An Improved Hybrid Beamforming Algorithm for Fast Target Tracking in Satellite and V2X Communication

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

Dear Authors,

I find your article very interesting because it deals with a problem that is, one might say, multidisciplinary. According to the title, the main problem is to develop an algorithm for fast beam targeting. The problem is interesting, topical and important.

 

In my opinion:

- The abstract is good and does not need modification,

- the introduction is correct although the contribution of the content of the article could be emphasized more,

- the mathematical relationships presented are clear, however, some lack explanations of the quantities used,

- I have no comments on the drawings, they are of adequate quality and are legible,

- worthy of emphasis is the comparison of the proposed algorithm with other solutions.

 

As for the issues that, in my eyes, need modification are:

- the algorithm on page 6 should be presented in a more accessible way, the description of the individual steps is missing here,

- in the summary it would be useful to use the full names of the methods and not just acronyms.

 

I have no further comments.

I believe that with minor corrections the article is suitable for publication.

Author Response

Thank you very much for your valuable feedback. Please note that we have responded to your comments below and corrections to your comments are in green color in the paper.

Author Response File: Author Response.docx

Reviewer 2 Report

Comments and Suggestions for Authors

1- abstract must be written again in a more effective way, containing the method followed and the results, not just a brief explanation of the topic.

2- When a variable occurs for the first time in an equation it should be described or defined, please kindly Take this into consideration

3- Some problems with formatting are also present for example " line 103 Equ (3), line 152 Equ (23)  

4- Please, be careful with notations. For instance, you interchange y and y^ several times through out the text

5- The fourth part should be included under the heading "Results and Discussions", and more space should be devoted to discussion of results and measurements

6-  Since some type of iterative algorithm is used (conjugate gradients), it must be thoroughly studied. It is not enough merely to state that “first fifteen iterations” is enough. This is not the way such methods are analyzed. Please, expand that part including convergence analysis

7- How do you measure the “Receive power gain”? What is this figure for? It seems to be misleading

 

Author Response

Thank you very much for your valuable feedback. Please note that we have responded to your comments below and corrections in accordance with your comments are in green color in the paper.

Author Response File: Author Response.docx

Reviewer 3 Report

Comments and Suggestions for Authors

The abstract does not contain the contribution clearly. The Abstract must have the following logic sections: Purpose, Design/methodology/approach, Findings, Practical implications, and Originality/value.

The paper requires a higher state of the art than similar works, both for satellites and vehicular communications. For example, the following recent reference proposes equally flexible satellite beamforming algorithms.

[Ref] J. A. Vásquez-Peralvo et al., "Flexible Beamforming for Direct Radiating Arrays in Satellite Communications," in IEEE Access, vol. 11, pp. 79684-79696, 2023, doi: 10.1109/ACCESS.2023.3300039.

Up to 4 users are presented in the results. Can this be increased? How would it affect the complexity since this number of users is very low for a communications system?

What future lines remain for this method?

The authors highlight the advantages or improvements, but what drawback does this proposed algorithm or method present?

How do they take Doppler into account in the case of satellites?

Author Response

Thank you very much for your valuable feedback. Please note that we have responded to your comments below and corrections to your comments are in green color in the paper.

Author Response File: Author Response.docx

Round 2

Reviewer 2 Report

Comments and Suggestions for Authors

The paper is good and is considered acceptable in its current form

Reviewer 3 Report

Comments and Suggestions for Authors

The authors have not directed my comments correctly.

 

The authors have not justified their decisions and comments in the paper.

 

There needs to be more consistency between the system model and the scenarios they present. There are failures to consider satellite communications and 5G simultaneously, although it is not 5G but vehicular communications. This isn't very clear. The parameters chosen for the simulation are trivial values and straightforward modulation schemes that do not reflect the reality of the communication systems they use.

 

The work has deficiencies from the signal processing point of view to resolve.