Angular-Domain Channel Model and Channel Estimation for MIMO System

A new MIMO channel model based on angular-domain, double-directional channel model is proposed. Angular domain is a more appropriate coordinate to describe the MIMO channel, since the incoming rays and outgoing rays appear in clusters in the real world. This model is developed based on linear space and sampling theory and is applicable to any practical antenna geometry and includes the actual radiation pattern of the antenna array. It is compared with other existing models, including i.i.d., Kronecker, virtual channel representation and eigenbeam model, using channel estimation based model validation.