From: Performance analysis of relay selection in cooperative networks over Rayleigh flat fading channels
T 11
T 12
T 21
T 22
S1
T x 1
–
S2
T x 2
Rb0
R x 1
R x 2
T x ~ 1 / T x 1
T x ~ 2 / T x 2
Rb1
D
R T 21 (BD) / R T 21 (BA)
R T 22 (BD) / R T 22 (BA)