I don't know how this system works but US hypersonic missile designs suggest how it could work without requiring radio signals. Inertial guidance gets you into

I don't know how this system works but US hypersonic missile designs suggest how it could work without requiring radio signals. Inertial guidance gets you into the general area of the target, at which point you switch to active terminal guidance i.e. the missile can identify and maneuver toward the selected target. This is much more difficult than it sounds. At hypersonic velocities, your entire terminal guidance system is being actively destroyed by atmospheric ablation. Decades of research went into how to make a terminal guidance system that survived just long enough while retaining sufficient precision of control to hit the target. It is an exotic materials science problem.