Area-Efficient Universal Code Generator for Multi-GNSS Receivers

Round 1

Reviewer 1 Report

This work presents an LFSR-based universal code generator that can reduce complexity for multi-constellation and multi frequency GNSS receivers. This is a timely research as multi-GNSS is now a trend for GNSS receivers. Experimental results verify the efficiency of the propose code generator. In my opinion, this work is acceptable for publication in Electronics as long as the authors address the following concerns.

• Title

I would suggest the title be revised to “Area-Efficient Universal Code Generator for Multi-GNSS receivers”. Authors talk about code generator. It is true different frequency signals use different PRN codes. However, for FDMA signals in GLONSS, different satellites share the same code. So “multi-frequency GNSS” is not exactly consistent with the authors’ work. In this regard, authors should also modify some descriptions like Line 39-40.

• Abbreviations

Please list the abbreviations and their full names. Sometimes, abbreviations are not defined, e.g., LFSR, ROM, etc. in Abstract.

• Experiments

Authors show the reduction in terms of hardware complexity. However, they didn’t show if the codes generated by their approach are correct or not. They may consider showing acquisition or tracking results to prove this.

• Typos

I found some typos such as Line 36, where L5 frequency is not 117.45MHz.

 

 

Author Response

This work presents an LFSR-based universal code generator that can reduce complexity for multi-constellation and multi frequency GNSS receivers. This is a timely research as multi-GNSS is now a trend for GNSS receivers. Experimental results verify the efficiency of the propose code generator. In my opinion, this work is acceptable for publication in Electronics as long as the authors address the following concerns.

 

Answer:

We sincerely appreciate your positive evaluation and valuable comments. According to reviewer’s comments, we revised the manuscript to address the reviewer’s concerns.

 

- Title

I would suggest the title be revised to “Area-Efficient Universal Code Generator for Multi-GNSS receivers”. Authors talk about code generator. It is true different frequency signals use different PRN codes. However, for FDMA signals in GLONSS, different satellites share the same code. So “multi-frequency GNSS” is not exactly consistent with the authors’ work. In this regard, authors should also modify some descriptions like Line 39-40.

 

Answer:

According to your request, the tile is revised from “Area-Efficient Universal Code Generator for Multi-Frequency Receivers” to “Area-Efficient Universal Code Generator for Multi-GNSS Receivers.” As you pointed out that most GNSS satellites including GPS, BDS, Galilieo employ CDMA, but some GNSS satellites of GLONASS use FDMA. In the revised manuscript, we have addressed this point and some sentences are newly added.

- Abbreviations

Please list the abbreviations and their full names. Sometimes, abbreviations are not defined, e.g., LFSR, ROM, etc. in Abstract.

 

Answer:

The manuscript is thoroughly checked, and all abbreviations including those in Abstract are newly defined.

 

- Experiments

Authors show the reduction in terms of hardware complexity. However, they didn’t show if the codes generated by their approach are correct or not. They may consider showing acquisition or tracking results to prove this.

 

Answer:

As you pointed out, the original manuscript shows only the comparison of hardware complexity for different universal code generators, and it is important to verify that the generated codes can be used for acquisition and tracking in a GNSS receiver. In fact, we checked whether the code generated from developed hardware and the code provided from official ICD are the same or not, and we concluded that the generated code can be used for acquisition and tracking in case that the both codes are the same. In the revised manuscript, we newly added this point that all codes generated from conventional, previous, and proposed are the same as the code provided from official ICD, and it implies that all the codes can be used for acquisition and tracking in a GNSS receiver.

 

- Typos

I found some typos such as Line 36, where L5 frequency is not 117.45MHz.

 

Answer:

The manuscript is thoroughly checked, and all typos including one on line 36 are corrected.

 

Author Response File: Author Response.docx

Reviewer 2 Report

The papetr vconcerns a very hot topic of designing multifrequency receiver for GNSS system. The main topic is reference code generation in the receiver, crucial for efficiency of receiver operation. The paper provides good explanation of the method of code generation for various GNSS frequencies. The Authors provide own hardware approach to challenging this task. The reasearch part is sound, and results may be interesting for GNSS community.

Author Response

The paper concerns a very hot topic of designing multi frequency receiver for GNSS system. The main topic is reference code generation in the receiver, crucial for efficiency of receiver operation. The paper provides good explanation of the method of code generation for various GNSS frequencies. The Authors provide own hardware approach to challenging this task. The research part is sound, and results may be interesting for GNSS community.

 

Answer:

We sincerely appreciate your positive evaluation and valuable comments.

Author Response File: Author Response.docx