Cancellation of passive intermodulation from multiple sources

Abstract

A system includes a receiver (RX) configured to receive an RX output signal in an RX frequency band, where the RX output signal has a first passive intermodulation (PIM) source in the RX frequency band and a second PIM source in the RX frequency band; and a processing device configured to receive an RX output signal from the receiver on an RX path, receive a CFR output signal from a crest factor reduction (CFR) on a transmit (TX) path, identify a first PIM source and a second PIM source based on the RX output signal and the CFR output signal, calibrate the CFR output signal based on the first PIM source and the second PIM source of the RX output signal to produce a non-linear excitation (NA) input signal, and output the non-linear excitation (NA) input signal to the receiver. And generating an intermodulation distortion signal by using the NA function on the NA input signal.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to U.S. Provisional Application No. 63 / 362,407, filed on April 3, 2022, the disclosure of which is incorporated herein by reference in its entirety. Technical Field

[0003] Embodiments discussed in this disclosure relate to enhancing receiver sensitivity through passive intermodulation cancellation (PIMC). Background Art

[0004] Unless otherwise indicated herein, the materials described herein are not prior art to the claims in this application and are not admitted to be prior art by inclusion in this section.

[0005] Passive intermodulation usually refers to the intermodulation products generated when two or more signals pass through passive devices with nonlinear characteristics. Passive intermodulation may be caused by communication equipment or environmental factors. Passive intermodulation may interfere with the desired received signal.

[0006] The claimed subject matter is not limited to embodiments that solve any disadvantages or operate only in environments such as those described above. Rather, this background is merely provided to illustrate one example technology area where some embodiments described in this disclosure may be practiced. Summary of the invention

[0007] In some embodiments, a base station may be configured for enhanced receiver sensitivity. The base station may include: a receiver (Rx) configured to receive an Rx output signal in an Rx frequency band; and a processing device. The processing device may be configured to: receive the Rx output signal from the receiver on an Rx path; receive a CFR output signal from a Crest Factor Reduction (CFR) on a Transmit (Tx) path; calibrate the CFR output signal based on the Rx output signal to generate a nonlinear excitation (NA) input signal; and generate an intermodulation distortion signal by applying a NA function to the NA input signal.

[0008] In some embodiments, a computer-readable storage medium may include computer-executable instructions that, when executed by one or more processors, may cause a base station to calculate one or more calibration parameters on a passive intermodulation cancellation (PIMC) control path to match a crest factor reduction (CFR) output signal with a receiver (Rx) output signal. The computer-executable instructions may cause the base station to calculate one or more PIMC coefficients of a nonlinear excitation (NA) function on the PIMC control path. The computer-executable instructions may cause the base station to send one or more calibration parameters and one or more PIMC coefficients from the PIMC control path to the PIMC data path to generate an intermodulation distortion signal based on the NA function.

[0009] In some embodiments, a base station may be configured for enhanced receiver sensitivity, the base station may include a receiver (Rx) and a processing device, the receiver configured to receive an Rx output signal in an Rx frequency band, wherein the Rx output signal has a first passive intermodulation (PIM) source in the Rx frequency band and a second PIM source in the Rx frequency band. The processing device may be configured to: receive the Rx output signal from the receiver on an Rx path; receive a CFR output signal from a CFR reduction (CFR) on a transmit (Tx) path; identify the first PIM source and the second PIM source based on the Rx output signal and the CFR output signal; calibrate the CFR output signal based on the first and second PIM sources in the Rx output signal to generate a nonlinear excitation (NA) input signal; and generate an intermodulation distortion signal by using a NA function on the NA input signal.

[0010] In some embodiments, a base station may be configured for enhanced receiver sensitivity, the base station may include a receiver (Rx) path, a diagnostic receiver (dRx) path, and a processing device, the receiver (Rx) path being configured to receive an Rx output signal, the diagnostic receiver (dRx) path being configured to receive a dRx output signal, wherein the dRx output signal has an external source. The processing device may be configured to: receive the Rx output signal from the receiver path; receive the dRx output signal from the dRx path; calibrate the dRx output signal based on the Rx output signal to generate a dRx nonlinear excitation (NA) input signal; and generate a dRx intermodulation distortion signal by applying a dRx NA function to the dRx NA input signal.

[0011] In some embodiments, a computer-readable storage medium may include computer-executable instructions that, when executed by one or more processors, may cause a base station to: calculate one or more diagnostic receiver (dRx) calibration parameters on a passive intermodulation cancellation (PIMC) control path to match a dRx output signal to a receiver (Rx) output signal, wherein the dRx output signal has an external source; calculate one or more dRx PIMC coefficients of a dRx nonlinear excitation (NA) function on the PIMC control path; and send one or more dRx calibration parameters and one or more dRx PIMC coefficients from the PIMC control path to the PIMC data path to generate a dRx intermodulation distortion signal based on the dRx NA function.

[0012] The objects and advantages of the embodiments may be realized and attained by at least the elements, features, and combinations particularly pointed out in the claims.

[0013] Both the foregoing general description and the following detailed description are presented by way of example and are explanatory and not restrictive of the invention, as claimed. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Additional specificity and detail will be described and illustrated with respect to example embodiments through the use of the accompanying drawings, in which:

[0015] Figure 1A An example radio frequency spectrum including passive intermodulation is shown.

[0016] Figure 1B An example radio frequency spectrum including passive intermodulation cancelled by passive intermodulation cancellation is shown.

[0017] Figure 2 An example communication system configured to cancel passive intermodulation is shown.

[0018] Figure 3 An example block diagram showing the data path and control path for passive intermodulation cancellation is shown.

[0019] Figure 4 An example signal propagation through the modules of a passive intermodulation cancellation system is shown.

[0020] Figure 5A —5C illustrates an example of passive intermodulation cancellation.

[0021] Figure 6 An example communication system configured to cancel passive intermodulation generated by multiple sources is shown.

[0022] Figure 7 An example communication system configured to eliminate internal and external passive intermodulation is shown.

[0023] Figure 8 An example block diagram showing the data path and control path for internal and external passive intermodulation cancellation is shown.

[0024] Fig. 9 A process flow for configuring a base station for enhanced receiver sensitivity is shown.

[0025] Fig.10 A process flow of a computer readable medium for enhanced receiver sensitivity is shown.

[0026] Fig.11 A process flow for configuring a base station for enhanced receiver sensitivity is shown.

[0027] Fig.12 A process flow for configuring a base station for enhanced receiver sensitivity is shown.

[0028] Fig.13 A process flow of a computer readable medium for enhanced receiver sensitivity is shown.

[0029] Fig.14An example communication system according to one example is shown.

[0030] Fig.15 A diagram is shown of a machine in the example form of a computing device within which a set of instructions may be executed, for causing the machine to perform any one or more of the methodologies described herein.

[0031] Fig.16 A graph of an example nonlinear excitation function for canceling passive intermodulation from one source is shown.

[0032] Fig.17 A graph of an example nonlinear excitation function that cancels passive intermodulation from two sources is shown. DETAILED DESCRIPTION

[0033] Communication systems can be subject to passive intermodulation that can interfere with communication signals. Passive intermodulation (PIM) can occur even when no active components are present due to the nonlinear response of passive components to signals. PIM can be generated by electronic components (e.g., coaxial connectors, headers, switches, feed lines, loose connections, dirty connections, isolators, etc.), oxidized metals (e.g., rusted nails), ferromagnetic metals (e.g., iron), or interfaces between dissimilar metals. In some cases, PIM can be generated by components that normally exhibit linear characteristics. When the magnitude of PIM exceeds a threshold, PIM can interfere with the desired signal.

[0034] When the amplitude is low enough, passive intermodulation and its effect on the desired signal will not interfere with the communication equipment. However, when modulation is applied to a signal with passive intermodulation, the modulated signal may occupy a larger bandwidth. In addition, when the transmitter and receiver share the same antenna by using a duplexer, the passive intermodulation affecting the transmitter can be removed by using filters and reduced to a level without excessive noise when the receiver receives it. In contrast, when the transmit and receive signal paths are combined in the antenna, the receiver may encounter passive intermodulation that cannot be eliminated. Various communication systems can use the same antenna, such as base stations, satellite systems, duplex communication systems, etc.

[0035] At higher power levels, passive components may exhibit nonlinear behavior and generate PIM. When PIM falls on the receive band, PIM may desensitize the receiver. PIM cancellation (PIMC) can be achieved by reducing or mitigating PIM to enhance receiver sensitivity. For frequency division duplex (FDD) use cases, PIMC can be applied to internal PIM, where both the PIM-generating components and the PIM-affected components are located within the same communication device (e.g., a radio unit).

[0036] In specific applications, such as macrocell and remote radio head (RRH) applications, PIM can be eliminated. PIMC allows the equipment to include low-cost duplex filters that would otherwise generate excessive PIM and interfere with the received signal. In addition, duplexers, cables, and connectors can degrade over time due to exposure to the elements, resulting in oxidation and increased PIM generation. As a result, PIMC can reduce technician visits, radio downtime, and generally reduce radio maintenance costs.

[0037] Disclosed herein are systems, devices, and methods for eliminating PIM to enhance receiver sensitivity. In some embodiments, a base station may include a receiver (Rx) configured to receive an Rx output signal in an Rx frequency band; and a processing device. The processing device may be configured to: receive the Rx output signal from the receiver on the Rx path, and receive a crest factor reduction (CFR) output signal from the CFR on the transmit (Tx) path. The processing device may be configured to calibrate the CFR output signal based on the Rx output signal to generate a nonlinear excitation (NA) input signal, and generate an intermodulation distortion signal by using a NA function on the NA input signal.

[0038] Disclosed herein are systems, devices, and methods for eliminating PIM from multiple sources. In some embodiments, a base station may include an Rx and processing device configured to receive an Rx output signal in an Rx band, wherein the Rx output signal has a first PIM source in the Rx band and a second PIM source in the Rx band. The processing device may be configured to: receive the Rx output signal from a receiver on an Rx path; receive a CFR output signal from a CFR on a Tx path, and identify a first PIM source and a second PIM source based on the Rx output signal and the CFR output signal. In some embodiments, the processing device may be configured to calibrate the CFR output signal based on the first PIM source and the second PIM source in the Rx output signal to generate a nonlinear excitation (NA) input signal, and generate an intermodulation distortion signal by using a NA function on the NA input signal.

[0039] Embodiments of the present invention will be described with reference to the accompanying drawings.

[0040] In some embodiments, Figure 1A As shown, a radio frequency (RF) spectrum 100 may include a receive (Rx) band 110 and a transmit (Tx) band 120. The Rx band 110 may include an Rx channel Rx C0 112 and an Rx channel Rx C1 114. The Tx band may include a Tx channel Tx C0 122 and a Tx channel Tx C1 124. When an Rx sensitivity threshold 130 is less than a receive signal amplitude 113, 115 of the receive signal in the Rx channels 112, 114, a receive signal may be sensed in the Rx channels 112, 114.

[0041] However, in some embodiments, the presence of intermodulation distortion (IMD) 142 may prevent the received signal in the Rx channel 114 from being sensed when the IMD has an amplitude 142 greater than the Rx sensitivity threshold 130 and the received signal amplitude 115. When greater than the Rx sensitivity threshold 130, the intermodulation distortion 142 may interfere with the sensing of the received signal in the Rx channel 114, as shown by the frequency and amplitude overlap between the Rx channel RxC1 114 and the intermodulation distortion 142. As shown by the intermodulation distortion 144, other IMD may exist in unrelated frequency bands.

[0042] In some embodiments, Figure 1B As shown, the RF spectrum 150 may include an Rx band 160 having an Rx channel RxC0 162 with an amplitude 163 and an Rx C1 164 with an amplitude 165, and a Tx band 170 having Tx channels Tx C0 172 and Tx C1 174. The Rx sensitivity threshold 180 may indicate when the intermodulation distortion 192 may interfere with the Rx signal in the Rx channel 164. In this example, Figure 1A Compared to the intermodulation distortion 142 in the receiver and the Rx sensitivity threshold 130, the intermodulation distortion 192 is less than the Rx sensitivity threshold 180. Therefore, reducing the intermodulation distortion can enhance the receiver sensitivity.

[0043] In some embodiments, Figure 2 As shown, the communication system 200 may include one or more of the following: a digital up conversion (DUC) block 202, a crest factor reduction (CFR) block 204, a digital predistortion exciter (DPD) 206, a transmitter (Tx) 208, a power amplifier (PA) 210, a Tx bandpass filter 212, an Rx bandpass filter 214, a low noise amplifier 216, a receiver (Rx) 218, a passive intermodulation cancellation (PIMC) block 220, a digital down conversion (DDC) block 222, an antenna 224, a duplexer 226, and the like.

[0044] In some embodiments, the base station may be configured for enhanced receiver sensitivity. The base station may include a receiver (Rx) 218 ​​configured to receive an Rx output signal 230 in an Rx frequency band. The base station may include a processing device (e.g., at the PIMC 220) configured to receive the Rx output signal 230 from the receiver 218 on an Rx path (e.g., a signal path from the antenna 224 to the Rx bandpass filter 214, to the low noise amplifier 216, to the receiver 218). The processing device may be configured to receive a crest factor reduction (CFR) output signal 228 from the CFR 204 on a transmit (Tx) path (e.g., a signal path from the DUC 202 to the CFR 204). The processor may be configured to calibrate the CFR output signal 228 based on the Rx output signal 230 to generate a nonlinear excitation (NA) input signal. The processor may be configured to generate an intermodulation distortion signal by using a NA function on the NA input signal.

[0045] In some embodiments, in the communication system 200, the CFR output 228 can be used to generate a cancellation signal to reduce the internal PIM in the Rx output signal 230, thereby enhancing the receiver sensitivity. In some embodiments, the communication system 200 can be configured to tap the transmit signal for generating the cancellation signal from different output blocks on the transmit path (e.g., outputs from DUC 202, DPD 206, Tx 208, Tx bandpass filter 212, etc.). In some embodiments, the communication system 200 can be configured to tap the receive signal from different output blocks on the receiver path (e.g., outputs from Rx bandpass filter 214, low noise amplifier 216, DDC 222, etc.). When no transmit signal is tapped at the CFR output 228 and no receive signal is tapped at the Rx Out 230, the PIMC module can be reconfigured to cancel the PIM based on the specific signal received.

[0046] In some embodiments, tapping at the CFR output 228 (by receiving the CFR output via connection 234) can enhance receiver sensitivity compared to other tapping locations on the transmit path. For example, tapping the signal before the DUC 202 may result in various types of distortion, such as aliasing, aperture error, and quantization. Aliasing may occur when the sampling rate is too low, which may be the case before digital up-conversion because the component carriers may overlap. In addition, tapping after the Tx 208 may result in undersampling and / or may result in intermodulation products that are not at the appropriate frequency. Therefore, tapping at the CFR output 228 can provide intermodulation at the appropriate frequency for generating a passive intermodulation cancellation signal. The DPD 206 can be configured to match the output of the power amplifier 210 to the CFR output so that the PIMC generated based on the CFR output can match the signal that generates the intermodulation distortion (e.g., the PIM source 232 from the signal path 236).

[0047] In some embodiments, when the transmit signal is tapped at the CFR output and the receive signal is tapped at Rx Out 230, the signal propagation in the frequency domain may be as follows: Figure 3 314 and 316. The PIMC system 300 is shown in FIG. 314. The PIMC system 300 shows a PIMC data path 314 and a PIMC control path 316. When samples become available, the sub-blocks in the PIMC data path 314 process data IQ samples in real time. Therefore, these sub-blocks can be implemented using high-speed hardware logic. On the other hand, the sub-blocks in the PIMC control path 316 provide configuration parameters and coefficients. These sub-blocks can be implemented using high-speed hardware logic or software running on a host processor.

[0048] In some embodiments, a receiver signal (e.g., Rx output signal 308) in Rx band 302 may be received at PIMC data path 314. PIMC data path 314 may also be configured to receive CFR output signal 310 in Tx band 304. PIMC data path 314 and PIMC control path 316 may be configured to generate a correct Rx signal 312 having reduced IMD compared to Rx output signal 308 to facilitate enhanced receiver sensitivity as shown in Rx band 306.

[0049] In some embodiments, the CFR output signal 310 may be calibrated based on one or more time delay coefficients in the time delay and gain adjustment operation 318. Alternatively or additionally, the CFR output signal 310 may be calibrated based on one or more gain adjustment coefficients. Alternatively or additionally, the CFR output signal 310 may be calibrated based on one or more phase adjustment coefficients. As shown in operation 332 on the PIMC control path 316, one or more time delay coefficients, gain adjustment coefficients, or phase adjustment coefficients may be calculated.

[0050] In some embodiments, as shown in operation 320, the NA function may be calculated using a nonlinear function including one or more of a lookup table (LUT), a polynomial, a wavelet function, a piecewise linear (PWL) function, and the like. As shown in operation 322, the nonlinear function may be calculated using passive intermodulation cancellation (PIMC) coefficients. As shown in operation 334, the PIMC coefficients may be estimated by calculating a least squares solution using one or more of the following: a closed form using an inverse matrix, or a gradient descent using a fixed step size parameter, or a conjugate gradient descent using a dynamic step size parameter. The PIMC coefficients may be estimated based on one or more parameters including a leakage factor, a batch number, or a batch size. The fixed step size parameter or the dynamic step size parameter may be configured based on one or more of closed loop stability, estimated noise suppression, or convergence time. The PIMC coefficients may be sent to the PIMC coefficient 322 operation for use in the nonlinear excitation operation 320.

[0051] In some embodiments, a frequency shift of the intermodulation distortion signal (i.e., the signal output from the nonlinear excitation operation 320) can be calculated at operation 336 and applied at operation 324 to match the frequency location of the passive intermodulation in the Rx output signal 308. Based on this frequency shift of the intermodulation distortion signal, one or more filters can be configured to remove signals outside the frequency range of the PIMC signal. Alternatively or additionally, the multi-band filter can be configured to select the Rx frequency range to remove interleaved uplink and downlink frequency bands.

[0052] In some embodiments, the intermodulation distortion signal may be resampled, as shown at operation 326 , to match the IQ sampling rate of the Rx output signal 308 based on the resampling ratio between the Rx output signal 308 and the CFR output signal 310 calculated at operation 336 .

[0053] In some embodiments, the PIMC data path 314 may include an adaptive filter configured to adjust the gain and / or phase of the intermodulation distortion signal, as shown in operation 328. The gain and / or phase may be adjusted based on automatic gain control (AGC) errors, low noise amplifier (LNA) errors, temperature induced errors, etc.

[0054] In some embodiments, the PIMC subtractor 330 may be configured to generate a corrected Rx signal based on the intermodulation distortion signal (i.e., the output of the nonlinear exciter 320, which may be processed by the frequency shift and filtering operation 324, the resampling operation 326, and the adaptive gain operation 328) and the Rx output signal 308.

[0055] In some embodiments, the PIMC data path 314 and / or the PIMC control path 316 can be configured to generate a PIMC bypass signal. The PIMC bypass signal can prevent passive intermodulation cancellation from occurring. The PIMC bypass signal can be generated when the antenna is being calibrated, a power amplifier (PA) protection process is being performed, or one or more of the PIMs are not detected based on one or more of the frequency assignment or estimated PIM correction levels.

[0056] In some embodiments, the PIMC data path may include an onboard calibration unit or an onboard coefficient estimation engine. The onboard calibration unit may be configured to calibrate the CFR output signal 310 based on the Rx output signal 308 using adaptive calculations and adaptive adjustments. The onboard coefficient estimation engine may be configured to calculate the NA function using one or more passive intermodulation cancellation (PIMC) coefficients, which may be calculated and updated based on radio communication data (e.g., which may be received in real time).

[0057] In some embodiments, PIMC data path 314 may be implemented using high-speed processing, which may be implemented using a field programmable gate array (FPGA) or an application specific integrated circuit (ASIC). PIMC control path 316 may be implemented using an FPGA or ASIC, or may be implemented as computer-readable instructions executed by a processor.

[0058] In some embodiments, Figure 4 As shown, the PIMC system 400 can be configured to direct the signal through one or more of a delay block 412, a gain block 414, a nonlinear excitation block 424 interfaced with a PIMC coefficient block 422, a frequency shift block 432, a bandpass filter block 434, and a resampling block 436. The PIM calibration block 410 can be configured to send PIM calibration parameters to one or more of the delay block 412, the gain block 414, or a phase block (not shown). The PIM estimator block 420 can be configured to send the PIMC coefficients to the PIMC coefficient block 422. The PIMC configuration block 430 can be configured to send PIM configuration parameters to one or more of the frequency shift block 432, the bandpass filter block 434, or the resampling block 436.

[0059] In some embodiments, the PIM elimination process may include: (i) generating a CFR output (i.e., u NA-IN ). signal(u NA-IN ) can be input to the nonlinear excitation block 424 to generate an output, namely u NA-OUT . signal(u NA-OUT) can be input to the frequency shift block 432 to generate the PIM cancellation signal to align the Rx output signal in the frequency domain. The frequency planning of the radio can be used to align the Rx output signal with the PIM cancellation signal.

[0060] In some embodiments, after frequency shifting, a bandpass filter block 434 can be used to filter out out-of-band frequency components to retain the desired cancellation signal. After filtering, a resampling block 436 can be configured to match the cancellation signal and the received signal sampling rate. In some examples, the Rx output sampling rate can be different from the CFR output sampling rate. When the sampling rates are matched, the PIM cancellation signal can be subtracted from the Rx output signal. After matching the sampling rates, an adaptive gain block (e.g., Figure 3 328 in the Rx output signal) can be configured to measure the PIM level in the Rx output signal and adaptively adjust the gain of the cancellation signal to achieve maximum cancellation. After adaptively adjusting the gain of the cancellation signal, the subtractor (e.g., Figure 3 330) in can be configured to eliminate the generated PIM elimination signal from the Rx output signal.

[0061] In some embodiments, the CFR output signal 402a may be directed to a delay block 412. The delay block 412 may be configured to facilitate time alignment between the CFR output signal 402a and the Rx output signal. Several methods may be used to calculate the delay, including one or more of a round trip delay, a cross-correlation error, or a mean square error between the CFR output signal 402a and the Rx output signal. In some examples, delay alignment may be applied using one or more of an integer delay (e.g., sampling alignment) or a fractional delay (e.g., sub-sampling alignment). When there are multiple PIM sources (e.g., PIM at a duplexer junction and PIM at an antenna connector interface), the delay of each source may be estimated and applied.

[0062] In some embodiments, the CFR output signal 402a can be configured to be directed to a gain block 414. The gain block can be configured to multiply an input signal (e.g., the CFR output signal 402a directed from the delay block 412) by a gain adjustment coefficient to align amplitude values ​​between the CFR output signal 402a and the Rx output signal. The gain adjustment coefficient can be calculated based on one or more of: (i) a gain adjustment match between the CFR output signal 402a and the NA function input signal, (ii) an automatic gain control (AGC) radio frequency (RF) attenuation state of the Rx output signal, or (iii) changes caused by temperature or component aging. Matching the CFR output gain adjustment to the nonlinear excitation function input can minimize rounding and saturation effects due to specific fixed-point hardware implementations. Changes caused by temperature or component aging may result in slow and continuous changes in PIM, which can be accommodated by using a PIM cancellation signal with dynamic runtime gain adjustment and / or phase adjustment.

[0063] In some embodiments, the CFR output signal 402a can be configured to be directed to a phase block (not shown). The phase block can be configured to multiply the input signal (e.g., the CFR output signal 402a directed from one or more of the delay block 412 or the gain block 414) by a phase adjustment coefficient to align the phase value between the CFR output signal 402a and the Rx output signal. The phase adjustment coefficient can be calculated based on one or more of the following: (i) phase adjustment matching between the CFR output signal and the NA function input signal, or (ii) changes due to temperature or component aging.

[0064] In some embodiments, the computer-readable storage medium may include computer-executable instructions that, when executed by one or more processors, may cause the base station to calculate one or more calibration parameters on a passive intermodulation cancellation (PIMC) control path to match the CFR output signal 402a to the receiver (Rx) output signal. The one or more calibration parameters may include one or more delay values, gain adjustment coefficients, or phase adjustment coefficients, which may be sent from the PIM calibration block 410 to the delay block 412, the gain block 414, or the phase block (not shown).

[0065] In some embodiments, the PIMC calibration parameters may be calculated on a control path (e.g., PIMC control path 316). For the control path, the data processing speed may be, for example, on the order of about one second, which may be slower than the processing speed of the data path (e.g., 314), which may be, for example, on the order of millions of samples per second. Generating a PIMC signal on the order of seconds may be sufficient to prevent PIM from interfering with the Rx output signal.

[0066] In some embodiments, PIMC coefficients may be calculated on a control path (e.g., PIMC control path 316). One or more PIMC coefficients may be calculated for a nonlinear excitation (NA) function. One or more PIMC coefficients may be calculated by calculating a least squares solution using one or more of the following: a closed form using an inverse matrix, or gradient descent using a fixed step size parameter, or conjugate gradient descent using a dynamic step size parameter. PIMC coefficients may be estimated based on one or more parameters including a leakage factor, number of batches, batch size, etc. One or more of the fixed step size parameters or the dynamic step size parameters may be configured based on one or more of closed-loop stability, estimated noise suppression, or convergence time. In some examples, one or more PIMC coefficients may be calculated using a coefficient vector that may be iteratively updated after a selected number of samples.

[0067] In some embodiments, the coefficients of the nonlinear function The PIM may be calculated by a PIM estimator block 420. The PIM estimator block 420 may be implemented as computer readable instructions executable by a processor. If a processor is not available, dedicated hardware logic may be used to implement the estimation. The estimator may be configured to measure changes in PIM over time.

[0068] In some embodiments, the PIMC coefficient estimates may be calculated based on a least squares equation of the form Ax=b. Several methods may be used to calculate this solution x=argmin|Ax-b|. In one example, a closed form solution based on pseudo-inverse (e.g., x=(A H A) -1 A H b) to calculate the solution x.

[0069] In some embodiments, a solution may be calculated using a computationally inexpensive gradient descent method. The coefficient vector may be updated iteratively periodically, for example, by updating each sample (or block of samples) in the direction of the gradient vector with a small step size, as determined by a step size parameter. The gradient may include a simple correlation of the error signal and the input signal associated with each coefficient, and computationally expensive matrix inversion may not be used. The gradient step size may be configured based on closed-loop stability, estimation noise suppression, and convergence time. A fixed step size may reduce computation time, but may also suffer from long convergence times. Long convergence times may be mitigated by using a dynamic step size based on a conjugate gradient descent technique, at the expense of additional complexity.

[0070] In some embodiments, a start time or duration of one or more of the Tx output samples or the Rx output samples may be identified to estimate one or more PIMC coefficients based on one or more of the Tx power level or the Rx interference level. In some embodiments, a sampling rate of the NA function may be calculated to minimize nonlinear components. In some embodiments, one or more sample amplitude delay pairs may be calculated for the NA function. In some embodiments, the NA function may be configured to eliminate more than one passive intermodulation source.

[0071] In some embodiments, the PIMC coefficients may be sent to a PIMC coefficient block 422, which may be configured to interface with a nonlinear excitation block 424. The nonlinear excitation block 424 may be configured to generate an intermodulation distortion signal using an NA function. The NA function generates an intermodulation distortion signal that may be used to generate a PIMC signal for PIM cancellation. Assuming u NA-IN [n] and u NA-OUT [n] are the input and output signals respectively, and the NA function can be calculated as follows:

[0072]

[0073] In some embodiments, A nonlinear function may be included that may be computed in several ways, including one or more of: (i) a lookup table (LUT), (ii) a polynomial, (iii) a wavelet function, or (iv) a piecewise linear (PWL) function. In one example, a LUT may help reduce computational complexity compared to other methods, but may involve a larger amount of memory than other methods. In another example, a polynomial approach for a nonlinear function may involve less memory than other methods, but may use a larger amount of computation than other methods. In another example, a wavelet function may facilitate: (i) computational complexity that may be lower than a polynomial approach but higher than a LUT approach, and (ii) more memory usage than a polynomial approach but less than a LUT approach. In another example, a piecewise linear approach may facilitate computational complexity and memory usage that may be between a polynomial approach and a LUT approach.

[0074] In some embodiments, nonlinear functions can be calculated using machine learning, neural networks, etc. In some examples, gradient descent methods can be used to calculate nonlinear functions, such as conjugate gradient descent, stochastic gradient descent (e.g., Adam deep learning optimizer), etc.

[0075] In some embodiments, the delay limits P1, P2, Q1, Q2 may be fixed for the implementation, or may be flexible to allow reconfiguration of the PIMC nonlinear excitation block. This flexibility allows the nonlinear excitation to model single or multiple PIM sources by reorganizing the memory relationships.

[0076] In some embodiments, one or more PIMC configuration parameters may be calculated to generate a PIMC signal, wherein the one or more PIMC configuration parameters include one or more of the following: a frequency shift of an intermodulation distortion signal, a filter configuration parameter, a resampling ratio between an Rx output signal and a CFR output signal, or a resampling timing phase adjustment between an Rx output signal and a CFR output signal. The PIMC configuration parameters may be sent from the PIMC configuration block 430 to the frequency shift block 432, the bandpass filter block 434, or the resampling block 436.

[0077] In some embodiments, after being processed by the nonlinear excitation block 424, the PIM configuration block can be configured to calculate a frequency shift to match the frequency location of the passive intermodulation in the Rx output signal. In one example, the frequency shift of the intermodulation distortion signal can be calculated to align with the frequency location of the PIM signal in the Rx output signal. In some examples, the frequency shift can be calculated based on the Tx / Rx frequency allocation between the Rx frequency band of the Rx output signal and the Tx frequency band of the CFR output signal.

[0078] In some embodiments, filter configuration parameters may be calculated for one or more filters to: (i) remove signals outside the frequency range of the PIMC signal, (ii) remove interleaved uplink and downlink frequency bands in the Rx frequency range; or (iii) based on one or more of a Tx / Rx duplexer profile or a Tx leakage suppression condition. In some examples, the PIM configuration block 430 may be configured to calculate a resampling ratio between the Rx output signal and the CFR output signal. In one example, the PIM configuration block 430 may be configured to generate filter parameters such that the cancellation signal remains while other frequency components are filtered out.

[0079] In some embodiments, the PIMC configuration block 430 can be configured to calculate the sampling rate of the NA function to minimize the nonlinear component. In another example, a resampling timing phase adjustment can be calculated. In one example, one or more sample amplitude delay pairs can be calculated for the NA function. In one example, the PIMC configuration block 430 can be configured to send one or more PIMC configuration parameters from the PIMC control path to the PIMC data path (e.g., to the frequency shift block 432, the bandpass filter block 434, or the resampling block 436) to generate a PIMC signal based on the intermodulation distortion signal.

[0080] In some embodiments, the signal introduced into the resampling block 436 can be downsampled so that the IQ sampling rate of the Rx output signal and the cancellation signal is the same. In some radios, due to DPD bandwidth extension, the sampling rate of the CFR output may be higher than the Rx signal. For example, the Rx sampling rate may be 491.52Msps and the CFR output sampling rate may be 983.04Msps. In this example, the resampling block 436 can downsample the signal at 2x so that the CFR output sampling rate matches the Rx sampling rate. The downsampling rate can be provided by the PIMC configuration module 430.

[0081] In some embodiments, the adaptive gain block (e.g., Figure 3 A single tap adaptive filter may be used to normalize the gain and phase between the PIM signal and the PIM cancellation signal. The adaptive gain block may be configured to adjust for any automatic gain control (AGC), low noise amplifier (LNA) related errors, or temperature effects in gain or phase.

[0082] In some embodiments, the AGC may operate without notifying the PIMC that the gain set by the AGC has changed (e.g., from x to y). Figure 3 328) can use a 1-tap finite impulse response (FIR) filter to measure the change in AGC (e.g., from x to y). The power of the signal may be variable due to temperature fluctuations and other aging of components. The adaptive gain block (e.g., Figure 3 328) can be configured to record the cumulative change in gain to provide the correct amplitude to generate the PIMC signal.

[0083] In some embodiments, the PIM elimination subtraction block (e.g., Figure 3 330) can be configured to subtract the PIM cancellation signal 437a from the Rx output signal to generate a corrected Rx signal. The corrected Rx signal can have a higher signal quality, which can lead to an improvement in receiver sensitivity.

[0084] In one example, if Figure 5A As shown, a graph of normalized frequency (having a normalized range from -1 to 1) and Tx signal (measured in decibels relative to full scale, dBFS) shows two peaks (e.g., at approximately -0.3 and approximately 0.3). Figure 5B As shown, a graph of normalized frequency (having a normalized range from -1 to 1) and the Rx signal before PIMC (measured in decibels relative to full scale, dBFS) shows a peak 510b (eg, at approximately -0.1). Figure 5CAs shown, when PIMC has been applied, the peak in the middle 501c has been removed (as shown using a dashed line instead of a solid line). As a result of removing PIM, Figure 5C The graph in shows that the receiver sensitivity increases by more than 20dB.

[0085] In some embodiments, passive intermodulation may be generated by multiple sources. For example, in an environment with multiple user equipment (UE), each UE may contribute to passive intermodulation. In some examples, passive intermodulation may be generated from within the communication device, or from external sources of different types, such as rusty nails, chain link fences, various metal-to-metal contacts, etc. The presence of multiple PIM sources may be identified during the time alignment calibration process (e.g., by identifying multiple cross-correlation peaks, each corresponding to a PIM source).

[0086] In some embodiments, Figure 6 As shown, a communication device 600 (e.g., a base station) can be configured for enhanced receiver sensitivity. The communication device 600 can be configured to eliminate passive intermodulation from multiple sources. In some examples, the multiple sources can include multiple internal sources 651, 653 (i.e., sources from a base station). The communication device 600 may include a receiver (Rx) 618, which is configured to receive and send an Rx output signal 628 in an Rx band, wherein the Rx output signal 628 has a first passive intermodulation (PIM) source 651 in the Rx band and a second PIM source 653 in the Rx band. The PIMC 620 may include a processing device. The processing device may be configured to receive the Rx output signal 628 from the receiver 618 on the Rx path and receive a crest factor reduction (CFR) output signal 630 from the CFR on a transmit (Tx) path (e.g., 634). The processing device can be configured to identify the first PIM source 651 and the second PIM source 653 based on the Rx output signal 628 and the CFR output signal 630, and calibrate the CFR output signal 630 based on the first PIM source 651 and the second PIM source 653 in the Rx output signal to generate a nonlinear stimulus (NA) input signal. The processing device can be configured to generate an intermodulation distortion signal by using a NA function on the NA input signal.

[0087] In some embodiments, the communication device 600 (e.g., a base station) may include one or more of a DUC 602, a CFR 604, a DPD 606, a Tx 608, a low noise amplifier 610, a Tx bandpass filter 612, an Rx bandpass filter 614, a power amplifier 616, an Rx 618, a PIMC 620 and a DDC 622, an antenna 624, a duplexer 626, etc., each of which may be configured as provided herein.

[0088] In some embodiments, the PIMC 620 can be configured to generate PIMC signals of multiple PIM sources. In one example, the PIMC 620 can be configured to calibrate the CFR output signal 630 based on one or more time delay coefficients of the first PIM source 651 and one or more time delay coefficients of the second PIM source 653. In another example, the PIMC 620 can be configured to calibrate the CFR output signal 630 based on one or more gain adjustment coefficients and / or phase adjustment coefficients.

[0089] In some embodiments, the PIMC 620 may be configured to adjust one or more delay constraints in the NA function based on identification of first 651 and second 653 PIM sources in the Rx output signal 628. The first 651 and second 653 PIM sources may be present in the passive intermodulation signal 632, which may be present in the corrupted Rx output signal (e.g., 628 before the PIMC). The first 651 and second 653 PIM sources in the Rx output signal 628 may be identified by identifying a first cross-correlation peak and a second cross-correlation peak. The PIMC 620 may be configured to identify one or more storage elements storing the one or more delay constraints in a storage device to model the first and second PIM sources.

[0090] In some embodiments, the PIMC 620 can be configured to select multiple PIM sources to be eliminated in real time. The multiple PIM sources can include a first 651 and a second 653 PIM source. The first PIM source 651 can be assigned to a first group of nonlinear terms in a nonlinear function in a NA function. The second PIM source 653 can be assigned to a second group of nonlinear terms in a nonlinear function in a NA function. The PIMC 620 can be configured to generate an intermodulation distortion signal. The intermodulation distortion signal can be configured to eliminate the first PIM source 651 using the first group of nonlinear terms and to eliminate the second PIM source 653 using the second group of nonlinear terms. The PIMC 620 nonlinear excitation block can be configured to eliminate one PIM source or multiple PIM sources (e.g., 651 and 653) by regrouping the nonlinear terms, where each group is selected to correct one PIM source.

[0091] In some embodiments, PIMC 620 can be configured to analyze Rx output signal 628 to identify multiple PIM sources. When multiple PIM sources are identified as present, the relative physical distances between multiple PIM source pairs can be calculated based on the echoes in the signal with PIM (e.g., Rx output signal 628).

[0092] In some embodiments, Figure 7As shown, multiple PIM sources (e.g., 728, 752, 754) may exist internally and externally. When the multiple PIM sources include an internal PIM source 732 and an external PIM source 752, 754, the intermodulation generated by the internal PIM source 732 and the intermodulation generated by the external PIM source 752, 754 may be separated by using the CFR output signal 730 as the source of the internal PIM 732 and using the diagnostic receiver (dRx) output signal as the source of the external PIM 752, 754. The source of the external PIM source 752, 754 may include an external communication device 752, 754 (e.g., UE) that is not accessible to the communication device 700. The dRx receiver path (e.g., the bandpass filter 740, the low noise amplifier 742, and the dRx 744) may be used to receive a dRx output signal 746, which may be used to receive parameters associated with the external communication device 752, 754.

[0093] In some embodiments, the communication device 700 can be configured to eliminate PIM from internal sources 732 and external sources 752, 754. The communication device 700 (e.g., a base station) can be configured for enhanced receiver sensitivity. The communication device 700 may include a receiver (Rx) path (e.g., Rx bandpass filter 714, low noise amplifier 716, Rx 718) configured to receive the Rx output signal 728. The communication device 700 may include a diagnostic receiver (dRx) path (e.g., bandpass filter 740, low noise amplifier 742, dRx 744) configured to receive the dRx output signal 746. The dRx output signal 746 may include an external PIM source (e.g., 752 or 754). Although Rx 718 and dRx 744 have been shown as separate blocks on separate receive paths, different configurations are possible, including configurations where Rx 718 and dRx 744 are in the same block and / or on the same path.

[0094] In some embodiments, the communication device 700 may include a processing device configured to receive an Rx output signal 728 from a receiver path and a dRx output signal 746 from a dRx path. The processing device may be configured to calibrate the dRx output signal 746 based on the Rx output signal 728 to generate a dRx nonlinear excitation (NA) input signal. The processing device may be configured to generate a dRx intermodulation distortion signal by using a dRx NA function on the dRx NA input signal. The processing device may include a transmit (Tx) path configured to transmit a crest factor reduction (CFR) output signal 730 in a Tx frequency band, which may communicate via a path 734.

[0095] In some embodiments, the communication device 700 may include one or more additional elements, including DUC 702, CFR 704, DPD 706, Tx 708, low noise amplifier 710, Tx bandpass filter 712, Rx bandpass filter 714, power amplifier 716, Rx 718, PIMC 720 and DDC 722, antenna 724, duplexer 726, diagnostic antenna 748, etc., each of which may be configured as provided herein.

[0096] In some embodiments, PIMC 700 may include a flexible architecture that allows the same PIM elimination block to be configured to: (i) allocate all available resources to eliminate PIM from one source, (ii) share available resources evenly or unevenly to eliminate PIM from multiple sources, (iii) and / or deploy single-source or multi-source PIM elimination based on real-time calculations.

[0097] In some embodiments, Figure 8 As shown, the functionality 800 of the PIMC 720 may include a PIMC data path 810 and a PIMC control path 840. The PIMC data path 810 may include one or more of the following: a time delay and gain adjustment block 812, a first nonlinear excitation block 814, a first PIMC coefficient block 816, a first frequency shift and filter block 818, a first resampling block 820, a first adaptive gain block 830, or a first subtractor 834. The PIMC data path 810 may further include one or more of the following: a second nonlinear excitation block 822, a second PIMC coefficient block 824, a second frequency shift and filter block 826, a second resampling block 828, a second adaptive gain block 832, or a second subtractor 836. In some embodiments, the PIMC control path 840 may include a PIMC calibration block 842, a PIMC coefficient block 844, and a PIMC configuration block 846.

[0098] In some embodiments, the PIMC data path 810 can be configured to receive the Rx output signal 802, the CFR output signal 804, and the diagnostic Rx output signal 806. The Rx output signal 802 can be received from an internal source. The dRx output signal 806 can be received from the dRx path. The PIMC data path 810 can be configured to calibrate the dRx output signal 806 based on the Rx output signal 802 to generate a dRx nonlinear excitation (NA) input signal. The PIMC data path 810 can be configured to generate a dRx intermodulation distortion signal by using a dRxNA function on the dRx input signal. The PIMC data path 810 can be configured to generate a corrected Rx signal 808.

[0099] In some embodiments, the PIMC datapath block 810 may be configured to calibrate the CFR output signal 804 based on the Rx output signal 802 to generate a Tx nonlinear stimulus (NA) input signal and generate a Tx intermodulation distortion signal by applying a Tx NA function to the Tx NA input signal.

[0100] In some embodiments, the time delay and gain adjustment block 812 may be configured to calibrate the dRx output signal 806 based on one or more time delay coefficients and to calibrate the dRx output signal 806 based on one or more gain adjustment coefficients and / or phase adjustment coefficients. The time delay and gain adjustment block 812 may be configured to receive PIMC configuration parameters (e.g., time delay coefficients, gain adjustment coefficients, or phase adjustment coefficients) from the PIMC calibration block 842.

[0101] In some embodiments, the dRx NA function may be calculated using a nonlinear function including one or more of a lookup table (LUT), a polynomial, a wavelet function, a piecewise linear (PWL) function, etc. The nonlinear function may be calculated using one or more passive intermodulation cancellation (PIMC) coefficients. As shown in block 844, the PIMC coefficients may be estimated by calculating a least squares solution. The PIMC coefficients may be sent to the PIMC coefficient block 816 for use by the nonlinear excitation block 814.

[0102] In some embodiments, the PIMC data path 810 may include one or more filters configured to remove signals outside of a frequency range of the PIMC signal calculated based on a frequency shift of the dRx intermodulation distortion signal, as shown in block 818. The one or more filters may include a multi-band filter configured to select an Rx frequency range to remove interleaved uplink and downlink frequency bands in the Rx output signal 802.

[0103] In some embodiments, the PIMC data path 810 may include a resampling block 820 configured to align a sampling rate of an input signal (e.g., the frequency shifted and filtered received signal from block 818) with a sampling rate of an output signal (e.g., the corrected Rx signal 808).

[0104] In some embodiments, the PIMC configuration block 846 may calculate one or more dRx PIMC configuration parameters, including: a frequency shift of a dRx intermodulation distortion signal, a dRx filter configuration parameter, a resampling ratio between the Rx output signal 802 and the dRx output signal 806, or a resampling timing phase adjustment between the Rx output signal 802 and the dRx output signal 806.

[0105] In some embodiments, the PIMC data path 810 may include an adaptive filter 830 configured to adjust the gain and / or phase of the dRx intermodulation distortion signal based on automatic gain control (AGC) error, low noise amplifier (LNA) error, or temperature-induced error.

[0106] In some embodiments, the PIMC data path 810 may include a PIMC subtractor 834 configured to generate a corrected Rx signal 808 based on the dRx intermodulation distortion signal and the Rx output signal 802 .

[0107] In some embodiments, the PIMC data path 810 may include an on-board calibration unit configured to calibrate the dRx output signal 806 based on the Rx output signal 802 using adaptive calculation and adaptive adjustment. The PIMC data path 810 may include an on-board coefficient estimation engine configured to calculate the NA function using one or more passive intermodulation cancellation (PIMC) coefficients, which may be calculated and updated based on radio traffic data.

[0108] In some embodiments, the PIMC control path 840 can be configured as software (e.g., software running on a computer system or a dedicated machine). Alternatively or additionally, the functionality of the PIMC control path 840 can be implemented on the PIMC data path 810 using processing logic, which can include hardware (circuitry, dedicated logic, etc.).

[0109] In some embodiments, the PIMC control path 840 may include one or more of a PIMC calibration block 842, a PIMC coefficient estimation block 844, or a PIMC configuration block 846. The PIMC calibration block 842 may be configured to calculate one or more diagnostic receiver (dRx) calibration parameters to match the dRx output signal 806 to the receiver (Rx) output signal 802, where the dRx output signal 806 may have an external source. The PIMC calibration block 842 may be configured to send the one or more dRx calibration parameters to the time delay and gain adjustment block 812.

[0110] In some embodiments, the PIMC calibration block 842 may be configured to calculate one or more time delay coefficients based on one or more of a round trip delay, a cross correlation, a mean square error between the dRx output signal 806 and the Rx output signal 802, etc. Alternatively or additionally, the PIMC calibration block 842 may be configured to calculate one or more alignment parameters, including one or more of a sample alignment parameter or a sub-sample alignment parameter. Alternatively or additionally, the PIMC calibration block 842 may be configured to calculate one or more gain adjustment coefficients and / or phase adjustment coefficients based on one or more of a gain adjustment match and / or a phase adjustment match between the dRx output signal 806 and the dRx NA function input signal.

[0111] In some embodiments, the PIMC coefficient estimation block 844 can be configured to calculate one or more dRx PIMC coefficients for a dRx nonlinear excitation (NA) function and send the one or more dRx PIMC coefficients from the PIMC control path 840 to the PIMC data path 810 to generate a dRx intermodulation distortion signal based on the dRx NA function. In some embodiments, the PIMC coefficient estimation block 844 can be configured to calculate the one or more dRx PIMC coefficients by calculating a least squares solution using one or more of: (i) a closed form using an inverse matrix, (ii) gradient descent using a fixed step size parameter, or (iii) conjugate gradient descent using a dynamic step size parameter. In some examples, the dRx PIMC coefficients can be estimated based on one or more parameters including a leakage factor, a batch number, a batch size, etc. In some examples, the fixed step size parameter or the dynamic step size parameter can be configured based on one or more of closed-loop stability, estimated noise suppression, convergence time, etc. In some examples, the PIMC coefficient estimation block 844 may be configured to calculate a coefficient vector including dRx PIMC coefficients, which may be iteratively updated after a selected number of samples.

[0112] In some embodiments, the PIMC configuration block 846 may be configured to calculate one or more dRx PIMC configuration parameters to generate a dRx PIMC signal. The one or more dRx PIMC configuration parameters may include: a frequency shift of a dRx intermodulation distortion signal, a dRx filter configuration parameter, a resampling ratio between the Rx output signal 802 and the dRx output signal 806, and a resampling timing phase adjustment between the Rx output signal 802 and the dRx output signal 806. The PIMC configuration block 846 may be configured to calculate one or more dRx PIMC configuration parameters and send them from the PIMC control path 840 to the PIMC data path 810 to generate a dRx PIMC signal based on the dRx intermodulation distortion signal.

[0113] In some embodiments, the PIMC configuration block 846 may be configured to calculate a frequency shift to match the frequency location of the dRx passive intermodulation in the Rx output signal 802. The frequency shift may be based on a frequency allocation between the Rx frequency band of the Rx output signal 802 and the frequency band of the dRx output signal 806.

[0114] In some embodiments, the PIMC configuration block 846 may be configured to calculate dRx filter configuration parameters for one or more filters to: (i) remove signals outside the frequency range of the dRx PIMC signal; or (ii) remove interleaved uplink and downlink frequency bands in the Rx frequency range.

[0115] In some embodiments, the PIMC configuration block 846 can be configured to calculate a resampling ratio between the Rx output signal 802 and the dRx output signal 806. In some examples, the PIMC configuration block 846 can be configured to calculate one or more sample amplitude delay pairs of the dRx NA function. In some examples, the PIMC configuration block 846 can be configured to calculate a sampling rate of the dRx NA function to minimize a nonlinear component.

[0116] In some embodiments, the adaptive gain blocks (e.g., 830, 832) may be configured to facilitate gain adjustment and / or phase adjustment based on: (i) automatic gain control (AGC) radio frequency (RF) attenuation state of the Rx output signal, or (ii) changes due to temperature or component aging.

[0117] In some embodiments, various parameters associated with the dRx output signal or the Rx output signal may be used to calculate the dRx PIMC coefficients. In one example, one or more dRx PIMC coefficients may be calculated at the PIMC coefficient estimation block 844 based on one or more of the dRx power level or the Rx interference level. The PIMC coefficient estimation block 844 may be configured to calculate one or more of the start time or duration of the dRx output sample to calculate the dRx power level. The PIMC coefficient estimation block 844 may be configured to calculate one or more of the start time or duration of the Rx output sample to calculate the Rx interference level.

[0118] In some embodiments, a dRx PIMC bypass signal may be generated. The dRx PIMC bypass signal may be calculated when one or more of the following occurs: (i) the antenna is being calibrated, (ii) a PA protection process is being performed, or (iii) no dRx PIM is detected based on one or more of a frequency assignment or an estimated dRx PIM correction level.

[0119] In some embodiments, a transmit intermodulation distortion signal may be generated to cancel the PIM of the transmit signal. In one example, the PIMC calibration block 842 may be configured to: (i) calculate one or more transmit (Tx) calibration parameters to match the CFR output signal 804 to the receiver (Rx) output signal, (ii) calculate one or more Tx PIMC coefficients for a Tx excitation (NA) function, and (iii) send one or more Tx calibration parameters and one or more Tx PIMC coefficients from the PIMC control path 840 to the PIMC data path 810 to generate a Tx intermodulation distortion signal based on the Tx NA function.

[0120] Fig. 9 A process flow of an example method 900 for enhanced receiver sensitivity according to at least one embodiment described in the present disclosure is shown. The method 900 may be arranged according to at least one embodiment described in the present disclosure.

[0121] Method 900 may be performed by processing logic that may include hardware (circuitry, dedicated logic, etc.), software (such as software running on a computer system or a dedicated machine), or a combination of both. Fig.14 processor 1454 or another device, combination of devices, or system.

[0122] Method 900 may begin at block 910 , where processing logic may be configured to receive an Rx output signal from a receiver on an Rx path.

[0123] At block 920, processing logic may receive a crest factor reduction (CFR) output signal from a CFR on a transmit (Tx) path.

[0124] At block 930 , processing logic may calibrate the CFR output signal based on the Rx output signal to generate a non-linear excitation (NA) input signal.

[0125] At block 940 , processing logic may generate an intermodulation distortion signal by applying a NA function to the NA input signal.

[0126] Without departing from the scope of the present invention, modifications, additions, or omissions may be made to the method 900. For example, in some embodiments, the method 900 may include any number of other elements that may not be explicitly shown or described.

[0127] Fig.10 A process flow of an example method 1000 that may be used for enhanced receiver sensitivity in accordance with at least one embodiment described in the present disclosure is shown. The method 1000 may be arranged in accordance with at least one embodiment described in the present disclosure.

[0128] Method 1000 may be performed by processing logic that may include hardware (circuitry, dedicated logic, etc.), software (such as software running on a computer system or a dedicated machine), or a combination of both. Fig.14 In the processing device 1454 or another device, combination of devices, or system.

[0129] Method 1000 may begin at block 1010 where processing logic may calculate one or more calibration parameters on a passive intermodulation cancellation (PIMC) control path to match a crest factor reduction (CFR) output signal to a receiver (Rx) output signal.

[0130] At block 1020, processing logic may calculate one or more PIMC coefficients for a nonlinear excitation (NA) function on the PIMC control path.

[0131] At block 1030 , processing logic may send one or more calibration parameters and one or more PIMC coefficients from the PIMC control path to the PIMC data path to generate an intermodulation distortion signal based on the NA function.

[0132] Without departing from the scope of the present invention, modifications, additions, or omissions may be made to method 1000. For example, in some embodiments, method 1000 may include any number of other elements that may not be explicitly shown or described.

[0133] Fig.11 A process flow of an example method 1700 that may be used for enhanced receiver sensitivity in accordance with at least one embodiment described in the present disclosure is shown. The method 1100 may be arranged in accordance with at least one embodiment described in the present disclosure.

[0134] The method 1100 may be performed by processing logic that may include hardware (circuitry, dedicated logic, etc.), software (such as software running on a computer system or a dedicated machine), or a combination of both. Fig.14 In the processing device 1454 or another device, combination of devices, or system.

[0135] Method 1100 may begin at block 1110 , where processing logic may receive an Rx output signal from a receiver on an Rx path.

[0136] At block 1120, processing logic may receive a crest factor reduction (CFR) output signal from a CFR on a transmit (Tx) path.

[0137] At block 1130 , processing logic may identify a first PIM source and a second PIM source based on the Rx output signal and the CFR output signal.

[0138] At block 1140 , the processing logic may calibrate the CFR output signal based on the first and second PIM sources in the Rx output signal to generate a nonlinear stimulus (NA) input signal.

[0139] At block 1150 , processing logic may generate an intermodulation distortion signal by applying a NA function to a NA input signal.

[0140] Without departing from the scope of the present invention, modifications, additions, or omissions may be made to the method 1100. For example, in some embodiments, the method 1100 may include any number of other elements that may not be explicitly shown or described.

[0141] Fig.12 A process flow of an example method 1200 that may be used for enhanced receiver sensitivity in accordance with at least one embodiment described in the present disclosure is shown. The method 1200 may be arranged in accordance with at least one embodiment described in the present disclosure.

[0142] The method 1200 may be performed by processing logic that may include hardware (circuitry, dedicated logic, etc.), software (such as software running on a computer system or a dedicated machine), or a combination of both. Fig.14 In the processing device 1454 or another device, combination of devices, or system.

[0143] Method 1200 may begin at block 1210 , where processing logic may receive an Rx output signal from a receiver path.

[0144] At block 1220 , processing logic may receive a dRx output signal from a dRx path.

[0145] At block 1230 , the processing logic may calibrate the dRx output signal based on the Rx output signal to generate a dRx nonlinear excitation (NA) input signal.

[0146] At block 1240 , processing logic may generate a dRx intermodulation distortion signal by applying a dRx NA function to the dRx NA input signal.

[0147] Without departing from the scope of the present invention, modifications, additions, or omissions may be made to the method 1200. For example, in some embodiments, the method 1200 may include any number of other elements that may not be explicitly shown or described.

[0148] Fig.13 A process flow of an example method 1300 that may be used to enhance receiver sensitivity according to at least one embodiment described in the present disclosure is shown. The method 1300 may be arranged according to at least one embodiment described in the present disclosure.

[0149] The method 1300 may be performed by processing logic that may include hardware (circuitry, dedicated logic, etc.), software (such as software running on a computer system or a dedicated machine), or a combination of both. Fig.14 In the processing device 1454 or another device, device, or system combination.

[0150] The method 1300 may begin at block 1310, where processing logic may calculate one or more diagnostic receiver (dRx) calibration parameters on a passive intermodulation cancellation (PIMC) control path to match a dRx output signal to a receiver (Rx) output signal, where the dRx output signal has an external source.

[0151] At block 1320, processing logic calculates one or more dRx PIMC coefficients for a dRx nonlinear excitation (NA) function on the PIMC control path.

[0152] At block 1330 , processing logic may send one or more dRx calibration parameters and one or more dRx PIMC coefficients from the PIMC control path to the PIMC data path to generate a dRx intermodulation distortion signal based on the dRx NA function.

[0153] Without departing from the scope of the present invention, modifications, additions, or omissions may be made to the method 1300. For example, in some embodiments, the method 1300 may include any number of other elements that may not be explicitly shown or described.

[0154] Fig.14 A block diagram of an example communication system 1400 configured for enhanced receiver sensitivity according to at least one embodiment described in the present disclosure is shown. The communication system 1400 may include a digital transmitter 1402, a radio frequency circuit 1404, a device 1414, a digital receiver 1406, and a processing device 1408. The digital transmitter 1406 and the processing device may be configured to receive a baseband signal via a connection 1410. The transceiver 1416 may include the digital transmitter 1402 and the radio frequency circuit 1404.

[0155] In some embodiments, the communication system 1400 may include a system of devices that can be configured to communicate with each other via wired or wired connections. For example, the wired connection in the communication system 1400 may include one or more Ethernet cables, one or more fiber optic cables, and / or other similar wired communication media. Alternatively or additionally, the communication system 1400 may include a system of devices that can be configured to communicate via one or more wireless connections. For example, the communication system 1400 may include one or more devices configured to send and / or receive radio waves, microwaves, ultrasound waves, light waves, electromagnetic induction, and / or similar wireless communications. Alternatively or additionally, the communication system 1400 may include a combination of wireless and / or wired connections. In these and other embodiments, the communication system 1400 may include one or more devices that can be configured to obtain a baseband signal, perform one or more operations on the baseband signal to generate a modified baseband signal, and send the modified baseband signal to, for example, one or more loads.

[0156] In some embodiments, communication system 1400 may include one or more communication channels that may communicatively couple systems and / or devices included in communication system 1400. For example, transceiver 1416 may be communicatively coupled to device 1414.

[0157] In some embodiments, the transceiver 1416 may be configured to obtain a baseband signal. For example, as described herein, the transceiver 1416 may be configured to generate a baseband signal and / or receive a baseband signal from another device. In some embodiments, the transceiver 1416 may be configured to send a baseband signal. For example, after obtaining the baseband signal, the transceiver 1416 may be configured to send the baseband signal to a separate device, such as device 1414. Alternatively or additionally, the transceiver 1416 may be configured to modify, adjust, and / or transform the baseband signal before sending the baseband signal. For example, the transceiver 1416 may include an orthogonal upconverter and / or a digital-to-analog converter (DAC), which may be configured to modify the baseband signal. Alternatively or additionally, the transceiver 1416 may include a direct radio frequency (RF) sampling converter, which may be configured to modify the baseband signal.

[0158] In some embodiments, the digital transmitter 1402 can be configured to obtain a baseband signal via connection 1410. In some embodiments, the digital transmitter 1402 can be configured to up-convert the baseband signal. For example, the digital transmitter 1402 may include an orthogonal up-converter applied to the baseband signal. In some embodiments, the digital transmitter 1402 may include an integrated digital-to-analog converter (DAC). The DAC may convert the baseband signal into an analog signal or a continuous time signal. In some embodiments, the DAC architecture may include a direct RF sampling DAC. In some embodiments, the DAC may be a separate component from the digital transmitter 1402.

[0159] In some embodiments, the transceiver 1416 may include one or more subcomponents that may be used to prepare baseband signals and / or transmit baseband signals. For example, the transceiver 1416 may include an RF front end (e.g., in a wireless environment; the RF front end may include a power amplifier (PA)), a digital transmitter (e.g., 1402), a digital front end, an Institute of Electrical and Electronics Engineers (IEEE) 1588v2 device, a long-term evolution (LTE) physical layer (L-PHY), (S-plane) device, a management plane (M-plane) device, an Ethernet media access control (MAC) / personal communication service (PCS), a resource controller / scheduler, etc. In some embodiments, the radio (e.g., the RF circuit 1404) of the transceiver 1416 may be synchronized with the resource controller via the S-plane device, which facilitates high-precision timing relative to a reference clock.

[0160] In some embodiments, transceiver 1416 can be configured to obtain a baseband signal for transmission. For example, transceiver 1416 can receive a baseband signal from a separate device (e.g., a signal generator). For example, the baseband signal can come from a transducer configured to convert a variable into an electrical signal, such as an audio signal output of a microphone that picks up a speaker's voice. Alternatively or additionally, transceiver 1416 can be configured to generate a baseband signal for transmission. In these and other embodiments, transceiver 1416 can be configured to send a baseband signal to another device (e.g., device 1414).

[0161] In some embodiments, device 1416 may be configured to receive transmissions from transceiver 1416. For example, transceiver 1416 may be configured to send a baseband signal to device 1414.

[0162] In some embodiments, RF circuit 1404 can be configured to transmit digital signals received from digital transmitter 1402. In some embodiments, RF circuit 1404 can be configured to send digital signals to device 1414 and / or digital receiver 1406. In some embodiments, digital receiver 1406 can be configured to receive digital signals from RF circuit and / or send digital signals to processing device 1408.

[0163] In some embodiments, as shown, processing device 1408 may be a stand-alone device or system. Alternatively or additionally, processing device 1408 may be an element of another device and / or system. For example, in some embodiments, processing device 1408 may be included in transceiver 1416. In the case where processing device 1408 is a stand-alone device or system, processing device 1408 may be configured to communicate with additional devices and / or systems (such as transceiver 1416 and / or device 1414) that are remote from processing device 1408. For example, processing device 1408 may be configured to send and / or receive transmissions from transceiver 1416 and / or device 1414. In some embodiments, processing device 1408 may be combined with other elements of communication system 1400.

[0164] In order to simplify the explanation, the method and / or process flow described herein are depicted and described as a series of actions. However, the actions according to the present disclosure may occur in various orders and / or simultaneously, and may occur together with other actions not presented and described herein. In addition, not all the actions shown may be used to implement the method according to the disclosed subject matter. In addition, those skilled in the art will understand and appreciate that these methods may be represented as a series of related states alternatively by state diagrams or events. In addition, the methods disclosed in this specification can be stored on articles (article of manufacture) such as non-transitory computer-readable media, so as to facilitate the transmission and transfer of these methods to computing devices. The term "article" used herein is intended to include a computer program accessible from any computer-readable device or storage medium. Although illustrated as discrete blocks, various blocks may be divided into additional blocks, combined into fewer blocks or eliminated according to the desired implementation.

[0165] Fig.15A diagram of a machine in the example form of a computing device 1500 is shown, in which a set of instructions can be executed to cause the machine to perform any one or more methods discussed herein. The computing device 1500 may include a rack server, a router computer, a server computer, a mainframe computer, a laptop computer, a tablet computer, a desktop computer, or any computing device with at least one processor, etc., in which a set of instructions can be executed to cause the machine to perform any one or more methods discussed herein. In an alternative embodiment, the machine can be connected (e.g., networked) to other machines in a LAN, an intranet, an extranet, or the Internet. The machine can operate in the capacity of a server machine in a client-server network environment. In addition, although only a single machine is shown, the term "machine" may also include any collection of machines that individually or jointly execute a set (or multiple sets) of instructions to perform any one or more methods discussed herein.

[0166] The example computing device 1500 includes a processing device (e.g., a processor) 1502, a main memory 1504 (e.g., read-only memory (ROM), flash memory, dynamic random access memory (DRAM), such as synchronous DRAM (SDRAM)), a static memory 1506 (e.g., flash memory, static random access memory (SRAM)), and a data storage device 1516, which communicate with each other via a bus 1508.

[0167] The processing device 1502 represents one or more general processing devices, such as a microprocessor, a central processing unit, etc. More specifically, the processing device 1502 may include a complex instruction set computing (CISC) microprocessor, a reduced instruction set computing (RISC) microprocessor, a very long instruction word (VLIW) microprocessor, or a processor that implements other instruction sets or a processor that implements a combination of instruction sets. The processing device 1502 may also include one or more special processing devices, such as an application specific integrated circuit (ASIC), a field programmable gate array (FPGA), a digital signal processor (DSP), a network processor, etc. The processing device 1502 is configured to execute instructions 1526 for performing the operations and steps described herein.

[0168] The computing device 1500 may also include a network interface device 1522 that may communicate with the network 1518. The computing device 1500 may also include a display device 1510 (e.g., a liquid crystal display (LCD) or a cathode ray tube (CRT)), an alphanumeric input device 1512 (e.g., a keyboard), a cursor control device 1514 (e.g., a mouse), and a signal generating device 1520 (e.g., a speaker). In at least one embodiment, the display device 1510, the alphanumeric input device 1512, and the cursor control device 1514 may be combined into a single component or device (e.g., an LCD touch screen).

[0169] The data storage device 1516 may include a computer-readable storage medium 1524 having stored thereon one or more sets of instructions 1526 that embody any one or more of the methods or functions described herein. The instructions 1526 may also reside completely or at least partially in the main memory 1504 and / or the processing device 1502 during execution by the computing device 1500, the main memory 1504 and the processing device 1502 also constituting computer-readable media. Instructions may also be sent or received over the network 1518 via the network interface device 1522.

[0170] Although computer-readable storage medium 1524 is shown as a single medium in the example embodiment, the term "computer-readable storage medium" may include a single medium or multiple media (e.g., a centralized or distributed database and / or associated caches and servers) that store one or more sets of instructions. The term "computer-readable storage medium" may also include any medium that is capable of storing, encoding, or carrying a set of instructions executed by a machine and causing the machine to perform any one or more methods of the present disclosure. Therefore, the term "computer-readable storage medium" may include, but is not limited to, solid-state memory, optical media, and magnetic media.

[0171] Example

[0172] Examples of performance characteristics according to embodiments of the present invention are provided below.

[0173] Example 1: Elimination of a PIM Source

[0174] like Fig.16 As shown in Figure 1, the nonlinear excitation function can be represented as a tile window with sampling delay and amplitude delay. Each black tile can represent Each black tile may be a LUT assigned for PIM cancellation. In this example, all available nonlinear exciter terms (eg, LUTs) are assigned to cancel PIM generated by a single source.

[0175] Example 2: Elimination of Two PIM Sources

[0176] like Fig.17 As shown, the nonlinear activation function can be described by the following figure. Each black block represents In this example, the black tiles (which correspond to the LUT) (which are substantially on the left side and outside the edge of the graph (e.g., 1-9)) are assigned to the first PIM source, and the grid pattern tiles (which correspond to the LUT) (which are substantially on the rideside and inside the outside edge of the graph (e.g., adjacent to 7-16)) are assigned to the second PIM source.

[0177] Note that the grouping of tiles can be adjusted by assigning a different number of tiles to each PIM source. In addition, some tiles can be assigned to more than one PIM source (e.g., 5). There can be any number of PIM sources, and in such cases, a corresponding number of groupings can be assigned. Any combination of tiles can be assigned to each PIM source, including overlapping tiles between PIM sources. In addition, any number of tiles (e.g., LUTs) can be used. For example, 20 tiles can be used for allocation, but any number of tiles can be used.

[0178] In some embodiments, the various components, modules, engines, and services described herein may be implemented as objects or processes executed on a computing system (e.g., as separate threads). Although some of the systems and methods described herein are generally described as being implemented in software (stored on hardware and / or executed by hardware), specific hardware implementations or combinations of software and specific hardware implementations are possible and contemplated.

[0179] The terms used in this document, especially in the appended claims (e.g., the bodies of the appended claims), are generally referred to as "open" terms (e.g., the term "including" should be interpreted as "including, but not limited to", the term "having" should be interpreted as "having at least", the term "including" should be interpreted as "including, but not limited to", etc.).

[0180] Furthermore, if a specific number of claim recitations is intended to be introduced, such intent will be expressly stated in the claim, and if no such statement is made, such intent is not present. For example, to aid understanding, the following appended claims may contain the use of the introductory phrases "at least one" and "one or more" to introduce claim recitations. However, the use of such phrases should not be interpreted as implying that a claim recitation introduced by the indefinite article "a" or "an" will limit any particular claim containing such introduced claim recitation to an embodiment containing only one such recitation, even when the same claim includes the introductory phrases "one or more" or "at least one" and an indefinite article such as "a" or "an" (e.g., "a" and / or "an" should be interpreted as meaning "at least one" or "one or more"); the same applies to the use of definite articles used to introduce claim recitations.

[0181] Furthermore, even if a specific number of an introduced claim recitation is explicitly recited, it should be understood that such recitation should be interpreted to mean at least the recited number (e.g., a simple recitation of "two recitations" without other modifiers means at least two recitations, or two or more recitations). Moreover, in the case of conventions like "at least one of A, B, and C, etc." or "one or more of A, B, and C, etc.", such constructions are generally intended to include A alone, B alone, C alone, A and B together, A and C together, B and C together, or A, B, and C together, etc. For example, the use of the term "and / or" is intended to be interpreted in this manner.

[0182] In addition, any disjunctive word or phrase indicating two or more optional terms, whether in the specification, claims or drawings, should be understood to include the possibility of one of the terms, the other of the terms, or both of the terms. For example, the phrase "A or B" should be understood to include the possibility of "A" or "B" or "A and B".

[0183] In addition, the use of the terms "first", "second", "third", etc. is not necessarily used in this article to imply a specific order or number of elements. Generally, the terms "first", "second", "third", etc. are used to distinguish different elements as general identifiers. It is not shown that the terms "first", "second", "third", etc. mean a specific order, but these terms should not be understood to mean a specific order. In addition, it is not shown that the terms "first", "second", "third", etc. mean a specific number of elements, but these terms should not be understood to mean a specific number of elements. For example, a first component can be described as having a first side and a second component can be described as having a second side. The use of the term "second side" about the second component can be to distinguish this side of the second component from the "first side" of the first component, rather than implying that the second component has two sides.

[0184] All examples and conditional language cited herein are intended as teaching objects to help readers understand the present invention and the concepts contributed by the inventors to promote the art, and should be interpreted as not being limited to these specifically cited examples and conditions. Although the embodiments of the present disclosure have been described in detail, it should be understood that various changes, substitutions and modifications may be made thereto without departing from the spirit and scope of the present disclosure.

Claims

1. A base station configured for enhanced receiver sensitivity, comprising: a receiver Rx configured to receive an Rx output signal in an Rx frequency band, wherein the Rx output signal has a first passive intermodulation (PIM) source in the Rx frequency band and a second PIM source in the Rx frequency band; and Processing equipment, configured as: receiving the Rx output signal from the receiver on an Rx path; receiving a CFR output signal from a CFR Crest Factor Reduction on a transmit Tx path; identifying the first PIM source and the second PIM source based on the Rx output signal and the CFR output signal; calibrating the CFR output signal based on the first PIM source and the second PIM source in the Rx output signal to generate a nonlinear excitation NA input signal; as well as An intermodulation distortion signal is generated by applying a NA function to the NA input signal.

2. The base station according to claim 1, wherein the processing device is further configured to: calibrating the CFR output signal based on one or more time delay coefficients of the first PIM source and one or more time delay coefficients of the second PIM source; calibrating the CFR output signal based on one or more gain adjustment factors; as well as The CFR output signal is calibrated based on one or more phase adjustment coefficients.

3. The base station according to claim 1, wherein the processing device is further configured to: adjusting one or more delay constraints in the NA function based on identification of the first PIM source and the second PIM source in the Rx output signal; and One or more memory elements storing the one or more delay constraints in a memory device are identified to model the first PIM source and the second PIM source.

4. The base station according to claim 1, wherein the processing device is further configured to: A first cross-correlation peak and a second cross-correlation peak are identified to identify the first PIM source and the second PIM source.

5. The base station according to claim 1, wherein the processing device is further configured to: selecting in real time a plurality of PIM sources to be eliminated, wherein the plurality of PIM sources include the first PIM source and the second PIM source; assigning the first PIM source to a first set of nonlinear terms in a nonlinear function in the NA function; assigning the second PIM source to a second set of nonlinear terms in the nonlinear function in the NA function; as well as An intermodulation distortion signal is generated to cancel the first PIM source using the first set of nonlinear terms and to cancel the second PIM source using the second set of nonlinear terms.

6. The base station according to claim 1, wherein the processing device is further configured to: A physical distance between the first PIM source and the second PIM source is calculated based on one or more echoes in the PIM signal in the Rx frequency band.

7. A base station configured for enhanced receiver sensitivity, comprising: a receiver Rx path configured to receive an Rx output signal; a diagnostic receiver dRx path configured to receive a dRx output signal, wherein the dRx output signal has an external source; and Processing equipment, configured as: receiving the Rx output signal from the receiver path; receiving the dRx output signal from the dRx path; calibrating the dRx output signal based on the Rx output signal to generate a dRx nonlinear excitation NA input signal; and A dRx intermodulation distortion signal is generated by applying a dRx NA function to the dRx NA input signal.

8. The base station according to claim 7, further comprising: The transmit Tx path is configured to transmit a crest factor reduced CFR output signal in a Tx frequency band.

9. The base station according to claim 8, wherein the processing device is further configured to: calibrating the CFR output signal based on the Rx output signal to generate a Tx nonlinear excitation NA input signal; and A Tx intermodulation distortion signal is generated by applying a Tx NA function to the Tx NA input signal.

10. The base station according to claim 7, wherein the processing device is further configured to: calibrating the dRx output signal based on one or more time delay coefficients; calibrating the dRx output signal based on one or more gain adjustment coefficients; and The dRx output signal is calibrated based on one or more phase adjustment coefficients.

11. The base station according to claim 7, wherein the processing device is further configured to: Calculating the dRx NA function using a nonlinear function, the nonlinear function comprising one or more of: a lookup table LUT, a polynomial, a wavelet function, or a piecewise linear PWL function; and The non-linear function is calculated using one or more passive intermodulation cancellation (PIMC) coefficients, wherein the PIMC coefficients are estimated by calculating a least squares solution.

12. The base station according to claim 7, further comprising: one or more filters configured to remove signals outside a frequency range of the PIMC signal calculated based on a frequency shift of the dRx intermodulation distortion signal; or A multi-band filter is configured to select an Rx frequency range to remove interleaved uplink and downlink frequency bands in the Rx output signal.

13. The base station according to claim 7, further comprising: an adaptive filter configured to adjust the gain of the dRx intermodulation distortion signal based on an automatic gain control AGC error, a low noise amplifier LNA error, or an error caused by temperature; or The adaptive filter is configured to adjust the phase of the dRx intermodulation distortion signal based on an automatic gain control AGC error, a low noise amplifier LNA error or an error caused by temperature; or A PIMC subtractor is configured to generate a corrected Rx signal based on the dRx intermodulation distortion signal and the Rx output signal.

14. The base station according to claim 7, further comprising: an onboard calibration unit configured to calibrate the dRx output signal based on the Rx output signal using adaptive calculation and adaptive adjustment; or An onboard coefficient estimation engine is configured to calculate the NA function using one or more passive intermodulation cancellation (PIMC) coefficients calculated and updated based on radio traffic data.

15. A computer-readable storage medium comprising computer-executable instructions which, when executed by one or more processors, cause a base station to: on a passive intermodulation cancellation PIMC control path, calculating one or more diagnostic receiver dRx calibration parameters to match a dRx output signal to a receiver Rx output signal, wherein the dRx output signal has an external source; On the PIMC control path, calculating one or more dRx PIMC coefficients of a dRx nonlinear excitation NA function; and The one or more dRx calibration parameters and the one or more dRx PIMC coefficients are sent from the PIMC control path to a PIMC data path to generate a dRx intermodulation distortion signal based on the dRx NA function.

16. The computer-readable storage medium of claim 15, wherein the instructions, when executed by the one or more processors, further cause the base station to: In the PIMC control path, one or more transmit Tx calibration parameters are calculated to match the CFR output signal with the receiver Rx output signal; On the PIMC control path, calculating one or more Tx PIMC coefficients for a Tx excitation NA function; as well as The one or more Tx calibration parameters and the one or more Tx PIMC coefficients are sent from the PIMC control path to a PIMC data path to generate a Tx intermodulation distortion signal based on the Tx NA function.

17. The computer-readable storage medium of claim 15, wherein the instructions, when executed by the one or more processors, further cause the base station to: calculating the one or more dRx calibration parameters including one or more time delay coefficients on the PIMC control path based on one or more of a round trip delay, a cross correlation, or a mean square error between the dRx output signal and the Rx output signal; or On the PIMC control path, the one or more dRx calibration parameters are calculated including one or more alignment parameters including one or more of a sample alignment parameter or a sub-sample alignment parameter.

18. The computer-readable storage medium of claim 15, wherein the instructions, when executed by the one or more processors, further cause the base station to: On the PIMC control path, the one or more dRx calibration parameters including one or more gain adjustment coefficients are calculated based on one or more of: Gain adjustment matching between the dRx output signal and the dRx NA function input signal, A gain adjustment based on the automatic gain control (AGC) of the Rx output signal and the RF attenuation state, or Gain adjustments based on changes due to temperature or component aging; and On the PIMC control path, the one or more dRx calibration parameters including one or more phase adjustment coefficients are calculated based on one or more of: The phase adjustment matching between the dRx output signal and the dRx NA function input signal, Phase adjustment of the automatic gain control AGC RF attenuation state based on the Rx output signal, or Phase adjustment based on changes due to temperature or component aging.

19. The computer-readable storage medium of claim 15, wherein the instructions, when executed by the one or more processors, further cause the base station to: On the PIMC control path, the one or more dRx PIMC coefficients are calculated by computing a least squares solution using one or more of the following: Use the closed form of the inverse matrix, or Use gradient descent with a fixed step size parameter, or Conjugate gradient descent using a dynamic step size parameter, wherein the dRx PIMC coefficient is estimated based on the one or more parameters, the one or more parameters comprising a leakage factor, a batch number or a batch size, and wherein the fixed step size parameter or the dynamic step size parameter is configured based on one or more of closed loop stability, estimated noise suppression, or convergence time, or On the PIMC control path, the one or more dRx PIMC coefficients are calculated, wherein a coefficient vector including the dRx PIMC coefficients is iteratively updated after a selected number of samples.

20. The computer-readable storage medium of claim 15, wherein the instructions, when executed by the one or more processors, further cause the base station to: calculating one or more sample amplitude delay pairs for the dRx NA function on the PIMC control path; or In the PIMC control path, the sampling rate of the dRx NA function is calculated to minimize the nonlinear component.

21. The computer-readable storage medium of claim 15, wherein the instructions, when executed by the one or more processors, further cause the base station to: calculating, on the PIMC control path, one or more of a start time or a duration of a dRx output sample to calculate a dRx power level; On the PIMC control path, calculating one or more of a start time or a duration of an Rx output sample to calculate an Rx interference level; and On the PIMC control path, the one or more dRx PIMC coefficients are calculated based on one or more of the dRx power level or the Rx interference level.

22. The computer-readable storage medium of claim 15, wherein: When executed by the one or more processors, the instructions further cause the base station to: The dRx PIMC bypass signal is calculated on the PIMC control path when one or more of the following conditions occur: Calibrating the antenna, The power amplifier PA protection procedure is being executed, or The dRx PIM is not detected based on one or more of the frequency assignment or the estimated dRx PIM correction level.

23. The computer-readable storage medium of claim 15, wherein the instructions, when executed by the one or more processors, further cause the base station to: On the PIMC control path, one or more dRx PIMC configuration parameters are calculated to generate a dRx PIMC signal, wherein the one or more dRx PIMC configuration parameters include: frequency shift of the dRx intermodulation distortion signal, dRx filter configuration parameters, a resampling ratio between the Rx output signal and the dRx output signal, and a resampling timing phase adjustment between the Rx output signal and the dRx output signal; and The one or more dRx PIMC configuration parameters are sent from the PIMC control path to the PIMC data path to generate the dRx PIMC signal based on the dRx intermodulation distortion signal.

24. The computer-readable storage medium of claim 23, wherein the instructions, when executed by the one or more processors, further cause the base station to: On the PIMC control path, calculating the frequency shift to match the frequency position of the dRx passive intermodulation in the Rx output signal; or On the PIMC control path, the frequency shift is calculated based on a frequency allocation between an Rx frequency band of the Rx output signal and a frequency band of the dRx output signal.

25. The computer-readable storage medium of claim 23, wherein when executed by the one or more processors, the instructions further cause the base station to: calculating the dRx filter configuration parameters of the one or more filters on the PIMC control path to remove signals outside a frequency range of the dRx PIMC signal; or On the PIMC control path, the dRx filter configuration parameters of the one or more filters are calculated to remove interleaved uplink and downlink frequency bands in an Rx frequency range.

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