An app demodulator for iterative decoding of turbo coded differential space-time modulation with unitary group codes

A modified technique for joint iterative decoding of serial concatenation of turbo code and unitary space-time group code is proposed and evaluated under temporally correlated fading channels. This approach further takes advantage of the system by exploiting the unitary space-time group code which possesses trellis structure of differential modulation. The extrinsic information of modulation symbols is calculated from this trellis structure by using a detector called an a posteriori probability (APP) demodulator. The simulation results show that our modified method is superior to the conventional one at the expense of more complexity.