Prerequisites & Notation

Before You Begin

This chapter builds on the sensing operator framework (Part II), OFDM/OTFS radar waveforms (Chapter 10), and MIMO radar (Chapter 11). Familiarity with matched-filter imaging (Chapter 13) is helpful for understanding how ISAC waveforms affect the imaging PSF.

OFDM and OTFS radar signal models, range-Doppler processing (Chapter 10) (Review ch10)
Self-check: Can you write the OFDM radar echo model and derive the range-Doppler map via 2D-FFT?
MIMO radar virtual arrays and spatial diversity (Chapter 11) (Review ch11)
Self-check: Can you explain how a MIMO radar creates a virtual array and its effect on angular resolution?
Matched-filter imaging and the sensing matrix $\mathbf{A}$ (Chapter 13) (Review ch13)
Self-check: Can you write the imaging model $\mathbf{y} = \mathbf{A}\mathbf{c} + \mathbf{w}$ and explain backpropagation imaging?

Notation for This Chapter

Symbols introduced or specialised in this chapter.

Symbol	Meaning	Introduced
$R_c$	Communication rate (bits/s/Hz)	s01
$\mathrm{CRB}(\theta)$	Cramer-Rao bound for target angle estimation	s02
$\mathbf{W}_c, \mathbf{W}_s$	Communication and sensing beamforming matrices	s01
$\mathbf{R}_x$	Transmit covariance matrix $\mathbf{R}_x = \mathbb{E}[\mathbf{x}\mathbf{x}^H]$	s02
$\rho$	Power split ratio between sensing and communication ( $0 \leq \rho \leq 1$ )	s01
$\mathrm{MI}_{\mathrm{sens}}$	Mutual information for sensing	s02
$D_s$	Sensing distortion (MSE of scene estimate)	s02
$R_b$	Bistatic range	s05

← Ch 28 ISAC Fundamentals