Wireless Terminal Carrier Aggregation Harmonic Interference Mitigation
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Solution Overview
Problem
In LTE/LTE-A systems, carrier aggregation leads to harmonic interference affecting downlink signal reception, causing sensitivity degradation in wireless terminals, particularly when using specific E-UTRA operating bands.
Innovation Solution
Applying a predetermined maximum sensitivity degradation (MSD) and determining a gap bandwidth to mitigate harmonic interference, ensuring successful signal reception by configuring wireless terminals with carrier aggregation involving E-UTRA operating bands 46 and others like 5, 7, 8, 21, 28, and 41, thereby protecting the downlink band from harmonic regions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If carrier aggregation is configured with E-UTRA operating bands 46 and other bands (5, 7, 8, 21, 28, 41), then communication capacity and spectral efficiency are improved, but harmonic interference affects downlink signal reception causing sensitivity degradation
Solution Approach 1:
The patent extracts and removes the harmful harmonic components from the received signal path by introducing a harmonic filter. This filter specifically targets and eliminates harmonic frequencies generated by uplink transmissions in aggregated bands before they can interfere with downlink signal reception in band 46, thereby resolving the sensitivity degradation issue while maintaining carrier aggregation benefits
Solution Approach 2:
The patent introduces a harmonic filter as an intermediary component in the signal reception path. This filter acts as a mediator that selectively blocks harmful harmonic frequencies from uplink bands while allowing the desired downlink signals in band 46 to pass through, thus preventing interference without sacrificing communication capacity
2Reliability
If gap bandwidth is increased to protect band 46 from harmonic regions, then sensitivity degradation is reduced, but frequency resource utilization is decreased
Solution Approach 1:
The patent changes the parameter of frequency band allocation by dynamically adjusting the gap bandwidth between uplink and downlink frequency ranges. By optimizing this gap parameter to be sufficient for filtering but not excessively large, the system achieves both harmonic protection and efficient frequency resource utilization, avoiding unnecessary spectrum waste
3Reliability
If MSD level is increased to mitigate harmonic interference, then downlink signal reception is protected, but uplink transmission power is reduced
Solution Approach 1:
The patent converts the harmful effect of harmonic generation into a beneficial filtering opportunity. By allowing harmonic components to be generated during uplink transmission and then systematically removing them through the harmonic filter in the downlink path, the system protects downlink reception without requiring uplink power reduction, effectively turning a potential interference source into a manageable parameter
Data Source
AI summary
There is provided a method for transmitting/receiving a signal. The method may be performed by a wireless terminal and comprise: transmitting, by the wireless terminal configured with a carrier aggregation, an uplink signal. The carrier aggregation may include a combination of a evolved universal terrestrial radio access (E-UTRA) operating band 46 and one of E-UTRA operation bands 5, 7, 8, 21, 28 and 41. The method may comprise: receiving a downlink signal. If the uplink signal is transmitted through one of E-UTRA operation bands 5, 7, 8, 21, 28 and 41 and if the downlink signal is received through the E-UTRA operating band 46, a predetermined maximum sensitivity degradation (MSD) is applied to receiving reference sensitivity of the downlink signal, thereby successfully receiving the signal.