PHS and Wireless LAN Base Station Interference Cancellation
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Solution Overview
Problem
Existing solutions fail to effectively eliminate radio wave interference between PHS and wireless LAN base stations operating in different frequency bands and communication methods when co-located, leading to decreased communication efficiency.
Innovation Solution
A wireless base station and terminal configuration that includes subtraction means to attenuate signals from one base station when the other is transmitting, using a predetermined attenuation ratio, and control mechanisms to synchronize transmission and reception times to prevent interference, ensuring interference elimination regardless of frequency bands and communication methods.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If PHS and wireless LAN base stations are placed in the same case as a combo, then installation space and installation cost are reduced, but mutual radio wave interference occurs between the different frequency bands
Solution Approach 1:
The patent segments the interference cancellation function into separate processing paths for PHS and wireless LAN systems. Each base station's transmission signal is independently extracted, attenuated, and subtracted from the other system's received signal, allowing simultaneous operation in the same housing without mutual interference
Solution Approach 2:
The patent introduces an intermediary signal processing mechanism that captures the transmission signal from one base station, applies attenuation to match the interference level in the other system's received signal, and subtracts it to cancel the interference before normal reception can proceed
2Duration of action of stationary object
If PHS and wireless LAN base stations operate simultaneously in different frequency bands, then communication continuity is maintained, but higher harmonics cause interference and decrease communication efficiency
Solution Approach 1:
The patent applies preliminary anti-action by proactively canceling the interference signal before it degrades the received signal quality. The transmission signal from one base station is extracted, attenuated to the appropriate level, and subtracted from the other base station's received signal in advance, preventing higher harmonic interference from reducing communication efficiency
3Reliability
If interference cancellation is implemented between different communication methods, then mutual interference is eliminated, but device complexity increases
Solution Approach 1:
The patent implements a universal interference cancellation mechanism that works across different communication methods and frequency bands. The same basic process of extracting transmission signals, applying attenuation, and performing subtraction is applied universally to both PHS-to-wireless LAN and wireless LAN-to-PHS interference paths, making the solution adaptable to various base station combinations
Data Source
AI summary
If a PHS wireless LAN combo is constituted in which a PHS base station and a wireless LAN base station are placed in the same case, their frequency bands are different but they interfere with each other due to an influence of higher harmonics, which decreases communication efficiency. When a PHS base station is in a transmitting state and a wireless LAN base station is in a receiving state, a transmission signal from the PHS base station is multiplied by a predetermined attenuation ratio so as to subtract an attenuated value from a received signal of the wireless LAN base station, and when the wireless LAN base station is in a transmitting state and the PHS base station is in a receiving state, a transmission signal from the wireless LAN base station is multiplied by the predetermined attenuation ratio so as to subtract an attenuated value from a received signal of the PHS base station.