WLAN Channel Estimation Using CDD Phase Compensation
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Solution Overview
Problem
Current channel estimation methods in wireless local area networks (WLANs) employing cyclic delay diversity (CDD) transmission schemes face challenges in accurately combining channel information from non-high throughput (HT) and very high throughput (VHT) long training fields, leading to reduced reliability in wireless channel estimation.
Innovation Solution
A channel estimation apparatus and method that combines channel estimation information based on the difference between CDD values of non-HT and VHT fields, using a phase applier to generate and apply phase values, and a final channel estimation value calculator to calculate a final channel estimation value, thereby enhancing channel estimation reliability by reflecting subcarrier and index information.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If channel information from non-HT and VHT fields is combined using conventional methods, then the quantity of channel estimation information is increased, but the reliability of channel estimation deteriorates due to inaccurate combination
Solution Approach 1:
The patent changes the combination method by introducing phase values derived from CDD value differences. Specifically, phase values are calculated based on the difference between CDD values of non-HT and VHT fields, and these phase values are applied to align the channel estimation information before combination. This parameter transformation enables accurate merging of channel information from different fields while maintaining reliability.
2Device complexity
If channel information is combined without phase compensation, then the device complexity is reduced, but the measurement precision of channel estimation deteriorates
Solution Approach 1:
The patent applies preliminary phase compensation before combining channel estimation information. Phase values are pre-calculated based on CDD value differences, and this preliminary adjustment ensures that subsequent combination operations yield precise results. This preliminary action approach maintains relatively simple device structure while achieving high measurement precision.
Data Source
AI summary
A method and apparatus for estimating a channel in a wireless local area network (WLAN) are provided. A channel estimation apparatus may include a channel estimation information combiner to combine at least one channel estimation information based on a difference between cyclic delay diversity (CDD) values, and a phase applier to generate a first phase value and to apply the first phase value to the combined channel estimation information.