Architecture and method in a wireless communication network

A radio network node configured for wireless communication with a user equipment (UE) in antenna streams of a wireless communication system, the radio network node comprising:

• a plurality of antenna sub arrays forming a multiple antenna array which is configured for beamforming, spatial multiplexing and Multiple Input Multiple Output (MIMO) transmission/reception, wherein the multiple antenna array processes a plurality of physical antenna streams, and wherein a number of physical antenna streams of the plurality of physical antenna streams is defined as N;
• one or more processing circuits for performing central base band (CBB) processing;
• and
• one or more processing circuits for performing antenna base band (ABB) processing connected to the one or more processing circuits for performing CBB processing, wherein the one or more processing circuits for performing ABB processing comprises:
• a plurality of active antenna (AA) processing circuits, wherein:
• each AA processing circuit of the plurality of AA processing circuits is connected to a respective one antenna sub array of the plurality of antenna sub arrays,
• each AA processing circuit of the plurality of AA processing circuits is configured for pre-processing of signals over the respective one antenna sub array, before any forwarding of signals is made to the one or more processing circuits for performing CBB processing, and
• the pre-processing performed by the plurality of AA processing circuits comprises one or more of:
• analog/digital conversion, digital/analog conversion, carrier modulation/demodulation, transmission power amplification and filtering, or receiver low noise amplification and filtering;
• and
• a plurality of sub-level ABB processing circuits, wherein each sub-level ABB processing circuit of the plurality of sub-level ABB processing circuits is connected to the plurality of AA processing circuits and is connected to the respective one antenna sub array, and wherein the each sub-level ABB processing circuit is configured for:
• spatial detection of a received signal for the antenna sub array, and
• selecting strongest paths to the UE,
• wherein:
• before any forwarding of signals is made to the one or more processing circuits performing CBB processing, the one or more processing circuits for performing ABB processing maps a plurality of logical antenna streams to clusters of signals of the N physical antenna streams based on the pre-processing of signals by the plurality of AA processing circuits and based on the selected strongest paths to the UE,
• a number of logical antenna streams of the plurality of logical antenna streams is defined as M, and
• M is less than N.