摘要:
A method of transmitting signals from a base station towards user terminals in a cellular communication system. The method includes generating (18) a plurality of diversity signals, wherein at least one of said diversity signals is subjected to a selectively variable RF phase shift (20). Specifically, a set of radio link quality indicators (KPI) is determined at the base station, wherein each radio link quality indicator (KPI) is representative for the quality of the radio link between the base station and a respective one of the user terminals (UE). The set of radio link quality indicators (KPI) is used to generate an aggregated radio quality indicator, which in turn is used to selectively vary the variable RF phase shift. For example, the phase shift may be selected, which optimizes the aggregated radio quality indicator.
摘要:
A tunable delay line (100) for radiofrequency or microwave frequency applications consists of at least one ridge waveguide in which the ridge (103) is movable in the waveguide body (102) so as to vary the width of an air gap (105) defined between the longitudinal end surface of the ridge (103) and a confronting member (104) of the waveguide. The ridge (103) is moved by an actuator external to the waveguide body (102).
摘要:
A system for diversity processing a signal (INPUT) propagated via two diversity antennas (1, 2) includes: respective propagation paths for propagating two replicas of the signal (INPUT), these propagation paths being coupled to the two diversity antennas (1, 2), so that the replicas are propagated via different antennas (1, 2) ; a time variable delay element (16) for subjecting at least one of the replicas to a time variable delay; and a level adjusting element, such as an asymmetric 15 splitter (14) to produce a level imbalance (A) between the power levels of the replicas propagated via the two diversity antennas (1, 2).
摘要:
A system for diversity processing a signal (INPUT) propagated via two diversity antennas (1, 2) includes: respective propagation paths for propagating two replicas of the signal (INPUT), these propagation paths being coupled to the two diversity antennas (1, 2), so that the replicas are propagated via different antennas (1, 2) ; a time variable delay element (16) for subjecting at least one of the replicas to a time variable delay; and a level adjusting element, such as an asymmetric 15 splitter (14) to produce a level imbalance (A) between the power levels of the replicas propagated via the two diversity antennas (1, 2).
摘要:
A system for diversity processing two signals (INPUT1, INPUT2) transmitted and/or received via two diversity antennas (1, 2) includes at least four respective propagation paths coupling the signals to the two diversity antennas (1, 2). Diversity processing is primarily in the form of decorrelation achieved by means of time variable delay elements (161 to 164; 261 to 264; 1261 to 1264) that apply time variable delays to the signals propagating over at least two of the propagation paths in the system. The related processing may take place either at RF or IF, or at baseband, whereby the time variable delays are applied by subjecting the baseband signals to multiplication by a complex signal.