Abstract: A multipair and twoway relaying system with amplifyandforward in Ricean fading environments is considered, where the relay station is equipped with a largescale multiple input multiple output (MIMO) antenna array. In order to efficiently reduce overhead for channel estimation and improve the spectral efficiency, firstly a linear transmission scheme only based on the line-of-sight (LoS) component is proposed. This scheme employs such a relaying process with low implement complexity that combines equal gain combining with equal gain transmission. For the proposed scheme, closedform expressions of asymptotically achievable rate with and without power scaling are derived. By comparing with the corresponding traditional linear transmission scheme based on perfect channel state information, this scheme is more suitable for application when the LOS component is relatively strong.