On the turbo coded bits allocation mode for the 64-QAM square modulation

This paper presents a study on turbo coded bit allocation in the modulator symbol for square quadrature amplitude modulation with 64 signal points. The simulations have involved both single binary turbo code of the LTE standard with coding rates 1/3 and 2/3 and double binary turbo code of the DVB-RCS2 with coding rate 2/3. The simulation results show that different investigated allocation methods affect dramatically the performance of bit/frame error rate versus signal to noise ratio of the turbo coded system. Hierarchies in performance of the allocation methods are completely different in regions with water fall versus error floor.