Interaction Design (IxD) is highly confused with UX because they are both about the experience. IxD differentiates from UX in a way that it focuses on creating desired user experiences by creating both physical and emotional communication. Thus, IxD improves users' interactions and experiences. For UX, the experiences are just some stops along with the user flow.
It is impossible to think of IxD without UX. They go hand in hand to create enjoyable experiences.