Transceiver and carrier leakage calibration method

Abstract

The application discloses a kind of transceiver and carrier leakage calibration method, device includes: control module, transmitting compensation module, transmitter, calibration switch module, receiver and receiving compensation module;When loopback mode is opened, transmitting compensation module generates analog direct current signal, transmitter converts analog direct current signal into uncalibrated radio frequency signal, uncalibrated radio frequency signal enters receiver via calibration switch module;Receiver converts uncalibrated radio frequency signal into analog intermediate frequency signal, receiving compensation module generates signal power according to analog intermediate frequency signal, control module adjusts direct current distortion parameter sent to receiver and receiving compensation parameter sent to receiving compensation module according to signal power, and direct current distortion calibration is carried out to receiver;Control module adjusts transmitting compensation parameter sent to transmitting compensation module according to signal power, and carrier leakage calibration is carried out to transmitter.The application can improve calibration effect and process deviation under calibration stability.

Description

Technical Field

[0001] This invention relates to the field of transceiver calibration technology, and in particular to a transceiver and a carrier leakage calibration method. Background Technology

[0002] In RF transceiver devices employing a direct conversion architecture, the DC component generated by the local oscillator signal after being coupled to the receiver input (LNA) or mixer via internal parasitic capacitance or substrate, along with the inherent DC component generated by the analog circuit due to manufacturing process deviations, is superimposed on the useful baseband signal, leading to DC offset.

[0003] DC offset in the receiver can severely degrade the quality of the received signal. To efficiently utilize the transceiver, transmitter calibration typically loops the RF signal back to the receiver's RF, down-converts it, and then quantizes it via an analog-to-digital converter (ADC) before outputting it to the digital domain for digital algorithm compensation. However, to distinguish between receiver DC offset and transmitter carrier leakage, the receiver's DC offset is usually calibrated first, followed by loopback mode calibration of the transmitter's carrier leakage. This calibration method has the following problems: 1. The self-mixing DC offset caused by the local oscillator signal coupling of the receiver will vary or even be opposite in normal operation and loopback mode depending on the different RF signal input paths; 2. DC offset caused by mismatch in self-mixing and analog circuits may lead to ADC saturation after being amplified by high gain in the receiver link, resulting in the complete loss of useful signals or transmitter calibration signals that cannot be recovered through digital calibration.

[0004] Therefore, in RF chip transceivers using a direct conversion architecture, calibrating receiver DC offset when the loopback mode is off and calibrating transmitter carrier leakage when the loopback mode is on will lead to calibration failure or even the opposite effect due to the difference in self-mixing DC offset. On the other hand, calibrating both simultaneously when the loopback mode is on will cause ADC saturation and signal distortion due to the superposition of DC energy, making it difficult to achieve independent calibration. This results in poor calibration effect of transmit carrier leakage and poor calibration stability under process deviations. Summary of the Invention

[0005] In order to overcome the shortcomings of the prior art, the present invention aims to provide a transceiver device and a carrier leakage calibration method, which can improve the calibration effect and calibration stability under process deviation.

[0006] This invention is implemented according to the following scheme: A transceiver device is provided, comprising: a control module, a transmission compensation module, a transmitter, a calibration switch module, a receiver, and a reception compensation module; the control module is connected to the transmission compensation module, the receiver, and the reception compensation module; the transmission compensation module is connected to the transmitter; the reception compensation module is connected to the receiver; and the calibration switch module is connected to the transmitter and the receiver. The calibration switch module is used to enable the loopback mode. When the loopback mode is enabled, the transmit compensation module generates an analog DC signal. The transmitter converts the analog DC signal into an uncalibrated radio frequency signal. The uncalibrated radio frequency signal enters the receiver via the calibration switch module. The receiver converts the uncalibrated radio frequency signal into an analog intermediate frequency signal. The receiving compensation module generates signal power based on the analog intermediate frequency signal. The control module adjusts the DC offset parameters sent to the receiver and the receiving compensation parameters sent to the receiving compensation module based on the signal power to perform DC offset calibration on the receiver. The control module adjusts the transmission compensation parameters sent to the transmission compensation module according to the signal power, and performs carrier leakage calibration on the transmitter.

[0007] Compared with the prior art, the beneficial effects of the transceiver device with calibration function of the present invention are as follows: by looping back the uncalibrated radio frequency signal including the transmitted carrier leakage to the receiver, and by performing frequency conversion processing on the uncalibrated radio frequency signal through an out-of-band intermediate frequency filter and filtering out the signal, an analog intermediate frequency signal is obtained, so as to realize the calibration of the DC offset of the receiver first and the carrier leakage of the transmitter in loop-back mode, thereby improving the calibration effect of the transmitted carrier leakage and the calibration stability under process deviation.

[0008] Optionally, the transmission compensation module includes: a signal generator, a transmission DC compensation unit, and a digital-to-analog converter; the transmission DC compensation unit is connected to the signal generator, the digital-to-analog converter, and the control module, and the digital-to-analog converter is connected to the transmitter.

[0009] Optionally, the transmitter includes: a transmit intermediate frequency unit, a transmit mixer, and a power preamplifier; the transmit mixer is connected to the transmit intermediate frequency unit and the power preamplifier, the transmit intermediate frequency unit is connected to the transmit compensation module, and the power preamplifier is connected to the calibration switch module.

[0010] Optionally, the receiver includes: a low-noise amplifier, a receiving mixer, and a receiving intermediate frequency unit; the calibration switch module is connected to the low-noise amplifier and the receiving mixer, and the receiving intermediate frequency unit is connected to the receiving mixer, the control module, and the receiving compensation module.

[0011] Optionally, the calibration switch module includes: a first switch, a second switch, and a third switch; the second switch is connected to the third switch, the receiver is connected to the first switch and the second switch, and the transmitter is connected to the third switch.

[0012] Optionally, the receiving compensation module includes: an analog-to-digital converter, a digital quadrature mixer, a digital filter, a receiving DC compensation unit, and a power detection unit; the analog-to-digital converter is connected to the power detection unit in sequence through the digital quadrature mixer, the digital filter, and the receiving DC compensation unit, and the control module is connected to the receiving DC compensation unit and the power detection unit.

[0013] A carrier leakage calibration method is also provided, applied to the aforementioned transceiver device, comprising: The loopback mode is activated by the calibration switch module, the transmit compensation module generates an analog DC signal, the transmitter converts the analog DC signal into an uncalibrated radio frequency signal, and the uncalibrated radio frequency signal enters the receiver via the calibration switch module. The receiver converts the uncalibrated radio frequency signal into an analog intermediate frequency signal. The receiving compensation module generates signal power based on the analog intermediate frequency signal. The control module adjusts the DC offset parameters sent to the receiver and the receiving compensation parameters sent to the receiving compensation module based on the signal power to perform DC offset calibration on the receiver. The control module adjusts the transmission compensation parameters sent to the transmission compensation module according to the signal power, and performs carrier leakage calibration on the transmitter.

[0014] Optionally, the receiving compensation module generates signal power based on the analog intermediate frequency signal, including: After the analog-to-digital converter of the receiving compensation module converts the analog intermediate frequency signal into a digital intermediate frequency signal, the digital quadrature mixer of the receiving compensation module performs spectrum shifting on the digital intermediate frequency signal. The digital filter extracts the zero-frequency signal from the frequency-shifted digital intermediate frequency signal and sends it to the power detection unit of the receiving compensation module through the receiving DC compensation unit of the receiving compensation module. The power detection unit of the receiving compensation module calculates the power of the zero-frequency signal to obtain the signal power.

[0015] Optionally, the control module adjusts the DC offset parameters transmitted to the receiver and the reception compensation parameters transmitted to the reception compensation module according to the signal power, and performs DC offset calibration on the receiver, including: The process of iteratively adjusting the DC offset parameters includes: The control module adjusts the initial DC offset parameters of the receiver according to the signal power, and the receiver generates an adjusted analog intermediate frequency signal according to the initial DC offset parameters. The receiving compensation module generates a new signal power based on the adjusted analog intermediate frequency signal; When the new signal power is greater than the signal power of the previous iteration, the initial DC offset parameter of the previous iteration is determined as the DC offset parameter, and the iteration ends; If the new signal power is less than or equal to the signal power of the previous iteration, then the new signal power is used as the signal power, and the next iteration is executed. After the DC offset parameters are adjusted, the following process for adjusting the receiving compensation parameters is performed iteratively, including: The control module adjusts the initial reception compensation parameters of the reception compensation module according to the signal power, and the reception compensation module generates the adjusted zero-frequency signal according to the initial reception compensation parameters. The receiving compensation module generates a new signal power based on the adjusted zero-frequency signal; When the new signal power is greater than the signal power of the previous iteration, the initial reception compensation parameter of the previous iteration is determined as the reception compensation parameter, and the iteration ends; If the new signal power is less than or equal to the signal power of the previous iteration, then the new signal power is used as the signal power, and the next iteration is performed.

[0016] Optionally, the control module adjusts the transmission compensation parameters sent to the transmission compensation module according to the signal power, and performs carrier leakage calibration on the transmitter, including: The process of iteratively adjusting the transmission compensation parameters of the transmission compensation module includes: The control module adjusts the initial transmission compensation parameters of the transmission compensation module according to the signal power, and the transmission compensation module generates an adjusted analog DC signal according to the initial transmission compensation parameters; The analog DC signal is processed sequentially by the transmitter, the receiver, and the receiver compensation module to generate a new signal power; When the new signal power is greater than the signal power of the previous iteration, the initial transmission compensation parameter of the previous iteration is determined as the transmission compensation parameter, and the iteration ends; If the new signal power is less than or equal to the signal power of the previous iteration, then the new signal power is used as the signal power, and the next iteration is performed. Attached Figure Description

[0017] Figure 1 This is a structural block diagram of the transceiver device of the present invention; Figure 2 This is a circuit diagram of the transceiver device of the present invention; Figure 3 These are spectrum diagrams of different structures in the transceiver device of the present invention; Figure 4 The time domain and spectrum diagrams for calibrating the received DC offset in the closed loop-loop mode and then calibrating the transmitted carrier leakage in the open loop-loop mode are presented in the existing technology. Figure 5 The time and frequency domain diagrams are shown for the existing technology of downconverting the transmitted carrier leakage loop to the received DC. Figure 6 The time and frequency domain diagrams for downconverting the transmitted carrier leakage loop to the received intermediate frequency in existing technologies; Figure 7 This is a time-domain and spectrum diagram of the transceiver device of the present invention; The attached diagram shows the following labels: 1. Control module; 2. Transmit compensation module; 201. Signal generator; 202. Transmit DC compensation unit; 203. Digital-to-analog converter; 3. Transmitter; 301. Transmit intermediate frequency unit; 302. Transmit mixer; 303. Power preamplifier; 4. Calibration switch module; 5. Receiver; 501. Low noise amplifier; 502. Receive mixer; 503. Receive intermediate frequency unit; 6. Receive compensation module; 601. Analog-to-digital converter; 602. Digital quadrature mixer; 603. Digital filter; 604. Receive DC compensation unit; 605. Power detection unit. Detailed Implementation

[0018] The preferred embodiments of the present invention will be described below with reference to the accompanying drawings. It should be understood that the preferred embodiments described herein are for illustration and explanation only and are not intended to limit the present invention.

[0019] In the following description, when referring to the accompanying drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this application. Rather, they are merely examples of apparatuses and methods consistent with some aspects of this application as detailed in the appended claims. In the description of this application, it should be understood that the terms "first," "second," "third," etc., are used only to distinguish similar objects and are not necessarily used to describe a specific order or sequence, nor should they be construed as indicating or implying relative importance. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0020] A transceiver device according to the present invention includes: a control module 1, a transmission compensation module 2, a transmitter 3, a calibration switch module 4, a receiver 5, and a reception compensation module 6; the control module 1 is connected to the transmission compensation module 2, the receiver 5, and the reception compensation module 6; the transmission compensation module 2 is connected to the transmitter 3; the reception compensation module 6 is connected to the receiver 5; and the calibration switch module 4 is connected to the transmitter 3 and the receiver 5. The calibration switch module 4 is used to enable the loopback mode. When the loopback mode is enabled, the transmit compensation module 2 generates an analog DC signal, and the transmitter 3 converts the analog DC signal into an uncalibrated RF signal. The uncalibrated RF signal enters the receiver 5 through the calibration switch module 4. The receiver 5 converts the uncalibrated RF signal into an analog intermediate frequency signal. The receive compensation module 6 generates a signal power based on the analog intermediate frequency signal. The control module 1 adjusts the DC offset parameters sent to the receiver 5 and the receive compensation parameters sent to the receive compensation module 6 based on the signal power to perform DC offset calibration on the receiver 5. The control module 1 adjusts the transmit compensation parameters sent to the transmit compensation module 2 based on the signal power to perform carrier leakage calibration on the transmitter 3.

[0021] This invention loops back an uncalibrated radio frequency signal, including transmitted carrier leakage, to receiver 5, and then performs frequency conversion processing on the uncalibrated radio frequency signal by performing an out-of-band intermediate frequency filter to obtain an analog intermediate frequency signal. This allows for the calibration of the DC offset of receiver 5 first in loop-back mode, and then the carrier leakage of transmitter 3, thus avoiding interference from received DC offset to transmitted carrier leakage in loop-back mode, and improving the calibration effect of transmitted carrier leakage and calibration stability under process deviations.

[0022] In one embodiment of the present invention, the transmission compensation module 2 includes: a signal generator 201, a transmission DC compensation unit 202, and a digital-to-analog converter 203; the transmission DC compensation unit 202 is connected to the signal generator 201, the digital-to-analog converter 203, and the control module 1, and the digital-to-analog converter 203 is connected to the transmitter 3.

[0023] The signal generator 201 generates a fixed digital code, which causes the digital-to-analog converter 203 to output a common-mode state. It also divides the signal into two paths, I and Q, with a 90° phase difference, and sends them to the transmit DC compensation unit 202. The transmit DC compensation unit 202 includes two identical transmit compensation circuits, I and Q. Each transmit compensation circuit has positive and negative compensation, that is, the transmit DC compensation unit 202 has four transmit compensation parameters, including: I-path positive compensation coefficient DCTUNE_P_I, I-path negative compensation coefficient DCTUNE_N_I, Q-path positive compensation coefficient DCTUNE_P_Q, and Q-path negative compensation coefficient DCTUNE_N_Q. Then, it is converted into an analog DC signal by the digital-to-analog converter 203 and sent to the transmitter 3.

[0024] In one embodiment of the present invention, the transmitter 3 includes: a transmit intermediate frequency unit 301, a transmit mixer 302, and a power preamplifier 303; the transmit mixer 302 is connected to the transmit intermediate frequency unit 301 and the power preamplifier 303, the transmit intermediate frequency unit 301 is connected to the transmit compensation module 2, and the power preamplifier 303 is connected to the calibration switch module 4.

[0025] The transmitting intermediate frequency unit 301 filters out out-of-band aliasing from the analog DC signal output by the digital-to-analog converter 203 and outputs it to the transmitting mixer 302. The transmitting mixer 302 then outputs the signal according to the transmitting local oscillator frequency f. txlo The signal output from the intermediate frequency unit 301 is up-converted to the same frequency as the local oscillator frequency f. txlo The same radio frequency signal, the transmit local oscillator frequency f txlo The signal obtained by dividing the phase-locked loop in transmitter 3 by two is then output to power preamplifier 303 for pre-amplification, resulting in an uncalibrated radio frequency signal including the transmitted carrier leakage. If this uncalibrated radio frequency signal is not calibrated, the carrier leakage will be superimposed on the main signal and sent out. Figure 3 The spectrum of the power preamplifier 303 is shown.

[0026] In one embodiment of the present invention, the receiver 5 includes: a low-noise amplifier 501, a receiving mixer 502, and a receiving intermediate frequency unit 503; the calibration switch module 4 is connected to the low-noise amplifier 501 and the receiving mixer 502, and the receiving intermediate frequency unit 503 is connected to the receiving mixer 502, the control module 1, and the receiving compensation module 6.

[0027] When loopback mode is enabled, the connection between the low-noise amplifier 501 and the receiving mixer 502 is disconnected via calibration switch module 4, and the connection between the power preamplifier 303 and the receiving mixer 502 is closed. The receiving mixer 502 downconverts the uncalibrated RF signal output from the power preamplifier 303 to frequency f. txlo -f rxlo The analog signal, if f txlo =f rxlo The analog signal is an analog DC signal, and the receiving local oscillator frequency is f. rxlo The analog signal is obtained by dividing the phase-locked loop in receiver 5 by two; then, the analog signal is amplified by A times by the receiving intermediate frequency unit 503 to obtain the analog intermediate frequency signal, which is then output to the receiving compensation module 6. Figure 3 The spectrum diagrams of the receiving mixer 502 and the receiving intermediate frequency unit 503 are shown.

[0028] In one embodiment of the present invention, the calibration switch module 4 includes: a first switch S1, a second switch S2, and a third switch S3; the second switch S2 is connected to the third switch S3, the receiver 5 is connected to the first switch S1 and the second switch S2, and the transmitter 3 is connected to the third switch S3; when the first switch S1 is open and the second switch S2 and the third switch S3 are closed, the loopback mode is enabled; when the first switch S1 is closed and the second switch S2 and the third switch S3 are open, the loopback mode is disabled.

[0029] In one embodiment of the present invention, the receiving compensation module 6 includes: an analog-to-digital converter 601, a digital quadrature mixer 602, a digital filter 603, a receiving DC compensation unit 604, and a power detection unit 605; the analog-to-digital converter 601 is connected to the power detection unit 605 in sequence through the digital quadrature mixer 602, the digital filter 603, and the receiving DC compensation unit 604, and the control module 1 is connected to the receiving DC compensation unit 604 and the power detection unit 605.

[0030] The analog-to-digital converter 601 converts the analog intermediate frequency signal output from the receiving intermediate frequency unit 503 into a digital intermediate frequency signal, which is then sent to the digital quadrature mixer 602 for processing. The digital quadrature mixer 602 includes a numerically controlled oscillator (NCO) and a digital quadrature mixing circuit. The NCO is used to generate NO_I and NO_Q frequencies of f. no The quadrature signal is output to the digital quadrature mixer circuit; then the digital intermediate frequency signal is mixed with... Multiplication yields a spectrum shifting effect. Figure 3 The spectrum diagram of the digital quadrature mixer 602 is shown, and its spectrum shifting effect includes two cases: (1) no shifting; (2) down-conversion to reduce the frequency f of the main signal. txlo -f rxlo The signal is moved to the vicinity of zero frequency; the two signals are output to the digital filter 603 and the receiving DC compensation unit 604 respectively for processing, and the signal located near zero frequency is extracted; finally, the signals are sent to the power detection unit 605 to obtain the signal power.

[0031] A carrier leakage calibration method of the present invention, applied to the above-mentioned transceiver device, includes: The loopback mode is activated by calibration switch module 4, the transmit compensation module 2 generates an analog DC signal, the transmitter 3 converts the analog DC signal into an uncalibrated radio frequency signal, and the uncalibrated radio frequency signal enters the receiver 5 through calibration switch module 4. Specifically, when the first switch S1 in the calibration switch module 4 is open and the second switch S2 and the third switch S3 are closed, the loopback mode is activated, forming a loop between the output of the transmitter 3 and the RF end of the receiver 5, thus modifying the receiving local oscillator frequency f of the receiving mixer 502. rxlo1This ensures that both the transmitting phase-locked loop and the receiving phase-locked loop are in a locked state; the transmitting compensation module 2 generates an analog DC signal, including: the signal generator 201 outputs the common-mode digital code of the digital-to-analog converter 203, which then passes through the transmitting DC compensation unit 202 and the digital-to-analog converter 203 in sequence to output the analog DC signal, and is sent to the transmitter 3.

[0032] Receiver 5 converts the uncalibrated radio frequency signal into an analog intermediate frequency signal. The receiving compensation module 6 generates signal power based on the analog intermediate frequency signal. The control module 1 adjusts the DC offset parameters sent to receiver 5 and the receiving compensation parameters sent to receiving compensation module 6 based on the signal power to perform DC offset calibration on receiver 5. The control module 1 adjusts the transmission compensation parameters sent to the transmission compensation module 2 according to the signal power, and performs carrier leakage calibration on the transmitter 3.

[0033] In one embodiment of the present invention, the receiving compensation module 6 generates signal power based on the analog intermediate frequency signal, including: after the analog-to-digital converter 601 of the receiving compensation module 6 converts the analog intermediate frequency signal into a digital intermediate frequency signal, the digital quadrature mixer 602 of the receiving compensation module 6 performs spectrum shifting on the digital intermediate frequency signal; the digital filter 603 extracts the zero-frequency signal from the spectrum-shifted digital intermediate frequency signal and sends it to the power detection unit 605 of the receiving compensation module 6 through the receiving DC compensation unit 604; the power detection unit 605 of the receiving compensation module 6 calculates the power of the zero-frequency signal to obtain the signal power.

[0034] The uncalibrated radio frequency signal is down-converted to frequency f by the receiving mixer 502. txlo -f rxlo1 The analog signal falls outside the receiving intermediate frequency filter band and has a power of p. tx The equivalent DC offset power of the self-mixing DC offset and intermediate frequency mismatch in receiver 5, as output from receiver mixer 502, is p. mix2 +p if Next, the DC offset and frequency f output from mixer 502 are received. txlo -f rxlo After the analog signal is filtered and amplified by the receiving intermediate frequency unit 503, the DC offset power is amplified to (p mix2 +p if ) A 2 And frequency f txlo -f rxlo1 The analog signal is suppressed by the out-of-band filter in the receiving intermediate frequency unit 503 and its power is negligible. Finally, the analog intermediate frequency signal output by the receiving intermediate frequency unit 503 is output to the receiving compensation module 6.

[0035] The analog-to-digital converter 601 in the receiving compensation module 6 converts the analog intermediate frequency signal into a digital frequency conversion signal, and then quantizes it before sending it to the digital quadrature mixer 602 and the digital filter 603 to extract the zero-frequency signal. The power detection unit 605 then extracts the signal power of the zero-frequency signal as p. rx =(p mix2 +p if ) A 2 .

[0036] In one embodiment of the present invention, the control module 1 adjusts the DC offset parameters transmitted to the receiver 5 and the reception compensation parameters transmitted to the reception compensation module 6 according to the signal power, and performs DC offset calibration on the receiver 5, including: The process of iteratively adjusting the DC offset parameters includes: control module 1 adjusting the initial DC offset parameters of receiver 5 according to the signal power; receiver 5 generating an adjusted analog intermediate frequency signal according to the initial DC offset parameters; receiver compensation module 6 generating a new signal power according to the adjusted analog intermediate frequency signal; when the new signal power is greater than the signal power of the previous iteration, the initial DC offset parameters of the previous iteration are determined as the DC offset parameters, and the iteration ends; when the new signal power is less than or equal to the signal power of the previous iteration, the new signal power is used as the signal power, and the next iteration is executed. After the DC offset parameters are adjusted, the following process of adjusting the receiving compensation parameters is executed iteratively: control module 1 adjusts the initial receiving compensation parameters of receiving compensation module 6 according to the signal power; receiving compensation module 6 generates an adjusted zero-frequency signal according to the initial receiving compensation parameters; receiving compensation module 6 generates a new signal power according to the adjusted zero-frequency signal; when the new signal power is greater than the signal power of the previous iteration, the initial receiving compensation parameters of the previous iteration are determined as the receiving compensation parameters, and the iteration ends; when the new signal power is less than or equal to the signal power of the previous iteration, the new signal power is used as the signal power, and the next iteration is executed.

[0037] Specifically, the power p of the zero-frequency signal is extracted by the power detection unit 605 mentioned above. rx Subsequently, control module 1 injects the DC offset parameter RXIF_DC_P / N into the current input PN terminal of the receiving intermediate frequency unit 503. The injection port is selected to input to either the P or N terminal based on the output polarity of the analog-to-digital converter 601, in order to adjust the DC offset value and reread the signal power p. rx (New signal power), select signal power p rx The minimum DC offset parameter RXIF_DC_P / N value achieves a DC offset accuracy of approximately 40mV, ensuring that the analog-to-digital converter 601 will not saturate.

[0038] Next, control module 1 adjusts the receiving compensation parameters of the receiving DC compensation unit 604 and rereads the signal power p. rx (New signal power), select signal power p rx At the minimum receiving compensation parameters, the loopback mode is enabled, and the receiving DC offset calibration is eliminated when the transmit carrier leakage occurs.

[0039] In one embodiment of the present invention, the control module 1 adjusts the transmission compensation parameters sent to the transmission compensation module 2 according to the signal power, and performs carrier leakage calibration on the transmitter 3, including: The process of iteratively adjusting the transmission compensation parameters of the transmission compensation module 2 includes: the control module 1 adjusts the initial transmission compensation parameters of the transmission compensation module 2 according to the signal power; the transmission compensation module 2 generates an adjusted analog DC signal according to the initial transmission compensation parameters; the analog DC signal is processed sequentially by the transmitter 3, the receiver 5, and the compensation module of the receiver 5 to generate a new signal power; when the new signal power is greater than the signal power of the previous iteration, the initial transmission compensation parameters of the previous iteration are determined as the transmission compensation parameters, and the iteration ends; when the new signal power is less than or equal to the signal power of the previous iteration, the new signal power is used as the signal power, and the next iteration is executed.

[0040] Specifically, this involves modifying the local oscillator frequency f of the receiving mixer 502. rxlo2 This ensures the receiving phase-locked loop is locked; the uncalibrated RF signal is down-converted to frequency f by the receiving mixer 502. txlo -f rxlo2 The analog signal falls within the receiving intermediate frequency filter band. After intermediate frequency filtering and amplification by the receiving intermediate frequency unit 503, the power of the transmitted carrier frequency is p. tx A 2 .

[0041] Next, the signal output from the intermediate frequency unit 503 is received, quantized by the analog-to-digital converter 601, and then enters the digital processing circuit. The digitally controlled oscillator (NCO) of the digital quadrature mixer 602 down-converts the signal to f. NO , where f NO =f txlo -f rxlo2 After passing through digital filter 603, the zero-frequency signal is extracted, and its signal power is p. tx A 2 .

[0042] Finally, control module 1 adjusts the transmission compensation parameters of the transmission DC compensation unit 202 and rereads the signal power p. tx A 2(New signal power), select signal power p tx A 2 The minimum transmit compensation parameters are used to complete the transmit carrier leakage calibration.

[0043] See Figure 4 The diagram illustrates the time-domain and spectrum of calibrating the receive DC offset in closed loop-loop mode and then calibrating the transmit carrier leakage in open loop-loop mode in the prior art. If the receive DC offset is calibrated when loop-loop mode is closed and then the transmit carrier leakage is calibrated when loop-loop mode is open, the DC offset v at the output of the receive mixer 502 due to self-mixing is significant when loop-loop mode is closed. mix1 The equivalent DC offset v of the receiving intermediate frequency unit 503 to the input if After being amplified by A times through a filter, the voltage is (V mix1 +v if ) A. Assuming that the voltage is calibrated to near 0 through calibration, and then the loopback mode is activated, due to the physical location limitations of the chip layout, in the LO path of receiver 5, and the present invention... Figure 2 The distance between the first switch S1 and the second switch S2 cannot be exactly the same; assuming the circuit layout in the prior art differs from that in this invention... Figure 2 The circuit layout shown is similar, so the parasitic capacitance of the loopback path is completely different from the parasitic capacitance of the receiver channel when the loopback mode is off and when it is working normally.

[0044] Therefore, when switching to loopback mode, the DC offset generated by self-mixing becomes v mix2 The total DC offset of the received intermediate frequency unit 503 output becomes (v mix2 +v if ) A, Add the previous calibration result -(v mix1 +v if ) After A, the filter output is approximately (v mix2 -v mix1 ) A, V in different RF chips mix2 and v mix1 The sizes are different, and in extreme cases, the difference may still be close to the full scale of the analog-to-digital converter 601.

[0045] If you want to calibrate the receive DC offset directly when loopback mode is enabled, then the filter output offset voltage caused by the receive DC offset is (v mix2 +v if ) A, similarly, may occur when the analog-to-digital converter 601 is close to full scale.

[0046] See Figure 5 As shown, the time and frequency domain diagrams of downconverting the transmitted carrier leakage loop to the received DC in the prior art are illustrated, i.e., f txlo -f rxlo =0, voltage is v tx A, this DC offset is superimposed on the previous two cases respectively, regardless of (v) mix2 +v if ) A, or (v) mix2 -v mix1 ) A, none of them can achieve the expected result (v) mix2 +v if +v tx ) A、(v) mix2 -v mix1 +v tx ) A, but rather the full-scale voltage of the ADC is obtained. Therefore, no matter how the transmit DC offset value is modified, it is impossible to receive the power p output by the analog-to-digital converter 601. adcfs Things have changed.

[0047] See Figure 6 As shown, the time and frequency domain diagrams of downconverting the transmitted carrier leakage loop to the received intermediate frequency in the prior art are illustrated, i.e., f txlo -f rxlo If the value is greater than 0, it is because the sine wave output by the filter has been saturated and generated a large number of harmonics. It is difficult to distinguish the power contributions of the receiving DC offset, the transmitting carrier leakage and the harmonics, and the calibration results obtained are also inaccurate.

[0048] See Figure 7 The diagram shown is the time domain and spectrum diagram of the transceiver device of the present invention. The present invention is related to... Figure 4-6 The difference in the prior art shown is that: the loopback mode is first enabled, and the transmitted carrier leakage is loop-downconverted to the received intermediate frequency, which is greater than the bandwidth f of the intermediate frequency filter (the filter in the received intermediate frequency unit 503). bw That is, f txlo -f rxlo1 >f bw .

[0049] Therefore, the DC offset v at the output of the receiving mixer 502 due to self-mixing mix2 The equivalent DC offset v of the receiving intermediate frequency unit 503 to the input if The superimposed transmit carrier leakage loop back to the output of the receive mixer 502 f txlo- f rxlo1 After the signal, such as Figure 7As shown in step 3, after filtering and amplification by the receiving intermediate frequency unit 503, the received DC offset signal is amplified, with a power of (p mix2 +p if ) A 2 The transmitted carrier leakage power p tx A 2 It is significantly attenuated to the point that it can be basically ignored, and then after Figure 7 Steps 5-6 of the process involve analog DC offset calibration and digital DC offset calibration, which will completely eliminate the received DC offset.

[0050] Then, modify the receiving local oscillator frequency of the receiving mixer 502 to f. rxlo2 Let 0 < f txlo -f rxlo2 <f bw At this point, only the transmitted carrier leakage signal remains. After being amplified by A times by the receiving intermediate frequency unit 503, its output spectrum is as follows: Figure 7 As shown in step 7 of the process.

[0051] Finally, after quantization by the analog-to-digital converter 601, the separated f is frequency-shifted by the digital quadrature mixer 602 (digital oscillator NCO). txlo -f rxlo2 The frequency is down-converted to zero, then filtered to complete the transmit carrier leakage calibration.

[0052] This invention loops back an uncalibrated radio frequency signal, including a transmitted carrier leakage signal, to receiver 5, and then performs frequency conversion processing on the uncalibrated radio frequency signal by performing an out-of-band intermediate frequency filter to obtain an analog intermediate frequency signal. This allows for the calibration of the DC offset of receiver 5 first and then the carrier leakage of transmitter 3 in loop-back mode, thereby improving the calibration effect of transmitted carrier leakage and the calibration stability under process deviations.

[0053] The above are merely preferred embodiments of this application and are not intended to limit this application. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A transceiver device, characterized in that, include: Control module, transmit compensation module, transmitter, calibration switch module, receiver and receive compensation module; The control module is connected to the transmit compensation module, the receiver, and the receive compensation module; the transmit compensation module is connected to the transmitter; the receive compensation module is connected to the receiver; and the calibration switch module is connected to the transmitter and the receiver. The calibration switch module is used to enable the loopback mode. When the loopback mode is enabled, the transmit compensation module generates an analog DC signal. The transmitter converts the analog DC signal into an uncalibrated radio frequency signal. The uncalibrated radio frequency signal enters the receiver via the calibration switch module. The receiver converts the uncalibrated radio frequency signal into an analog intermediate frequency signal. The receiving compensation module generates signal power based on the analog intermediate frequency signal. The control module adjusts the DC offset parameters sent to the receiver and the receiving compensation parameters sent to the receiving compensation module based on the signal power. The receiver is calibrated for DC offset under the loopback mode enabled. The control module iteratively executes the following process of adjusting the DC offset parameters, including: the control module adjusts the initial DC offset parameters of the receiver according to the signal power; the receiver generates an adjusted analog intermediate frequency signal according to the initial DC offset parameters; the receiver compensation module generates a new signal power according to the adjusted analog intermediate frequency signal; when the new signal power is greater than the signal power of the previous iteration, the initial DC offset parameters of the previous iteration are determined as the DC offset parameters, and the iteration ends; when the new signal power is less than or equal to the signal power of the previous iteration, the new signal power is used as the signal power, and the next iteration is executed. With the loopback mode enabled, after the control module performs DC offset calibration on the receiver, it adjusts the transmission compensation parameters sent to the transmission compensation module according to the signal power to perform carrier leakage calibration on the transmitter.

2. The transceiver device according to claim 1, characterized in that, The transmission compensation module includes: a signal generator, a transmission DC compensation unit, and a digital-to-analog converter; the transmission DC compensation unit is connected to the signal generator, the digital-to-analog converter, and the control module, and the digital-to-analog converter is connected to the transmitter.

3. The transceiver device according to claim 1, characterized in that, The transmitter includes: a transmit intermediate frequency unit, a transmit mixer, and a power preamplifier; the transmit mixer is connected to the transmit intermediate frequency unit and the power preamplifier, the transmit intermediate frequency unit is connected to the transmit compensation module, and the power preamplifier is connected to the calibration switch module.

4. The transceiver device according to claim 1, characterized in that, The receiver includes: a low-noise amplifier, a receiving mixer, and a receiving intermediate frequency unit; the calibration switch module is connected to the low-noise amplifier and the receiving mixer, and the receiving intermediate frequency unit is connected to the receiving mixer, the control module, and the receiving compensation module.

5. A transceiver device according to claim 1, characterized in that, The calibration switch module includes a first switch, a second switch, and a third switch; the second switch is connected to the third switch, the receiver is connected to the first switch and the second switch, and the transmitter is connected to the third switch.

6. A transceiver device according to claim 1, characterized in that, The receiving compensation module includes: an analog-to-digital converter, a digital quadrature mixer, a digital filter, a receiving DC compensation unit, and a power detection unit; the analog-to-digital converter is connected to the power detection unit in sequence through the digital quadrature mixer, the digital filter, and the receiving DC compensation unit, and the control module is connected to the receiving DC compensation unit and the power detection unit.

7. A carrier leakage calibration method, applied to a transceiver device according to any one of claims 1-6, characterized in that, include: The loopback mode is activated by the calibration switch module, the transmit compensation module generates an analog DC signal, the transmitter converts the analog DC signal into an uncalibrated radio frequency signal, and the uncalibrated radio frequency signal enters the receiver via the calibration switch module. The receiver converts the uncalibrated radio frequency signal into an analog intermediate frequency signal. The receiving compensation module generates signal power based on the analog intermediate frequency signal. The control module adjusts the DC offset parameters sent to the receiver and the receiving compensation parameters sent to the receiving compensation module based on the signal power to perform DC offset calibration on the receiver. The control module adjusts the transmission compensation parameters sent to the transmission compensation module according to the signal power, and performs carrier leakage calibration on the transmitter.

8. The carrier leakage calibration method according to claim 7, characterized in that, The receiving compensation module generates signal power based on the analog intermediate frequency signal, including: After the analog-to-digital converter of the receiving compensation module converts the analog intermediate frequency signal into a digital intermediate frequency signal, the digital quadrature mixer of the receiving compensation module performs spectrum shifting on the digital intermediate frequency signal. The digital filter extracts the zero-frequency signal from the frequency-shifted digital intermediate frequency signal and sends it to the power detection unit of the receiving compensation module through the receiving DC compensation unit of the receiving compensation module. The power detection unit of the receiving compensation module calculates the power of the zero-frequency signal to obtain the signal power.

9. A carrier leakage calibration method according to claim 8, characterized in that, The control module adjusts the DC offset parameters transmitted to the receiver and the reception compensation parameters transmitted to the reception compensation module according to the signal power, and performs DC offset calibration on the receiver, including: The process of iteratively adjusting the DC offset parameters includes: The control module adjusts the initial DC offset parameters of the receiver according to the signal power, and the receiver generates an adjusted analog intermediate frequency signal according to the initial DC offset parameters. The receiving compensation module generates a new signal power based on the adjusted analog intermediate frequency signal; When the new signal power is greater than the signal power of the previous iteration, the initial DC offset parameter of the previous iteration is determined as the DC offset parameter, and the iteration ends; If the new signal power is less than or equal to the signal power of the previous iteration, then the new signal power is used as the signal power, and the next iteration is executed. After the DC offset parameters are adjusted, the following process for adjusting the receiving compensation parameters is performed iteratively, including: The control module adjusts the initial reception compensation parameters of the reception compensation module according to the signal power, and the reception compensation module generates the adjusted zero-frequency signal according to the initial reception compensation parameters. The receiving compensation module generates a new signal power based on the adjusted zero-frequency signal; When the new signal power is greater than the signal power of the previous iteration, the initial reception compensation parameter of the previous iteration is determined as the reception compensation parameter, and the iteration ends; If the new signal power is less than or equal to the signal power of the previous iteration, then the new signal power is used as the signal power, and the next iteration is performed.

10. A carrier leakage calibration method according to claim 7, characterized in that, The control module adjusts the transmission compensation parameters sent to the transmission compensation module according to the signal power, and performs carrier leakage calibration on the transmitter, including: The process of iteratively adjusting the transmission compensation parameters of the transmission compensation module includes: The control module adjusts the initial transmission compensation parameters of the transmission compensation module according to the signal power, and the transmission compensation module generates an adjusted analog DC signal according to the initial transmission compensation parameters; The analog DC signal is processed sequentially by the transmitter, the receiver, and the receiver compensation module to generate a new signal power; When the new signal power is greater than the signal power of the previous iteration, the initial transmission compensation parameter of the previous iteration is determined as the transmission compensation parameter, and the iteration ends; If the new signal power is less than or equal to the signal power of the previous iteration, then the new signal power is used as the signal power, and the next iteration is performed.

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