Multi-Channel Equalization for Interleaved Channel Impairments
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing equalizers fail to effectively compensate for channel-dependent impairments introduced by interleaved devices, such as mismatches in frequency responses of time interleaved track-and-hold units, in high-speed communication systems like 10 Gb/s Ethernet over multimode fiber links.
Innovation Solution
A multi-channel equalizer is introduced that can apply different equalization to each interleaved channel, utilizing techniques like maximum likelihood sequence estimation (MLSE) and decision feedback equalization (DFE) with MIMO FIR filters, allowing for independent adjustment of each channel's equalizer coefficients.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single-channel equalizer is used to process interleaved ADC channels, then the device complexity is reduced, but the ability to compensate for channel-dependent impairments deteriorates
Solution Approach 1:
The equalizer is segmented into multiple independent equalization filters, one for each interleaved ADC channel. Each filter processes its respective channel independently with channel-specific coefficients, allowing targeted compensation for channel-dependent impairments while maintaining manageable complexity through modular architecture
Solution Approach 2:
Each equalization filter is configured with locally optimized coefficients tailored to the specific characteristics of its corresponding ADC channel. This local quality approach enables precise compensation for channel-specific frequency response variations and impairments rather than applying a uniform equalization approach across all channels
2Reliability
If multi-channel equalization is implemented to address channel-dependent impairments, then the impairment compensation improves, but the device complexity increases
Solution Approach 1:
The overall equalization function is divided into multiple independent segments (one per channel), each with its own filter structure. This segmentation allows the system to achieve comprehensive impairment compensation across all channels while keeping each individual filter's complexity manageable and suitable for implementation
Solution Approach 2:
The equalization approach transitions from a single-channel dimension to a multi-channel dimension, adding the channel index as an additional dimension. This dimensional expansion enables independent optimization for each channel while maintaining a systematic and structured implementation framework
3Ease of operation
If traditional equalization treating ADC as black box is used, then the ease of operation is maintained, but the measurement precision of channel characteristics deteriorates
Solution Approach 1:
The equalization system applies locally optimized coefficients to each channel based on measured channel characteristics. This approach maintains ease of operation through automated coefficient calculation while achieving high measurement precision by accounting for channel-specific variations in frequency response and impairments
Data Source
Figure 1
Figure 2~3
Figure 4~6
AI summary
A system includes a time-interleaved device. An equalizer effectively can apply different equalization to different interleaved channels. For convenience, these equalizers will be referred to as multi-channel equalizers. In one aspect, an apparatus includes an interleaved device having M interleaved channels, and a multi-channel equalizer coupled to the interleaved device. The multi-channel equalizer is capable of applying a different equalization to different interleaved channels, thus compensating for channel-dependent impairments.