Wireless communication device and method for compensating non-linear distortion of wireless communication device

Abstract

The invention provides a wireless communication device and a method for compensating non-linear distortion of the wireless communication device. The wireless communication device comprises a transmission fundamental frequency circuit, an amplitude modulation (AM) circuit, a phase modulation (PM) circuit, a power amplifier, a calculation circuit and a compensation circuit. The transmission fundamental frequency circuit outputs a transmission signal for the AM circuit and the PM circuit to generate an AM signal and a PM signal respectively. The power amplifier takes the AM signal as a supply voltage and generates an output signal according to the PM signal. The calculation circuit estimates a delay difference between the AM signal and the PM signal according to a detection result of the output signal to generate an estimation result, and the compensation circuit compensates the AM signal or the PM signal according to the estimation result to reduce the delay difference.

Description

Technical Field

[0001] This invention relates to compensation for nonlinear distortion, and more particularly to a wireless communication device and a method for compensating for nonlinear distortion in a wireless communication device. Background Technology

[0002] In the design of wireless communication modulation transceivers, polar coordinate transmitter architectures offer significant improvements in power consumption compared to in-phase / quadrature modulation architectures, particularly in reducing power amplifier performance requirements at specific target output power levels. However, besides the nonlinear distortion related to signal swing caused by the power amplifier, other factors contribute to nonlinearity in the output signal within polar coordinate transmitters. While related technologies have proposed analytical methods for the relationship between these factors and output signal nonlinearity, these methods typically utilize external signal generators and spectrum analyzers to obtain measurement results, rather than being verified based on the complete transmitter architecture.

[0003] Furthermore, the nonlinear distortion of the transmitter's output signal can be caused by multiple different factors, and existing techniques cannot effectively separate the effects of these factors, resulting in poor performance of the compensation operation after analysis. Therefore, a novel architecture and related methods are needed to solve the problems of existing techniques with little or no side effects. Summary of the Invention

[0004] The purpose of this invention is to provide a wireless communication device and a method for compensating for nonlinear distortion in a wireless communication device, so as to effectively separate various factors that cause nonlinear distortion and perform linearity compensation accordingly.

[0005] At least one embodiment of the present invention provides a wireless communication device. The wireless communication device includes a baseband transmission circuit, an amplitude modulation (AM) circuit, a phase modulation (PM) circuit, a power amplifier, a delay calculation circuit, and a delay compensation circuit. The power amplifier is coupled to the AM and PM circuits, and the delay compensation circuit is coupled to the baseband transmission circuit and the delay calculation circuit. The baseband transmission circuit outputs a transmission signal. The AM circuit generates an amplitude-modulated output signal based on an amplitude-modulated transmission signal of the transmission signal, and the PM circuit generates a phase-modulated output signal based on a phase-modulated transmission signal of the transmission signal. The power amplifier uses the amplitude-modulated output signal as a supply voltage and generates an output signal based on the phase-modulated output signal. In particular, the delay calculation circuit is used to estimate a delay difference between the amplitude-modulated output signal and the phase-modulated output signal based on a detection result of the output signal to generate an estimation result, and the delay compensation circuit is used to compensate the amplitude-modulated output signal or the phase-modulated output signal based on the estimation result to reduce the delay difference.

[0006] At least one embodiment of the present invention provides a method for compensating for nonlinear distortion in a wireless communication device. The method includes: outputting a transmission signal using a transmission baseband circuit of the wireless communication device; generating an amplitude-modulated output signal using an amplitude modulation circuit of the wireless communication device based on an amplitude-modulated transmission signal of the transmission signal; generating a phase-modulated output signal using a phase-modulated transmission circuit of the wireless communication device based on a phase-modulated transmission signal of the transmission signal; using a power amplifier of the wireless communication device as a supply voltage for the amplitude-modulated output signal, and generating an output signal based on the phase-modulated output signal; estimating a delay difference between the amplitude-modulated output signal and the phase-modulated output signal using a delay calculation circuit of the wireless communication device based on a detection result of the output signal to generate an estimation result; and compensating the amplitude-modulated output signal or the phase-modulated output signal based on the estimation result using a delay compensation circuit of the wireless communication device to reduce the delay difference.

[0007] The wireless communication device and related method provided by embodiments of the present invention can estimate the delay difference between the amplitude modulation path and the phase modulation path based on the detection results of the output signal, such as the third-order intermodulation distortion (IMD3) value, and compensate the amplitude modulation path or the phase modulation path accordingly to reduce the delay difference, thereby compensating for the nonlinear distortion caused by the delay difference. Furthermore, embodiments of the present invention do not significantly increase additional costs. Therefore, the present invention can improve the compensation effect for nonlinear distortion without or with minimal side effects. Attached Figure Description

[0008] Figure 1 This is a schematic diagram of a wireless communication device according to one embodiment of the present invention.

[0009] Figure 2 This is a schematic diagram illustrating the relationship between delay differences and third-order intermodulation distortion values ​​at different frequency intervals in a dual-frequency test according to an embodiment of the present invention.

[0010] Figure 3 This is a schematic diagram of the main signal and the third-order intermodulation signal in the spectrum according to an embodiment of the present invention.

[0011] Figure 4 This is a schematic diagram of a wireless communication device according to one embodiment of the present invention.

[0012] Figure 5 This is a schematic diagram of a wireless communication device according to one embodiment of the present invention.

[0013] Figure 6 This is a schematic diagram of a wireless communication device according to one embodiment of the present invention.

[0014] Figure 7 This is a schematic diagram illustrating the improvement of signal linearity through delay compensation and digital predistortion according to an embodiment of the present invention.

[0015] Figure 8 This is a schematic diagram illustrating the workflow of a method for compensating for nonlinear distortion in a wireless communication device according to an embodiment of the present invention. Detailed Implementation

[0016] Figure 1 This is a schematic diagram of a wireless communication device 10 according to one embodiment of the present invention, wherein the wireless communication device 10 may be a polar coordinate transmitter or a transceiver including a polar coordinate transmitter. Figure 1As shown, the wireless communication device 10 may include a transmission baseband circuit (TX baseband circuit) 110, an amplitude modulation (AM) circuit 120, a phase modulation (PM) circuit 130, a power amplifier such as a switched capacitor power amplifier (SCPA) 100, a delay calculation circuit such as a delay skew calculation circuit 101, and a delay compensation circuit such as a delay skew compensation circuit 102. The switched capacitor power amplifier 100 is coupled to the AM circuit 120 and the PM circuit 130, and the delay skew compensation circuit 102 is coupled to the TX baseband circuit 110 and the delay skew calculation circuit 101. In this embodiment, the TX baseband circuit 110 is used to output a transmission signal such as the signal STX. AM and STX PM Among them, the signal STX AM It can transmit signals for the AM path in a polar coordinate transmitter architecture, as well as the STX signal. PM This can be a transmission signal for the PM path under a polar coordinate transmitter architecture. AM circuit 120 belongs to the AM path under a polar coordinate transmitter architecture and is used to transmit AM signals such as signal STX based on the transmission signal. AM Generate an AM output signal such as signal VDD ENV The PM circuit 130 is a PM path within a polar coordinate transmitter architecture and is used to transmit signals such as the signal STX based on the transmitted signal. PM Generate a PM output signal such as the SRF signal. PM The switched capacitor power amplifier 100 is used to convert the signal VDD ENV As a supply voltage, and according to the signal SRF PM Generate an output signal such as signal S OUT (e.g., for the signal SRF) PM Amplification is performed to generate signal S OUT Additionally, the delay difference calculation circuit 101 is used to calculate the delay difference based on the signal S. OUT The detection result estimates the signal VDD ENV With signal SRF PM A delay difference between them to produce an estimate τ CAL And the delay difference compensation circuit 102 is used to calculate the delay difference based on the estimated result τ. CAL For signal VDD ENV or signal SRF PM Compensation is performed to reduce this delay difference.

[0017] For example, signal VDD ENV With signal SRF PM This delay difference can be considered as the delay difference between the AM path and the PM path under this polar coordinate transmitter architecture, which can be simply referred to as the AM-PM delay. Since the wireless communication device 10 divides the signal to be transmitted into a modulation part (e.g., signal STX),... AM ) and phase modulation components (e.g., signal STX) PM The signals are processed through the AM and PM paths respectively. Therefore, when the signals on the AM and PM paths are out of sync (for example, when the signal delays of the AM and PM paths are inconsistent, resulting in the aforementioned AM-PM delay), the signal S output by the switched capacitor power amplifier 100 will be affected. OUT This produces nonlinear distortion. Therefore, the delay difference calculation circuit 101 can calculate the delay difference based on the signal S. OUT The delay difference is estimated by the index value of the nonlinear distortion (i.e. the detection result) so that the delay difference compensation circuit 102 can properly adjust the signal delay of the AM path or PM path, thereby synchronizing the signals on the AM path and the PM path.

[0018] In this embodiment, the delay difference compensation circuit 102 is coupled between the TX baseband circuit 110 and the AM circuit 120, wherein the delay difference compensation circuit 102 can compensate for the delay difference based on the estimated result τ. CAL For signal STX AM Delay difference control is performed to generate a compensated amplitude-modulated transmission signal, such as signal SC. AM And AM circuit 120 can be based on signal SC AM Generate signal VDD ENV For example, the delay difference compensation circuit 102 can receive the signal STX using its programmable delay unit. AM To output a signal SC with a programmable delay. AM Thus achieving control over the signal VDD ENV The purpose of delay control. Figure 1 In the architecture shown, the AM digital-to-analog converter (DAC) 121 (labeled "AMDAC" in the figure for simplicity) in AM circuit 120 can process the signal SC output by delay difference compensation circuit 102. AM The digital-to-analog conversion is performed, and the reconstruction filter 122 in the AM circuit 120 can filter the output of the AM digital-to-analog converter 121 to generate the signal VDD. ENV Additionally, the PM digital-to-analog converter 131 in the PM circuit 130 (labeled "PM DAC" in the figure for simplicity) can process the signal STX.PM Digital-to-analog conversion is performed, and the PM modulator 132 in the PM circuit 130 can be based on the local oscillation frequency f. LO The output of the PM digital-to-analog converter 131 is up-converted to generate the signal SRF. PM .

[0019] In this embodiment, the wireless communication device 10 may further include a receiving circuit 140 and a receiving baseband circuit (hereinafter referred to as RX baseband circuit) 150, wherein the receiving circuit 140 is coupled to the switched capacitor power amplifier 100, and the RX baseband circuit 150 is coupled to the receiving circuit 140 and the delay difference calculation circuit 101. The receiving circuit 140 receives signal S from the switched capacitor power amplifier 100. OUT And according to signal S OUT A received signal, such as signal SRX, is generated. For example, coupler 141 in receiver circuit 140 can receive signal S. OUT And output signal S OUT The AC component, the mixer 142 in the receiving circuit 140 can be based on the local oscillation frequency f LO The output of coupler 141 is down-converted, and the analog-to-digital converter 143 (labeled "ADC" in the figure for simplicity) in receiver circuit 140 performs analog-to-digital conversion on the output of mixer 142 to generate signal SRX. Additionally, RX baseband circuit 150 is used to generate signal S based on signal SRX. OUT The detection result. For example, the detection result may include signal S. OUT The third-order intermodulation distortion (IMD3) value, such as the signal S IMD3 And the delay difference calculation circuit 101 can calculate the delay difference based on the signal S. IMD3 Perform calculations to estimate the signal VDD ENV With signal SRF PM The difference in delay between them, thus outputting the estimated result τ CAL .

[0020] Signal S OUT The AM and PM components can be obtained from the signal S. AM and signal S PM To represent, and signal S AM and signal S PM It can be represented based on the time parameter t as follows:

[0021] S AM =A OUT ×|cos(ω m t)|;

[0022] S PM =Sgn(cos(ω) m (t+τ)))=C(ω m +τ);

[0023] Where A OUT =A IN ×G SCPA A IN Can represent signal VDD ENV The amplitude, G SCPA This can represent the gain of the switched capacitor power amplifier 100, ω m τ can represent the frequency of the dual-frequency test (which can correspond to the frequency interval of the dual-frequency test), and τ can represent the AM-PM delay (e.g., the signal VDD). ENV With signal SRF PM The delay difference between them), and Sgn() can represent a function of phase modulation. Additionally, Sgn(cos(ω) m (t+τ)) can be used with C(ω) m +τ) is used for simplicity. Therefore, signal S OUT Can be accessed via S AM ×S PM It is expressed as follows:

[0024] S AM ×S PM =A OUT ×|cos(ω m t)|×C(ω m +τ)

[0025] =A OUT ×|cos(ω m t)|×[C(ω m +τ)-C(ω m )+C(ω m )]

[0026] =A OUT ×cos(ω m t)+A OUT ×|cos(ω m t)|×[C(ω m +τ)-C(ω m )]

[0027] =A OUT ×cos(ω m t)+A OUT ×u(ω m t)

[0028] Where A OUT ×cos(ω m t) is the main signal, and AOUT ×|cos(ω m t)|×[C(ω m +τ)-C(ω m The intermodulation signal is |cos(ω)|. m t)|×[C(ω m +τ)-C(ω m )] can be simplified to u(ω) m Therefore, the representation of the intermodulation signal can be simplified to A. OUT ×u(ω m t). Overall intermodulation distortion (IMD) TOTAL It can be represented as follows:

[0029]

[0030] The overall intermodulation distortion (IMD) TOTAL The relationship between the third-order intermodulation distortion value IMD3 and the AM-PM delay τ can be derived based on the Taylor expansion. Specifically, the coefficients of the Taylor expansion {a k ,b k} can be represented as follows:

[0031]

[0032] By setting k to 3, the correlation coefficients of the third-order intermodulation distortion value IMD3, such as a3 and b3, can be obtained. Furthermore, the relationship between the third-order intermodulation distortion value IMD3 and the AM-PM delay τ is as follows:

[0033]

[0034]

[0035] Therefore, the RX baseband circuit 150 can perform spectral analysis on the signal SRX to obtain the third-order intermodulation distortion value IMD3 of the signal SRX (e.g., signal S...). OUT The third-order intermodulation distortion value (IMD3) is obtained through signal S. IMD3 The information of the third-order intermodulation distortion value IMD3 is transmitted to the delay difference calculation circuit 101, which can calculate based on the third-order intermodulation distortion value IMD3 to estimate the AM-PM delay τ, thereby generating the estimation result τ. CAL .

[0036] Figure 2 This is a schematic diagram illustrating the relationship between delay differences (e.g., AM-PM delay τ) and third-order intermodulation distortion (IMD3) at different frequency intervals (e.g., 0.1MHz, 1MHz, and 10MHz) in dual-frequency testing according to an embodiment of the present invention. Figure 2The curves calculated using the above formulas and the curves obtained through circuit simulation software are displayed at various frequency intervals of the dual-frequency tests. Figure 2 As shown, at each frequency interval of the dual-frequency test, the results calculated according to the above formula are roughly consistent with the results obtained through circuit simulation software.

[0037] Figure 3 This is a schematic diagram of the spectrum of a primary signal (e.g., a signal with frequency f1) and a third-order intermodulation signal (e.g., a signal with frequency 3×f1) according to an embodiment of the present invention, wherein... Figure 3 The horizontal axis represents frequency, and Figure 3 The vertical axis represents the power spectrum density (PSD). Specifically, the RX baseband circuit 150 can calculate the power of the primary signal and the power of the third-order intermodulation signal separately, and calculate the ratio between the two to obtain the third-order intermodulation distortion value IMD3. In some embodiments, the delay difference calculation circuit 101 can perform the operation shown in the above formula to calculate the AM-PM delay τ based on the information of the third-order intermodulation distortion value IMD3 provided by the RX baseband circuit 150. In some embodiments, the delay difference calculation circuit 101 can pre-record the calculation results of the above formula (e.g., the values ​​of AM-PM delay τ corresponding to each result of the third-order intermodulation distortion value IMD3) in a built-in lookup table, and upon receiving the signal S... IMD3 The corresponding estimated result τ is output based on the lookup table. CAL .

[0038] Figure 4 This is a schematic diagram of a wireless communication device 40 according to one embodiment of the present invention. Compared to Figure 1 The wireless communication device 10 shown may further include a digital pre-distortion (DPD) circuit 160, wherein the DPD circuit 160 is coupled between the TX baseband circuit 110 and the delay difference compensation circuit 102. Specifically, the nonlinear operating region of the switched capacitor power amplifier 100 is what causes the signal S OUT Another factor contributing to nonlinear distortion is that the DPD circuit 160 is used to predistort the transmitted signal, such as the signal STX, from the TX baseband circuit 110 according to a nonlinear model to generate the signal STX. AM A predistorted AM signal, such as the SD signal AM and signal STX PM A predistorted PM signal, such as the SD signal PM In particular, the AM circuit 120 can be based on the signal SD AM Generate signal VDD ENV(For example, the delay difference compensation circuit 102 can be based on the estimated result τ) CAL For signal SD AM Perform delay control to generate signal SC AM The AM circuit 120 can further base its signal on the SC signal. AM Generate signal VDD ENV ), and PM circuit 130 can be based on signal SD PM Generate signal SRF PM .

[0039] It should be noted that the AM-PM delay τ does not change with different signal swings, therefore the nonlinear distortion caused by the AM-PM delay τ does not change with different signal swings. However, different signal swings affect whether the switched capacitor power amplifier 100 operates in the nonlinear region, therefore the nonlinear distortion caused by the nonlinear region of the switched capacitor power amplifier 100 will change with different signal swings. In this embodiment, the gain of the switched capacitor power amplifier 100 can be initially set to a first gain, wherein the first gain ensures that the signal S OUT The signal swing is small enough to prevent the switched capacitor power amplifier 100 from entering the nonlinear region. When the gain of the switched capacitor power amplifier 100 is set to this first gain, the delay difference calculation circuit 101 can calculate the delay difference based on the signal S. OUT The first detection result (i.e., the third-order intermodulation distortion value IMD3 obtained when the gain of the switched capacitor power amplifier 100 is the first gain) generates the estimation result τ. CAL Since the nonlinear distortion occurring when the gain of the switched capacitor power amplifier 100 is the first gain is caused solely by the AM-PM delay τ, the delay difference calculation circuit 101 can estimate the AM-PM delay τ after excluding factors affecting the nonlinear region of the switched capacitor power amplifier 100, and generate the estimation result τ accordingly. CAL In the delay difference compensation circuit 102, based on the estimated result τ... CAL For signal VDD ENV or signal SRF PM After compensation, the gain of the switched capacitor power amplifier 100 can be set to a second gain greater than the first gain, so that the signal S OUT The signal swing is large enough to cause the switched capacitor power amplifier 100 to enter the nonlinear region. Since the delay difference compensation circuit 102 has reduced or eliminated the AM-PM delay τ, the nonlinear distortion caused by the AM-PM delay τ can be reduced or eliminated, and the nonlinear distortion detected at this time is only caused by the nonlinear region of the switched capacitor power amplifier 100. Therefore, the DPD circuit 160 can adjust the signal based on the signal S. OUTA second detection result (e.g., a nonlinear distortion value such as the third-order intermodulation distortion value IMD3 obtained when the gain of the switched capacitor power amplifier 100 is the first gain) controls the nonlinear model so that the nonlinear model cancels out the nonlinear distortion of the switched capacitor power amplifier 100. Since the correction and implementation of this nonlinear model of the DPD circuit 160 is a technique well known to those skilled in the art, it will not be described in detail here for the sake of brevity.

[0040] Figure 5 This is a schematic diagram of a wireless communication device 50 according to one embodiment of the present invention. It should be noted that... Figure 5 The wireless communication device 50 shown Figure 1 The difference between the wireless communication device 10 and the wireless communication device 50 is that the delay difference compensation circuit 101 in the wireless communication device 50 is coupled between the TX baseband circuit 110 and the PM circuit 130, wherein the delay difference compensation circuit 102 can be based on the estimated result τ CAL For signal STX PM Delay difference control is performed to generate a compensated phase-modulated transmission signal such as signal SC. PM And PM circuit 130 can be based on signal SC PM Generate signal SRF PM .exist Figure 5 In the architecture shown, the PM digital-to-analog converter 131 in the PM circuit 130 can process the signal SC output by the delay difference compensation circuit 102. PM Digital-to-analog conversion is performed, and the PM modulator 132 in the PM circuit 130 can be based on the local oscillation frequency f. LO The output of the PM digital-to-analog converter 131 is up-converted to generate the signal SRF. PM Additionally, the AM digital-to-analog converter 121 in the AM circuit 120 (capable of processing signal STX) AM The digital-to-analog conversion is performed, and the reconstruction filter 122 in the AM circuit 120 can filter the output of the AM digital-to-analog converter 121 to generate the signal VDD. ENV All other operations are related to Figure 1 The wireless communication device 10 shown is the same, and will not be described again here for the sake of simplicity.

[0041] Figure 6 This is a schematic diagram of a wireless communication device 60 according to one embodiment of the present invention. Compared to Figure 5 The wireless communication device 50 and wireless communication device 60 shown may further include a DPD circuit 160. It should be noted that the DPD circuit 160 in the wireless communication device 60 is related to... Figure 4 The DPD circuit 160 in the wireless communication device 40 shown is the same, and Figure 6The wireless communication device 60 shown Figure 4 The differences between the wireless communication devices 40 shown can be referred to Figure 1 The wireless communication device 10 shown and Figure 5 The differences between the wireless communication devices 50 shown are known, but will not be elaborated here for the sake of simplicity.

[0042] Figure 7 This is a schematic diagram illustrating the improvement of signal linearity through delay compensation and digital predistortion according to an embodiment of the present invention, wherein... Figure 7 The horizontal axis can represent the output power of the switched capacitor power amplifier 100 (e.g., signal S). OUT (power), and Figure 7 The vertical axis represents the error vector magnitude (EVM) at different power levels. In particular, a higher EVM value indicates more severe nonlinear distortion. For example... Figure 7 As shown, when neither DPD compensation nor AM-PM delay compensation mechanisms are used, the output signal S OUT It has the largest EVM value (indicating the worst linearity). When the DPD compensation mechanism is used while the AM-PM delay compensation mechanism remains off, the output signal S... OUT The EVM value can be effectively reduced (linearity is improved). When both DPD compensation and AM-PM delay compensation mechanisms are used, the output signal S OUT The EVM value can be further reduced (linearity is further improved). Therefore, the linearity compensation mechanism provided by this invention (first performing AM-PM delay compensation, then DPD compensation) can effectively improve the signal S. OUT The linearity.

[0043] Figure 8 This is a schematic diagram illustrating the workflow of a method for compensating for nonlinear distortion in a wireless communication device (e.g., wireless communication device 10, 40, 50, or 60) according to one embodiment of the present invention. It should be noted that... Figure 8 The illustrated workflow is for illustrative purposes only and is not intended to limit the invention. For example, one or more steps may be performed... Figure 8 The workflow shown has been added, deleted, or modified. Furthermore, these steps do not necessarily need to be followed exactly to achieve the same result. Figure 8 Execute in the order shown.

[0044] In step S810, the wireless communication device can output a transmission signal using a transmission baseband circuit within it.

[0045] In step S820, the wireless communication device can use an amplitude modulation circuit within it to generate an amplitude modulation output signal based on an amplitude modulation transmission signal of the transmitted signal.

[0046] In step S830, the wireless communication device can use a phase modulation circuit within it to generate a phase modulation output signal based on a phase modulation transmission signal of the transmitted signal.

[0047] In step S840, the wireless communication device can use a power amplifier within it to use the amplitude-modulated output signal as a supply voltage, and generate an output signal based on the phase-modulated output signal.

[0048] In step S850, the wireless communication device may use a delay calculation circuit within it to estimate a delay difference between the amplitude-modulated output signal and the phase-modulated output signal based on a detection result of the output signal to generate an estimation result.

[0049] In step S860, the wireless communication device may use a delay compensation circuit within it to compensate the amplitude modulation output signal or the phase modulation output signal based on the estimation result, so as to reduce the delay difference.

[0050] In summary, the wireless communication device and related method provided by the embodiments of the present invention can estimate the delay difference between the AM path and the PM path based on the third-order intermodulation distortion value of the output signal, and perform compensation accordingly. In particular, the correlation correction of digital predistortion is performed only after the delay difference between the AM path and the PM path has been corrected, thereby ensuring that the digital predistortion correction process is less susceptible to the influence of the delay difference between the AM path and the PM path. Furthermore, the embodiments of the present invention do not significantly increase additional costs. Therefore, the present invention can improve the compensation efficacy of nonlinear distortion without or with minimal side effects.

[0051] The above description is only a preferred embodiment of the present invention. All equivalent changes and modifications made in accordance with the claims of the present invention shall fall within the scope of the present invention.

[0052] [Symbol Explanation]

[0053] 10, 40, 50, 60: Wireless communication devices

[0054] 100: Switched Capacitor Power Amplifier

[0055] 101: Delay Difference Calculation Circuit

[0056] 102: Delay Difference Compensation Circuit

[0057] 110: Baseband transmission circuit

[0058] 120: Amplitude Modulation Circuit

[0059] 121: Amplitude Modulation Digital-to-Analog Converter

[0060] 122: Reconstruction Filter

[0061] 130: Phase modulation circuit

[0062] 131: Phase Modulation Digital-to-Analog Converter

[0063] 132: Phase modulation modulator

[0064] 140: Receiver circuit

[0065] 141: Coupler

[0066] 142: Mixer

[0067] 143: Analog-to-Digital Converter

[0068] 150: Baseband receiving circuit

[0069] f LO Local oscillation frequency

[0070] f1: Frequency

[0071] τ CAL Estimation results

[0072] STX, STX AM STX PM ,SC AM ,SC PM SD AM SD PM :Signal

[0073] VDD ENV SRF PM ,S OUT ,SRX,S IMD3 :Signal

[0074] S810~S860: Steps.

Claims

1. A wireless communication device, comprising: A baseband transmission circuit is used to output a transmission signal; An amplitude modulation circuit is used to generate an amplitude-modulated output signal based on the amplitude-modulated transmission signal of the transmitted signal. A phase modulation circuit is used to generate a phase-modulated output signal based on the phase-modulated transmission signal of the transmitted signal. A power amplifier, coupled to the amplitude modulation circuit and the phase modulation circuit, is used to use the amplitude-modulated output signal as a supply voltage and to generate an output signal based on the phase-modulated output signal. A delay calculation circuit is used to estimate a delay difference between the amplitude-modulated output signal and the phase-modulated output signal based on a detection result of the output signal to generate an estimation result; and A delay compensation circuit, coupled to the transmission baseband circuit and the delay calculation circuit, is used to compensate the amplitude-modulated output signal or the phase-modulated output signal based on the estimation result, so as to reduce the delay difference.

2. The wireless communication device according to claim 1, wherein the detection result includes the third-order intermodulation distortion value of the output signal.

3. The wireless communication device according to claim 1, further comprising: A digital predistortion circuit, coupled between the transmission baseband circuit and the delay compensation circuit, is used to perform a predistortion operation on the transmitted signal according to a nonlinear model to generate a predistorted amplitude modulation signal of the amplitude modulation transmitted signal and a predistorted phase modulation signal of the phase modulation transmitted signal. The amplitude modulation circuit generates the amplitude modulation output signal based on the predistortion amplitude modulation signal, and the phase modulation circuit generates the phase modulation output signal based on the predistortion phase modulation signal.

4. The wireless communication device according to claim 3, wherein: When the power amplifier is set to a first gain, the delay calculation circuit generates the estimation result based on a first detection result of the output signal; as well as After the delay compensation circuit compensates the amplitude-modulated output signal or the phase-modulated output signal according to the estimation result, the power amplifier is set to a second gain greater than the first gain, and the digital predistortion circuit controls the nonlinear model according to a second detection result of the output signal so that the nonlinear model and the nonlinear distortion of the power amplifier cancel each other out.

5. The wireless communication device according to claim 1, further comprising: A receiving circuit, coupled to the power amplifier, receives the output signal from the power amplifier and generates a received signal based on the output signal; and A baseband receiving circuit, coupled to the receiving circuit and the delay calculation circuit, is used to generate the detection result of the output signal based on the received signal.

6. The wireless communication device according to claim 1, wherein the delay compensation circuit is coupled between the transmission baseband circuit and the amplitude modulation circuit, the delay compensation circuit performs delay control on the amplitude modulation transmission signal according to the estimation result to generate a compensated amplitude modulation transmission signal, and the amplitude modulation circuit generates the amplitude modulation output signal according to the compensated amplitude modulation transmission signal.

7. The wireless communication device according to claim 1, wherein the delay compensation circuit is coupled between the transmission baseband circuit and the phase modulation circuit, the delay compensation circuit performs delay control on the phase modulation transmission signal according to the estimation result to generate a compensated phase modulation transmission signal, and the phase modulation circuit generates the phase modulation output signal according to the compensated phase modulation transmission signal.

8. A method for compensating for nonlinear distortion in a wireless communication device, comprising: A transmission signal is output using a baseband circuit of the wireless communication device. An amplitude modulation circuit of the wireless communication device generates an amplitude-modulated output signal based on an amplitude-modulated transmission signal of the transmitted signal. A phase modulation circuit of the wireless communication device generates a phase modulation output signal based on a phase modulation transmission signal of the transmitted signal. The amplitude-modulated output signal is used as a supply voltage by a power amplifier of the wireless communication device, and an output signal is generated based on the phase-modulated output signal. The delay calculation circuit of the wireless communication device estimates a delay difference between the amplitude-modulated output signal and the phase-modulated output signal based on a detection result of the output signal to generate an estimation result; and The delay compensation circuit of the wireless communication device compensates for the amplitude modulation output signal or the phase modulation output signal based on the estimation result, so as to reduce the delay difference.

9. The method of claim 8, further comprising: A digital predistortion circuit of the wireless communication device performs a predistortion operation on the transmitted signal according to a nonlinear model to generate a predistorted amplitude modulation signal of the amplitude modulation transmitted signal and a predistorted phase modulation signal of the phase modulation transmitted signal. The amplitude modulation circuit generates the amplitude modulation output signal based on the predistorted amplitude modulation signal, and the phase modulation circuit generates the phase modulation output signal based on the predistorted phase modulation signal.

10. The method according to claim 8, wherein: The operation of the delay calculation circuit of the wireless communication device to estimate the delay difference between the amplitude-modulated output signal and the phase-modulated output signal based on the detection result of the output signal to generate the estimation result includes: Based on the power amplifier being set to a first gain, the estimation result is generated by the delay calculation circuit according to a first detection result of the output signal; and The method also includes: After the delay compensation circuit compensates the amplitude-modulated output signal or the phase-modulated output signal according to the estimation result, the power amplifier is set to a second gain greater than the first gain, and a nonlinear model is controlled by the digital predistortion circuit according to a second detection result of the output signal, so that the nonlinear model cancels out the nonlinear distortion of the power amplifier.

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