Performance Analysis of a Two-Hop MIMO Mobile-to-Mobile via Stratospheric-Relay Link Employing Hierarchical Modulation

Table 1

System parameters used in the performance evaluation.

Wireless network	Two-hop AF MMSR
Transmission mode	MIMO with two antennas at each node; 𝐿𝑆=𝐿𝑅=𝐿𝐷=2
Frame size (𝑁)	100 symbols
Modulation	Hierarchical 4/16QAM
Channel model	3-D geometry-based MIMO MMSR [23]
Channel conditions	Static for one frame period
Operating carrier frequency	𝑓=2 GHz
Carrier wavelength	𝜆=0.15 m
Rician factor of the S-R and R-D subsystems, respectively	𝐾SR=0,𝐾RD=0 (Double-Rayleigh)
Height of the relay antennas	ℎ𝑅=20 km
Azimuth angle of the relay with respect to the source and destination, respectively	𝜔𝑆=𝜋/4,𝜔𝐷=3𝜋/4
Elevation angle of the relay with respect to the source and destination, respectively	𝛽𝑆=𝜋/3,𝛽𝐷=𝜋/3
Antenna spacing at the source, relay, and destination, respectively	𝛿𝑆=𝜆,𝛿𝑅=200𝜆,𝛿𝐷=𝜆
Orientation of antenna arrays at the source, relay, and destination, respectively	𝜃𝑆=𝜋/2,𝜃𝑅=𝜋/2,𝜃𝐷=𝜋/2
Εlevation angle of the 𝑝th source and the 𝑙th destination antenna element, respectively	𝜓𝑆=𝜋/18,𝜓𝐷=𝜋/18
The radius of cylinders 1 and 2, respectively	𝑅𝑆,max=180 m, 𝑅𝐷,max=180 m
The height of cylinders 1 and 2, respectively	𝐻𝑆,max=70 m, 𝐻𝐷,max=70 m
The spread of the scatterers within cylinders 1 and 2, respectively, around the mean azimuth angle	𝑘𝑆=5,𝑘𝐷=5
Mean azimuth angle at which the scatterers are distributed within cylinders 1 and 2, respectively	𝜇𝑆=𝜋/6,𝜇𝐷=𝜋/6
The spread of scatterers around the source and destination, respectively	𝑢𝑆=0.01,𝑢𝐷=0.01
Mean height of the scatterers within cylinders 1 and 2, respectively	𝐻𝑆,mean=17.6 m, 𝐻𝐷,mean=17.6 m
Standard deviation of scatterers height within cylinders 1 and 2, respectively	𝜎𝑆=0.31,𝜎𝐷=0.31