Searching for Optimal Scheduling of MIMO Doubly Iterative Receivers: An Ant Colony Optimization-Based Method

When an iterative receiver has more than one iteration loop, scheduling the iterative decoding process is an important issue. To find the optimal scheduling, extrinsic information transfer (EXIT) function was the main tool in the literature. However, it is only very efficient when the codeword is significantly long. In this paper, under the consideration of a packet-based transmission scenario, we propose modeling the scheduling search problem as the foraging problem of ant colony. And then, an ant colony optimization (ACO) algorithm, labeled as max-min ant system (MMAS), is adopted and tailored for our problem. Simulation results show MMAS outperforms the EXIT function-based method when practical length codewords are used.