Predictive Channel Estimation for Low-Latency Pre-DMRS Uplink Reception
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Solution Overview
Problem
The existing uplink receive processing in wireless communication systems, such as 5G NR, introduces latency due to the delay in starting processing for pre-DMRS data symbols until after receiving DMRS reference symbols, which can exceed 25% of the overall slot duration.
Innovation Solution
Implementing predictive channel estimation to determine predicted data for early data symbols, such as pre-DMRS symbols, based on initial baseband IQ data, allowing early processing to commence, followed by adaptation using actual data from subsequent DMRS symbols.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If uplink receive processing waits for complete DMRS data before processing pre-DMRS data symbols, then channel estimation accuracy is improved, but processing latency increases significantly
Solution Approach 1:
The patent performs preliminary channel estimation for pre-DMRS data symbols using predicted channel responses before the actual DMRS data is received. This preliminary action enables early processing of data symbols while maintaining the option to refine estimates later when actual DMRS data becomes available, thus reducing latency without completely sacrificing accuracy.
Solution Approach 2:
The channel estimation process is segmented into two stages: an initial stage using predicted channel responses for early processing, and a refinement stage using actual DMRS data. This segmentation allows different parts of the processing pipeline to operate at different times, enabling early data processing while preserving accuracy through subsequent refinement.
2Loss of time
If uplink receive processing starts early for pre-DMRS data symbols, then processing latency is reduced, but processing accuracy deteriorates due to incomplete DMRS data
Solution Approach 1:
The patent implements a feedback mechanism where the preliminary channel estimates obtained using predicted responses are refined when actual DMRS data becomes available. The system compares predicted versus actual channel responses and uses this feedback to correct and improve the initial estimates, thereby maintaining accuracy despite early processing.
Solution Approach 2:
The channel estimation approach is made dynamic by allowing the system to switch between using predicted channel responses for early processing and actual DMRS data for refinement. This dynamic adaptation enables the system to optimize for speed when time is critical and for accuracy when time permits, making the processing pipeline flexible and adaptable to different timing requirements.
Data Source
AI summary
One embodiment is directed to adaptive predictive uplink receive chain processing that involves determining predicted data for one or more early data symbols of a slot based on first baseband IQ data received for the slot. The predicted data for the early data symbols of the slot comprises a predicted version of data used at some point in performing a first portion of uplink receive processing for the early data symbols. The first portion of the uplink receive processing for the early data symbols of the slot is performed using the predicted data. Actual data corresponding to the predicted data is determined based on at least second baseband IQ data received for the slot. In connection with performing a remaining portion of the uplink receive processing for the early data symbols, the preliminary output data for the early data symbols of the slot are adapted based on the actual data.