A method, system and medium for correcting local oscillator leakage of a zero intermediate frequency architecture transceiver

Abstract

The invention discloses a method, system and medium for correcting local oscillator leakage of a zero intermediate frequency architecture transceiver; it relates to the technical field of leakage correction; at a receiving end, a DC offset correction is performed on a baseband signal of a zero intermediate frequency receiving channel by receiving a DC offset, and at a transmitting end, a DC offset response variation and a correction coefficient are calculated based on a first DC offset response and a second DC offset response; a period sum value calculated in combination with received baseband data is brought into a correction coefficient model to solve the local oscillator leakage coefficient, thereby correcting the transmitted baseband signal and realizing accurate correction of the local oscillator leakage, so as to suppress its influence on system performance as much as possible.

Description

Technical Field

[0001] The present invention relates to the technical field of leakage correction, and in particular to a method, system and medium for correcting local oscillator leakage of a zero intermediate frequency architecture transceiver. Background Art

[0002] The zero-IF architecture transceiver is a direct-conversion system based on orthogonal mixing. It has the characteristics of simple structure, high integration, low power consumption, small size, and few peripheral components. It has been widely used in the field of wireless communications. However, due to the existence of many non-ideal factors such as production process deviation and materials, the local oscillator signal leaks into the RF link through the coupling of the device or PCB substrate, which manifests as spurious containing the local oscillator frequency in the output signal spectrum in the transmit channel and as a DC offset in the baseband signal in the receive channel. Moreover, both the transmit local oscillator leakage frequency and the receive DC offset are within the signal passband and cannot be eliminated by filters. Large local oscillator leakage will deteriorate the system EVM index and reduce communication performance. Therefore, the local oscillator leakage must be corrected to minimize its impact on system performance. Summary of the invention

[0003] The technical problem to be solved by the present invention is that local oscillator leakage cannot be removed by a filter, and a larger local oscillator leakage will deteriorate the system EVM index and reduce the communication performance. The purpose of the present invention is to provide a method, system and medium for correcting local oscillator leakage of a zero intermediate frequency architecture transceiver, wherein a DC offset correction is performed on the baseband signal of a zero intermediate frequency receiving channel by receiving a DC offset at the receiving end, and a DC offset response change and a correction coefficient are calculated based on a first DC offset response and a second DC offset response at the transmitting end; the periodic sum value calculated by combining the received baseband data is brought into the correction coefficient model to solve the local oscillator leakage coefficient, thereby realizing the correction of the transmitted baseband signal and realizing the accurate correction of the local oscillator leakage, so as to suppress its influence on the system performance as much as possible.

[0004] The present invention is achieved through the following technical solutions:

[0005] This solution provides a method for correcting local oscillator leakage of a zero intermediate frequency architecture transceiver, comprising:

[0006] On the receiving end:

[0007] Collecting a baseband signal of a zero intermediate frequency receiving channel, and calculating a receiving DC offset according to the baseband signal; performing a DC offset correction on the baseband signal of the zero intermediate frequency receiving channel using the receiving DC offset;

[0008] On the transmitter side:

[0009] The transmit channel is coupled to the receive channel which has completed DC offset correction;

[0010] After respectively superimposing a first low-frequency DC offset level and a second low-frequency DC offset level on the transmission baseband signal, respectively acquiring first receiving baseband data and second receiving baseband data, and calculating a first DC offset response and a second DC offset response based on the first receiving baseband data and the second receiving baseband data;

[0011] Calculating a DC offset response variation based on the first DC offset response and the second DC offset response, and calculating a correction coefficient according to the DC offset response variation;

[0012] Collecting received baseband data and calculating a periodic summation value of the received baseband data;

[0013] The correction coefficient and the period sum value are brought into the correction coefficient model to solve the local oscillator leakage coefficient, and the transmission baseband signal is corrected according to the local oscillator leakage coefficient.

[0014] A further optimization scheme is that the receiving DC offset is calculated according to the baseband signal, including the method:

[0015] The in-phase receiving DC offset a0 and the quadrature receiving DC offset b0 are calculated according to the following formula:

[0016]

[0017] Where N represents the total number of samples of the baseband signal; y′ I (n) represents the nth sampling value of the in-phase baseband signal; y′ Q (n) represents the nth sampling value of the orthogonal baseband signal.

[0018] A further optimization scheme is that the baseband signal of the zero intermediate frequency receiving channel is corrected for the DC offset by receiving the DC offset; including the method:

[0019] The in-phase baseband signal y after DC offset correction is obtained according to the following formula I [N] and the orthogonal baseband signal y after DC offset correction Q [N]:

[0020] y I [N] = y I ′[N]+a0;

[0021] y Q [N] = y Q ′[N]+b0;

[0022] a0=[a0,a0 ... a0] N ;

[0023] b0=[b0,b0 ... b0] N ;

[0024] Among them; y I ′[N] and y Q ′[N] represents the original in-phase baseband signal and the original quadrature baseband signal respectively; a0 represents the in-phase receiving DC offset matrix; b0 represents the quadrature receiving DC offset matrix.

[0025] A further optimization scheme is that the calculation method of the first DC offset response or the second DC offset response includes:

[0026] Substituting the i-th received baseband data into the following formula, the first DC offset response or the second DC offset response is obtained:

[0027]

[0028] Where i is one or two; represents the i-th in-phase DC offset response; represents the i-th orthogonal DC offset response; y Ii [n] represents the nth sampling value of the i-th in-phase received baseband data; y Qi [n] represents the nth sampling value of the i-th orthogonal received baseband data; N represents the total number of samples of the baseband signal.

[0029] A further optimization scheme is that the DC offset response variation is calculated based on the first DC offset response and the second DC offset response, including the following method:

[0030] The difference between the first DC offset response and the second DC offset response is used to obtain the change in the first DC offset response:

[0031]

[0032] The difference between the first low-frequency DC offset level and the second low-frequency DC offset level is used to obtain the second DC offset response change:

[0033]

[0034] in, represents the difference of the first in-phase DC offset response; represents the difference of the first orthogonal DC offset response; Δa represents the difference of the second in-phase DC offset response; Δb represents the difference of the second orthogonal DC offset response; represents the first in-phase DC offset response; represents the second in-phase DC offset response; represents the first orthogonal DC offset response; represents the second orthogonal DC offset response; a1 represents the first low-frequency DC offset level superimposed on the in-phase baseband signal; a2 represents the second low-frequency DC offset level superimposed on the in-phase baseband signal; b1 represents the first low-frequency DC offset level superimposed on the orthogonal baseband signal; b2 represents the second low-frequency DC offset level superimposed on the orthogonal baseband signal.

[0035] A further optimization scheme is that the correction coefficient is calculated according to the DC offset response change, including a method of: substituting the DC offset response change into the following formula to obtain a first correction coefficient ξ and a second correction coefficient ρ:

[0036]

[0037] A further optimization scheme is that the calculation of the periodic summation value of the received baseband data includes the following method:

[0038] The received baseband data is summed in phase within period T to obtain a periodic summation value and the orthogonal period summation value

[0039]

[0040] Among them, y I [n] represents the nth in-phase received baseband data; y Q [n] represents the nth orthogonal received baseband data; A represents the amplitude response of the transmitted signal coupled to the receiving channel; a represents the first local oscillator leakage coefficient; b represents the second local oscillator leakage coefficient; φ represents the phase response of the transmitted signal coupled to the receiving channel.

[0041] A further optimization scheme is that the correction coefficient and the period sum value are brought into the correction coefficient model to solve the local oscillator leakage coefficient, and the transmission baseband signal is corrected according to the local oscillator leakage coefficient, including the method:

[0042] Substitute the correction coefficient and the period sum value into the correction coefficient model to solve the first local oscillator leakage coefficient a and the second local oscillator leakage coefficient b; the correction coefficient model is: Substituting the first local oscillator leakage coefficient a and the second local oscillator leakage coefficient b into the following formula, the corrected transmission baseband signal is obtained:

[0043] I′[N]=I[N]-a;

[0044] Q′[N]=Q[N]-b;

[0045] a=[a,a ... a] N ;

[0046] b=[b,b ... b] N ;

[0047] Among them, I'[N] represents the corrected in-phase transmission baseband signal; Q'[N] represents the corrected orthogonal transmission baseband signal; I[N] represents the original in-phase transmission baseband signal; Q[N] represents the original orthogonal transmission baseband signal; a represents the first local oscillator leakage coefficient matrix; b represents the second local oscillator leakage coefficient matrix.

[0048] The present solution also provides a zero intermediate frequency architecture transceiver local oscillator leakage correction system, which is used to implement the above-mentioned zero intermediate frequency architecture transceiver local oscillator leakage correction method; the system includes:

[0049] On the receiving end:

[0050] The first correction module is used to collect the baseband signal of the zero intermediate frequency receiving channel, and calculate the receiving DC offset according to the baseband signal; and perform DC offset correction on the baseband signal of the zero intermediate frequency receiving channel according to the receiving DC offset;

[0051] On the transmitter side:

[0052] A coupling module, used for coupling a transmitting channel to a receiving channel that has completed DC offset correction;

[0053] A first calculation module is used to respectively superimpose a first low-frequency DC offset level and a second low-frequency DC offset level on a transmission baseband signal, and then respectively collect first received baseband data and second received baseband data, and calculate a first DC offset response and a second DC offset response based on the first received baseband data and the second received baseband data;

[0054] A second calculation module, configured to calculate a DC offset response variation based on the first DC offset response and the second DC offset response, and calculate a correction coefficient according to the DC offset response variation;

[0055] A third calculation module is used to collect received baseband data and calculate a period sum value of the received baseband data;

[0056] The second correction module is used to bring the correction coefficient and the period sum value into the correction coefficient model to solve the local oscillator leakage coefficient, and correct the transmission baseband signal according to the local oscillator leakage coefficient.

[0057] The present solution also provides a computer-readable medium on which a computer program is stored. The computer program is executed by a processor to implement the above-mentioned method for correcting local oscillator leakage of a zero intermediate frequency architecture transceiver.

[0058] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0059] The present invention provides a method, system and medium for correcting local oscillator leakage of a zero intermediate frequency architecture transceiver. At a receiving end, a DC offset correction is performed on a baseband signal of a zero intermediate frequency receiving channel by using a received DC offset. At a transmitting end, a DC offset response variation and a correction coefficient are calculated based on a first DC offset response and a second DC offset response. A periodic sum value calculated in combination with received baseband data is brought into a correction coefficient model to solve for a local oscillator leakage coefficient, thereby correcting a transmitted baseband signal and achieving accurate correction of local oscillator leakage to minimize its influence on system performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0060] In order to more clearly illustrate the technical solutions of the exemplary embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments. It should be understood that the following drawings only illustrate certain embodiments of the present invention and should not be regarded as limiting the scope. For those of ordinary skill in the art, other relevant drawings can be obtained based on these drawings without creative work. In the drawings:

[0061] Figure 1 This is a schematic diagram of the DC offset correction principle at the receiving end;

[0062] Figure 2 This is a schematic diagram of the transmitter correction principle;

[0063] Figure 3 This is a schematic diagram of the simulation results of the DC offset correction of the receiving channel;

[0064] Figure 4 This is a schematic diagram of the simulation results of the local oscillator leakage correction of the transmitting channel. DETAILED DESCRIPTION

[0065] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with embodiments and drawings. The exemplary embodiments of the present invention and their description are only used to explain the present invention and are not intended to limit the present invention.

[0066] The local oscillator leakage cannot be removed by a filter, and a larger local oscillator leakage will deteriorate the system EVM index and reduce the communication performance. In view of this, the present solution provides the following embodiments to correct the local oscillator leakage.

[0067] Embodiment 1: This embodiment provides a method for correcting local oscillator leakage of a zero intermediate frequency architecture transceiver, comprising:

[0068] At the receiving end: collecting the baseband signal of the zero intermediate frequency receiving channel, and calculating the receiving DC offset according to the baseband signal; performing DC offset correction on the baseband signal of the zero intermediate frequency receiving channel by using the receiving DC offset;

[0069] like Figure 1As shown in the figure, the zero intermediate frequency receiver adopts orthogonal direct conversion technology. The input RF signal x(t) is divided into two signals with the same amplitude and phase, which are respectively I (t) and the quadrature local oscillator signal LO Q (t) Down-conversion is performed, wherein the in-phase local oscillator leakage signal of the local oscillator signal LO is LOL I , the quadrature local oscillator leakage signal is LOL Q After down-conversion, two baseband analog signals with a center frequency of 0 are output, and the original in-phase baseband signal y in digital form is output through the low-pass filter LPF and the analog-to-digital converter ADC I ′[N] and the original orthogonal baseband signal y Q ′[N], for an ideal zero-IF receiving channel, the baseband digital signal will not contain a DC component, but the actual baseband digital signal affected by the local oscillator leakage will have a DC offset, y I ′[N] and y Q '[N] respectively includes a fixed in-phase receiving DC offset and an orthogonal receiving DC offset, the matrix form of the in-phase receiving DC offset is a0, and the matrix form of the orthogonal receiving DC offset is b0. The mean a0 of a0 and b0 can be calculated by summing, and b0 is used as the in-phase receiving DC offset and the orthogonal receiving DC offset; specifically, the receiving DC offset is calculated according to the baseband signal, including a method:

[0070] Sample the baseband signals of the N zero-IF receiving channels from 0 to N: the original in-phase baseband signal y I ′[N] and the original orthogonal baseband signal y Q ′[N], where:

[0071] y I ′[N]=[y I ′[0],y I ′[1] ... y I ′[N-1]] (1a);

[0072] y Q ′[N]=[y Q ′[0],y Q ′[1] ... y Q ′[N-1]] (1b);

[0073] Among them, y′ I (n) represents the nth sampling value of the original in-phase baseband data of the i-th channel, n=0, 1, 2, ..., N-1; y′ Q (n) represents the nth sampling value of the i-th original orthogonal baseband data, n=0, 1, 2, ..., N-1;

[0074] The in-phase receiving DC offset a0 and the quadrature receiving DC offset b0 are calculated according to the following formula:

[0075]

[0076]

[0077] The DC offset of the baseband signal of the zero intermediate frequency receiving channel is corrected by receiving the DC offset; the method includes: obtaining the in-phase baseband signal y after the DC offset correction according to the following formula I [N] and the orthogonal baseband signal y Q [N]:

[0078] y I [N] = y I ′[N]+a0 (3a);

[0079] y Q [N] = y Q ′[N]+b0 (3b);

[0080] a0=[a0,a0 ... a0] N ;

[0081] b0=[b0,b0 ... b0] N .

[0082] On the transmitter side:

[0083] like Figure 2 As shown, the in-phase transmission baseband signal and the orthogonal transmission baseband signal I[N], Q[N] are analog intermediate frequency in-phase signals and analog intermediate frequency orthogonal signals after passing through the digital-to-analog converter DAC and the low-pass filter LPF respectively. T (t), Q T (t), and then through orthogonal mixing, the two signals output by the mixer are synthesized to be the output signal of the zero intermediate frequency transmitter. The ideal transmission channel output signal TX(t) is expressed as:

[0084] TX(t)=I T (t)cos(ω c t)+Q T (t)sin(ω c t) (4)

[0085] The transmit local oscillator leakage signal LOL(t) of the local oscillator signal LO will be superimposed on the transmit channel output signal TX(t). The frequency of the transmit local oscillator leakage signal LOL(t) is ω c ; t represents time; any local oscillator leakage signal of any amplitude and phase can be expressed as:

[0086] LOL(t)=a cos(ωc t)+b sin(ω c t) (5)

[0087] Where a and b represent the first local oscillator leakage coefficient and the second local oscillator leakage coefficient respectively.

[0088] Affected by the transmission local oscillator leakage signal, the final output signal TX′(t) of the actual transmission channel is:

[0089] TX′(t)=TX(t)+LOL(t)=[I T (t)+a]cos(ω c t)+[Q T (t)+b]sin(ω c t) (6)

[0090] It is necessary to calculate the first local oscillator leakage coefficient and the second local oscillator leakage coefficient, and then compensate them in the baseband digital signal. The corrected in-phase transmission baseband signal and the corrected orthogonal transmission baseband signal are respectively:

[0091] I′[N]=I[N]-a; Q′[N]=Q[N]-b; (7)

[0092] a=[a,a ... a] N ;

[0093] b=[b,b ... b] N ;

[0094] Among them, I'[N] represents the corrected in-phase transmission baseband signal; Q'[N] represents the corrected orthogonal transmission baseband signal; I[N] represents the original in-phase transmission baseband signal; Q[N] represents the original orthogonal transmission baseband signal; N represents the number of samples of the baseband signal; a represents the first local oscillator leakage coefficient matrix; b represents the second local oscillator leakage coefficient matrix.

[0095] Then the method for correcting the local oscillator leakage of the transmitting channel is as follows: after the baseband signal is compensated, the local oscillator leakage signal in the final output signal will be offset. In order to calculate the first local oscillator leakage coefficient and the second local oscillator leakage coefficient, it is necessary to use the receiving channel that has completed the DC offset correction, and send the transmitting output signal to the receiving channel through switch switching or coupling. Through different test signals, different baseband digital signals will be output in the receiving channel to calculate the first local oscillator leakage coefficient and the second local oscillator leakage coefficient.

[0096] Specifically, the gain and delay of the transmitted signal when it reaches the receiving end are A and Δt respectively. The signal after the transmitted signal reaches the receiving channel is expressed as:

[0097]

[0098] where φ=ω c Δt;I T (t+Δt) represents the analog intermediate frequency in-phase signal after the delay time Δt; Q T (t+Δt) is the analog intermediate frequency quadrature signal after the delay time Δt.

[0099] This signal is down-converted and low-pass filtered through the receiving channel, and the output analog in-phase baseband signal I R (t) and the simulated quadrature baseband signal Q R (t) is:

[0100]

[0101] Q R (t) = A[I T (t+Δt)+a]sinφ / 2-A[Q T (t+Δt)+b]cosφ / 2 (9b)

[0102] Then it is converted into a digital in-phase baseband signal y through the analog-to-digital converter ADC I [N] and the digital quadrature baseband signal y Q [N], expressed as:

[0103] y I [N]=A[I[N+ΔN]+a]cosφ / 2+A[Q[N+ΔN]+b]sinφ / 2 (10a)

[0104] y Q [N]=A[I[N+ΔN]+a]sinφ / 2-A[Q[N+ΔN]+b]cosφ / 2 (10b)

[0105] Among them, the intermediate coefficient ΔN=Δt×f s ;f s is the data sampling rate; I[N+ΔN] represents the in-phase transmission baseband signal superimposed with the intermediate coefficient; Q[N+ΔN] represents the orthogonal transmission baseband signal superimposed with the intermediate coefficient.

[0106] The in-phase received baseband data I[N] and the orthogonal received baseband data Q[N] have no DC component, and the sum is 0 within the period. The received baseband data is summed within the period T to obtain the in-phase period sum value and the orthogonal period summation value

[0107]

[0108] Among them, y I [n] represents the nth in-phase received baseband data; y Q[n] represents the nth in-phase received baseband data; A represents the amplitude response of the transmit signal coupled to the receive channel; φ represents the phase response of the transmit signal coupled to the receive channel.

[0109] It can be expressed as a matrix:

[0110]

[0111] Among them, the first correction coefficient The second correction coefficient ρ=tanφ.

[0112] The transformation can be obtained:

[0113]

[0114] The first local oscillator leakage coefficient and the second local oscillator leakage coefficient can be obtained by only calculating the first correction coefficient ξ and the second correction coefficient ρ.

[0115] The first correction factor ξ and the second correction factor ρ can be calculated using an algorithm that applies a low-level DC offset to the transmitted baseband signal; the offset level is periodically adjusted and the output of the observation receiver shows these disturbances. The algorithm then analyzes and compares the observed value increments with the input value difference to obtain the loop transfer function.

[0116] The transmitting baseband signal generator superimposes a low-frequency DC offset level on the in-phase receiving baseband data I[N] and the orthogonal receiving baseband data Q[N] respectively:

[0117]

[0118] Among them: a i represents the i-th low-frequency DC offset level matrix superimposed on the in-phase received baseband data I[N], i=1 represents the first low-frequency DC offset level, and i=2 represents the second low-frequency DC offset level; b i represents the i-th low-frequency DC offset level matrix superimposed on the orthogonal received baseband data Q[N]; a i =[a i , a i ... a i ] N , b i =[b i , b i ... b i ] N ; a i represents the i-th low-frequency DC offset level superimposed on the in-phase received baseband data Q[N]; b irepresents the i-th low-frequency DC offset level superimposed on the orthogonal reception baseband data Q[N]; I1[N] represents the in-phase reception baseband data after superimposing the first low-frequency DC offset level; Q1[N] represents the orthogonal reception baseband data after superimposing the first low-frequency DC offset level; I2[N] represents the in-phase reception baseband data after superimposing the second low-frequency DC offset level; Q2[N] represents the orthogonal reception baseband data after superimposing the second low-frequency DC offset level.

[0119] The two groups of signals pass through the transmitting channel and then loop back to the receiving channel. The first in-phase receiving baseband data, the first orthogonal receiving baseband data, the second in-phase receiving baseband data and the second orthogonal receiving baseband data are y I1 [N], y Q1 [N] and y I2 [N], y Q2 [N].

[0120] You can get:

[0121]

[0122] in

[0123]

[0124] Subtracting the results of the two sets of tests, we can get:

[0125]

[0126] in:

[0127]

[0128] Where i is one or two; represents the i-th in-phase DC offset response; represents the i-th orthogonal DC offset response; y Ii [n] represents the nth sampling value of the i-th in-phase received baseband data; y Qi [n] represents the nth sampling value of the i-th orthogonal received baseband data; N represents the total number of received baseband data samples; represents the difference of the first in-phase DC offset response; represents the difference of the first orthogonal DC offset response; Δa represents the difference of the second in-phase DC offset response; Δb represents the difference of the second orthogonal DC offset response; represents the first in-phase DC offset response; represents the second in-phase DC offset response; represents the first orthogonal DC offset response; represents the second orthogonal DC offset response; a1 represents the first low-frequency DC offset level superimposed on the in-phase baseband signal; a2 represents the second low-frequency DC offset level superimposed on the in-phase baseband signal; b1 represents the first low-frequency DC offset level superimposed on the orthogonal baseband signal; b2 represents the second low-frequency DC offset level superimposed on the orthogonal baseband signal.

[0129] In this way, through two sets of tests, the first local oscillator leakage coefficient a and the second local oscillator leakage coefficient b can be offset by subtraction, and the first correction coefficient and the second correction coefficient can be calculated.

[0130]

[0131]

[0132] Thus, the first local oscillator leakage coefficient and the second local oscillator leakage coefficient are obtained to compensate the transmission baseband signal.

[0133] This embodiment simulates the DC offset correction of the receiving channel and the local oscillator leakage correction of the transmitting channel. The results are as follows: Figure 3 and Figure 4 As shown, the receive DC offset can be reduced to -75dBc and the transmit local oscillator leakage can be reduced to -60dBc.

[0134] Embodiment 2: This embodiment provides a zero intermediate frequency architecture transceiver local oscillator leakage correction system, which is used to implement a zero intermediate frequency architecture transceiver local oscillator leakage correction method described in Embodiment 1; the system includes:

[0135] On the receiving end:

[0136] The first correction module is used to collect the baseband signal of the zero intermediate frequency receiving channel, and calculate the receiving DC offset according to the baseband signal; and perform DC offset correction on the baseband signal of the zero intermediate frequency receiving channel according to the receiving DC offset;

[0137] On the transmitter side:

[0138] A coupling module, used for coupling a transmitting channel to a receiving channel that has completed DC offset correction;

[0139] A first calculation module is used to respectively superimpose a first low-frequency DC offset level and a second low-frequency DC offset level on a transmission baseband signal, and then respectively collect first received baseband data and second received baseband data, and calculate a first DC offset response and a second DC offset response based on the first received baseband data and the second received baseband data;

[0140] A second calculation module, configured to calculate a DC offset response variation based on the first DC offset response and the second DC offset response, and calculate a correction coefficient according to the DC offset response variation;

[0141] A third calculation module is used to collect received baseband data and calculate a period sum value of the received baseband data;

[0142] The second correction module is used to bring the correction coefficient and the period sum value into the correction coefficient model to solve the local oscillator leakage coefficient, and correct the transmission baseband signal according to the local oscillator leakage coefficient.

[0143] Embodiment 3: This embodiment provides a computer-readable medium having a computer program stored thereon. The computer program is executed by a processor to implement a method for correcting local oscillator leakage of a zero intermediate frequency architecture transceiver as described in Embodiment 1.

[0144] The specific implementation methods described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific implementation method of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A method for correcting local oscillator leakage of a zero intermediate frequency architecture transceiver, characterized in that: include: On the receiving end: Collecting a baseband signal of a zero intermediate frequency receiving channel, and calculating a receiving DC offset according to the baseband signal; Performing DC offset correction on the baseband signal of the zero intermediate frequency receiving channel by using the receiving DC offset; On the transmitter side: The transmit channel is coupled to the receive channel which has completed DC offset correction; After respectively superimposing a first low-frequency DC offset level and a second low-frequency DC offset level on the transmission baseband signal, first receiving baseband data and second receiving baseband data are obtained respectively, and a first DC offset response and a second DC offset response are calculated based on the first receiving baseband data and the second receiving baseband data; Calculating a DC offset response variation based on the first DC offset response and the second DC offset response, and calculating a correction coefficient according to the DC offset response variation; Collecting received baseband data and calculating a periodic summation value of the received baseband data; The correction coefficient and the period sum value are brought into the correction coefficient model to solve the local oscillator leakage coefficient, and the transmission baseband signal is corrected according to the local oscillator leakage coefficient.

2. The method for correcting local oscillator leakage of a zero intermediate frequency architecture transceiver according to claim 1, characterized in that: The method of calculating the receiving DC offset according to the baseband signal includes: The in-phase receiving DC offset is calculated according to the following formula: and quadrature receive DC offset b 0 : ； ； in, N Indicates the total number of samples of the baseband signal; Represents the nth sampling value of the in-phase baseband signal; Represents the nth sample value of the orthogonal baseband signal.

3. The method for correcting local oscillator leakage of a zero intermediate frequency architecture transceiver according to claim 2, characterized in that: The method of performing DC offset correction on the baseband signal of the zero intermediate frequency receiving channel by receiving the DC offset includes: The in-phase baseband signal y after DC offset correction is obtained according to the following formula I [N] and the orthogonal baseband signal y after DC offset correction Q [N]: ； in; and Respectively represent the original in-phase baseband signal and the original orthogonal baseband signal; Represents the in-phase receiving DC offset matrix; Represents the orthogonal receive DC offset matrix.

4. The method for correcting local oscillator leakage of a zero intermediate frequency architecture transceiver according to claim 1, characterized in that: The calculation method of the first DC offset response or the second DC offset response includes: Substituting the i-th received baseband data into the following formula, the first DC offset response or the second DC offset response is obtained: ； ； Where i is one or two; represents the i-th in-phase DC offset response; represents the i-th orthogonal DC offset response; Represents the nth sampling value of the i-th in-phase received baseband data; Represents the nth sampling value of the i-th orthogonal received baseband data; N Indicates the total number of samples of the baseband signal.

5. The method for correcting local oscillator leakage of a zero intermediate frequency architecture transceiver according to claim 4, characterized in that: The method of calculating the DC offset response variation based on the first DC offset response and the second DC offset response includes: The difference between the first DC offset response and the second DC offset response is used to obtain the change in the first DC offset response: ； The difference between the first low-frequency DC offset level and the second low-frequency DC offset level is used to obtain the second DC offset response change: ； in, represents the difference of the first in-phase DC offset response; represents the difference of the first quadrature DC offset response; represents the difference of the second in-phase DC offset response; represents the difference of the second quadrature DC offset response; represents the first in-phase DC offset response; represents the second in-phase DC offset response; represents the first orthogonal DC offset response; represents the second orthogonal DC offset response; represents the first low-frequency DC offset level superimposed on the in-phase baseband signal; represents the second low-frequency DC offset level superimposed on the in-phase baseband signal; b1 represents the first low-frequency DC offset level superimposed on the orthogonal baseband signal; b2 represents the second low-frequency DC offset level superimposed on the orthogonal baseband signal.

6. A method for correcting local oscillator leakage of a zero intermediate frequency architecture transceiver according to claim 5, characterized in that: The method of calculating the correction coefficient according to the DC offset response variation includes: Substituting the DC offset response change into the following formula, we can get the first correction coefficient. and the second correction factor : ； 。 7. The method for correcting local oscillator leakage of a zero intermediate frequency architecture transceiver according to claim 1, characterized in that: The method of calculating the periodic summation value of the received baseband data includes: The received baseband data is summed within period T to obtain the in-phase period summation value and the orthogonal period summation value : ； ； Among them, y I [n] represents the nth in-phase received baseband data; y Q [n] represents the nth orthogonal received baseband data; A represents the amplitude response of the transmit signal coupled to the receive channel; represents the first local oscillator leakage coefficient; b represents the second local oscillator leakage coefficient; represents the phase response of the transmit signal coupled to the receive channel; N represents the total number of samples of the baseband signal.

8. The method for correcting local oscillator leakage of a zero intermediate frequency architecture transceiver according to claim 7, characterized in that: The correction coefficient and the period sum value are brought into the correction coefficient model to solve the local oscillator leakage coefficient, and the transmission baseband signal is corrected according to the local oscillator leakage coefficient, including the following method: Substitute the correction coefficient and the period sum value into the correction coefficient model to solve for the first local oscillator leakage coefficient and the second local oscillator leakage coefficient b; the correction coefficient model is: ;in, represents the first correction coefficient; represents the second correction coefficient; The first local oscillator leakage coefficient Substitute the second local oscillator leakage coefficient b into the following formula to obtain the corrected transmit baseband signal: ； ； ； ； Among them, I'[ N ] represents the corrected in-phase transmitted baseband signal; Q'[ N ] represents the corrected orthogonal transmission baseband signal; I [ N ] represents the original in-phase transmitted baseband signal; Q[ N ] represents the original orthogonal transmitted baseband signal; N Indicates the total number of samples of the baseband signal; represents the first local oscillator leakage coefficient matrix; represents the second local oscillator leakage coefficient matrix.

9. A zero intermediate frequency architecture transceiver local oscillator leakage correction system, characterized in that: A method for correcting local oscillator leakage of a zero intermediate frequency architecture transceiver according to any one of claims 1 to 8; the system comprises: On the receiving end: The first correction module is used to collect the baseband signal of the zero intermediate frequency receiving channel, and calculate the receiving DC offset according to the baseband signal; and perform DC offset correction on the baseband signal of the zero intermediate frequency receiving channel according to the receiving DC offset; On the transmitter side: A coupling module, used for coupling a transmitting channel to a receiving channel that has completed DC offset correction; A first calculation module is used to respectively superimpose a first low-frequency DC offset level and a second low-frequency DC offset level on a transmission baseband signal, thereby obtaining first received baseband data and second received baseband data, and to calculate a first DC offset response and a second DC offset response based on the first received baseband data and the second received baseband data; A second calculation module, configured to calculate a DC offset response variation based on the first DC offset response and the second DC offset response, and calculate a correction coefficient according to the DC offset response variation; A third calculation module is used to collect received baseband data and calculate a period sum value of the received baseband data; The second correction module is used to bring the correction coefficient and the period sum value into the correction coefficient model to solve the local oscillator leakage coefficient, and correct the transmission baseband signal according to the local oscillator leakage coefficient.

10. A computer readable medium having a computer program stored thereon, characterized in that: The computer program is executed by a processor to implement a method for correcting local oscillator leakage of a zero intermediate frequency architecture transceiver as described in any one of claims 1 to 8.

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