Beamforming Based CSI Reference Signal Transmission for FDD Massive MIMO Systems

Abstract

Since FDD massive MIMO (multiple-input multiple-output) system deploys hundreds of transmit antennas at base station (BS) compared to conventional MIMO system, the overhead of transmitting channel state information reference signal (CSI-RS) increases proportionally to the number of transmit-antennas. To overcome these disadvantages, we proposed beamforming based CSI-RS transmission technique for FDD massive MIMO system which transmit CSI-RS by limited amount of downlink resources.

Full-Duplex Communication in Cooperative Cognitive Radio Network

“…한편, 여러 연구에서 여러 입력 여러 출력 (multipleinput-multiple-output) 시스템이 통신과 신호처리 기 법의 성능을 높일 수 있다는 점을 다루었다 [7][8][9][10] . 또한, 협력 인지 통신망은 (cooperative cognitive radio network) 부 쓰는이가 주파수를 언제나 확실히 쓸 수 없다는 인지 통신망의 단점을 고치고자 제안되었다 [11] .…”