Coarse Phase Estimation for ISI-Tolerant Spectral Efficiency
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Solution Overview
Problem
Existing communications methods and systems are overly power hungry and spectrally inefficient, failing to effectively handle non-linearity and inter-symbol interference (ISI) in communication channels.
Innovation Solution
A system for low-complexity, highly-spectrally-efficient communications is implemented, utilizing a partial response pulse shaping filter and decision feedback equalization with coarse phase estimation, which includes a mapper, pulse shaping filter, timing pilot insertion, transmitter and receiver front-ends, equalization and sequence estimation circuit, and de-mapping, to optimize symbol constellation and tolerate non-linearity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conventional communications methods are used, then system implementation is straightforward, but spectral efficiency is poor and power consumption is high
Solution Approach 1:
The patent changes the fundamental parameters of communication signaling by using partial response pulse shaping that intentionally introduces controlled ISI, and employs coarse phase estimation algorithms that operate effectively in the presence of non-linearity. These parameter changes enable higher spectral efficiency while reducing power consumption by avoiding complex compensation mechanisms.
Solution Approach 2:
The system dynamically adapts to channel conditions by using decision feedback equalization that continuously adjusts to compensate for ISI and non-linear distortions. The coarse phase estimation algorithm dynamically tracks phase rotations without requiring complex feedback loops, enabling efficient operation in varying channel conditions.
2Reliability
If conventional equalization methods are used, then implementation is simple, but performance degrades in presence of non-linearity and ISI
Solution Approach 1:
The patent converts the harmful effects of non-linearity and ISI into beneficial features by designing a detection scheme that explicitly exploits these effects. The coarse phase estimation algorithm uses the deterministic nature of ISI to improve phase tracking, and the decision feedback equalizer uses detected symbols to predict and remove ISI, transforming what were previously performance-degrading factors into mechanisms that enhance reliability.
Solution Approach 2:
The patent introduces an intermediary coarse phase estimation stage that operates between the received signal and the final detection process. This intermediary algorithm compensates for phase rotations caused by non-linearity and ISI before the main detection occurs, simplifying the overall system while improving reliability in distorted channel conditions.
3Productivity
If high spectral efficiency is achieved through advanced modulation, then bandwidth utilization improves, but tolerance to channel distortions decreases
Solution Approach 1:
The patent applies preliminary action by performing coarse phase estimation and equalization before final symbol detection. The system pre-compensates for phase rotations and ISI effects using decision feedback from previously detected symbols, enabling high-order modulation schemes to maintain tolerance to channel distortions while achieving high spectral efficiency.
Data Source
AI summary
Methods and systems are provided for coarse phase estimation for highly-spectrally efficient communications. An example method may include, equalizing, in a receiver, a received inter-symbol correlated (ISC) signal to generate an equalized ISC signal. A phase adjustment signal may be generated based on an ISC feedback signal. The ISC feedback signal may be generated using a sequence estimation process and a non-linearity function. A phase of the equalized ISC signal may be adjusted using the generated phase adjustment signal, to generate a phase adjusted partial response signal. The phase adjustment signal may be generated based on a phase difference between the equalized ISC signal and the partial response feedback signal. At least one ISC vector may be generated by buffering samples of the phase adjusted ISC signal.