Signal-Driven AP Selection for Cell-Free mMIMO ISAC Systems in Clutter-Intensive Environments

Sixth-generation (6G) networks integrate sensing and communication (ISAC) to support both high data rates and environmental awareness. In Cell-Free (CF) Massive MIMO systems, distributed access points (APs) enhance spatial diversity, but efficient distributed sensing under realistic propagation conditions remains challenging. This paper proposes the Dynamic Angle and Signal-driven Association (DASA) scheme, a two-step AP selection framework for clutter-intensive CF-ISAC environments. DASA combines a post-convergence local SNR proxy with geometric angular refinement to identify reliable sensing APs. Simulations under the 3GPP UMa model show that DASA consistently outperforms conventional methods, achieving near-unity detection probability even under severe clutter.