This work presents the simulation results of the performances of Turbo Trellis-Coded Modulation (TTCM) using Constellation Shaping (CS). The proposed method consists on increasing the constellation order and selecting only the most significant constellation points in order to increase the Euclidean free distance (d f ) of the entire encoding scheme. These performances were investigated over Additive White Gaussian Noise (AWGN) channel and Memoryless Rayleigh Fading (MRF) channel using Space-Time Block Coding (STBC) diversity technique.