ABSTRACT
In this chapter, the authors describe different conventional waveform types with special reference to the unique requirements for through-the-wall applications. Conventional radar waveforms used in through-the-wall radar imaging and sensing encompass a broad range of signals, ranging from classical such as short-pulse or Frequency-Modulated to more sophisticated waveforms including phase coded and noise. The authors discuss the effects of the operational and electromagnetic environment on wave propagation and describe how the waveforms can be appropriately selected to enhance the detection of targets behind walls. They provide the design of emerging waveforms to optimize target detection, with special reference to matched illumination–based signature exploitation waveform design. M-sequence phase-coded waveforms are maximum-length-binary-sequence waveforms, which can be generated up to tenths of GHz of bandwidth using a digital shift register clocked by a stable single-tone Radio Frequency oscillator.
