Echo Cancellation for Self-Interference in Wideband Transceivers
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Solution Overview
Problem
Conventional approaches to enhancing bandwidth in cable television systems for high-speed data services require high transmission powers, leading to issues with signal distortion and operational costs, especially in home-based modems, and fail to effectively minimize interference such as adjacent channel interference (ACI) and adjacent leakage interference (ALI).
Innovation Solution
The implementation of systems and methods that utilize echo cancellation components with trained filters to process wideband communications signals, specifically converting digital ACI and ALI signals into analog form to subtract from downstream signals, thereby reducing interference and optimizing receiver performance in access devices like cable modems.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If high transmission powers are used to enhance bandwidth for high-speed data services, then the bandwidth and data transmission capability are improved, but signal distortion increases and operational costs become problematic
Solution Approach 1:
The patent converts the harmful self-interference signal into a useful cancellation signal by capturing the transmitted signal through a coupler, processing it through adaptive filters to generate an estimate of the interference, and then subtracting this estimate from the received signal. This transforms the harmful high-power transmission signal into a beneficial interference cancellation mechanism, allowing high bandwidth operation without the associated signal distortion problems.
2Productivity
If high transmission powers are used for bidirectional high-speed data services, then data transmission capability is improved, but power consumption and operational costs increase
Solution Approach 1:
The system performs self-interference cancellation using its own transmitted signal. The coupler captures a portion of the transmitted signal, the adaptive filters process this captured signal to generate an interference estimate, and this estimate is subtracted from the received signal. This self-service mechanism allows the system to eliminate interference without requiring additional external power or resources, thereby enabling high data transmission capability without proportionally increasing power consumption.
3Object-affected harmful factors
If conventional approaches are used without interference cancellation, then device complexity is lower, but interference such as ACI and ALI cannot be effectively minimized
Solution Approach 1:
The patent introduces intermediate components to manage interference: a coupler acts as an intermediary to capture the transmitted signal, and adaptive filters serve as intermediaries to process this signal and generate interference estimates. These intermediary elements enable effective interference cancellation of ACI and ALI while keeping the overall system architecture manageable and modular.
Data Source
AI summary
Approaches provide for processing a communications signal, such as a wideband communications signal. For example, a communications signal can be received at an access device, such as a cable modem or a wireless transceiver/radio. The access device can include components operable to process the communications signal to enable access to, for example, video, data, voice, high-speed Internet services. At least some of the components include an echo cancellation component among other components to cancel interference (e.g., ACI, ALI). For example, the echo cancellation component can use trained filters and samples of the upstream signal, echoed samples of the transmitted signal, feedback signals of the echoed signal, etc., to estimate one or more types of interference. Thereafter, the estimated interference can be used to cancel interference at the access device.