Imperfect CSI Based Multi-Way Satellite Relaying

The problem of multi-way satellite relaying is discussed in this letter. A new transmission method is proposed to improve the performance of the considered system. Further, it is well known that for detecting the transmitted data in a multiway relaying system, global channel state information (CSI) is required at each earth station (ES). Due to nonreciprocal channels and high value of latency, it is very difficult to estimate the channel gains at respective ESs. A method of training is proposed to estimate the channel gains. Detection of data is performed by replacing exact CSI by estimated CSI in decision metric. Analytical results of the proposed system are obtained by using moment generating function (MGF) approach. An approximate closed-form expression of MGF is obtained by ignoring higher order noise terms. The symbol error rate and diversity order of the proposed system are derived by using MGF expression.