Abstract: The present disclosure provides a device, a base station device, and a method for obtaining an estimate of a downlink (DL) covariance matrix from an uplink (UL) covariance matrix. The device and method are particularly suitable for massive Multiple Input Multiple Output (MIMO) scenarios, and are particularly applicable to Frequency-Division Duplexing (FDD) systems. The device includes a processor configured to compute an angular power spectrum (APS) of an antenna array, in particular in the continuous angular domain, based on the UL covariance matrix of a communication channel and an UL response of the antenna array. Further, the processor is configured to compute the DL covariance matrix of the communication channel based on the APS and a DL response of the antenna array. The base station device includes the device and the antenna array.

Abstract: The present invention provides a device, a base station device, and a method for respectively obtaining an estimate of a DL covariance matrix from an UL covariance matrix. The devices and method are particularly suitable for massive MIMO scenarios, and are particularly applicable to FDD systems. The device comprises a processor configured to compute an APS of an antenna array, in particular in the continuous angular domain, based on the UL covariance matrix of a communication channel and an UL response of the antenna array. Further, the processor is configured to compute the DL covariance matrix of the channel based on the APS and a DL response of the antenna array. The base station device includes the device and the antenna array.