Techniques for Passive Intermodulation Avoidance
AssigneeTelefonaktiebolaget LM Ericsson (publ)
InventorTorbjörn Wigren
Life of this patent
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Abstract
There is provided techniques for PIM avoidance. A method is performed by a nonlinear controller. A method comprises determining, based on presence of uplink PIM, to which fraction of total transmission resources within a transmission slot a set of transmission power reduction factors is to be applied. The method comprises applying the set of transmission power reduction factors to the determined fraction of total transmission resources as distributed over a set of DL transmission carriers within the transmission slot during transmission of a set of signals in the set of DL transmission carriers.
Claims20
1-26. (canceled)
A method for passive intermodulation, PIM, avoidance, the method being performed by a nonlinear controller, the method comprising:
- determining (S102), based on presence of uplink PIM, to which fraction of total transmission resources within a transmission slot a set of transmission power reduction factors is to be applied,
- wherein the fraction of total transmission resources is, in a logarithmic domain and according to a nonlinear feedback control loop, computed as a function of a comparison between a measured uplink PIM when having applied the set of transmission power reduction factors in a most recent transmission slot and a reference value for the uplink PIM,
- wherein the nonlinear feedback control loop is based on characteristics, having a curved nonlinear envelope, that transforms a control signal expressed in terms of maximum number of resource blocks as allowed to be scheduled within the transmission slot, to a corresponding logarithmic domain downlink power reduction, and
- wherein the measured uplink PIM is given by, in each transmission slot, probing a radio channel over which the uplink PIM is received;
- and
- applying the set of transmission power reduction factors to the determined fraction of total transmission resources as distributed over a set of downlink, DL, transmission carriers within the transmission slot during transmission of a set of signals in the set of DL transmission carriers.
The method according to claim 1, wherein the curved nonlinear envelope has a logarithmic shape.
A nonlinear controller for passive intermodulation, PIM, avoidance, the nonlinear controller comprising processing circuitry, the processing circuitry being configured to cause the nonlinear controller to:
- determine, based on presence of uplink PIM, to which fraction of total transmission resources within a transmission slot a set of transmission power reduction factors is to be applied,
- wherein the fraction of total transmission resources is, in a logarithmic domain and according to a nonlinear feedback control loop, computed as a function of a comparison between a measured uplink PIM when having applied the set of transmission power reduction factors in a most recent transmission slot and a reference value for the uplink PIM,
- wherein the nonlinear feedback control loop is based on characteristics, having a curved nonlinear envelope, that transforms a control signal expressed in terms of maximum number of resource blocks as allowed to be scheduled within the transmission slot, to a corresponding logarithmic domain downlink power reduction, and
- wherein the measured uplink PIM is given by, in each transmission slot, probing a radio channel over which the uplink PIM is received;
- and
- apply the set of transmission power reduction factors to the determined fraction of total transmission resources as distributed over a set of downlink, DL, transmission carriers within the transmission slot during transmission of a set of signals in the set of DL transmission carrier.
A non-transitory computer readable medium comprising computer code THAT, when run on processing circuitry of a nonlinear controller, causes the nonlinear controller to:
- determine, based on presence of uplink PIM, to which fraction of total transmission resources within a transmission slot a set of transmission power reduction factors is to be applied,
- wherein the fraction of total transmission resources is, in a logarithmic domain and according to a nonlinear feedback control loop, computed as a function of a comparison between a measured uplink PIM when having applied the set of transmission power reduction factors in a most recent transmission slot and a reference value for the uplink PIM,
- wherein the nonlinear feedback control loop is based on characteristics, having a curved nonlinear envelope, that transforms a control signal expressed in terms of maximum number of resource blocks as allowed to be scheduled within the transmission slot, to a corresponding logarithmic domain downlink power reduction, and
- wherein the measured uplink PIM is given by, in each transmission slot, probing a radio channel over which the uplink PIM is received;
- and
- apply the set of transmission power reduction factors to the determined fraction of total transmission resources as distributed over a set of downlink, DL, transmission carriers within the transmission slot during transmission of a set of signals in the set of DL transmission carrier.
Dependencies are inferred from the claim text.