Prosecution Insights
Last updated: April 19, 2026
Application No. 17/972,965

SYSTEM AND METHODS FOR CLOSED LOOP DOPPLER TRACKING IN INTER-SATELLITE LINKS

Non-Final OA §101§103§112
Filed
Oct 25, 2022
Examiner
KELLER, MICHAEL A
Art Unit
2446
Tech Center
2400 — Computer Networks
Assignee
Altera Corporation
OA Round
1 (Non-Final)
86%
Grant Probability
Favorable
1-2
OA Rounds
2y 6m
To Grant
99%
With Interview

Examiner Intelligence

Grants 86% — above average
86%
Career Allow Rate
588 granted / 682 resolved
+28.2% vs TC avg
Strong +17% interview lift
Without
With
+16.8%
Interview Lift
resolved cases with interview
Typical timeline
2y 6m
Avg Prosecution
26 currently pending
Career history
708
Total Applications
across all art units

Statute-Specific Performance

§101
10.5%
-29.5% vs TC avg
§103
56.9%
+16.9% vs TC avg
§102
10.9%
-29.1% vs TC avg
§112
8.6%
-31.4% vs TC avg
Black line = Tech Center average estimate • Based on career data from 682 resolved cases

Office Action

§101 §103 §112
DETAILED ACTION The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA . This action is in response to the communication filed on 10/25/2022. Claims 1-25 are pending in this application. Examiner Note The examiner is here to serve, to assist, and to help applicant to the very best of his ability. The Primary Patent Examiner position is a position of serving and it is an honor to externally serve the applicant and attorney and to internally serve junior examiners and supervisors. The goal of the examiner is to work with and assist applicant to move cases along as efficiently as possible. Applicant is encouraged to call examiner to schedule an interview if applicant has any questions about this action, wants to discuss any possible paths forward, has proposed amendments to the claims to run by the examiner, or for any other issues that applicant would like to discuss. Examiner can normally be reached at (571) 270-3863 or michael.keller@uspto.gov, Monday-Friday, from about 6 AM - 10 PM EST and if your call is missed examiner will try to return call quickly, thank you. Priority This application is effectively filed 10/25/2022. The assignee of record is Altera Corporation. The listed inventor(s) is/are: Krishnamurthy, Sundar; O'Keeffe, Conor; Dasalukunte, Deepak; O'Regan, Finbarr; Vinod, Abhinav. Information Disclosure Statement The information disclosure statement(s) (IDS) submitted on 2/14/2023 is/are in compliance with the provisions of 37 CFR 1.97. Accordingly, the IDS(s) is/are being considered by the examiner. Allowable Subject Matter Claims 2-15, 17-21, 23-25 objected to as being dependent upon a rejected base claim, but would be allowable if rewritten in independent form including all of the limitations of the base claim and any intervening claims provided that all other rejections under 35 USC 101/112 (if any) are obviated upon upcoming amendments/arguments without raising new issues that necessitate further consideration/search. Claim Rejections - 35 USC § 101 35 U.S.C. 101 reads as follows: Whoever invents or discovers any new and useful process, machine, manufacture, or composition of matter, or any new and useful improvement thereof, may obtain a patent therefor, subject to the conditions and requirements of this title. Claims 22-25 are rejected under 35 U.S.C. 101 because the claimed invention is directed to non-statutory subject matter. The claims recite “A computer-readable medium comprising instructions that, when executed on processing circuitry, cause the processing circuitry to execute operations…” The claims fail to place the invention squarely within one statutory class of invention. Based on the broadest reasonable interpretation of the term “computer-readable medium …” the term is not limited to non-transitory computer readable storage media, and may include transitory media. The transitory media generally stores/encodes/transmits data/information in form of signals. As such, the claim is drawn to a signal per se. Signal per se does not appear to be a process, machine, manufacture or composition of matter. [Claims that recite nothing but the physical characteristics of a form of energy, such as frequency, voltage or the strength of a magnetic field, define energy or magnetism, per se, and as such are nonstatutory natural phenomena. O'Reilly, 56 U. S. (15 How.) at 112-14. See also In re Nuijten. Docket no. 2006-1371 (Fed. Cir. Sept. 20, 2007)(slip. Op. at 18): "A propagating signal is not a process, machine, manufacture or composition of matter"] Wording such as non-transitory computer-readable medium would overcome the rejection. Claim Rejections - 35 USC § 112 The following is a quotation of 35 U.S.C. 112(b): (b) CONCLUSION.—The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the inventor or a joint inventor regards as the invention. The following is a quotation of 35 U.S.C. 112 (pre-AIA ), second paragraph: The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the applicant regards as his invention. Claim 15 rejected under 35 U.S.C. 112(b) or 35 U.S.C. 112 (pre-AIA ), second paragraph, as being indefinite for failing to particularly point out and distinctly claim the subject matter which the inventor or a joint inventor (or for applications subject to pre-AIA 35 U.S.C. 112, the applicant), regards as the invention. Claim 15 recites: 15. The apparatus of claims 14, wherein the processing circuitry is configured to: switch between a primary and an auxiliary laser when the satellites have moved past one another based on a transceiver measurement of a Doppler sign flip; and operate using a primary laser in one hemisphere when orbiting around the earth and using an auxiliary laser when orbiting in another hemisphere. It is unclear if the hemisphere (used twice) is referring to a dynamic “orbital hemisphere” that aligns with seasonal states OR an earth hemisphere which is static and based on geographic divisions. There is a significant positional difference between earth and orbital hemisphere, and therefore the examiner is providing a 112 rejection rather than a claim objection. After reviewing the applicant’s specification the examiner was unable to determine if applicant had provided further clarification. Examiner notes that a clarifying argument or explanation may be one possible way to overcome the current rejection, thank you. Claim Rejections - 35 USC § 103 In the event the determination of the status of the application as subject to AIA 35 U.S.C. 102 and 103 (or as subject to pre-AIA 35 U.S.C. 102 and 103) is incorrect, any correction of the statutory basis (i.e., changing from AIA to pre-AIA ) for the rejection will not be considered a new ground of rejection if the prior art relied upon, and the rationale supporting the rejection, would be the same under either status. The following is a quotation of 35 U.S.C. 103 which forms the basis for all obviousness rejections set forth in this Office action: A patent for a claimed invention may not be obtained, notwithstanding that the claimed invention is not identically disclosed as set forth in section 102, if the differences between the claimed invention and the prior art are such that the claimed invention as a whole would have been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art to which the claimed invention pertains. Patentability shall not be negated by the manner in which the invention was made. The factual inquiries for establishing a background for determining obviousness under 35 U.S.C. 103 are summarized as follows: 1. Determining the scope and contents of the prior art. 2. Ascertaining the differences between the prior art and the claims at issue. 3. Resolving the level of ordinary skill in the pertinent art. 4. Considering objective evidence present in the application indicating obviousness or nonobviousness. This application currently names joint inventors. In considering patentability of the claims the examiner presumes that the subject matter of the various claims was commonly owned as of the effective filing date of the claimed invention(s) absent any evidence to the contrary. Applicant is advised of the obligation under 37 CFR 1.56 to point out the inventor and effective filing dates of each claim that was not commonly owned as of the effective filing date of the later invention in order for the examiner to consider the applicability of 35 U.S.C. 102(b)(2)(C) for any potential 35 U.S.C. 102(a)(2) prior art against the later invention. Claim(s) 1, 16, & 22 is/are rejected under 35 U.S.C. 103 as being unpatentable over Frankel et al. (US 12323199 B2, filed 9/26/2022; hereinafter Fra) in view of Gurumani et al. (US 20160187489 A1, published 6/30/2016; hereinafter Gur). For Claim(s) 1, the claim(s) is/are substantially similar to claim 16 and therefore is/are rejected for the same reasoning set forth below. For Claim 16, Fra teaches a satellite system comprising: transceiver circuitry configured to receive an input signal from a target satellite (Fra Claim 1 A coherent transceiver for use in a first satellite comprising: a transmitter including a modulator configured to modulate a light transmitted by laser; a receiver including a Local Oscillator (LO) laser configured to provide a down conversion signal for received signal; and circuitry configured to tune a frequency of the transmitter laser and the LO laser based on an amount of Doppler frequency shift to be compensated, wherein only the LO laser is tuned responsive to a maximum Doppler frequency shift not exceeding a maximum frequency tuning range of the LO laser); and a processing circuitry configured to: determine position information of the satellite system and the target satellite (Fra Cols 18-19. Please see screenshot of Fra Figs. 30A-30C below, thank you: PNG media_image1.png 886 624 media_image1.png Greyscale ); based on the position information, calculate a relative velocity and determine a Doppler shift or carrier frequency offset in the input signal based on the relative velocity (Fra Col 15 Lns 33-34 Doppler shift is equal to the relative velocity divided by wavelength (λ). Please see screenshot of Fra Fig. 24 below, thank you: PNG media_image2.png 866 762 media_image2.png Greyscale ); adjust a local oscillator frequency based on a Doppler measured using the position information in an initial link acquisition phase (Fra Col 19 Ln 59 – Col 20 Ln 7 Responsive to the first and second satellite approaching each other, the steps further include setting a transmitter laser frequency to a near lowest edge of a fine-tuning range for both satellites, determining an LO laser setting, and tuning the transmitter laser and LO laser to maximize future tuning range. Responsive to the first and second satellite moving away from each other, the steps further include setting a transmitter laser frequency to a near highest edge of a fine-tuning range for both satellites, determining an LO laser setting, and tuning the transmitter laser and LO laser to maximize future tuning range. Only the LO laser is tuned responsive to a maximum Doppler shift not exceeding a maximum frequency tuning range of the LO laser.); and track the Doppler continuously over a range of tens of gigahertz… (Fra Col 13 Ln 57-65 Coherent optical communications between LEO satellites are subject to Doppler shift of laser wavelength (or frequency). This phenomenon is exhibited most prominently when communicating satellites are propagating in counter-rotating circular orbits with small angles between their orbit planes. In this scenario satellites are first approaching and then moving apart from each other at almost double the first cosmic velocity (orbital velocity), resulting in up to ±10 GHz Doppler frequency shift at 1550 nm.) and correct for a tracked Doppler shift by partially adjusting a local oscillator frequency and by correcting a residual Doppler shift digitally (Fra Col 19 Lns 12-16 Doppler down-shifted TX laser line is shown as dashed arrow, positioned next to the LO laser line within the residual laser tuning uncertainty. This residual laser de-tuning being successfully compensated by receiver-side DSP). Fra does not explicitly teach track the Doppler continuously accounting for Doppler phase ambiguities. However, Gur teaches track the Doppler continuously accounting for Doppler phase ambiguities (Gur ¶ 0015-0017, 0024-0025 tracking doppler frequency over time and correcting ambiguities through phase modulator filtering. Please see Gur Claims 1, 7-10 below, thank you: 1. A telecommunications system comprising: a satellite receiver programmed to estimate a Doppler frequency associated with a satellite signal, wherein estimating the Doppler frequency includes sampling the satellite signal, sampling the sampled satellite signal, and compensating for a frequency offset associated with the satellite signal. 7. The telecommunications system of claim 1, wherein the satellite receiver includes an incremental phase modulator programmed to filter the resampled satellite signal to compensate for the frequency offset and output a filtered satellite signal. 8. The telecommunications system of claim 7, wherein the incremental phase modulator includes at least one of a numerically controlled oscillator and a complex multiplier. 9. The telecommunications system of claim 7, wherein the satellite receiver includes a controller programmed to receive and process the filtered satellite signal. 10. The telecommunications system of claim 9, wherein the controller is programmed to estimate the Doppler frequency associated with the satellite signal based at least in part on the filtered satellite signal output by the incremental phase modulator. Please see Gur screenshot of Fig. 3 below, thank you: PNG media_image3.png 908 374 media_image3.png Greyscale ). Gur and Fra are analogous art because they are both related to inter-satellite signaling. Before the effective filing date of the claimed invention it would have been obvious to one of ordinary skill in the art to use the phase modulator of Gur with the system of Fra to filter a frequency offset from the resampled satellite signal (Gur ¶ 0006). For Claim(s) 22, the claim(s) is/are substantially similar to claim 16 and therefore is/are rejected for the same reasoning set forth above. Citation of Pertinent Prior Art The prior art made of record and not relied upon is considered pertinent to applicant's disclosure is listed below, thank you: i. US 12003350 B1, Configurable Orthogonal Frequency Division Multiplexing (OFDM) Signal And Transmitter And Receiver For User Terminal To Satellite Uplink Communications Please see PTO-892 for additional listing of relevant prior art made of record but not relied upon, thank you. Conclusion Any inquiry concerning communications from the examiner should be directed to Michael Keller at (571)270-3863 or michael.keller@uspto.gov. If attempts to reach the examiner are unsuccessful, the examiner’s supervisor, Brian Gillis can be reached on 571-272-7952. Information regarding the status of published or unpublished applications may be obtained from Patent Center. Unpublished application information in Patent Center is available to registered users. To file and manage patent submissions in Patent Center, visit: https://patentcenter.uspto.gov. Visit https://www.uspto.gov/patents/apply/patent-center for more information about Patent Center and https://www.uspto.gov/patents/docx for information about filing in DOCX format. For additional questions, contact the Electronic Business Center (EBC) at 866-217-9197 (toll-free). If you would like assistance from a USPTO Customer Service Representative, call 800-786-9199 (IN USA OR CANADA) or 571-272-1000. /MICHAEL A KELLER/ Primary Patent Examiner, Art Unit 2446
Read full office action

Prosecution Timeline

Oct 25, 2022
Application Filed
Jun 14, 2023
Response after Non-Final Action
Mar 07, 2024
Response after Non-Final Action
Dec 14, 2025
Non-Final Rejection — §101, §103, §112 (current)

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Study what changed to get past this examiner. Based on 5 most recent grants.

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Prosecution Projections

1-2
Expected OA Rounds
86%
Grant Probability
99%
With Interview (+16.8%)
2y 6m
Median Time to Grant
Low
PTA Risk
Based on 682 resolved cases by this examiner. Grant probability derived from career allow rate.

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