Main-Branch Structure Iterative Detection Using Approximate Message Passing for Uplink Large-Scale Multiuser MIMO Systems

Algorithm 2

Processing procedure of the proposed Main-Branch structure turbo iteration detection.

(1)  Initialization:

  if  , input the initial a priori LLRs of the main detector and the branch detector, set , , .

(2)  if  , combining with the a priori LLR from the decoders and the branch detector, let , do

  computation extrinsic LLRs of the main detector by Algorithm 1.

(3) Pass to the decoders and to the branch detector in parallel, respectively.

(4) The decoders Calculate by decoding algorithm.

(5) Calculate between and by (14).

(6) Generate by (12).

(7) While given the a priori LLRs ,

     do computation extrinsic LLRs of the branch detector by Algorithm 1.

(8) Calculate between and by (13).

(9) Set , do computation the a priori LLRs by (11) for the next iteration.