High speed inter-chip communications are required to operate despite multiple waveguide bends. Valley photonic crystal waveguides have a great potential in this area as bends can be implemented with near-zero losses. Here we demonstrate a 50 Gbit/s terahertz communication using QAM-16 modulation in the 300 GHz band. The experiment employed a uni-traveling-carrier photo-diode transmitter, 10-bend VPC waveguide and sub-harmonic mixer receiver and performance results show a bit error rate of 2×10^-7 was achieved.