On the Use of Waveform Diversity in the Design of RF Signal Systems

While the benefit of waveform diversity to real-time operations in active RF (radio frequency) systems (e.g. radar and communications) is generally recognized, its role in the design of RF signal systems is less appreciated. Although one generally strives to develop signal systems that produce as few artifacts as possible, developing specifications to ensure that the artifacts are inconsequential to overall operations is not always a straightforward process. In addition, trades that should consider RF hardware design and down-stream signal and data processing concurrently typically get little exposure and substantially less attention. A more holistic view during the design process can expose additional trades and lead to either better performing systems or systems that meet requirements with less risk and expense [e.g. 1]. To make the case we consider the implementation of a popular "stretch" radar receiver and describe, quantitatively, artifacts frequently associated with the architecture. An example that includes a mix of three frequently encountered additive (independent of signal level) and multiplicative (related to signal level) artifacts is simulated, and the impact of the artifacts on system performance is quantified. Both non-adaptive and adaptive signal and array processing techniques applicable to the mitigation of the artifacts are described, and their efficacy to the mitigation of signal system anomalies demonstrated. The techniques may or may not be applicable to specific systems. The purpose, here, is simply to motivate RF system developers to consider waveform diversity and complementary signal processing as part of the signal system design process.