Figure 7From: Design of Uniformly Most Powerful Alphabets for HDF 2-Way Relaying Employing Non-Linear Frequency ModulationsDistances of hierarchical symbols corresponding to different XC symbols for QFSK and the critical parameter value α= e j φ c . Minimal value of modulation index fulfilling the UMP condition is κ= 5 ∕6 (green thick line meets blue thick line).Back to article page