Summary
International Symposium on Antennas and Propagation
2010
Session Number:3TF4
Session:
Number:3TF4-5
Proposal of De-noise and Forward Relay Transmission Scheme under Interference Condition
Kosuke Kinami, Naoki Honma, Kentaro Nishimori,
pp.-
Publication Date:2010/11/23
Online ISSN:2188-5079
Summary:
Recently, MIMO (Multiple-Input Multiple-Output) transmission system has received a lot of attention as way of enhancing spectral efficiency [1]. MIMO system enables high-speed transmission using spatial multiplexing by using multiple antennas. However, MIMO is not suitable for long-distance transmission. Because long-distance transmission limits the number of the available paths, and this affects the spatial multiplex performance. MIMO relay transmission system can be one of the candidates that solve this problem [2]. MIMO relay transmission enables enhancing spectral efficiency even for long distance data transmission. AF (Amplify and Forward) and DF (Decode and Forward) have been commonly studied for the MIMO relay schemes [3]. AF is the easiest transmission scheme in which relay node only amplifies received signals since it can be achieved with a simple configuration. Since this scheme enhances the noise, it causes deterioration in communication quality. DF is transmission scheme in which the relay node retransmits after decoding the signal. It does not amplify the noise, but relay node needs multiple antennas corresponding to number of streams. DNF (De-noise and Forward) is the transmission scheme where the relay node identifies constellation by eliminating the noise, and retransmits after amplification [4]. Before the data transmission, the relay node estimates ideal constellation points that do not contain the noise components. DNF can be operated even with small number of antennas compared with the number of streams, and not amplify the noise. Furthermore, the channel information is unnecessary in the transmitting side. However, DNF suffers from the serious performance deterioration when interference exists. Therefore, DNF needs to have a function that can suppress the interference to maintain these advantages. In this paper, we report interference cancellation method. Also, we propose a new scheme, which select the adequate paths from all available relay nodes based on not only signal-to-interference ratio (SIR) but the correlation between the signals. The simulation demonstrates the proposed scheme can improve the data transmission quality even when the interference exists