Wireless Node PIM Reduction via Oscillator Signal Injection
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Solution Overview
Problem
Existing wireless communication network nodes face inefficiencies and complexity in reducing passive intermodulation (PIM) distortion, particularly in multi-carrier or multi-band systems, due to non-linear behavior in passive devices which introduces distortion into received signals.
Innovation Solution
A wireless communication network node is designed with an antenna and transmitter arrangement, a power distribution device, and an oscillator that adds a continuous wave signal of a higher frequency band to the output signals, which is filtered out by the receiver to prevent distortion, allowing undistorted signals to be received.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If polynomial modeling or tunable non-linear circuits are used to cancel PIM distortion, then PIM distortion reduction is achieved, but device complexity and computational requirements increase
Solution Approach 1:
The patent extracts the problematic non-linear interaction by introducing a separate oscillator that generates a counteracting signal. Instead of trying to model and cancel PIM through complex digital signal processing, the invention extracts the intermodulation problem and addresses it with a dedicated analog counter-signal generator that operates independently from the main signal path.
Solution Approach 2:
The patent introduces an intermediary oscillator that generates a counteracting signal to neutralize PIM distortion. This intermediary component mediates between the transmit and receive paths by injecting a carefully controlled signal that cancels the harmful intermodulation products without requiring complex processing of the main communication signals.
2Power
If high power transmit signals are used, then transmission performance is improved, but PIM distortion increases in passive devices
Solution Approach 1:
The patent applies preliminary anti-action by generating a counteracting signal before the PIM distortion adversely affects the receive signal. The oscillator produces a signal that anticipates and neutralizes the harmful intermodulation products, allowing high transmit power to be used without suffering from PIM distortion in the receive path.
Solution Approach 2:
The patent converts the harmful non-linear effect into a beneficial cancellation mechanism. By understanding how PIM distortion is generated through non-linear interactions, the invention uses a similar non-linear approach (through the oscillator) to generate a signal that benefits the system by canceling the harmful distortion, effectively turning the non-linearity problem into a solution.
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
This approach provides an uncomplicated and efficient reduction of PIM distortion without requiring signal processing, ensuring clear reception in wireless communication nodes.
Implementation Method 1
an oscillator arranged to supply an additional signal of a third frequency band that is added to the output signals
Implementation Method 2
a receiver filter arranged to prevent the additional signal from reaching the receiver
Data Source
Figure 1~2
Figure 3
Figure 4
AI summary
The present disclosure relates to a wireless communication network node (1, 1') comprising an antenna arrangement (2), a transmitter arrangement (3) that is arranged to transmit output signals (S1) of a first frequency band (B1), and a receiver arrangement (4) that is arranged to receive input signals (S2) of a second frequency band (B2). The node (1, 1') further comprises a first power distribution device (5) that is arranged to distribute power between said antenna arrangement (2) and both of said transmitter arrangement (3) and said receiver arrangement (4). The node (1, 1') further comprises an oscillator (6) that is arranged to supply an additional signal (S3) of a third frequency band (B3) that is added to the output signals (S1). The frequencies comprised in the third frequency band (B3) exceed the frequencies comprised in the first frequency band (B1). The node (1, 1') further comprises a receiver filter (9) that is arranged to prevent the additional signal (S3) to reach the receiver arrangement (4).