Prosecution Insights
Last updated: April 19, 2026
Application No. 18/361,380

Frequency-shift Symmetric Chirp Spread Spectrum Modulation and Demodulation Method for Interstellar Communication Links

Non-Final OA §103§112§DP
Filed
Jul 28, 2023
Examiner
JOHNSON, AMY COHEN
Art Unit
2400
Tech Center
2400 — Computer Networks
Assignee
ZHEJIANG UNIVERSITY
OA Round
1 (Non-Final)
57%
Grant Probability
Moderate
1-2
OA Rounds
2y 7m
To Grant
80%
With Interview

Examiner Intelligence

Grants 57% of resolved cases
57%
Career Allow Rate
284 granted / 499 resolved
-1.1% vs TC avg
Strong +23% interview lift
Without
With
+22.9%
Interview Lift
resolved cases with interview
Typical timeline
2y 7m
Avg Prosecution
342 currently pending
Career history
841
Total Applications
across all art units

Statute-Specific Performance

§101
3.9%
-36.1% vs TC avg
§103
55.7%
+15.7% vs TC avg
§102
21.4%
-18.6% vs TC avg
§112
10.9%
-29.1% vs TC avg
Black line = Tech Center average estimate • Based on career data from 499 resolved cases

Office Action

§103 §112 §DP
DETAILED ACTION Notice of Pre-AIA or AIA Status The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA . Claim interpretation – Formal Matters 1. A double patenting rejection is NOT put forth. 2. The examiner interprets that the claims are statutory under the requirements and guidelines as set forth in 35 USC 112 (except as found below). Written support is found and the claims particularly point out the inventive concept(s). 3. The examiner interprets that the claims are statutory under the requirements and guidelines as set forth in 35 USC 101 (ie. directed to one of the four patent-eligible subject matter categories, no abstract idea, above judicial bar). 4. Also note well-known technology used in the claims such as Gray Codes, Fast Fourier Transform, Bandwidth used (i.e. Shannon’s Law dictates the maximum amount of bandwidth that can be used for data transmission), etc.. Claim Objections Claim 1 is objected to because of the following informalities: Claim 1 does not end with a “period”. Claim 1 uses several phrases that are not spelled out when they are initially used. “SF” should be “spreading factor (SF)” “Nsync” should be “synchronization data (Nsync)”” “Npre” should be “preamble data (Npre)” “Ndata” should be “User data (Ndata)” Claim 1 uses the term “Gray”. It should be “Gray coding” or “Gray encoding”. Appropriate correction is required. 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 1 is 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. The claim uses the term “interstellar” communications which means communications “between stars”. Since humans haven’t sent a satellite to another star and communicated with it (from our star/sun), how can the applicant claim to perform this ability? Perhaps the claims, title and specification should be changed to “satellite communication” or “space-based communication” or “long range communication”, etc.? 2. The term “symmetric” is not defined in the claim. What is the applicant describing as being “symmetric”? Is it the modulation procedure, the actual data that is modulated, or something else? How does the applicant’s design “create” the symmetric data? These is no description of the procedure OR hardware that is creating the symmetric data in the claim(?) 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. Claim(s) 1 and 7 is/are rejected under 35 U.S.C. 103 as being unpatentable over Hanif et al. FSCSS with Index Modulation and further in view of Fu et al. US 2003/0026200 and Shearer III et al. US US 2010/0265927. As per claim 1, Hanif et al. FSCSS with Index Modulation teaches a frequency shift symmetric chirp spread spectrum modulation and demodulation method for interstellar communication links (Title, Abstract – Note that “symmetric can be “orthogonal signals” which are taught by Hanif), comprising; using high M bits of the information blocks as index codes of branches, where M=log2R (below teaches A = log2M formula and an example with M = 8); PNG media_image1.png 204 502 media_image1.png Greyscale PNG media_image2.png 714 524 media_image2.png Greyscale PNG media_image3.png 270 510 media_image3.png Greyscale the information blocks are encoded by Gray (Encoding) and then represented by decimal information, and a decimal information represented by the i-th information block is defined as di, where a value range of i is 1-R (Hanif teaches “encoding” such as DQPSK and/or QAM (below #1). He also teaches a “codebook” and “codewords” which also encod data (see below#2). Thusly, the use of an alternative encoding scheme (such as the well-known Gray code would be used by one skilled and thusly represent the data in “decimal” (binary coding) for the information blocks and can be defined as di for a value range of I is 1-R. NOTE: See US 2019/0174027, Para #86 (pertinent but not cited) who explicitly teaches spread spectrum using Gray encoding)) ; Passage #1 below: PNG media_image4.png 120 510 media_image4.png Greyscale Passage #2 below: PNG media_image5.png 306 498 media_image5.png Greyscale where Bw represents a transmission bandwidth of the original symmetric chirp signal (Hanif teaches transmitting the data in a wireless channel with finite bandwidth – See Figure 1 showing “CHANNEL” that provides/supports the bandwidth for the transmission of the data), and the frequency-shift symmetric chirp signal modulated by the i-th information block is called Si; (Subsequent FSS Chirp signals modulated over time by the information block can be represented as a number with subscript, e.g. Si) R information blocks corresponding to R frequency-shift symmetric chirp signals are linearly superimposed and transmitted through a channel (Figure 1 shows that the information blocks corresponding to FSS chirp signals are “linearly superimposed and transmitted” – the Transmitter side uses FSS chirp signals to modulate the data and sends it linearly to the Channel); performing, by a receiving end, desymmetric chirp, fast Fourier transform, frequency domain peak retrieval, Gray decoding, deindexing and information block splicing on the signal in sequence to restore the input information bits (Demodulation is the reverse process of the modulation process (as shown in Hanif’s Figure 1, and hence the modulation process above/previous will be performed in reverse to obtain the baseband signal transmitted from the transmitter. Hanif teaches Foutier Transform support below); PNG media_image6.png 54 588 media_image6.png Greyscale PNG media_image7.png 120 512 media_image7.png Greyscale wherein a frame structure used in the sending and receiving process comprises preamble, synchronization word and user data (It is well-known/inherently to use a framed structure to send data, i.e. TCP/IP Packets have a header that is interpreted as having a preamble, sychnronization data/words and user data contained in a single packet); the number of preamble is Npre, the number of synchronization word is Nsync, and the user data is Ndata (A framed structure such as a TCP/IP packet contains a preamble of finite length (e.g. Npre), a synchronization word of finite length (e.g. Nsynch and the user data of finite length); Npre and Nsync are determined by the transmitting and receiving ends, and Ndata is determined by the user data packet length (A TCP/IP packet’s header is based on the data that is being transmitted – header parameters such as LENGTH, TOS, Total Length, Source/Destination address, FLAGS, TTL, Protocol, Checksum, etc. can all be interpreted as providing Npre and Nsync information) But is silent on dividing, by a transmitting end, input information bits into R information blocks with a depth of SF according to a spreading factor SF and a branch number R, and the information block uses (di·Bw/2SF) as a relative frequency shift pair to perform frequency-shift chirp spread-spectrum modulation on an original symmetric chirp signal. Regarding “..dividing, by a transmitting end, input information bits into R information blocks with a depth of SF according to a spreading factor SF and a branch number R..”, at least Fu et al. US 2003/0026200 teaches (figure 2) serial-to-parallel conversion breaking “information bits” #201 into branches and adding spreading codes). It would have been obvious to one skilled in the art at the time of the invention’s filing date, to modify Hanif, such that dividing, by a transmitting end, input information bits into R information blocks with a depth of SF according to a spreading factor SF and a branch number R , to provide the ability to divide the information being transmitted using a spreading factor (known in spread spectrum). With regard to “…the information block uses (di·Bw/2SF) as a relative frequency shift pair to perform frequency-shift chirp spread-spectrum modulation on an original symmetric chirp signal …”, at least Shearer III et al. US 2010/0265927 teaches that relative frequency shifts between carriers can be performed over the Bandwidth thusly the individual data streams (information blocks) can use (di·Bw/2SF) as a frequency shifting pair (on the original signal), which reads on the limitation: [0034] Buffers 30 may also drive conventional digital processes (not shown) known to those skilled in the art, such as digital coding, digital modulation, direct sequence spread spectrum (DSSS) coding, and the like. Such coding and modulation activities may be carried out in accordance with digital rate control (DRC) codes provided to base station 20 from the access terminals for which the data streams are intended. Eventually, the individual data streams intended for the different carriers 32 are routed to frequency shift sections 38 to achieve the relative frequency spacing between carriers 32 depicted in FIG. 6, except that carriers 32 are still positioned at or near baseband. The individual data streams also pass through respective gain sections 40, where signal amplitudes are adjusted to determine the relative power levels at which carriers 32 will be transmitted. It would have been obvious to one skilled in the art at the time of the invention’s filing date, to modify the combo, such that the information block uses (di·Bw/2SF) as a relative frequency shift pair to perform frequency-shift chirp spread-spectrum modulation on an original symmetric chirp signal, to provide the ability for modulation on a signal. As per claim 7, the combo teaches claim 1, wherein during the demodulation process, the receiving end multiplies the received signal by a symmetric chirp signal with opposite polarity (the demodulation process is an “opposite” process of the modulation process, hence the demodulation process taught by Hanif will receive the modulated signals and demodulate them by using symmetric chirp signals with “opposite polarity”. Similar to Orthogonal demodulation using opposite carrier/polarity); but is silent on when the transmission employs a positive symmetric chirp signal for modulation, the receiving end uses a negative symmetric chirp signal for demodulation, and vice versa. Fukuma et al. US 2022/0247448 teaches support for both positive and negative symmetric chirp signals that can be used for modulation and demodulation, which reads on the limitation. Again note that if modulation uses positive symmetric chirp signal, then the demodulation would use the opposite (negative symmetric chirp signal) as is well known: [0005] In response to such a problem, Non Patent Literature 1, Yubi Qian, et al., “The Acquisition Method of Symmetry Chirp Signal Used in LEO Satellite Internet of Things” IEEE Commun. Lett., vol. 22, no. 11, pp. 2230-2233, November 2018. discloses a technique in which a transmitter transmits, as a preamble, a symmetry chirp signal (SCS) that is a revised LoRa chirp signal and includes two symmetric chirp signals of a positive-chirp signal (PCS) whose frequency linearly increases from a certain start frequency and a negative-chirp signal (NCS) whose frequency linearly decreases from the same start frequency as the PCS. In Non Patent Literature 1 described above, a receiver estimates the spread code timing for each of the PCS and the NCS, and then estimates the frequency offset and the spread code timing using fast Fourier transform (FFT). Non Patent Literature 1 described above assumes low-earth-orbit satellite IoT for a low data rate, and the initial acquisition can be performed with high accuracy even in a case where there is a large frequency offset due to the Doppler effect. It would have been obvious to one skilled in the art at the time of the invention’s filing date, to modify the combo, such that when the transmission employs a positive symmetric chirp signal for modulation, the receiving end uses a negative symmetric chirp signal for demodulation, and vice versa, to provide the ability to use an “opposite” process when demodulating the modulation signal (i.e. demodulation is the opposite of modulation). Allowable Subject Matter Claims 2-6 and 8-10 are 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. These claims recite highly detailed technical designs that are not found in at least the prior art of record, either alone or in combination: Claim 2: the symmetric chirp signal comprises a pair of chirp signals with opposite frequency variation rates; based on the polarity of frequency variation rates, the chirp signals are classified into a upward chirp signal and a downward chirp signal; the upward chirp signal has a positive frequency variation rate, with its instantaneous frequency increasing over time, while the downward chirp signal has a negative frequency variation rate, causing instantaneous frequency of the downward chirp signal to decrease over time; the symmetric chirp signals are arranged in two ways based on the concatenation order of upward and downward chirp signals: if the upward chirp signal precedes the downward chirp signal, it is referred to as the positive symmetric chirp signal; conversely, if the downward chirp signal comes before the upward chirp signal, it is known as the negative symmetric chirp signal. Claim 3: wherein the process of concatenating the upward and downward chirp signals of the symmetric chirp signal ensures the continuity of the instantaneous frequency; within one period of a chirp signal, the ending frequency of the upward chirp signal is equal to the starting frequency of the downward chirp signal, and the starting frequency of the upward chirp signal is equal to the ending frequency of the downward chirp signal. Claim 4: wherein the process of concatenating the upward and downward chirp signals of the symmetric chirp signal ensures the continuity of the phase; within one period of a chirp signal, the ending phase of the upward chirp signal is equal to the starting phase of the downward chirp signal, and the starting phase of the upward chirp signal is equal to the ending phase of the downward chirp signal. Claim 5: wherein the process of concatenating the upward and downward chirp signals requires that the frequency variation rates of the upward and downward chirp signals are opposite to each other and vary linearly within the range of -Bw/2 to Bw/2, where Bw represents the bandwidth; after frequency shifting, the symmetric chirp signal maintains the continuity of both the inter-signal phase and the instantaneous frequency. Claim 6: wherein the continuity of phase and frequency during the concatenation of the upward and downward chirp signals requires that the frequency shifting process of the symmetric chirp signal is a form of cyclic shift in instantaneous frequency; when the instantaneous frequency reaches the boundary of the frequency range, a jump is generated, transitioning from Bw/2 to -Bw/2 and vice versa, from -Bw/2 to Bw/2; for a positive symmetric chirp signal with a frequency shift of Δf, the frequency is varied linearly in the following order: (-Bw/2 + Δf) to (Bw/2), (-Bw/2) to (-Bw/2 + Δf), (-Bw/2 + Δf) to (-Bw/2), and (Bw/2) to (-Bw/2 + Δf); for a negative symmetric chirp signal with a frequency shift of Δf, the frequency is varied linearly in the following order: (-Bw/2 + Δf) to (-Bw/2), (Bw/2) to (-Bw/2 + Δf), (-Bw/2 + Δf) to (Bw/2), and (-Bw/2) to (-Bw/2 + Δf). Claim 8: wherein the demodulated signal after symmetrical chirp demodulation is subjected to a Fast Fourier Transform to obtain its frequency domain characteristics; based on the peak positions in the frequency domain, the relative frequency shift is determined and converted into decimal information, represented as di; after Gray decoding the decimal information di, the resulting information code Bi is used, taking high M bits as an index to concatenate the information for the R channels. Claim 9: wherein the preamble code uses an unmodulated symmetric chirp signal with the same polarity as the modulated symmetric chirp signal during transmission; the synchronization word employs an unmodulated symmetric chirp signal with the same polarity as the demodulated symmetric chirp signal during reception; if the modulation signal is a positive symmetric chirp signal and the demodulation signal is a negative symmetric chirp signal, the preamble code will be a positive symmetric chirp signal, and the synchronization word is a negative symmetric chirp signal, and vice versa; the user data is a linear combination of the R channels’ frequency-shift symmetric chirp signals. Claim 10: wherein the synchronization word uses a symmetric chirp signal with the opposite polarity of the preamble code; during reception, fast positioning of the synchronization word is achieved through forward and reverse scanning; the forward scanning spectrum is obtained by demodulating the received signal using a positive symmetric chirp signal and then applying Fast Fourier Transform; the reverse scanning spectrum is obtained by demodulating the received signal using a negative symmetric chirp signal and then applying Fast Fourier Transform; by analyzing the differences between the forward and reverse scanning spectra, the synchronization word is located, allowing for the separation of the preamble code and user data based on the position of the synchronization word. . Conclusion The prior art made of record and not relied upon is considered pertinent to applicant's disclosure is found in the PTO-892 form. Any inquiry concerning this communication or earlier communications from the examiner should be directed to STEPHEN M. D'AGOSTA whose telephone number is (571)272-7862. The examiner can normally be reached 8am to 4pm (IFW). Examiner interviews are available via telephone, in-person, and video conferencing using a USPTO supplied web-based collaboration tool. To schedule an interview, applicant is encouraged to use the USPTO Automated Interview Request (AIR) at http://www.uspto.gov/interviewpractice. If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Edan (Dan) Orgad can be reached at 571-272-7884. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300. 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. /STEPHEN M D AGOSTA/Primary Examiner, Art Unit 2414
Read full office action

Prosecution Timeline

Jul 28, 2023
Application Filed
Sep 11, 2025
Non-Final Rejection — §103, §112, §DP (current)

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Prosecution Projections

1-2
Expected OA Rounds
57%
Grant Probability
80%
With Interview (+22.9%)
2y 7m
Median Time to Grant
Low
PTA Risk
Based on 499 resolved cases by this examiner. Grant probability derived from career allow rate.

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