Linear Precoding for Relay Networks: A Perspective on Finite-Alphabet Inputs

作者：Zeng Weiliang^*; Zheng Yahong Rosa; Wang Mingxi; Lu Jianhua

来源：IEEE Transactions on Wireless Communications, 2012, 11(3): 1146-1157.

DOI：10.1109/TWC.2012.012412.110747

• Relay networks
• amplify-and-forward
• precoder design
• finite-alphabet input

This paper considers the precoder design for dualhop amplify-and-forward relay networks and formulates the design from the standpoint of finite-alphabet inputs. In particular, the mutual information is employed as the utility function, which, however, results in a nonlinear and nonconcave problem. This paper exploits the structure of the optimal precoder that maximizes the mutual information and develops a two-step algorithm based on convex optimization and optimization on the Stiefel manifold. By doing so, the proposed algorithm is insensitive to initial point selection and able to achieve a near global optimal precoder solution. Besides, it converges fast and offers high mutual information gain. These advantages are verified by numerical examples, which also show the large performance gain in mutual information also represents the large gain in the coded bit-error rate.

• 出版日期2012-3
• 单位清华大学