$I(t)$ [@kahn2002wireless], given by $$x(t)=JI(t)=JA\left(\mu+\sum_{k=-\infty}^{\infty}a_{k}q(t-k{T_\mathrm{s}})\right),\label{eq:TxSignal}$$ where $J$ is the laser conversion factor, $A$ is a scaling factor that can be adjusted depending on the desired transmitted power, $\mu$ is the required DC bias, $q(t)$ is an arbitrary pulse, and ${T_\mathrm{s}}$ is the symbol duration.

Three requirements are placed on $x(t)$: it should be nonnegative, bandlimited, and ISI-free. The nonnegativity constraint, $x(t)\geq0$ for all $t\in\mathbb{R}$, is fulfilled by choosing $\mu$ in (\[eq:TxSignal\]) sufficiently large, see Sec. \[sec:Required-DC-bias\]. This DC bias is added equally to each symbol to maintain a strictly bandlimited signal $x(t)$, in contrast to works like [@karout2010power; @780164; @HranilovicLattice] in which the bias is allowed to vary with time. The bandwidth constraint is fulfilled by choosing the pulse $q(t)$ such that $$Q(\omega)=\intop_{-\infty}^{\infty}q(t)e^{-j\omega t}dt=0,\; |\omega|\geq 2\pi B,\label{eq:bandwidthLimitation}$$ where $Q(\omega)$ denotes the Fourier transform of $q(t)$. The condition of ISI-free transmission, finally, is fulfilled by either choosing $q(t)$ as a Nyquist pulse, see Sec. \[sec:Pulse-shaping\], when using a sampling receiver, or choosing $q(t)$ as a root-Nyquist pulse (also known as ${T_\mathrm{s}}$-orthogonal pulse), see Sec. \[sec:RootPulse-shaping\], when using a matched filter in the receiver. Fig. \[fig:TxSig\_RC\] illustrates an example of the transmitted intensity given by (\[eq:TxSignal\]) where $\mathcal{C}=\left\{ 0,1\right\} $.

Depending on 