New Adaptive HARQ Schemes in MIMO TDD System Using SVD

Abstract

Inheriting the main advantages of hybrid automatic retransmission request (HARQ) and multi-input multi-output (MIMO), we apply HARQ scheme into MIMO systems to get high reliability and throughput. This paper presents three kinds of adaptive HARQ schemes in MIMO-TDD system using SVD for different system complexity and quality of service (QoS) requirements. The first scheme makes full use of the freedom of antennas permutation and the process is very simple. The other two schemes utilize two degrees of freedom which include antennas permutation and power allocation to achieve better performance.