© 2011-2012 IEEE. In this paper, we propose a multi-carrier THz wireless communication system using an injection-locked gain-switched laser as an optical comb source. The phase noise of the 192 GHz signal resulting from the beating of two optical comb lines is theoretically analyzed and experimentally examined. Moreover, a three channel, 10 Gbaud QPSK THz signal is generated, and transmission over 40 km standard single mode fiber (SSMF) is experimentally demonstrated.