negative, they must be used in a system with $\mu>0$. We denote these four pulses as *regular* Nyquist pulses.

Another option is to use *nonnegative* Nyquist pulses, which satisfy all the three aforementioned constraints. As a result, in (\[eq:TxSignal\]), $\mu=0$ and $q(t)\geq0$ for all $t\in\mathbb{R}$. In [@4132995], it has been shown that pulses that satisfy these requirements must be the square of a general Nyquist pulse. This will result in having pulses with bandwidth twice that of the original Nyquist pulses. Three pulses that satisfy these constraints were introduced in [@4132995], and we use them in our study for compatibility with previous works: squared sinc (S2), squared RC (SRC), and squared double-jump (SDJ), also defined in Table \[pulse-def\]. Their low-pass bandwidth is $B=1/{T_\mathrm{s}}$ for S2 and $B=(1+\alpha)/{T_\mathrm{s}}$ for SRC and SDJ, where $0\le\alpha\le 1$.

Figs. \[fig:TxSig\_RC\] and \[fig:TxSig\_SquareRC\] depict the normalized transmitted signal $x(t)/A$ using the RC and SRC pulses, respectively, assuming $\mathcal{C}= \left\{0,1\right\}$. The most important parameters of the pulses are summarized in Table \[tab:All\_Info\_Nyq\].

Bandlimited Root-Nyquist Pulses\[sec:RootPulse-shaping\]
========================================================

ISI-free transmission is achieved with the pulses in Sec. \[sec:Pulse-shaping\] as long as the input of the sampling unit satisfies the Nyquist criterion given in (\[eq:NyquistInTime\]). In addition to the 