Modular antenna system

1. A modular antenna system comprising:

at least one radio-unit comprising at least two radio-subunits;

each radio-subunit comprising a radio-module and/or an antenna-module;

wherein said radio-module comprising a digital signal-processing unit, at least a transceiver, a front-end and a power amplifier;

wherein the at least two radio-subunits provide an identical architecture and are mutually connected via a connector interface, and each radio-subunit has an IQ-input and an IQ-output; and

wherein the IQ-input and the IQ-input of the radio-subunit are connected to at least one adjacent radio-subunit and the IQ-unit of a first root-radio-subunit (RSU-R) are connected to the base station via IQ-signal lines.

2. The modular antenna system according to claim 1 , wherein the IQ-input and the IQ-output of each radio-subunit are connected to a base station.

3. The modular antenna system according to claim 1 , further comprising an interface-subunit (ISU) connected to the root-radio-subunit (RSU-R).

4. The modular antenna system according to claim 1 , wherein the root-radio-subunit comprises an FPGA boot image for supporting a hierarchical boot procedure of the radio-subunits.

5. The modular antenna system according to claim 1 , wherein the radio-subunit is combined with optically active elements.

6. The modular antenna system according to claim 1 , wherein the radio-subunit is connected to exactly one parent-radio-subunit and to n child-radio-subunits, with n≥0.

7. The modular antenna system according to claim 6 , wherein the radio-subunit comprises a clock generator that serves as a clock slave for the parent-radio-subunit and serves as a clock master for the child-radio-subunits.

8. The modular antenna system according to claim 1 , wherein the connector interface of the radio-subunit comprises parent-connectors, child-connectors and route-through connectors.

9. The modular antenna system according to claim 1 , wherein the antenna-module comprises at least one antenna, and the antenna comprises at least one antenna element.

10. The modular antenna system according to claim 9 , wherein the at least one antenna element of the antenna are cross-polarized.

11. The modular antenna system according to claim 9 , wherein the at least one antenna elements of the antenna has a Vivaldi-structure.

12. A method for signal processing using the modular antenna system according to claim 1 , wherein beamforming, calibration, clock and timer procedures are performed within a radio-subunit, and wherein the radio-subunit possesses a timer that is clocked by an integer multiple of a sample rate, wherein a sampling offset time calibration is preformed and a measured integer time offset is used to correct the timer, and a fractional time offset is compensated for by a fractional time correction block in the radio-subunit.

13. The method for signal processing according to claim 12 , wherein an inter-calibration procedure is performed between modularly connected radio-subunits within a radio-unit to synchronize all locally generated reference signals with a reference signal received by a parent radio-subunit.

14. The method for signal processing according to claim 11 , wherein an intra-calibration procedure is performed within a radio-subunit to synchronize all transceivers connected to antenna elements of the radio-subunit with a locally generated reference signal.

15. The method for signal processing according to claim 12 , wherein

in receive direction:

the IQ-signals from all radio-subunits are weighted, aggregated and forwarded to the root-radio-subunit (RSU-R) and further forwarded to the base station;

and in transmit direction:

the IQ signals are replicated and forwarded to the radio-subunits.