Time-Interleaved ADC Dispersion Compensation With Lower Power
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Solution Overview
Problem
In ultrahigh-speed optical communication, the circuit scale and electric consumption of A/D converter apparatuses increase due to the need for high-speed sampling and error correction, leading to signal quality deterioration and significant power consumption.
Innovation Solution
A time-interleaved A/D converter apparatus with a primary signal A/D converter circuit group operating at 1/N of the Baud rate, combined with a correction signal generation part and digital signal processing to extract and compensate for dispersion, reducing the circuit scale and electric consumption without compromising signal quality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If high-speed sampling is implemented using time-interleaved A/D converter circuits, then sampling rate is improved, but circuit scale and electric consumption increase
Solution Approach 1:
The A/D conversion function is segmented into multiple parallel channels, each operating at a lower sampling rate (1/N of the target rate). These channels are then time-interleaved to achieve the overall high sampling rate, reducing the burden on each individual circuit component
Solution Approach 2:
A dispersion compensation control signal is introduced as an intermediary element to correct waveform distortion in the time-interleaved signal. This signal compensates for the effects of dispersion without requiring each A/D converter to operate at the full high speed, thereby reducing circuit complexity
2Speed
If high-speed sampling is implemented using time-interleaved A/D converter circuits, then sampling rate is improved, but electric consumption increases
Solution Approach 1:
The total sampling task is divided into N parallel channels, each operating at 1/N of the target sampling rate. This segmentation reduces the power consumption of each individual A/D converter circuit while maintaining the overall high sampling rate through time-interleaving
Solution Approach 2:
The sampling rate parameter of each individual A/D converter is changed from the target high rate to a lower rate (1/N of target), reducing power consumption. The system compensates for this by using time-interleaving and dispersion compensation to achieve the desired overall performance
3Device complexity
If sampling rate is reduced to decrease circuit scale, then circuit scale is reduced, but signal quality deteriorates due to waveform distortion from dispersion
Solution Approach 1:
A dispersion compensation control signal is used as an intermediary to correct waveform distortion caused by dispersion. This signal is generated based on the time-interleaved A/D converter output and is used to compensate for signal quality degradation without requiring high-speed operation of individual converters
Solution Approach 2:
The system uses feedback through the dispersion compensation control signal to detect and correct waveform distortion. The control signal is generated based on the output of the time-interleaved A/D converter and is fed back to compensate for dispersion effects, maintaining signal quality even at reduced sampling rates
4Measurement precision
If dispersion compensation is performed with high precision signal processing, then signal quality is improved, but sampling rate must be increased to 2x oversampling
Solution Approach 1:
The high-speed sampling requirement is segmented into N parallel channels operating at lower rates. This allows dispersion compensation to be performed on each channel at a manageable sampling rate while achieving the equivalent of high-speed sampling through time-interleaving
Solution Approach 2:
The system dynamically combines the outputs of N parallel A/D converters operating at different time slots. This dynamic time-interleaved combination allows the system to achieve high effective sampling rate for dispersion compensation without requiring each individual converter to operate at the full high speed
Data Source
AI summary
A time-interleaved A/D converter apparatus has a primary signal A/D converter circuit group that is time-interleaved with a combination of N A/D converter circuits, a correction signal generation part operable to receive the input analog signal and a 1/m-sampling signal having a speed that is 1/m of a rate of the sampling signal inputted to the primary signal A/D converter circuit group, to extract a dispersion of a transmission line that is immanent in the input analog signal, and to output the dispersion as a dispersion compensation control signal used for digital signal compensation, and a signal processing part operable to convert the N digital signals into one digital signal based upon the dispersion compensation control signal and to compensate a dispersion included in the converted digital signal.