HRPD系统调制与编码技术

Based on a brief introduction to the link structure of HRPD system, in this paper, the corresponding modulation and coding techniques are studied. In order to increase the data transmission rate, high order modulation techniques such as 16QAM and 64QAM and compound modulation with Walsh codes are used, besides, Turbo code is also adopted in this system. The 16QAM which exemplifies high order soft-demodulation algorithm is deduced, furthermore, a necessary modification of Turbo decoder needed to adapt to the input soft information of high order modulation is also presented in this paper. Then the performance of demodulation and decoding algorithms is examined by the simulation of the link of HRPD system on different kinds of channels.