Wireless Device Interference Cancellation via Signal Reconstruction
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Solution Overview
Problem
Interference between carrier frequency bands in carrier aggregation schemes, particularly between band 4 (2100 MHz) and band 17 (700 MHz), leads to receiver sensitivity degradation due to third-harmonic products, which existing hardware filters have not effectively addressed.
Innovation Solution
A method involving a wireless device that generates a reconstructed interference signal by mixing an instance of the second signal with a frequency location of an interfering harmonic from the second carrier frequency band falling within the first carrier frequency band, and removes this signal to mitigate interference, with parameters such as gain, timing, and phase tuned to maximize the signal-to-noise ratio.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If hardware filters are used to suppress third-harmonic interference from band 17 uplink into band 4 downlink, then interference suppression is attempted, but the interference reappears at other locations and receiver sensitivity degradation persists
Solution Approach 1:
The patent reconstructs the interfering third-harmonic signal from the transmitted band 17 uplink signal and subtracts it from the received band 4 downlink signal. By converting the harmful interference into a useful reference signal through reconstruction and subtraction, the system eliminates receiver sensitivity degradation while maintaining the ability to transmit at high power levels.
Solution Approach 2:
The patent introduces an intermediary processing stage that reconstructs the interference signal and subtracts it from the received signal. This intermediary reconstruction and subtraction process acts as a mediator between the interfering uplink signal and the affected downlink reception, effectively removing the harmful third-harmonic products without requiring hardware filters.
2Reliability
If maximum transmit power is constrained to reduce third-harmonic interference, then receiver sensitivity degradation is reduced, but transmission bandwidth utilization and overall system performance are compromised
Solution Approach 1:
The patent enables high-power transmission by converting the harmful third-harmonic interference into a useful reference signal. Through reconstruction and subtraction, the system can transmit at maximum power levels while maintaining receiver sensitivity, thus achieving both high productivity (bandwidth utilization) and high reliability (receiver sensitivity).
3Productivity
If carrier aggregation is implemented to increase overall transmission bandwidth, then transmission capacity is improved, but interference between aggregated carrier bands occurs
Solution Approach 1:
The patent enables effective carrier aggregation by converting the harmful inter-band third-harmonic interference into a useful reference signal. Through reconstruction from the transmitted signal and subtraction from the received signal, the system maintains high transmission bandwidth utilization while eliminating receiver sensitivity degradation in aggregated bands.
Solution Approach 2:
The patent introduces an intermediary reconstruction and subtraction process that mediates between aggregated carrier bands. This process reconstructs the interfering signal from one band and subtracts it from another band, enabling effective carrier aggregation without harmful inter-band interference.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Substantially reduces interference effects, enhancing receiver sensitivity and overall transmission performance by accurately estimating and subtracting the interfering signal, thereby improving the signal-to-noise ratio.
Implementation Method 1
mixing an instance of the second signal with a frequency location of an interfering harmonic from the second carrier frequency band falling in the first carrier frequency band
Implementation Method 2
removing the reconstructed interference signal from the first signal
Data Source
AI summary
A method of mitigating interference between carrier frequency bands of a carrier aggregation scheme. The method comprises: at a wireless device, receiving a first signal on a first carrier frequency band of the carrier aggregation scheme; mixing a second signal onto a second carrier frequency band of the carrier aggregation scheme and transmitting the second signal from the wireless device; executing code on a processing apparatus of the device to generate a reconstructed interference signal, by mixing an instance of the signal with a frequency location of an interfering harmonic from the second carrier frequency band falling in the first carrier frequency band; and removing the reconstructed interference signal from the first signal.