Generalized Maximum Delay Estimation for Enhanced Channel Estimation in IEEE 802.11p/OFDM Systems

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

The article presents a generalized statistical framework for estimating the maximum access delay (Lmax) in OFDM-based vehicular communication systems. The authors reformulate the conventional Lmax estimation problem into a likelihood-based approach by leveraging the statistical properties of CP-based energy difference metrics. A weighted likelihood function is introduced, allowing for flexibility in assigning significance to different CP samples through a parameterized weighting function. Furthermore, the authors propose using a geometric mean of the likelihoods to improve robustness and estimation accuracy, particularly in scenarios with limited reliable samples. Extensive simulations under IEEE 802.11p and highway mobility conditions demonstrate the effectiveness of the proposed method over conventional estimators.

Several issues require attention:

1. A deeper theoretical analysis or guideline on how to select or adapt g(l) under different channel models (e.g., urban vs. highway, long vs. short delay spreads) would strengthen the method’s applicability.
2. Although the geometric mean improves robustness, a more formal statistical explanation (e.g., in terms of bias-variance trade-off or concentration bounds) would help justify its use beyond empirical observation.
3. A table or brief section quantifying the computational cost of the proposed method (especially LLR evaluation and geometric mean computation) relative to baseline methods would be valuable.

Author Response

We sincerely thank the reviewer for their valuable comments and insightful suggestions, which have helped us to improve the clarity and depth of our manuscript. 
Below, we provide detailed responses to each point raised.

Please see the attachment. 

Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

The manuscript roposes a generalized maximum access delay time (MADT) estimation  method for orthogonal frequency division multiplexing (OFDM) systems operating over multipath fading channels.

The lack of any experimental evidence makes this manuscript of low interest for the readers of Electronics.

Author Response

We sincerely thank the reviewer for their time and constructive feedback.

Please see the attachment. 

Author Response File: Author Response.pdf

Reviewer 3 Report

Comments and Suggestions for Authors

Please see the comments in the attached file.

Comments for author File: Comments.pdf

Author Response

We would like to express our sincere gratitude to the reviewer for the encouraging and constructive feedback. 
We are pleased that the reviewer found the paper to be well-organized, relevant, and clearly written. 
Below, we provide point-by-point responses to all comments and indicate the corresponding revisions made to the manuscript.

Please see the attachment. 

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

Comments and Suggestions for Authors

The authors have addressed all of my comments. I have no further comments.

Reviewer 2 Report

Comments and Suggestions for Authors

Accept