Comparative Quality and Reliability Analysis for Relay-Assisted Communication with PSK Modulation in Presence of Heavy Fading

The presented research performs a comparative joint quality and reliability numerical analysis of a wireless communication system that uses M-ary Phase Shift Keying (MPSK) modulation and either a two-hop amplify-and-forward (AF) or two-hop decode-and-forward (DF) relay for signal transmission. It is assumed that the propagation channel undergoes heavy fading, which is described in terms of the Lomax fading model. The transmission quality for each relay is assessed in terms of the average bit error rate (ABER) and the reliability - in terms of the outage probability (OP). The difference between each of the performance metrics (i.e., differential ABER and OP) is numerically studied for all possible ranges of system and channel parameters at each hop (i.e., average signal-to-noise ratio, fading distribution scale parameter, constellation size, etc.). Some specific peculiarities of relay- assisted communication in the presence of Lomax fading were observed, e.g., the existence of a pronounced extremum of the differential outage probability that depends on the channel's average SNR and evolves with the outage threshold SNR. The identified effects can be of possible help in choosing the specific relay-based solution for increasing the coverage area in cases of poor propagation conditions and heavy fading.