在介绍差分空时分组码编译码原理的基础上,给出了基于最大似然判决的差分检测和多符号差分检测方案,并对这两种译码方案的性能进行了比较。相对于普通的相干译码,这两种方案在发射和接收端都不需要对传输信道进行估计,因此具有较低的译码复杂度。最后,通过仿真结果可以看出相干检测、差分检测和多符号差分检测性能间的差异。 On the basis of introduction of the principle of coding and decoding of differential space-time block codes, the schemes of differential detection and multi-symbol differential detection based on maximum likelihood decision are given. The performances of these two decoding schemes are compared. Compared with ordinary coherent decoding, these two schemes do not need to estimate the transmission channel at transmitting and receiving end, and therefore have lower decoding complexity. Finally, we can see the difference between coherent detection, differential detection and multi-symbol differential detection through simulation results.