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 .
1. This office action, in response to the amendment received 9/16/2025, is a final office action.
Response to Amendment and Arguments
2. Independent claims 1, 13 and 27 are amended to recite determine the size, in terms of number of coefficients, of each DPD according to a utility function that depends on the channel gain estimates per antenna, the utility function being derived from an optimization criterion, the optimization criterion pertaining to a maximization of downlink capacity of the access node, a minimization of power consumption of the DPDs for a given system performance of the access node, and a maximization of system performance of the access node for a given power consumption of the DPDs; and allocate the determined number of coefficients to each DPD.
The previous rejection of claim 9 under 35 U.S.C. 103 as being unpatentable over Gutman et al (US 2019/0089389) in view of Weiss (US 2018/0102799) further in view of Moosavi et al (US 2019/0288822) disclosed wherein the utility function is derived from an optimization criterion, and wherein the optimization criterion pertains to any of: maximization of downlink capacity of the access node, minimization of power consumption of the DPDs for a given system performance of the access node (Weiss: Paragraph 0043 by varying the memory and the polynomial order, in case of a memory polynomial function, it can be estimated, how complex it will be to implement the predistortion. If, for example, a reduction of the number of taps from 11 to three does not change the performance of the predistortion, a memory of three taps is sufficient. This is very advantageous if the predistortion is implemented as an FPGA. This will minimize the power consumed while maintaining performance at the same level as when more taps are used.), maximization of system performance of the access node for a given power consumption of the DPDs. In addition, Weiss discloses the optimization criterion pertains to maximization of system performance of the access node for a given power consumption of the DPDs since Weiss discloses by varying the memory and the polynomial order, in case of a memory polynomial function, it can be estimated, how complex it will be to implement the predistortion. If, for example, a reduction of the number of taps from 11 to three does not change the performance of the predistortion, a memory of three taps is sufficient. This is very advantageous if the predistortion is implemented as an FPGA. In this case, the system performance will be maximized for a given power consumption since the performance will be the same as the performance level achieved when many more taps are utilized.
Applicant states the combination of Gutman and Weiss does not disclose the recited features of amended claims 1, 13 and 27 on page 12 of the remarks. Applicant states the amended claims 1, 13 and 27 now require that the utility is derived from an optimization criterion pertaining to three features including a maximization of downlink capacity of the access node. Applicant states the office action does not cite Weiss as teaching the three features as stated on page 12 of the remarks. As stated above, Weiss discloses two of the three recited features. The rejections of the claims stated below address all of the amended features.
The claims are rejected as stated below.
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.
3. Claims 1-8, 10, 13-15, 18 and 27 are rejected under 35 U.S.C. 103 as being unpatentable over Gutman et al (US 2019/0089389) in view of Weiss (US 2018/0102799) in view of Strong (US 2008/0112506) further in view of Moosavi et al (US 2019/0288822).
Regarding claims 1, 13 and 27, Gutman discloses an access node, a method and a computer program (Paragraph 0127: alternatively, various method described herein can be provided via storage means (e.g., RAM, ROM, a physical storage medium such as a CD or floppy disc.).) for digital pre-distorter, DPD, size determination of the access node, the access node being configured for operation in a digital massive multiple-input multiple-output, MIMO, system (Figures 13 and 14. Paragraph 0102: Figure 13 illustrates an example of a MIMO system 1300 with access points and user terminals.), the access node comprising a plurality of antennas, one radio chain per antenna, and one DPD per radio chain, the access node comprising processing circuitry (Figure 2: Each transmit chain comprises a DPD 104 and antenna 114 per transmit chain.), the processing circuitry being configured to cause the access node to:
obtain channel gain estimates per each of the plurality of antennas (Paragraph 0032: driving the PA close to saturation improves accuracy but can distort the output signal of the PA. The resulting signal distortion has two man components: an in-band component and an out-of-band component. The in-band component can result in an increase in the EVM of the in-band component. The out-of-band distortion can result in pollution or interference to adjacent channel transmission, i.e., adjacent channel interference (ACI). Figure 2: the signal to be transmitted from the antenna is provided as feedback to the DPD controller 124. Paragraph 0040: the digital feedback signal provides the DPD controller 124 with feedback of the PA output signal. This allows the DPD controller to determine the non-linear characteristics of the PA output signal and to dynamically or adaptively adjust the predistortion coefficients of the DPD 104 based on the current and/or historical non-linear characteristics of the PA output signal to reduce non-linearity at the output of the PA 110. This will occur in each of the transmit chains shown in figure 2.); and
allocate the adjusted number of coefficients for each DPD (Figure 2: the signal to be transmitted from the antenna is provided as feedback to the DPD controller 124. Paragraph 0040: the digital feedback signal provides the DPD controller 124 with feedback of the PA output signal. This allows the DPD controller to determine the non-linear characteristics of the PA output signal and to dynamically or adaptively adjust the predistortion coefficients of the DPD 104 based on the current and/or historical non-linear characteristics of the PA output signal to reduce non-linearity at the output of the PA 110. This will occur in each of the transmit chains shown in figure 2. Paragraph 0037: in one example, the DPD 104 may comprise one or more non-linear filters in which the predistortion coefficients of the DPD 104 correspond to filter coefficients of the one or more non-linear filters.).
Gutman does not disclose determining the size, in terms of number of coefficients, of each DPD according to a utility function that depends on the channel gain estimates per antenna; and allocating the determined number of coefficients to each DPD.
Weiss discloses a predistortion system and method using a predistortion function as described in the abstract. Paragraph 0043 discloses by varying the memory and the polynomial order, in case of a memory polynomial function, it can be estimated, how complex it will be to implement the predistortion. If, for example, a reduction of the number of taps from 11 to three does not change the performance of the predistortion, a memory of three taps is sufficient. This is very advantageous if the predistortion is implemented as an FPGA. In the example in Weiss, the performance of the predistortion is determined using different numbers of taps in the predistortion filter. When it has been determined that performance is not changed by using a lower number of taps, the lower number of taps is utilized. When the lower number of taps is utilized, a corresponding lower number of coefficients will be utilized. When the three taps are used, the corresponding three coefficients, one for each tap, will be used and allocated to the predistortion filter.
Weiss discloses wherein the utility function is derived from an optimization criterion, and wherein the optimization criterion pertains to minimization of power consumption of the DPDs for a given system performance of the access node (Weiss: Paragraph 0043 by varying the memory and the polynomial order, in case of a memory polynomial function, it can be estimated, how complex it will be to implement the predistortion. If, for example, a reduction of the number of taps from 11 to three does not change the performance of the predistortion, a memory of three taps is sufficient. This is very advantageous if the predistortion is implemented as an FPGA. This will minimize the power consumed while maintaining performance at the same level as when more taps are used.), and maximization of system performance of the access node for a given power consumption of the DPDs (Weiss: Paragraph 0043 by varying the memory and the polynomial order, in case of a memory polynomial function, it can be estimated, how complex it will be to implement the predistortion. If, for example, a reduction of the number of taps from 11 to three does not change the performance of the predistortion, a memory of three taps is sufficient. The system performance will be maximized for this given power consumption since the performance will be the same as the performance level achieved when many more taps are utilized.). Using less taps and coefficients will be very advantageous as stated by Weiss. For these reasons, it would have been obvious for one of ordinary skill in the art before the effective filing date of the claimed invention to combine the method of reducing the taps and corresponding coefficients of Weiss in the predistortion system of Gutman.
The combination of Gutman and Weiss does not disclose the utility function is derived from an optimization criterion, and wherein the optimization criterion pertains to a maximization of downlink capacity of the access node.
Strong discloses the communication system shown in figure 1. Strong discloses the communication system determines how close a transceiver’s power amplifier is to non-linear operation, and to set the transmission power of the power amplifier to a maximal level to achieve an acceptable level of distortion at the amplifier output. The wireless communication system may then employ an adaptive modulation and coding technique and/or a digital predistortion technique consistent with the maximal power level setting to increase data capacity of the radio link as stated in paragraphs 0006 and 0018. Strong will employ the digital pre-distortion technique to be consistent with the maximum power level to achieve a corresponding data capacity of the link and to achieve an acceptable level of distortion. This allow the transmitter to operate efficiently and effectively. For these reasons, it would have been obvious for one of ordinary skill in the art before the effective filing date of the claimed invention to combine the teachings of Strong into the method and node of the combination of Gutman and Weiss.
The combination of Gutman, Weiss and Strong does not disclose obtain channel gain estimates per each of the plurality of antennas by acquiring pilot signals from at least one user equipment (UE).
Moosavi discloses a method of each wireless communication device transmits sounding symbols in an uplink phase which are then used by the base stations to estimate their corresponding radio channels. The amount of required pilot signals is thus equal to the number of wireless communication devices. These pilot signals may be referred to as reciprocity references signals RRS as stated in paragraph 0038. Paragraph 0039 and claims 12-19 discuss pilot contamination and how the pilot contamination is well known and is subsequently suppressed. Using pilot signals to determine channel estimates is well known. By using a known pilot signal, the effect of the channel on this known signal can be determined and can be compensated for. It would have been obvious for one of ordinary skill in the art before the effective filing date of the claimed invention to utilize the teaching of receiving transmitted pilot signals to determine channel estimates as taught by Moosavi in the node and method of the combination of Gutman, Weiss and Strong. Using well known methods will reduce the complexity and cost of a system.
Regarding claims 2 and 14, the combination discloses select values of the coefficients as determined for each DPD (Gutman: Paragraph 0040: the digital feedback signal provides the DPD controller 124 with feedback of the PA output signal. This allows the DPD controller to determine the non-linear characteristics of the PA output signal and to dynamically or adaptively adjust the predistortion coefficients of the DPD 104 based on the current and/or historical non-linear characteristics of the PA output signal to reduce non-linearity at the output of the PA 110. This will occur in each of the transmit chains shown in figure 2.).
Regarding claims 3 and 15, the combination discloses transmitting a downlink signal from the access node, wherein the downlink signal is pre-distorted by the DPDs according to the selected values of the coefficients (Gutman: Paragraph 0040: the digital feedback signal provides the DPD controller 124 with feedback of the PA output signal. This allows the DPD controller to determine the non-linear characteristics of the PA output signal and to dynamically or adaptively adjust the predistortion coefficients of the DPD 104 based on the current and/or historical non-linear characteristics of the PA output signal to reduce non-linearity at the output of the PA 110. This will occur in each of the transmit chains shown in figure 2.).
Regarding claim 4, the combination discloses wherein the channel gain estimates represent a moving average of channel conditions (Gutman: paragraph 0040: the digital feedback signal provides the DPD controller 124 with feedback of the PA output signal. This allows the DPD controller to determine the non-linear characteristics of the PA output signal and to dynamically or adaptively adjust the predistortion coefficients of the DPD 104 based on the current and/or historical non-linear characteristics of the PA output signal to reduce non-linearity at the output of the PA 110. This will occur in each of the transmit chains shown in figure 2. Since historical characteristics over time are used, the estimates represent a moving average.).
Regarding claim 5, the combination discloses wherein the sizes of all the DPDs are collectively determined to maximize the utility function (Weiss: Paragraph 0043: by varying the memory and the polynomial order, in case of a memory polynomial function, it can be estimated, how complex it will be to implement the predistortion. If, for example, a reduction of the number of taps from 11 to three does not change the performance of the predistortion, a memory of three taps is sufficient. This is very advantageous if the predistortion is implemented as an FPGA. This will be implemented in each of the DPDs of the combination. These adjustments will maximize the efficiency of the transmitter.).
Regarding claim 6, the combination discloses wherein the utility function is constrained by a maximum total number of coefficients collectively allocatable to all DPDs (The DPDs cannot exceed the maximum total number of taps of all of the filters of the DPD. Therefore, the transmitter is constrained by that maximum.).
Regarding claim 7, the combination discloses wherein the maximum total number of coefficients is dependent on a total available power budget for the DPDs (The DPDs cannot exceed the maximum total number of taps of all of the filters of the DPD. Therefore, the transmitter is constrained by that maximum. The function of the DPDs cannot exceed the DPDs’ maximum power.).
Regarding claim 8, the combination discloses wherein the utility function further depends on properties of hardware components per radio chain (Gutman: Figure 2: the signal to be transmitted from the antenna is provided as feedback to the DPD controller 124. Paragraph 0040: the digital feedback signal provides the DPD controller 124 with feedback of the PA output signal. This allows the DPD controller to determine the non-linear characteristics of the PA output signal and to dynamically or adaptively adjust the predistortion coefficients of the DPD 104 based on the current and/or historical non-linear characteristics of the PA output signal to reduce non-linearity at the output of the PA 110. This will occur in each of the transmit chains shown in figure 2.).
Regarding claim 10, the combination discloses wherein the maximum total number of coefficients varies over time (Weiss: Paragraph 0043 by varying the memory and the polynomial order, in case of a memory polynomial function, it can be estimated, how complex it will be to implement the predistortion. If, for example, a reduction of the number of taps from 11 to three does not change the performance of the predistortion, a memory of three taps is sufficient. This is very advantageous if the predistortion is implemented as an FPGA. This will minimize the power consumed while maintaining performance at the same level as when more taps are used.).
Regarding claim 18, the combination discloses wherein the utility function is constrained by a maximum total number of coefficients collectively allocatable to all DPDs and wherein the maximum total number of coefficients is one of: dependent on a total available power budget for the DPDs (The DPDs cannot exceed the maximum total number of taps of all of the filters of the DPD. Therefore, the transmitter is constrained by that maximum. The function of the DPDs cannot exceed its maximum power.); and varying over time (Weiss: Paragraph 0043 by varying the memory and the polynomial order, in case of a memory polynomial function, it can be estimated, how complex it will be to implement the predistortion. If, for example, a reduction of the number of taps from 11 to three does not change the performance of the predistortion, a memory of three taps is sufficient. This is very advantageous if the predistortion is implemented as an FPGA. This will minimize the power consumed while maintaining performance at the same level as when more taps are used.).
4. Claims 11 and 23 are rejected under 35 U.S.C. 103 as being unpatentable over Gutman et al (US 2019/0089389) in view of Weiss (US 2018/0102799) in view of Strong (US 2008/0112506) in view of Moosavi et al (US 2019/0288822) further in view of Weber et al (US 2020/0186103).
Regarding claims 11 and 23, the combination of Gutman, Weiss, Strong and Moosavi disclose the node and method stated above. The combination does not disclose wherein the sizes of the DPDs are, according to a dynamic model, adaptively determined over time based on previously determined sizes of the DPDs.
Weber discloses polyphase digital signal predistortion in radio transmission as stated in the abstract. Weber discloses figure 5 illustrates the predistortion model taps used in the third setup as discussed in relation to figure 4. By fully optimizing which taps to use with which predistorter, the number of taps may be reduced without compromising the performance which leads to a reduction in the complexity of the required implementations as stated in paragraph 0056. Since the previous number of taps used to achieve the previous performance is necessary to determine if performance is compromised, the previously determined number of taps of the DPD is used to determine the new reduced number of taps. It would have been obvious for one of ordinary skill in the art before the effective filing date of the claimed invention to combine the teaching of Weber in the node and method of the combination of Gutman, Weiss, Strong and Moosavi to lead to a reduction in the complexity of the required implementations as stated by Weber.
5. Claims 12 and 24 are rejected under 35 U.S.C. 103 as being unpatentable over Gutman et al (US 2019/0089389) in view of Weiss (US 2018/0102799) in view of Strong (US 2008/0112506) in view of Moosavi et al (US 2019/0288822) further in view of Cheng et al (US 2015/0280657).
Regarding claims 12 and 24, the combination of Gutman, Weiss, Strong and Moosavi disclose the node and method stated above. The combination does not disclose wherein the access node obtains channel gain estimates per each of the plurality of antennas for a plurality of user equipment served by the access node, and wherein the utility function depends on downlink capacity for each of the user equipment.
Cheng discloses an adaptive digital pre-distortion (DPD) device as described in the abstract. Paragraph 0036 discloses the type and amount of distortion introduced to the input signal by the adaptive DPD circuit may change based on transmission parameters (e.g., data rate or transmission power) associated with the input signal. Paragraph 0039 discloses if the transmission parameter meets a threshold (e.g., the data rate is below a data rate threshold) the wireless device may select a DPD mode to achieve a non-linear power output. The maximum data rate will correspond to the downlink capacity for the receiver. It would have been obvious for one of ordinary skill in the art before the effective filing date of the claimed invention to combine the teaching of Cheng into the node and method of the combination of Gutman, Weiss and Moosavi to better control the type, amount and degree of distortion that takes place in the DPD in response to conditions in the communication system and improve the efficiency and effectiveness of the communication system.
Conclusion
Applicant's amendment necessitated the new ground(s) of rejection presented in this Office action. Accordingly, THIS ACTION IS MADE FINAL. See MPEP § 706.07(a). Applicant is reminded of the extension of time policy as set forth in 37 CFR 1.136(a).
A shortened statutory period for reply to this final action is set to expire THREE MONTHS from the mailing date of this action. In the event a first reply is filed within TWO MONTHS of the mailing date of this final action and the advisory action is not mailed until after the end of the THREE-MONTH shortened statutory period, then the shortened statutory period will expire on the date the advisory action is mailed, and any nonprovisional extension fee (37 CFR 1.17(a)) pursuant to 37 CFR 1.136(a) will be calculated from the mailing date of the advisory action. In no event, however, will the statutory period for reply expire later than SIX MONTHS from the mailing date of this final action.
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/KEVIN M BURD/Primary Examiner, Art Unit 2632 10/2/2025