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 .
Priority
Receipt is acknowledged of certified copies of papers required by 37 CFR 1.55.
Specification
The lengthy specification has not been checked to the extent necessary to determine the presence of all possible minor errors. Applicant’s cooperation is requested in correcting any errors of which applicant may become aware in the specification.
Claim Rejections - 35 USC § 102
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 the appropriate paragraphs of 35 U.S.C. 102 that form the basis for the rejections under this section made in this Office action:
A person shall be entitled to a patent unless –
(a)(1) the claimed invention was patented, described in a printed publication, or in public use, on sale, or otherwise available to the public before the effective filing date of the claimed invention.
Claim 1 is rejected under 35 U.S.C. 102(a)(1) as being anticipated by Cao et al. (NPL, Low complexity transmitter precoding for MU MIMO-OTFS, IDS Reference, 23 July 2025; hereinafter “Cao”).
Regarding claim 1, Cao discloses a method, comprising: applying, by a device, a precoder to input information symbols to generate delay-Doppler (DD) domain symbols (page 3, section 2.2, [001]; a transmitter is precoding in the DD domain);
utilizing, by the device, an inverse symplectic finite Fourier transform (ISFFT) to transform the DD domain symbols into a time-frequency (TF) domain signal (page 2, section 2, [002]; orthogonal time frequency space modulation (OTFS) for a single-input-single-output system (SISO) and that OTFS can be further be applied to multi-carrier modulation with additional pre and post processing blocks – can be applied to a multiple user (MU) multiple-input-multiple-output (MIMO) system; and page 3, section 2.2, [001]; and page 2 section 2.1, [002]; the transmitter takes symbols in the DD domain and transforms them into symbols in the TF domain, through an ISFFT);
utilizing, by the device, a Heisenberg transform to convert the TF domain signal to a time domain signal (page 2, section 2, [002] and page 3, section 2.2, [001]; OTFS modulation in a MU MIMO system; and page 3, section 3 [004]; the symbol in the TF domain is converted to a continuous time-domain signal through a discrete Heisenberg transform);
adding, by the device, a cyclic prefix to the time domain signal to generate a modified time domain signal (page 3, section 2.1, [011]; OTFS can eliminate inter-symbol interference (ISI) caused by time dispersion by adding a cyclic prefix (CP); and page 7, section 4, [003]; the effect of the delay can be eliminated by adding a CP to the MU MIMO system);
and transmitting, by the device, the modified time domain signal to at least one user equipment (page 2, section 2.1 [001] – page 3, section 2.1 [006]; OTFS system results in conversion of symbols from DD domain to TF domain to time domain before transmission; and Fig. 3; base station takes in an input, performs precoding and OTFS modulation before transmission to one or more users that perform demodulation and equalization; and Fig 1; base stations need to communicate with forms of user equipment like vehicles, trains, and unmanned aerial vehicles simultaneously).
Claim Rejections - 35 USC § 103
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.
Claims 2, 8-9, 11, and 14-15 are rejected under 35 U.S.C. 103 as being unpatentable over Cao (NPL, Low complexity transmitter precoding for MU MIMO-OTFS) in view of Pfadler et al. (US 2022/0417062 A1; hereinafter “Pfadler”).
Regarding claim 2, Cao teaches the method of claim 1.
Cao does not teach the user equipment converting the modified time domain signal to the TF domain signal and to convert the TF domain signal to the DD domain symbols.
Pfadler, in the same field of communication, teaches transmitting the modified time domain signal causes at least one user equipment to convert the modified time domain signal to the TF domain signal and to convert the TF domain signal to the DD domain symbols ([0033]; exemplary embodiments of this system include user equipment for wireless communication systems comprising of a wireless transmitter comprising the apparatus for a wireless transmitter device and a wireless receiver comprising the apparatus for a wireless receiver device; and [0023]; the processing module of a transmitter device generates symbols in the DD domain, transforms said signals into a TF domain, transforms the TF representation into a time domain representation and transmits the time domain representation to a wireless receiver device; and [0028]; the apparatus of a wireless receiver device comprises of a receiver module and a processor module to control the receiver. The processing module is configured to receive a time domain representation of a signal and transform said signal to a TF representation and transform the TF representation into a DD domain to obtain a DD representation).
It would have been obvious to one skilled in the art before the effective filing date of the claimed invention to modify the method of Cao wherein transmitting the modified time domain signal causes the user equipment to convert the modified time domain signal to a TF domain signal and further convert the TF domain signal to a DD domain signal, as taught by Pfadler, because it can reduce multiuser uplink pilot overhead (Pfadler, [0022]). Processing signals in the DD domain can also reduce effects of multi-path superpositions and Doppler shifts (Pfadler, [0027]). The motivation for doing this is to free up resources for pilot symbols (Pfadler, [0021]), avoid interference (Pfadler, [0022]), and potentially increase overall spectral efficiency (Pfadler [0027]).
Regarding claim 8, Cao teaches a device that can apply a precoder to input information symbols to generate delay-Doppler (DD) domain symbols (page 3, section 2.2, [001]; a transmitter is precoding in the DD domain);
utilize an inverse symplectic finite Fourier transform to transform the DD domain symbols into a time-frequency (TF) domain signal (page 2, section 2, [002]; orthogonal time frequency space modulation (OTFS) for a single-input-single-output system (SISO) and that OTFS can be further be applied to multi-carrier modulation with additional pre and post processing blocks – can be applied to a multiple user (MU) multiple-input-multiple-output (MIMO) system; and page 3, section 2.2, [001]; and page 2 section 2.1, [002]; the transmitter takes symbols in the DD domain and transforms them into symbols in the TF domain, through an inverse symplectic finite Fourier transform, or ISFFT);
utilize a Heisenberg transform to convert the TF domain signal to a time domain signal (page 2, section 2, [002] and page 3, section 2.2, [001]; OTFS modulation in a MU MIMO system; and page 3, section 3 [004]; the symbol in the TF domain is converted to a continuous time-domain signal through a discrete Heisenberg transform);
add a cyclic prefix to the time domain signal to generate a modified time domain signal (page 3, section 2.1, [011]; OTFS can eliminate inter-symbol interference (ISI) caused by time dispersion by adding a cyclic prefix (CP) in the same was as orthogonal frequency division multiplexing (ODFM); and page 7, section 4, [003]; the effect of the delay can be eliminated by adding a CP to the MU MIMO system).
Cao does not teach a device comprising: one or more memories, and one or more processors, coupled to the one or more memories configured to:
…
transmit the modified time domain signal to at least one user equipment to cause the at least one user equipment to convert the modified time domain signal to the TF domain signal and to convert the TF domain signal to the DD domain symbols.
Pfadler, in the same field of communication, teaches a device, comprising: one or more memories ([0078]; methods may be performed by programmed computers, processors, or program storage devices including digital memories);
and one or more processors, coupled to the one or more memories ([0023]; a wireless transmitter device, comprising of a transmitter module and a processing module configured to the transmitter module; and [0081]; processor may be one or more singular or shared processors, and other hardware, conventional or custom, may be included) configured to:
…
transmit the modified time domain signal to at least one user equipment to cause the at least one user equipment to convert the modified time domain signal to the TF domain signal and to convert the TF domain signal to the DD domain symbols ([0023]; the processing module of a transmitter module generates symbols in the DD domain, transforms said signals into TF domain representation, transforms the TF representation into a time domain representation and transmits the time domain representation to a wireless receiver device; and [0033]; exemplary embodiments of this system include user equipment for wireless communication systems; and [0028]; the apparatus of a wireless receiver device comprises of a receiver module and a processor module to control the receiver. The processing module is configured to receive a time domain representation of a signal and transform said signal to a TF representation and transform the TF representation into a DD domain to obtain a DD representation).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify the device of Cao to include a memory and processor, as taught by Pfadler, since it is readily understood by one of ordinary skill in the art that a device that includes a processor and memory can be configured to complete any variation of steps. Completing the signal modifications as described by Cao with a device including a memory and processor would yield predictable results since programming a device to perform modifications to a signal better prepares the signal for transmission to the user equipment and increases efficiency of the communication system (Cao, page 1, section 1, [0030]; The utilization of multiple antennas at both ends of a wireless link has been shown to have the potential of achieving extraordinary rates; and page 2, section 1, [004]; excellent performance can be achieved by combining MU MIMO and OTFS with transmitter precoding, besides, the performance of MU MIMO-OTFS is almost the same at various user speeds). It would have been obvious to further modify the device of Cao wherein transmitting the modified time domain signal causes the user equipment to convert the modified time domain signal to a TF domain signal and further convert the TF domain signal to a DD domain signal, as taught by Pfadler, because it can reduce multiuser uplink pilot overhead (Pfadler, [0022]). Processing signals in the DD domain can also reduce effects of multi-path superpositions and Doppler shifts (Pfadler, [0027]). The motivation for doing this is to free up resources for pilot symbols (Pfadler, [0021]), avoid interference (Pfadler, [0022]), and potentially increase overall spectral efficiency (Pfadler [0027]).
Regarding claim 9, Cao, in view of Pfadler, teaches the device of claim 8, wherein the inverse symplectic finite Fourier transform and the Heisenberg transform are used in OTFS modulation (Fig 3; input undergoes precoding and then OTFS modulation in the base station before transmission to the user; and page 2-3, section 2.1, [002 - 005]; the OTFS modulation includes an ISFFT function and a Heisenberg transform).
Cao does not teach an orthogonal time and frequency modulator of the device.
Pfadler further teaches an orthogonal time and frequency space modulator of the device ([0045]; the transmitter and receiver modules may include one or more modulators; and [0051]; OTFS is an appropriate modulation scheme).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to further modify the device of Cao to include an OTFS modulator because a physical modulator to perform the same OTFS function yields the same predicable result as using the OTFS modulation scheme (Pfadler, [0045], [0077]).
Regarding claim 11, Cao, in view of Pfadler, teaches the device of claim 8, wherein the precoder provides a zero forcing precoding scheme (page 4, section 3, [001]; zero-forcing based precoding is used as the precoding algorithm).
Regarding claim 14, Cao, in view of Pfadler, teaches the device of claim 8, wherein the device is a multi-user multi-input multi-output (MIMO) orthogonal time and frequency space (OTFS) system (Fig 3; and page 2, section 1, [004]; and page 4, section 2.2, [001]). While Cao does not explicitly teach the device is a single-user MIMO OTFS system, a multi-user MIMO OTFS system is capable of only being used by one user as a single-user MIMO OTFS system (page 3, section 2.2, [001]; where K may equal 1).
Regarding claim 15, Cao teaches one or more instructions that: apply a precoder to input information symbols to generate delay-Doppler (DD) domain symbols (page 3, section 2.2, [001]; a transmitter is precoding in the DD domain);
utilize an inverse symplectic finite Fourier transform to transform the DD domain symbols into a time-frequency (TF) domain signal (page 2, section 2, [002]; orthogonal time frequency space modulation (OTFS) for a single-input-single-output system (SISO) and that OTFS can be further be applied to multi-carrier modulation with additional pre and post processing blocks – can be applied to a multiple user (MU) multiple-input-multiple-output (MIMO) system; and page 3, section 2.2, [001]; and page 2 section 2.1, [002]; the transmitter takes symbols in the DD domain and transforms them into symbols in the TF domain, through an ISFFT);
utilize a Heisenberg transform to convert the TF domain signal to a time domain signal (page 2, section 2, [002] and page 3, section 2.2, [001]; OTFS modulation in a MU MIMO system; and page 3, section 3 [004]; the symbol in the TF domain is converted to a continuous time-domain signal through a discrete Heisenberg transform);
add a cyclic prefix to the time domain signal to generate a modified time domain signal (page 3, section 2.1, [011]; OTFS can eliminate inter-symbol interference (ISI) caused by time dispersion by adding a cyclic prefix (CP); and page 7, section 4, [003]; the effect of the delay can be eliminated by adding a CP to the MU MIMO system);
and transmit the modified time domain signal to at least one user equipment (page 2, section 2.1 [001] – page 3, section 2.1 [006]; OTFS system results in conversion of symbols from DD domain to TF domain to time domain before transmission; and Fig. 3; base station takes in an input, performs precoding and OTFS modulation before transmission to one or more users that perform demodulation and equalization; and Fig 1; base stations need to communicate with forms of user equipment like vehicles, trains, and unmanned aerial vehicles simultaneously).
Cao does not teach a non-transitory computer-readable medium storing the set of instructions, and that the inverse symplectic finite Fourier transform and the Heisenberg transform are provided in an orthogonal time and frequency space modulator of the device.
Pfadler, in the same field of communication, teaches a non-transitory computer-readable medium storing the set of instructions that, when executed by one or more processors of a device, cause the device to perform tasks ([0036]; an exemplary embodiment is a computer readable storage medium storing instructions which, when executed by a computer, processor, or programmable hardware component, cause the computer to implement one of the methods described herein);
and that the inverse symplectic finite Fourier transform and the Heisenberg transform are provided in an orthogonal time and frequency space modulator of the device ([0045]; the transmitter and receiver modules may include one or more modulators; and [0051]; OTFS is an appropriate modulation scheme).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify the instructions of Cao to be stored in a non-transitory computer readable medium, as taught by Pfadler, since it is readily understood by one of ordinary skill in the art that a non-transitory computer readable medium can be configured to complete any variation of steps. Completing the signal modifications as described by Cao with a non-transitory computer readable medium would yield predictable results since programming the non-transitory computer readable medium to perform modifications to a signal better prepares the signal for transmission to the user equipment and increases efficiency of the communication system (Cao, page 1, section 1, [0030]; The utilization of multiple antennas at both ends of a wireless link has been shown to have the potential of achieving extraordinary rates; and page 2, section 1, [004]; excellent performance can be achieved by combining MU MIMO and OTFS with transmitter precoding, besides, the performance of MU MIMO-OTFS is almost the same at various user speeds). It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to further modify the device of Cao to include an OTFS modulator because a physical modulator to perform the same OTFS function yields the same predicable result as using the OTFS modulation scheme (Pfadler, [0045], [0077]).
Claim Rejections - 35 USC § 103
Claim 3 is rejected under 35 U.S.C. 103 as being unpatentable over Cao (NPL, Low complexity transmitter precoding for MU MIMO-OTFS) in view of Mahmood et al. (US 2023/0276368 A1; hereinafter “Mahmood”).
Regarding claim 3, Cao teaches the method of claim 1, wherein the precoder is a zero forcing (ZF) precoder for MU MIMO-OTFS in a DD domain based on a doubly block circulant (DBC) property of a channel matrix (page 4, section 3, [001]; the MU MIMO-OTFS system has high complexity because the dimension of the channel matrix in the DD dimension is relatively high, so zero-forcing based precoding is used as the precoding algorithm; and page 4, section 3.1, [001-008]; the DBC matrix used for a SISO system can be modified for use in the MU MIMO- OTFS system thus that the channel matrix maintains the DBC property).
However, Cao does not teach that the precoder is both a zero forcing and minimum mean square error (MMSE) based precoder.
Mahmood, in a similar field of communication to Cao, teaches the use of both a ZF and MMSE based precoder for precoding a downlink signal for transmission from a base station to a user equipment ([008]; the precoder is initialized using zero-forcing, adjusted to jointly maximize the signal and minimize the interference with respect to noise, and further adjusted on a power constraint using MMSE to generate the signal for transmission).
It would have been obvious to one skilled in the art before the effective filing date of the claimed invention to modify the method of Cao to use both ZF and MMSE in the precoder, as taught by Mahmood, because both precoding methods will better prepare the signal according to the requirements of the receiver; ZF precoding initializes the data based on a channel estimate, and MMSE precoding adjusts the data based on the power constraint (Mahmood, Fig 17 and [0148, 0150-0151]). The motivation for combining is to better prepare the signal for transmission to the user equipment for efficient use.
Claim Rejections - 35 USC § 103
Claims 10, 12-13, and 16 are rejected under 35 U.S.C. 103 as being unpatentable over Cao (NPL, Low complexity transmitter precoding for MU MIMO-OTFS) in view of Pfadler (US 2022/0417062 A1), and further in view of Mahmood (US 2023/0276368 A1).
Regarding claim 10, Cao, in view of Pfadler, teaches the device of claim 8.
Cao does not teach the device is a radio access network.
Mahmood, in a similar field of communication, teaches the device is a radio access network ([0006]; a base station may be configured for beamforming estimation in a MIMO radio access network, and may comprise a processing device that may be configured to precode a signal for transmission to a user equipment).
It would have been obvious to one skilled in the art before the effective filing date of the claimed invention to modify the device of Cao to be a radio access network, as taught by Mahmood, because it would allow the base station to operate in additional networks (Mahmood, [0053]), and it may enhance network capacity for user equipment (Mahmood, [0054-0055]).
Regarding claim 12, Cao, in view of Pfadler, teaches the device of claim 8.
Cao does not teach that the precoder provides a minimum mean square error precoding scheme.
Mahmood, in a similar field of communication, teaches the use of a MMSE based precoder for precoding a downlink signal for transmission from a base station to a user equipment ([008]; the precoder is adjusted on a power constraint using MMSE to generate the signal for transmission).
It would have been obvious to one skilled in the art before the effective filing date of the claimed invention to modify the device of Cao to use MMSE in the precoder, as taught by Mahmood, because MMSE is an additional linear precoding algorithm that can better prepare the signal according to the requirements of the receiver by adjusting the data based on a power constraint (Mahmood, [0150-0151]). The motivation for combining is to better prepare the signal for transmission to the user equipment for efficient use.
Regarding claim 13, Cao, in view of Pfadler, and further in view of Mahmood, teaches the device of claim 12, wherein there is a minimum mean square error precoding scheme.
Cao teaches a zero forcing precoding scheme (page 4, section 3, [001]; zero-forcing based precoding is used as the precoding algorithm).
Cao does not teach a MMSE precoding scheme that includes a zero forcing precoding scheme and a maximum ratio transmission precoding scheme.
Mahmood, in a similar field of communication, teaches the MMSE precoding scheme includes a zero forcing precoding scheme and a maximum ratio transmission precoding scheme (Mahmood, Fig 17; the MMSE precoder uses the output from the ZF precoding and therefore incorporates ZF precoding into its result; and [0041]; maximum radio transmission (MRT) is another scheme that can be incorporated into the system with ZF).
It would have been obvious to one skilled in the art before the effective filing date of the claimed invention to modify the device of Cao to use a ZF precoding scheme and MR precoding scheme in the MMSE precoding scheme, as taught by Mahmood, because incorporating ZF precoding improved the results of the MMSE precoder (Mahmood, [0175]), and MRT may provide increased uniformity of power distribution (Mahmood, [0041]). The motivation for incorporating both schemes is to improve the power adjustment computations while also reducing complexity (Mahmood, [0108-0109]).
Regarding claim 16, Cao in view of Pfadler, teaches the non-transitory computer-readable medium of claim 15, wherein the precoder is a zero forcing (ZF) precoder for MU MIMO-OTFS in a DD domain based on a doubly block circulant (DBC) property of a channel matrix (page 4, section 3, [001]; the MU MIMO-OTFS system has high complexity because the dimension of the channel matrix in the DD dimension is relatively high, so zero-forcing based precoding is used as the precoding algorithm; and page 4, section 3.1, [001-008]; the DBC matrix used for a SISO system can be modified for use in the MU MIMO- OTFS system thus that the channel matrix maintains the DBC property).
However, Cao does not teach that the precoder is both a zero forcing and minimum mean square error (MMSE) based precoder.
Mahmood, in a similar field of communication, teaches the use of both a ZF and MMSE based precoder for precoding a downlink signal for transmission from a base station to a user equipment ([008]; the precoder is initialized using zero-forcing, adjusted to jointly maximize the signal and minimize the interference with respect to noise, and further adjusted on a power constraint using MMSE to generate the signal for transmission).
It would have been obvious to one skilled in the art before the effective filing date of the claimed invention to modify the instructions of Cao to use both ZF and MMSE in the precoder, as taught by Mahmood, because both precoding methods will better prepare the signal according to the requirements of the receiver; ZF precoding initializes the data based on a channel estimate, and MMSE precoding adjusts the data based on the power constraint (Mahmood, Fig 17 and [0148, 0150-0151]). The motivation for combining is to better prepare the signal for transmission to the user equipment for efficient use.
Claim Rejections - 35 USC § 103
Claim 4 is rejected under 35 U.S.C. 103 as being unpatentable over Cao (NPL, Low complexity transmitter precoding for MU MIMO-OTFS) in view of Mahmood (US 2023/0276368 A1), and further in view of Tsatsanis et al. (WO 2018032016 A1; hereinafter “Tsatsanis”).
Regarding claim 4, Cao teaches the method of claim 1, wherein the precoder is a zero forcing (ZF) precoder for MU MIMO-OTFS (page 4, section 3, [001]; the MU MIMO-OTFS system has high complexity because the dimension of the channel matrix in the DD dimension is relatively high, so zero-forcing based precoding is used as the precoding algorithm)
However, Cao does not teach that the precoder is both a zero forcing and minimum mean square error (MMSE) based precoder in a time-frequency domain for a single-antenna receiver.
Mahmood, in a similar field of communication to Cao, teaches the use of both a ZF and MMSE based precoder for precoding a downlink signal for transmission from a base station to a user equipment ([008]; the precoder is initialized using zero-forcing, adjusted to jointly maximize the signal and minimize the interference with respect to noise, and further adjusted on a power constraint using MMSE to generate the signal for transmission).
It would have been obvious to one skilled in the art before the effective filing date of the claimed invention to modify the method of Cao to use both ZF and MMSE in the precoder, as taught by Mahmood, because both precoding methods will better prepare the signal according to the requirements of the receiver; ZF precoding initializes the data based on a channel estimate, and MMSE precoding adjusts the data based on the power constraint (Mahmood, Fig 17 and [0148, 0150-0151]). The motivation for combining is to better prepare the signal for transmission to the user equipment for efficient use.
Tsatsanis, in a similar field of communication to both Cao and Mahmood, teaches implementation of MMSE or ZF in the time frequency domain for a single antenna receiver ([0071]: a linear MMSE or ZF receiver can be implemented in either the time-frequency domain or the delay-Doppler domain; and [0072]; in the SISO case, a linear MMSE receiver may be less complex).
It would have been obvious to one skilled in the art before the effective filing date of the claimed invention to modify the method of Cao and Mahmood to implement the combined precoder in the TF domain because both MMSE and ZF are linear techniques that can be utilized in either the TF or DD domain and higher performance can be obtained with more advanced receivers (Tsatsanis, [0071]). The motivation for doing this is to assist in better channel estimation and improve multiplexing in both or either domain (Tsatsanis, [0074]).
Claim Rejections - 35 USC § 103
Claim 5 is rejected under 35 U.S.C. 103 as being unpatentable over Cao (NPL, Low complexity transmitter precoding for MU MIMO-OTFS) in view of Mahmood (US 2023/0276368 A1), further in view of Tsatsanis (WO 2018032016 A1), and even further in view of Wang et al. (US 20190245602 A1; hereinafter “Wang”).
Regarding claim 5, Cao, in view of Mahmood, and in further view of Tsatsanis, teaches the method of claim 4.
Cao does not teach converting the ZF and MMSE precoder to a DD domain.
Wang, in a similar field of communication as Cao, Mahmood, and Tsatsanis, teaches converting the channel response or covariance matrix from the TF domain to the DD domain ([0016]; base station should transform the channel response/covariance matrix from Frequency-Time domain into Delay-Doppler domain). The channel response includes the ZF and MMSE precoder because the precoder is part of the conditions between the device transmitting the modified time domain signal to at least one user equipment of claim 1 [0038]; In an embodiment, the channel response can refer to the channel conditions between a receiver antenna and a transmitter antenna (for single antenna systems) or between respective antenna elements on a receiver and a transmitter (for MIMO systems). The covariance matrix can refer a set of channel responses for each antenna pair of the MIMO system).
It would have been obvious to one skilled in the art before the effective filing date of the claimed invention to modify the method of Cao, Mahmood, and Tsatsanis to implement the conversion of the channel response as taught by Wang because by converting channel state information from a traditional frequency-time domain to a Delay-Doppler domain, the channel state information feedback overhead can be reduced (Wang, [0015]).
Claim Rejections - 35 USC § 103
Claim 6 is rejected under 35 U.S.C. 103 as being unpatentable over Cao (NPL, Low complexity transmitter precoding for MU MIMO-OTFS) in view of Hadani et al. (WO 2017165697 A1; hereinafter “Hadani”).
Regarding claim 6, Cao teaches the method of claim 1, wherein the precoder is a block diagonalization based precoder for multi-user multi-input multi-output orthogonal time and frequency space (page 4, section 3 [001]; BD precoding is a benchmark algorithm for MU MIMO-OTFS).
Cao does not teach that the block diagonalization precoder is in a time-frequency domain for a multi-antenna receiver.
Hadani, in a similar field of communication, teaches the block diagonalization precoder is in a time-frequency domain for a multi-antenna receiver ([006], the OTFS modulation scheme generates time-frequency domain samples and performs linear equalization of the TF signals; and [0061]; the equalization is performed across the time-frequency grid with the block diagonal matrix; and [007]; the apparatus includes a module for processing a wireless signal received at one or more antennas of the apparatus. A module may perform linear equalization in the time-frequency domain). Linear equalization has the same role as precoding since they are performing the same function of preparing the signal for conversion (Hadani, [0006]; linear equalization takes the time frequency domain samples and prepares them to a filter to obtain delay time domain signals; and [0067]; the signal is converted from delay-time to delay doppler domain).
It would have been obvious to one skilled in the art before the effective filing date of the claimed invention to modify the method of Cao to use the block diagonalization precoder in the TF domain for a multi-antenna receiver as taught by Hadani, because OTFS modulated signals are modulated across the DD grid, traditional reception techniques are not as efficient (Hadani, [0026]). Ensuring that the precoder can perform in both the TF and DD domain ensures greater efficiency of OTFS to extract and recover information (Hadani, [0026]).
Claim Rejections - 35 USC § 103
Claim 7 is rejected under 35 U.S.C. 103 as being unpatentable over Cao (NPL, Low complexity transmitter precoding for MU MIMO-OTFS) in view of Hadani (WO 2017165697 A1) and in further view of Wang (US 20190245602 A1).
Regarding claim 7, Cao, in view of Hadani, teaches the method of claim 6.
Cao does not teach converting the block diagonalization precoder to a DD domain.
Wang, in a similar field of communication as Cao, teaches converting the channel response or covariance matrix from the TF domain to the DD domain ([0016]; base station should transform the channel response/covariance matrix from Frequency-Time domain into Delay-Doppler domain). The channel response includes the BD precoder because the precoder is part of the conditions between the device transmitting the modified time domain signal to at least one user equipment of claim 1 ([0038]; In an embodiment, the channel response can refer to the channel conditions between a receiver antenna and a transmitter antenna (for single antenna systems) or between respective antenna elements on a receiver and a transmitter (for MIMO systems). The covariance matrix can refer to a set of channel responses for each antenna pair of the MIMO system).
It would have been obvious to one skilled in the art before the effective filing date of the claimed invention to modify the method of Cao, to implement the conversion of the channel response as taught by Wang because by converting channel state information from a traditional frequency-time domain to a Delay-Doppler domain, the channel state information feedback overhead can be reduced (Wang, [0015]).
Claim Rejections - 35 USC § 103
Claim 17 is rejected under 35 U.S.C. 103 as being unpatentable over Cao (NPL, Low complexity transmitter precoding for MU MIMO-OTFS), in view of Pfadler (US 2022/0417062 A1), in further view of Mahmood (US 2023/0276368 A1), and even further in view of Tsatsanis (WO 2018032016 A1).
Regarding claim 17, Cao, in view of Pfadler, teaches the non-transitory computer readable medium of claim 15, wherein the precoder is a zero forcing (ZF) precoder for MU MIMO-OTFS (page 4, section 3, [001]; the MU MIMO-OTFS system has high complexity because the dimension of the channel matrix in the DD dimension is relatively high, so zero-forcing based precoding is used as the precoding algorithm).
However, Cao does not teach that the precoder is both a zero forcing and minimum mean square error (MMSE) based precoder in a time-frequency domain for a single-antenna receiver.
Mahmood, in a similar field of communication to Cao, teaches the use of both a ZF and MMSE based precoder for precoding a downlink signal for transmission from a base station to a user equipment ([008]; the precoder is initialized using zero-forcing, adjusted to jointly maximize the signal and minimize the interference with respect to noise, and further adjusted on a power constraint using MMSE to generate the signal for transmission).
It would have been obvious to one skilled in the art before the effective filing date of the claimed invention to modify the non-transitory computer readable medium of Cao to use both ZF and MMSE in the precoder, as taught by Mahmood, because both precoding methods will better prepare the signal according to the requirements of the receiver; ZF precoding initializes the data based on a channel estimate, and MMSE precoding adjusts the data based on the power constraint (Mahmood, Fig 17 and [0148, 0150-0151]). The motivation for combining is to better prepare the signal for transmission to the user equipment for efficient use.
Tsatsanis, in a similar field of communication to both Cao, Pfadler, and Mahmood, teaches implementation of MMSE or ZF in the time frequency domain for a single antenna receiver ([0071]: a linear MMSE or ZF receiver can be implemented in either the time-frequency domain or the delay-Doppler domain; and [0072]; in the SISO case, a linear MMSE receiver may be less complex).
It would have been obvious to one skilled in the art before the effective filing date of the claimed invention to modify the non-transitory computer readable medium of Cao, Pfadler, and Mahmood to implement the combined precoder in the TF domain because both MMSE and ZF are linear techniques that can be utilized in either the TF or DD domain and higher performance can be obtained with more advanced receivers (Tsatsanis, [0071]). The motivation for doing this is to assist in better channel estimation and improve multiplexing in both or either domain (Tsatsanis, [0074]).
Claim Rejections - 35 USC § 103
Claim 18 is rejected under 35 U.S.C. 103 as being unpatentable over Cao (NPL, Low complexity transmitter precoding for MU MIMO-OTFS), in view of Pfadler (US 2022/0417062 A1), in further view of Mahmood (US 2023/0276368 A1), further in view of Tsatsanis (WO 2018032016 A1), and even further in view of Wang (US 20190245602 A1).
Regarding claim 18, Cao, in view of Pfadler, in further view of Mahmood, and in even further view of Tsatsanis teaches the non-transitory computer readable medium of claim 17.
Cao does not teach converting the ZF and MMSE precoder to a DD domain.
Wang, in a similar field of communication as Cao, Pfadler, Mahmood, and Tsatsanis, teaches converting the channel response or covariance matrix from the TF domain to the DD domain ([0016]; base station should transform the channel response/covariance matrix from Frequency-Time domain into Delay-Doppler domain). The channel response includes the ZF and MMSE precoder because the precoder is part of the conditions that must exist for the non-transitory computer readable medium to transmit the modified time domain signal to at least one user equipment of claim 15 ([0038]; In an embodiment, the channel response can refer to the channel conditions between a receiver antenna and a transmitter antenna (for single antenna systems) or between respective antenna elements on a receiver and a transmitter (for MIMO systems). The covariance matrix can refer to a set of channel responses for each antenna pair of the MIMO system).
It would have been obvious to one skilled in the art before the effective filing date of the claimed invention to modify the non-transitory computer readable medium of Cao, Pfadler, Mahmood, and Tsatsanis to implement the conversion of the channel response as taught by Wang because by converting channel state information from a traditional frequency-time domain to a Delay-Doppler domain, the channel state information feedback overhead can be reduced (Wang, [0015]).
Claim Rejections - 35 USC § 103
Claim 19 is rejected under 35 U.S.C. 103 as being unpatentable over Cao (NPL, Low complexity transmitter precoding for MU MIMO-OTFS), in view of Pfadler (US 2022/0417062 A1), and in further view of Hadani et al (WO 2017165697 A1).
Regarding claim 19, Cao, in view of Pfadler, teaches the non-transitory computer readable medium of claim 15, wherein the precoder is a block diagonalization based precoder for multi-user multi-input multi-output orthogonal time and frequency space (page 4, section 3 [001]; BD precoding is a benchmark algorithm for MU MIMO-OTFS).
Cao does not teach that the block diagonalization precoder is in a time-frequency domain for a multi-antenna receiver.
Hadani, in a similar field of communication, teaches the block diagonalization precoder is in a time-frequency domain for a multi-antenna receiver ([006], the OTFS modulation scheme generates time-frequency domain samples and performs linear equalization of the TF signals; and [0061]; the equalization is performed across the time-frequency grid with the block diagonal matrix; and [007]; the apparatus includes a module for processing a wireless signal received at one or more antennas of the apparatus. A module may perform linear equalization in the time-frequency domain). Linear equalization has the same role as precoding since they are performing the same function of preparing the signal for conversion (Hadani, [0006]; linear equalization takes the time frequency domain samples and prepares them to a filter to obtain delay time domain signals; and [0067]; the signal is converted from delay-time to delay doppler domain).
It would have been obvious to one skilled in the art before the effective filing date of the claimed invention to modify the non-transitory computer readable medium of Cao to use the block diagonalization precoder in the TF domain for a multi-antenna receiver as taught by Hadani, because OTFS modulated signals are modulated across the DD grid, and traditional reception techniques are not as efficient (Hadani, [0026]). Ensuring that the precoder can perform in both the TF and DD domain ensures greater efficiency of OTFS to extract and recover information (Hadani, [0026]).
Claim Rejections - 35 USC § 103
Claim 20 is rejected under 35 U.S.C. 103 as being unpatentable over Cao (NPL, Low complexity transmitter precoding for MU MIMO-OTFS), in view of Pfadler (US 2022/0417062 A1), in further view of Hadani (WO 2017165697 A1) and even further in view of Wang (US 20190245602 A1).
Regarding claim 20, Cao, in view of Pfadler, and in further view of Hadani, teaches the non-transitory computer readable medium of claim 19.
Cao does not teach converting the block diagonalization precoder to a DD domain.
Wang, in a similar field of communication as Cao, teaches converting the channel response or covariance matrix from the TF domain to the DD domain ([0016]; base station should transform the channel response/covariance matrix from frequency-time domain into the Delay-Doppler domain). The channel response includes the BD precoder because the precoder is part of the conditions between the device transmitting the modified time domain signal to at least one user equipment of claim 1 ([0038]; In an embodiment, the channel response can refer to the channel conditions between a receiver antenna and a transmitter antenna (for single antenna systems) or between respective antenna elements on a receiver and a transmitter (for MIMO systems). The covariance matrix can refer to a set of channel responses for each antenna pair of the MIMO system).
It would have been obvious to one skilled in the art before the effective filing date of the claimed invention to modify the non-transitory computer readable medium of Cao, to implement the conversion of the channel response, as taught by Wang, because by converting channel state information from a traditional frequency-time domain to a Delay-Doppler domain, the channel state information feedback overhead can be reduced (Wang, [0015]).
Conclusion
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure.
Du et al., CN 117294561 A; An orthogonal time-frequency space method in mobile network comprising of precoding, inverse Fourier transform, and Heisenberg transformation on data to be transmitted.
Tusha et al., WO 2023121584 A1; Multicarrier connection design using multi-user diversity in delay-Doppler domain with orthogonal time frequency space signaling.
Any inquiry concerning this communication or earlier communications from the examiner should be directed to KHUSHI PARIKH whose telephone number is (571)272-1119. The examiner can normally be reached Mon-Fri 9am-5pm EST.
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, Gary Mui can be reached at (571)270-1420. 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.
/KHUSHI PARIKH/Examiner, Art Unit 2465
/GARY MUI/Supervisory Patent Examiner, Art Unit 2465
Prosecution Insights