Abstract: As the modern society is changing from the information age to the intelligent age, the number and performance requirements of navigation, communication and detection signals have increased dramatically, and the demand for multi-functional integrated signals is becoming more and more urgent. In this field, it is a crucial issue to achieve efficient utilization of resources and dynamic adjustment of functions through flexible signal design. This paper first proposes a signal design framework based on the idea of “building blocks”. The designed signals are represented in the form of signal vectors and waveform basis functions. The corresponding signal design can be equivalently represented by reconstructing the signal vector with the coefficient combinations of the basis functions, thereby converting the signal optimization in the waveform space into the vector optimization in the signal space. Further, this paper analyzes the traditional signal evaluation methods, and derives the navigation, communication, and detection signal evaluation criteria under the integrated signal design framework. Finally, this paper proposes quantifiable optimization objectives for integrated signal design, and makes some discussion on design constraints, including energy constraints, spectrum constraints, peak-to-average ratio, etc.