Multiband Transceiver Feedback Cross-Talk Cancellation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Multiband transceivers face challenges in canceling cross-talk between adjacent transmit paths, leading to deteriorated performance due to insufficient RF/IF path isolation and interference between feedback paths, which complicates TX noise compensation.
Innovation Solution
A cross-talk canceller is implemented within the multiband transceiver to estimate and cancel interference between feedback paths using techniques like Least Squares estimation, allowing for effective compensation of TX noise across different radio frequency bands.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If multiple transmit paths are closely spaced in a multiband transceiver, then the device can transmit signals in different RF bands simultaneously with compact structure, but cross-talk between adjacent transmit paths deteriorates signal quality
Solution Approach 1:
A cross-talk canceller is introduced as an intermediary component between the transmit paths to actively cancel the harmful cross-talk interference. The canceller estimates the cross-talk signals from adjacent paths and subtracts them from the received signals, thereby eliminating the interference while allowing the transmit paths to remain closely spaced
Solution Approach 2:
The system employs feedback mechanisms where the output of each transmit path is fed back through estimated cross-talk transfer functions to model and cancel the interference. The cross-talk canceller uses feedback from the transmit paths to continuously estimate and compensate for cross-talk effects, improving signal quality despite close spacing
2Object-affected harmful factors
If RF/IF path isolation is increased to reduce cross-talk, then signal quality improves, but device complexity and manufacturing difficulty increase
Solution Approach 1:
The patent replaces physical mechanical isolation structures with signal processing methods. Instead of using complex RF/IF path isolation hardware to prevent cross-talk, the system uses digital signal processing in the cross-talk canceller to estimate and subtract cross-talk signals, achieving interference reduction without complex physical isolation
Solution Approach 2:
The cross-talk canceller serves as a signal processing intermediary that handles the interference problem electronically rather than requiring complex physical isolation. This mediates the cross-talk issue through software/digital processing, avoiding the need for complex RF/IF isolation hardware
3Reliability
If cross-talk cancellation is implemented, then TX noise performance improves, but computational complexity and processing requirements increase
Solution Approach 1:
The cross-talk canceller implements partial cancellation by focusing on the dominant cross-talk paths rather than attempting to cancel all possible interference sources. The system estimates cross-talk transfer functions for adjacent paths and cancels these specific interference components, achieving significant performance improvement without the excessive computational complexity of complete cancellation
Data Source
AI summary
Embodiments relate to a multiband transceiver apparatus (100), comprising a first transmit path (110) operable to transmit a first transmit signal (sig1) in a first radio frequency band (RF1), wherein the first transmit path (110) comprises an input (112), an output (114) and a first feedback path (116) from the output towards the input of the first transmit path, a second transmit path (130) operable to transmit a second signal (sig2) in a second radio frequency band (RF2), the second radio frequency band (RF2) being different from the first radio frequency band (RF1), wherein the second transmit path (130) comprises an input (132), an output (134) and a second feedback path (136) from the output towards the input of the second transmit path, and a cross-talk canceller (150) operable to cancel cross-talk from the second feedback path (136) to the first feedback path (116) and/or to cancel cross-talk from the first feedback path (116) to the second feedback path (136) of the multiband transceiver apparatus (100).