KR101345126B1 - Mismatch calibration method for harmonic rejection mixer architecture and mixing apparatus using the same - Google Patents

Abstract

A mismatch compensation method for a harmonic rejection mixer structure and a mixing apparatus using the same are provided. The mixing apparatus estimates and compensates for signal magnitude mismatch and signal phase mismatch between two selected mixers of a plurality of mixers. In addition, since the signal magnitude mismatch and the signal phase mismatch can be independently estimated and compensated together through a relational expression, the computation required for mismatch estimation can be reduced, thereby enabling fast mismatch compensation.

Description

Mismatch calibration method for harmonic rejection mixer architecture and mixing apparatus using the same}

The present invention relates to a mismatch compensation method, and more particularly, to a method for compensating for mismatches occurring in a harmonic elimination mixer structure and a mixing apparatus using the same.

Harmonic removal The mixer structure is useful in that it can remove third and fifth harmonic components, but there is a problem that unwanted mismatch occurs. Mismatches occurring in the harmonic rejection mixer structure are classified into magnitude mismatch and phase mismatch between different phase signals.

Both of them must be compensated because they reduce the transmission and reception performance, the premise for compensating for this is mismatch estimation. However, there is a problem in that mismatch estimation takes a lot of calculations, and thus, delayed mismatch compensation is delayed.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object of the present invention is to provide a mismatch compensation method for estimating and compensating a signal magnitude mismatch and a signal phase mismatch between a plurality of mixers, and a mixing apparatus using the same. .

Mixing apparatus according to an embodiment of the present invention for achieving the above object, a plurality of mixers; A selection unit for selecting two of the plurality of mixers; An estimator for estimating a signal magnitude mismatch and a signal phase mismatch between two mixers selected by the selector; And a compensator for compensating the signal magnitude mismatch and the signal phase mismatch estimated by the estimator.

The estimator may estimate the signal magnitude mismatch and the signal phase mismatch together.

The estimator may independently estimate the signal magnitude mismatch and the signal phase mismatch together through a relational expression.

The relational expression may be expressed as a sum of a quadratic term for the signal magnitude mismatch and a quadratic term for the signal phase mismatch.

The estimator may estimate the value that minimizes the quadratic term for the signal magnitude mismatch as the signal magnitude mismatch, and estimate the value that minimizes the quadratic term for the phase magnitude mismatch as the phase magnitude mismatch. have.

The phase difference between signals generated by the two selected mixers may be 45 ° or 135 °.

On the other hand, the mismatch compensation method according to another embodiment of the present invention, the step of selecting two of the plurality of mixers; Estimating a signal magnitude mismatch and a signal phase mismatch between the two mixers selected in the selecting step; And compensating for the signal magnitude mismatch and the signal phase mismatch estimated by the estimating step.

In the estimating step, the signal magnitude mismatch and the signal phase mismatch can be independently estimated together through a relational expression.

As described above, according to the present invention, the signal magnitude mismatch and the signal phase mismatch can be independently estimated and compensated together through one relational expression, and thus, the computation required for mismatch estimation can be reduced, so that fast mismatch compensation is possible. Become.

1 is a block diagram of a mixing apparatus according to a preferred embodiment of the present invention, and
FIG. 2 is a detailed block diagram of the mismatch estimator shown in FIG. 1.

Hereinafter, with reference to the drawings will be described the present invention in more detail.

1 is a block diagram of a mixing apparatus according to a preferred embodiment of the present invention. The mixing apparatus according to the present embodiment employs a Harmonic Rejection Mixer Architecture, which improves the characteristics of the mixer by estimating and compensating for mismatches occurring in such a structure.

The mismatches to be estimated / compensated include a signal magnitude mismatch and a signal phase mismatch. In this embodiment, the signal magnitude mismatch includes an I-signal (a signal having a phase of 0 °) and an X-signal (a signal having a phase of 135 °). ), And signal phase mismatch refers to signal phase mismatch between the I-signal and the X-signal.

On the other hand, the mixing apparatus according to the present embodiment independently estimates the signal magnitude mismatch and the signal phase mismatch together through one relational expression.

As shown in FIG. 1, the mixing apparatus according to the present exemplary embodiment which performs such a function includes mixers 121, 122, 123, and 124, ADCs 131, 132, 133, and 134 and a mismatch compensation unit. 140, a selector 150, and a mismatch estimator 160.

In FIG. 1, "ΔA ₁ " by reference numerals "111" and "112" indicates a signal magnitude mismatch between the I-signal and the X-signal.

1) Mixer-1 121 generates an I-signal (signal with phase 0 °), 2) Mixer-2 122 generates a P-signal (signal with phase 45 °), 3) Mixer-3 123 generates a Q-signal (signal of phase 90 °), and 4) mixer-4 124 generates an X-signal (signal of phase 135 °).

FIG X- phase of the signal generated by the mixer in 1 -4 124 there is indicated by 135 ° -φ _{ε2, ε2} φ denotes the signal phase mismatch between the I- signal and the X- signal.

ADC-1 131 A / D converts the I-signal, ADC-2 132 A / D converts the P-signal, ADC-3 133 A / D converts the Q-signal ADC-4 134 converts the X-signal to A / D. For convenience of understanding and explanation, the I-signal, P-signal, Q-signal and X-signal will be represented as sinusoidal signals in the future, but it should be noted that these are actually digital signals.

The mismatch compensator 140 compensates and outputs a signal magnitude mismatch and a signal phase mismatch between the I-signal and the X-signal. Compensation by the mismatch compensator 140 is performed based on mismatch estimation (ME) by the mismatch estimator 160 which will be described later.

The selector 150 selects two of the signals output from the mixers 121, 122, 123, and 124 and applies them to the mismatch estimator 160. In the present embodiment, the selector 150 selects the I-signal output from the mixer-1 121 and the X-signal output from the mixer-4 124 and applies it to the mismatch estimator 160.

The mismatch estimator 160 estimates a signal magnitude mismatch and a signal phase mismatch between signals output from the mixers selected by the selector 150. The signal magnitude mismatch and the signal phase mismatch are estimated together. Specifically, the mismatch estimator 160 independently estimates the signal magnitude mismatch and the signal phase mismatch together through a relational expression.

This relation is represented by the sum of the quadratic terms for signal magnitude mismatch and the quadratic terms for signal phase mismatch. Accordingly, a value for minimizing the quadratic term for the signal magnitude mismatch is estimated as a signal magnitude mismatch, and a value for minimizing the second term for the phase magnitude mismatch is estimated as a phase magnitude mismatch.

Hereinafter, the mismatch estimator 160 will be described in detail with reference to FIG. 2. FIG. 2 is a detailed block diagram of the mismatch estimator 160 shown in FIG. As shown in FIG. 2, the mismatch estimator 160 includes gain units 161-1 and 161-2, mixers 162-1, 162-2, 162-3, and 162-4, and synthesizers ( 163-1 and 163-2, squares 164-1 and 164-2, a summation unit 165, and a filter 166.

Gain unit-1 161-1 applies gain ΔA ₂ to the X-signal and applies it to mixer-3 162-3, and gain unit-2 161-2 applies gain ΔA ₂ to X-signal Is added to Mixer-4 (162-3).

Mixer-1 162-1 combines the frequency of the I-signal with ω _LO2 to generate an II-signal, which can be represented by Equation 1 below.

Mixer-2 162-2 combines the frequency of the I-signal with ω _LO2 −φ _ε2 to generate an IX-signal, which can be represented by Equation 2 below.

Mixer-3 162-3 combines the frequency of the X-signal with ω _LO2 to generate the XI-signal, which can be represented by Equation 3 below.

Mixer-4 162-4 combines the frequency of the X-signal with ω _LO2 −φ _ε2 to generate the XX-signal, which can be expressed by Equation 4 below.

The synthesis unit-1 163-1 adds and outputs the IX-signal generated by the mixer-2 162-2 and the XI-signal generated by the mixer-3 162-3.

ΔA ₁ , ΔA ₂ , (ΔA ₁ -ΔA ₂ ) < ₁ , sin (φ _ε1 -φ _ε2 ) ≒ φ _ε1 -φ _ε2 , and cos (φ _ε1 -φ _ε2 ) ≒ 1, The output signal at 1 (163-1) can be expressed by Equation 5 below.

The synthesis unit-2 163-2 subtracts and outputs the XX-signal generated by the mixer-4 162-4 from the II-signal generated by the mixer-1 162-1.

ΔA ₁ , ΔA ₂ , (ΔA ₁ -ΔA ₂ ) < ₁ , sin (φ _ε1 -φ _ε2 ) ≒ φ _ε1 -φ _ε2 , and cos (φ _ε1 -φ _ε2 ) ≒ 1, The output signal at 2 (163-2) can be expressed by Equation 6 below.

Meanwhile, the square unit-1 (164-1) squares the output signal of the synthesis unit-2 (163-2) and outputs the square unit-2 (164-2) of the synthesis unit-1 (163-1). Output the squared output signal. In addition, the adder 165 adds the output signal of the square unit-1 (164-1) and the output signal of the square unit-2 (164-2). Estimation: final output.

ME can be expressed by Equation 7 below.

Equation (7) is a relational expression that can independently estimate the signal magnitude mismatch and the signal phase mismatch. Equation 7 is represented by the sum of the quadratic terms for signal magnitude mismatch and the quadratic terms for signal phase mismatch.

When ΔA ₂ and φ _{ε 2} are adjustable variables in the phase estimator 160, ΔA _{1, which} is a value that minimizes the quadratic terms for signal magnitude mismatches, is an estimated signal magnitude mismatch, and a second term for phase magnitude mismatches is obtained. The minimum value φ _{ε 1} corresponds to the estimated phase magnitude mismatch.

Thus far, the mixing apparatus for estimating and compensating for the mismatch of signal magnitude and phase occurring in the harmonic rejection mixer structure has been described in detail with reference to a preferred embodiment.

In the above embodiment, the mismatch estimation / compensation between the I-signal and the X-signal is assumed, but this is merely an example for convenience of description and may be modified. For example, it is possible to control the selection by the selector 150 to estimate / compensate the mismatch between the I-signal and the P-signal (signal whose phase is 45 °).

On the other hand, stepwise mismatch estimation / compensation is also possible. For example, after estimating / compensating a mismatch between the I-signal and the Q signal (signal having a phase of 90 °), the selecting unit 150 estimates / compensates a mismatch between the I-signal and the P-signal or the X-signal. It is also possible to control.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, but, on the contrary, It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the present invention.

121, 122, 123, and 124: Mixers 131, 132, 133, and 134: ADC
140: mismatch compensation unit 150: selection unit
160: mismatch estimator 161-1 and 161-2: gain unit
162-1, 162-2, 162-3 and 162-4
163-1 and 163-2: synthesis section 164-1 and 164-2: square section
165: adding unit 166: filter

Claims (8)

Multiple mixers;
A selection unit for selecting two of the plurality of mixers;
An estimator for estimating a signal magnitude mismatch and a signal phase mismatch between two mixers selected by the selector; And
And a compensator for compensating the signal magnitude mismatch and the signal phase mismatch estimated by the estimator.
And estimating the signal magnitude mismatch and the signal phase mismatch together as a relational expression.
delete delete The method of claim 1,
The relationship is
And a quadratic term for the signal magnitude mismatch and a quadratic term for the signal phase mismatch.
5. The method of claim 4,
Wherein the estimating unit comprises:
Estimating a value that minimizes a quadratic term for the signal magnitude mismatch as the signal magnitude mismatch,
And a value that minimizes a second order term for the phase magnitude mismatch as the phase magnitude mismatch.
The method of claim 1,
Mixing apparatus, characterized in that the phase difference of the signals generated in the selected two mixers, 45 ° or 135 °.
Selecting two of the plurality of mixers;
Estimating a signal magnitude mismatch and a signal phase mismatch between the two mixers selected in the selecting step; And
Compensating for the signal magnitude mismatch and the signal phase mismatch estimated by the estimating step;
The estimating step,
And estimating the signal magnitude mismatch and the signal phase mismatch together as a relational expression.
delete

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