As a practical technique for enhancing relay and HARQ transmissions, modulation diversity (MoDiv) uses distinct constellation mappings for data retransmissions. In this work, we study the MoDiv optimization in a amplify-and-forward (AF) two-way relay channel (TWRC). The design of MoDiv to minimize the bit-error rate (BER) is formulated into a successive Koopmans-Beckmann quadratic assignment problem (QAP), which is solved sequentially with a robust tabu search method. The performance gain of our MoDiv scheme over retransmission without remapping and a heuristic MoDiv scheme is demonstrated with numerical results.
- 2-way relay
- Modulation diversity
ASJC Scopus subject areas
- Control and Systems Engineering
- Electrical and Electronic Engineering