Abstract: Digital Transceiver (DTRX) usable in a radio communications systems for transmitting and receiving digital base-band signals, wherein the DTRX (300) comprises: at least one digital up-converter (DUC) (310) for transmitting digital base-band signals and at least one digital down-converter for receiving digital base-band signals. In one aspect of the teachings disclosed herein the DUC (310) comprises at least two over-sampling units (314, 315), at least one quadrature modulation unit (340), and at least one time-discrete sigma delta band-pass modulator (318). The digital down-converter comprises at least one quadrature demodulation unit (360), at least two decimator units (356,357), and at least two sub-sampling units (354, 355). The digital base-band signal comprises an in-phase component (I-signal) and a quadrature component (Q-signal).

Abstract: An interface, apparatus, and method are described for communication between a radio equipment control (REC) node and first and second radio equipment (RE) nodes in a radio base station that transceives information over radio interface using multiple antenna carriers. The REC node is separate from and coupled to the first RE node by a first transmission link, and the second RE node coupled to the first RE by a second transmission link. Both control information and user information intended for communication between the REC node and the first RE node and the REC and the second RE node are conveyed over the first transmission link. The first RE node also conveys information between the REC and second RE node. Many advantageous features are described.

Abstract: A digital sigma-delta modulator (100) for modulating a digital input signal (x) is described. The digital sigma-delta modulator (100) comprises a quantizer (115) for quantizing an input signal (s) and producing a quantized output signal (y) at a first output (110) and an error output signal (?q) at a second output (165), at least one feedback loop (120, 125) connected to an input adder (140) and the first outputs (110) and the second output (165) of the quantizer (115) and a feedback filter (130, 135) in the at least one feedback loop (120, 125). The input adder (140) produces the sum signal (s) by adding the digital input signal (x) at an input (105) and output signals of the at least one feedback loop filters (130,135).

Abstract: An interface, apparatus, and method are described for communication between a radio equipment control (REC) node and a radio equipment (RE) node in a radio base station that tranceives information over radio interface using multiple antenna carriers. The REC node is separate from and coupled to the RE node by a transmission link. Both control information and user information are generated for transmission over the transmission link from one of the REC node and the RE node to the other. Many advantageous interface features are described.

Abstract: Digital Transceiver (DTRX) usable in a radio communications systems for transmitting and receiving digital base-band signals, wherein the DTRX (300) comprises: at least one digital up-converter (DUC) (310) for transmitting digital base-band signals and at least one digital down-converter for receiving digital base-band signals. In one aspect of the teachings disclosed herein the DUC (310) comprises at least two over-sampling units (314, 315), at least one quadrature modulation unit (340), and at least one time-discrete sigma delta band-pass modulator (318). The digital down-converter comprises at least one quadrature demodulation unit (360), at least two decimator units (356,357), and at least two sub-sampling units (354, 355). The digital base-band signal comprises an in-phase component (I-signal) and a quadrature component (Q-signal).

Abstract: Antenna system connectable to a base station, the antenna system comprising a digital radio unit connectable to at least one antenna element, wherein the digital radio unit comprises: at least one micro radio for receiving/sending digital radio signals having a digital down-converter/a digital up-converter and a digital signal converter. The at least one micro radio converts the digital radio signals to analogue RF (radio frequency) signals and vice versa. The at least one micro radio has at least one hub for processing digital radio signals and control signals and for routing said digital radio signals and control signals via at least one serial link and at least one interface. The at least one serial link is provided between the at least one hub and the at least one micro radio.

Abstract: A digital sigma-delta modulator (100) for modulating a digital input signal (x) is described. The digital sigma-delta modulator (100) comprises a quantizer (115) for quantizing an input signal (s) and producing a quantized output signal (y) at a first output (110) and an error output signal (?q) at a second output (165), at least one feedback loop (120, 125) connected to an input adder (140) and the first outputs (110) and the second output (165) of the quantizer (115) and a feedback filter (130, 135) in the at least one feedback loop (120, 125). The input adder (140) produces the sum signal (s) by adding the digital input signal (x) at an input (105) and output signals of the at least one feedback loop filters (130,135).

Abstract: An interface, apparatus, and method are described for communication between a radio equipment control (REC) node and a radio equipment (RE) node in a radio base station that tranceives information over radio interface using multiple antenna carriers. The REC node is separate from and coupled to the RE node by a transmission link. Both control information and user information are generated for transmission over the transmission link from one of the REC node and the RE node to the other. Many advantageous interface features are described.

Abstract: In a method and network component of a communications network for switching connections of low bit rate between input modules and output modules, the input modules and the output modules form a first switching level, and an ATM switching stage arranged between the input modules and the output modules forms a second switching level. In the first switching level, a number of low bit rate connections at the input module, which are to be transmitted to the same output module, are respectively merged by the input module into at least one ATM connection. In the second switching level, the switching through of the ATM connections for transmitting data in ATM cells ensues by the ATM switching stage. Subsequently, in the first switching level, the ATM connections which have been switched through are converted by the output module into the low bit rate connections.