Capacity of rms bandlimited Gaussian multiple-access channels

Summary form only given, as follows. Continuous-time additive white Gaussian noise channels with strictly time-limited and root-mean-square (rms) bandlimited inputs are studied. RMS bandwidth is equal to the normalized second moment of the spectrum, which has proved to be a useful and analytically tractable measure of the bandwidth of strictly time-limited waveforms. The authors show how the classical formulas for the capacity of strictly bandlimited single- and two-user channels change under the rms bandwidth measure. In addition, they consider channels where the inputs are further constrained to be pulse-amplitude-modulated (PAM) waveforms. They analyze those channels under the assumption that the transmitters are symbol synchronous, and they find the pair of pulses that achieve the boundary of the capacity region. The shapes of the optimal pulses depend not only on the bandwidth but also on the respective signal-to-noise ratios.