On Robust MMSE-Based Filter Designs for Multi-User Peer-to-Peer Amplify-and-Forward Relay Systems

Abstract

In this paper, we propose robust relay and destination filter design methods for the multi-user peer-to-peer amplify-and-forward relaying systems while taking imperfect channel knowledge into consideration. Specifically, the relay and destination filter sets are developed to minimize the sum mean-squared-error (MSE). We first present a robust joint optimum relay and destination filter calculation method with an iterative algorithm.Motivated by the need to reduce computational complexity of the iterative scheme, we then formulate a simplified sum MSE minimization problem using the relay filter decomposability, which lead to two robust sub-optimum non-iterative design methods. Finally, we propose robust modified destination filter design methods which require only local channel state information between relay node and a specific destination node. The analysis and simulation results verify that, compared with the optimum iterative method, the proposed non-iterative schemes suffer a marginal loss in performance while enjoying significantly improved implementation efficiencies. Also it is confirmed that the proposed robust filter design methods provide desired robustness in the presence of channel uncertainty.주저자：한국전자통신연구원 B4G 이동통신방식연구부, joonoos@etri.re.kr, 정회원 논문번호：KICS 2013-07-293, 접수일자：2013년 7월 13일, 최종논문접수일자：2013년 9월 9일

Two-Way MIMO AF Relaying Methods Having a Legacy Device without Self-Interference Cancellation

“…amplify and forward) 방식은 복호화가 필요 없는 단 순한 구조를 장점으로 가지며, 활발한 연구가 이루어 져왔다 [11][12][13] . 양방향 릴레이(two-way relay) 통신 방식은 중계 전송에서 필연적으로 발생하는 주파수 효율의 손실을 극복할 수 있는 방안으로 제안되었다 [14,15] .…”