location based solution ensures sufficient coexistence between outdoor Micro networks. However, this method leads to conservative frequency reuse when a number of indoor private Pico networks are present nearby. In that scenario, long-term measurement shows benefits for low-power private networks at some tradeoff with the Micro network capacity.