Signaling for a Fluid Antenna System With Uniform Correlation

This is the authors' abstract. We don't add key points for this paper.

For a single-antenna fluid antenna system (FAS) with N fixed antenna locations or ports, analytical expressions for the error performance of four types of signaling schemes for digitally modulated data transmission and reception are found. The signaling schemes are: (1) M-ary phase-shift keying with coherent reception, (2) two-sided M-ary amplitude-shift keying (M-ASK) with coherent reception, (3) one-sided M-ASK with noncoherent reception, and (4) one-sided M-ASK with partially noncoherent reception. The N ports are evenly distributed on a line. The FAS error performance is analyzed when the ports are subject to identically distributed Rayleigh fading with uniform correlation between the channels at the ports. A series expression for the characteristic function (c.f.) of the random complex channel coefficient magnitude squared of the chosen FAS port, in terms of a series of elementary c.f.s, where each elementary c.f. is the c.f. of a sum of N independent gamma random variables, is obtained. Series expressions for the symbol error probabilities as weighted sums of functions in closed form are presented. Closed form asymptotic high signal-to-noise ratio results for error performance are also derived. Numerical are presented to show the variation of the error performance with respect to the spacing between the first and Nth ports and N.