KR20060066498A - Base multi station system and method for calibration of many-channel receiver - Google Patents

Abstract

1. TECHNICAL FIELD OF THE INVENTION

The present invention relates to a base station system having the error correction function of a multi-channel receiver and a method thereof.

2. The technical problem to be solved by the invention

The present invention applies a zero-forcing equalization algorithm to a multi-channel receiver so that each receiving channel has the same transfer function characteristics and compensates for signal distortion due to the nonlinear frequency response of the receiver, thereby allowing errors between channels of the multi-channel receiver in the array antenna system. And a base station system and a method thereof having an error correction function of a multichannel receiver capable of correcting frequency nonlinearity within a channel.

3. Summary of Solution to Invention

According to an aspect of the present invention, there is provided a base station system having an error correction function of a multi-channel receiver, comprising: an array antenna unit configured to combine an error correction signal from an error correction signal generator with a received signal received from the outside and transmit the combined error correction signal to a multi-channel receiver; The multi-channel receiver for signal processing and outputting a received signal combined with an error correction signal received from the array antenna unit; An error correction signal generator for generating an error correction signal and transmitting the error correction signal to the array antenna unit and the error correction unit; Compensate the error of the received signal by calculating an error correction coefficient by using the received signal combined with the error correction signal received from the multi-channel receiver and the error correction signal received from the error correction signal generator, and combining the received signal with the received signal. The error correction unit for removing the error correction signal; And a beamformer configured to receive an error-corrected received signal from the error corrector to form an antenna beam.

4. Important uses of the invention

The present invention is used in a base station system and the like.

Error correction, error correction coefficient estimation, error correction power control, zero-forcing adaptive algorithm, multi-channel receiver, base station system

Description

Base station system having error correction function of multichannel receiver and its method {Base multi station system and method for calibration of many-channel receiver}             

1 is a configuration diagram of a base station system having an error correction function of a multi-channel receiver according to the present invention;

2 is a diagram showing a baseband equivalent model for a base station system having an error correction function of a multi-channel receiver according to the present invention;

3 is a detailed configuration diagram illustrating in detail the error correction signal generator and the error corrector in the base station system according to the present invention;

4 is a flowchart illustrating an error correction method of a multi-channel receiver in a base station system according to the present invention.

* Explanation of symbols for the main parts of the drawings

100: array antenna unit 110: antenna

120: combiner 130, 240: power divider

200: multi-channel receiver 201: low noise amplifier

202: frequency mixer 203: surface acoustic wave filter

204: variable amplifier 205: antialiasing filter

206: analog / digital converter 207: digital I / Q converter

210: RF receiver 220: gain controller

230: local oscillator 300: error correction signal generator

310: error correction signal generator 311: error correction bit generator

312 pulse shaping filter 313 target response filter

320: digital-to-analog converter 330: variable amplifier

340: Frequency Mixer 350: Image Removal Filter

400: error correction unit 410: error correction unit

411: error correction coefficient calculator 412: error correction filter

413: complex multiplier 414: buffer

415: Combiner

The present invention relates to a base station system having an error correction function of a multi-channel receiver and a method thereof, and more particularly to applying a zero-forcing equalization algorithm to a multi-channel receiver so that each receiving channel has the same transfer function characteristics. A base station system having an error correction function of a multichannel receiver and a method thereof capable of correcting an error between channels of a multichannel receiver and frequency nonlinearity in a channel in an array antenna system by compensating for signal distortion due to a nonlinear frequency response. will be.

Smart antenna has the advantage of increasing the maximum distance and capacity in the mobile communication base station system. In such a smart antenna system, an antenna beam directed at a user is formed to increase the antenna gain and to remove interference from other users.

Here, since the antenna beam is generally generated in the baseband and each user has a different spatial signal, different beamforming weights may be applied to the user transmit / receive data.

On the other hand, the transfer function of the RF transceiver is different for each channel of the array antenna because the size and phase characteristics of the analog elements are not the same. Therefore, it is possible to form an accurate beam only when all channels have the same transfer function through the error correction process. In the case of wideband receivers, the frequency response of the receiver is nonlinear even within one channel, which also interferes with the formation of accurate beams.

Such a method of correcting an error in the receiver is very complicated because the gain of the receiver continuously changes with the change of an auto gain controller (AGC).

Conventionally, many algorithms regarding error correction of a multi-channel receiver have been proposed in radar or direction detection system applications. Some of them were to automatically compensate for errors in both array antennas and multichannel receivers using the received signal.

However, since there are many signals of multiple paths having many different angles of arrival in the signal received by the base station array antenna, it is advantageous to process the error correction process between the antenna and the receiver separately in the smart antenna. In addition, since the error of the antenna itself does not significantly reduce the system performance, it is important to accurately correct the error of the multichannel receiver rather than the error correction of the antenna.

In addition, the smart antenna system should be able to perform error correction not only at the beginning of system operation but also when the system is operating. This is called real-time error correction. That is, the error correction should be performed periodically because the transfer function of the receiver varies with time due to a change in temperature or humidity over time.

One method of such real-time error correction is non-blind error correction, which injects a known signal into a working multi-channel receiver and uses it as a reference error correction signal. However, this method has a problem in that the error correction signal interferes with the operating system and degrades system performance.

Most error correction methods for the smart antenna system assume a narrow band and express the receiver transfer function as a complex scalar. However, in the wideband receiver, since the transfer function must be expressed as a complex vector, the error should be corrected by multi-tap filtering rather than single tap complex multiplication. Therefore, there is a need for a wideband error correction method in which all receive channels have the same frequency response.

The present invention has been proposed to solve the above problems, by applying a zero-forcing equalization algorithm to a multi-channel receiver to ensure that each receiving channel has the same transfer function characteristics and to compensate for the signal distortion due to the non-linear frequency response of the receiver, SUMMARY OF THE INVENTION An object of the present invention is to provide a base station system having the error correction function of a multichannel receiver and a method thereof capable of correcting errors between channels of a multichannel receiver and frequency nonlinearity within a channel in an antenna system.

Other objects and advantages of the present invention can be understood by the following description, and will be more clearly understood by the embodiments of the present invention. Also, it will be readily appreciated that the objects and advantages of the present invention may be realized by the parts and combinations thereof indicated in the claims.

The apparatus of the present invention for achieving the above object, in the base station system having the error correction function of the multi-channel receiver, combining the error correction signal from the error correction signal generation unit with the received signal received from the outside to the multi-channel receiver An array antenna unit for transmitting; The multi-channel receiver for signal processing and outputting a received signal combined with an error correction signal received from the array antenna unit; An error correction signal generator for generating an error correction signal and transmitting the error correction signal to the array antenna unit and the error correction unit; Compensate the error of the received signal by calculating an error correction coefficient by using the received signal combined with the error correction signal received from the multi-channel receiver and the error correction signal received from the error correction signal generator, and combining the received signal with the received signal. The error correction unit for removing the error correction signal; And a beam forming unit configured to receive the error-corrected received signal from the error correction unit to form an antenna beam.

On the other hand, the method of the present invention, in the error correction method of the multi-channel receiver in the base station system, generating an error correction bit signal and through the filtering error correction signal generation step of generating an error correction signal; A signal processing step of combining the error correction signal with a received signal received from the outside and processing the signal; An error correction step of estimating an error correction coefficient using the signal-processed received signal and the error correction signal to correct an error of the received signal; And an error correction signal power control step of controlling the power of the error correction signal to remove the error correction signal coupled to the received signal.

The above objects, features and advantages will become more apparent from the following detailed description taken in conjunction with the accompanying drawings, whereby those skilled in the art may easily implement the technical idea of the present invention. There will be. In addition, in describing the present invention, when it is determined that the detailed description of the known technology related to the present invention may unnecessarily obscure the gist of the present invention, the detailed description thereof will be omitted. Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 is a configuration diagram of a base station system having an error correction function of a multi-channel receiver according to the present invention.

As shown in FIG. 1, a base station system having an error correction function of a multi-channel receiver according to the present invention includes an array antenna unit 100, a multi-channel receiver 200, an error correction signal generator 300, and an error correction unit. 400, and a beam forming unit 500.

The array antenna unit 100 combines the error correction signal generated from the error correction signal generator 300 with the received signal received from the outside and transmits the combined error correction signal to the multi-channel receiver 200.

Here, the array antenna unit 100 includes a plurality of array antennas 110, a combiner 120, and a power divider 130.

In addition, the multi-channel receiver 200 processes the received signal combined with the error correction signal received from the array antenna unit 100 through amplification, frequency down-conversion, filtering, and analog / digital conversion. It plays a role of outputting.

Here, the multi-channel receiver 200 will be described in more detail with reference to FIG. 1.

The received signal received through the array antenna 110 is transmitted to the multi-channel receiver 200 and amplified by a low noise amplifier (LNA) 201. At this time, the thermal noise power spectral density at the output of the low noise amplifier 201 of the m-th channel can be expressed by Equation 1 below.

와

는 m번째 채널의 저잡음 증폭기(201)에서 잡음 지수와 전력 이득을 나타내고,

는 입력 백색 열잡음의 전력 스펙트럼 밀도를 나타낸다.here,

Wow

Denotes the noise figure and the power gain in the low noise amplifier 201 of the m-th channel,

Denotes the power spectral density of the input white thermal noise.

The output of the low noise amplifier LNA 201 is down-converted to an intermediate frequency band by a local oscillator (LO) 230 and filtered by a surface acoustic wave (SAW) filter 203. At this time, all channels use the same local oscillator 230 to maintain consistency between the channels.

The received signal is then amplified by the variable amplifier 204 whose gain is determined by an auto gain control (AGC) of the gain controller 220. At this time, the receiver gain for all channels is controlled by a single gain control signal so that the gain difference between channels is kept constant as a result, so that the error correction coefficient is determined only by the relative transfer function between channels. Therefore, the error compensator only needs to track the characteristics that change slowly by temperature and humidity without having to track the fast change of the transfer function by the automatic gain control.

The signal passing through the variable amplifier 204 is then passed to an antialiasing filter 205 to remove noise and spurious, and the resulting received signal is converted to digital at the analog-to-digital converter 206 and then digital. The I / Q demodulator (DIQ) 207 converts the complex baseband signal to the error correction unit 400.

The error correction signal generator 300 generates an error correction signal and transmits the error correction signal to the array antenna unit 100 and the error correction unit 400.

Here, the error correction signal generator 300 converts the error correction signal generator 310 for generating the error correction signal and the digital error correction signal generated from the error correction signal generator 310 into an analog error correction signal. A digital / analog converter 320, a variable amplifier 330 for amplifying the error correction signal under the control of the gain controller 220 in the multi-channel receiver 200, and an error amplified by the variable amplifier 330 A frequency mixer 340 for upconverting the frequency of the correction signal, and an image removal filter 350 for removing noise of the frequency upconverted error correction signal.

The error correction unit 400 calculates an error correction coefficient by receiving a received signal combined with an error correction signal of the rotor of the multi-channel receiver 200 and an error correction signal from the error correction signal generator 300. By correcting the error of the received signal, and serves to remove the error correction signal coupled to the received signal.

Here, the error correction unit 400 includes an error corrector 410 corresponding to the number of channels of the multi-channel receiver 200.

On the other hand, the beam forming unit 500 serves to form an antenna beam by receiving the error signal received by the error correction unit 400.

Here, the error correction signal generator 300 and the error correction unit 400 will be described in more detail with reference to FIG. 1.

The error correction signal is generated by the error correction signal generator 310 and passed through the digital / analog converter 320, the variable amplifier 330 and the frequency mixer 340, and the image cancellation filter 350 to the power divider 130 and the combiner. Through the 120 is injected into each channel of the multi-channel receiver 200. At this time, the frequency mixer 340 with respect to the error correction signal to have a uniform gain and linear phase frequency response as much as possible, the gain of the variable amplifier 330 by the gain controller 220 of the multi-channel receiver 200 Controlled.

The received signal transmitted to the error correction unit 400 through the multi-channel receiver 200 is a signal including an error correction signal. At this time, the error correction signal acts as interference to the received signal. Therefore, the error correction unit 400 removes the error correction signal from the received signal through the interference canceller after calculating the error correction coefficient and transmits the error correction signal to the beamformer 500.

2 is a diagram illustrating a baseband equivalent model for a base station system having an error correction function of a multi-channel receiver.

는 공간적, 시간적으로 백색 가우스 잡음으로 가정한다. 또한 복수채널 수신부(200)의 채널 잡음 지수가 같으므로 잡음은 동일한 분산을 갖는 것으로 가정하여 각 수신기 출력에서의 잡음 전력은 수신기 이득과 잡음 온도에 의존한다.As shown in FIG. 2, the error correction signal is injected into the receive channel through the power divider 130 and the combiner 120. At this time, thermal noise

Is assumed to be spatially and temporally white Gaussian. In addition, since the channel noise figure of the multi-channel receiver 200 is the same, the noise is assumed to have the same dispersion, and thus the noise power at each receiver output depends on the receiver gain and the noise temperature.

In addition, the transfer function of the RF receiver is modeled with a finite impulse response (FIR) filter. In addition, the noise is combined with the antenna received signal before being passed through the RF receiver 210, which is different from the noise added after channel distortion in the communication channel equalization problem.

3 is a detailed block diagram illustrating in detail the error correction signal generator and the error corrector in the base station system according to the present invention.

As shown in FIG. 3, in the base station system according to the present invention, the error correction signal generator 310 includes an error correction bit generator 311, a pulse shaping filter 312, and a target response filter 313. The unit 400 includes an error correction coefficient calculator 411 and an error correction filter 412.

First, the error correction signal generator 310 will be described.

The error correction bit generator 311 generates an error correction bit signal that is a real value.

The pulse shaping filter 312 receives the error correction bit signals generated by the error correction bit generator 311 and performs pulse shaping.

At this time, the pulse shaping filter 312 in the present invention is applied only to the error correction signal, it is irrelevant to the pulse shaping filter for the transmission and reception signal in a general communication system.

The bandwidth of the error correction signal is determined to include the bandwidth of the system for error correction. In a typical communication system, the bandwidth of the RF receiver is wider than that of the antenna signal, and therefore, the bandwidth of the error correction signal should be wider than the bandwidth of the antenna signal.

The target response filter 313 receives a pulse-formed error correction bit signal from the pulse shaping filter 312 and determines a transfer function of all channels of the multi-channel receiving unit 200. For example, in a single carrier communication system, the target response filter becomes a square root raised cosine (SRRC) filter.

In addition, the outputs of the error correction bit generator 311 and the target response filter 313 are transmitted to the error correction unit 400 after a predetermined time delay to compensate the error correction signal delay, and used to calculate the error correction coefficient. .

Next, the error correction unit 400 will be described.

Here, the error correction unit 400 is composed of m error correction unit 410. Each error corrector 410 includes an error correction coefficient calculator 411, and an error correction filter 412, and each error corrector 410 is assigned to one receiving channel and operates independently.

간격으로 전달받은 오차보정 신호와 상기 오차보정 신호발생부(300)로부터 전달받은 오차보정 비트 신호, 및 오차보정 필터(412)로부터 전달받은 오차보정 필터링값을 제로-포싱 적응 알고리즘에 적용하여 오차보정 필터의 탭 계수를 계산하는 역할을 한다.The error correction coefficient calculator 411 from the array antenna unit 100

The error correction signal received at intervals, the error correction bit signal received from the error correction signal generator 300, and the error correction filtering value received from the error correction filter 412 are applied to the zero-forcing adaptive algorithm. Calculates the tap coefficient of the filter.

Here, the error correction coefficient calculator 411 is assigned to each channel to calculate the tap coefficient of the corresponding error correction filter 412 using a zero-forcing adaptive algorithm. The zero-forcing adaptive algorithm is suitable for RF error correction because it ignores noise and only considers channel distortion.

The error correction filter 412 assigned to each channel has a feedforward filtering structure, the tap coefficient received from the error correction coefficient calculator 411 and the error correction signal received from the multichannel receiver 200. Compensates for the transfer function distortion of the corresponding channel using the combined received signal.

Here, the error correction filter 412 includes a complex multiplier 413, a buffer 414, and a combiner, and one complex multiplier 413 is assigned to every K buffer 414 to determine the baseband response of the filter. This allows the duplicate signal to appear in the high frequency band. This duplicated signal can increase the noise power over the entire band, but since the noise in the high frequency band is actually filtered by the surface acoustic wave (SAW) filter and the anti-aliasing filter, the sampled received signal has four or eight times the signal bandwidth. If so, the noise increase due to the replica signal can be ignored.

4 is a flowchart illustrating an error correction method of a multi-channel receiver in a base station system according to the present invention. The operation process starts on the assumption that an external reception signal is received by an array antenna.

First, the error correction signal generator 300 generates an error correction signal (610).

Thereafter, the array antenna unit 100 couples the error correction signal to the received signal received from the outside (620).

Thereafter, the multi-channel receiver 200 processes the received signal to which the error correction signal is coupled and transmits the received signal to the error correction unit 400 (630).

Thereafter, the error correction unit 400 calculates an error correction coefficient by using the received signal to which the error correction signal is combined and the error correction signal received from the error correction signal generator 300 to correct the error of the received signal (640). ).

Thereafter, the error correction unit 400 removes the error correction signal coupled to the received signal after error correction of the received signal (650).

Thereafter, the beam forming unit 500 receives the error-corrected received signal to form an antenna beam (660).

In general, the error correction in the wideband receiver is similar to the channel equalization method of eliminating inter-symbol interference (ISI) due to the multipath effect. In the conventional channel equalization method, a minimum mean squared error (MMSE) based algorithm is mainly used, and the zero-forcing adaptive algorithm is rarely used because it does not consider noise, although it is simple.

However, zero-forcing adaptive algorithms are better suited for receiver error correction than MMSE-based algorithms because the purpose of error correction is to correct only receiver distortion. This zero-forcing adaptive algorithm fills with zeros at points other than the exact time point in the impulse response of the entire signal path.

In the present invention, a zero-forcing adaptive algorithm is used to calculate the error correction coefficient. Since the error correctors 410 are the same for each channel, the algorithm for one channel is sufficient to describe the entire operation. In the present invention, the m-th channel will be described as an example.

The error corrector 410 output for the m th channel is expressed by Equation 2 below.

은 오차보정 비트 신호이고,

은 m번째 채널 출력에서의 수신 신호와 잡음의 합이다. 또한,

은 오차보정 출력에서의 오차보정 비트에 대한 복소 임펄스 응답으로서 하기의 [수학식 3]과 같이 나타낼 수 있다.here,

Is the error correction bit signal,

Is the sum of the received signal and the noise at the m-th channel output. Also,

Is a complex impulse response to the error correction bits in the error correction output, which can be expressed as Equation 3 below.

은 컨벌루션을 뜻하고

와

는 도 3에서의 크기 이득이다. 또한,

과

은 각각 m번째 채널에 대한 오차보정 필터(412)와 RF 수신기(210)의 임펄스 응답이며,

는 펄스 성형 필터(312)의 임펄스 응답이고,

은 m번째 채널의 전력 분배기(130)의 전달함수이다.here,

Means convolution

Wow

Is the magnitude gain in FIG. Also,

and

Are the impulse responses of the error correction filter 412 and the RF receiver 210 for the m-th channel, respectively.

Is the impulse response of the pulse shaping filter 312,

Is the transfer function of the power divider 130 of the m-th channel.

The zero-forcing algorithm according to the present invention finds a tap coefficient vector that minimizes the cost function using Equations 4 to 6 described below.

는

이 수렴하는 기준 임펄스 응답이며 하기의 [수학식 5]와 같이 주어진다.Here, Re (.) And Im (.) Represent the real part and the imaginary part of the complex value, respectively. And,

Is

This convergent reference impulse response is given by Equation 5 below.

는 표적 응답 필터(513)의 임펄스 응답이다. 상기의 [수학식 3]에서의

은

이

에 수렴함에 따라

에 수렴하는데 이는 m번째 채널 수신기(210)의 전달함수 왜곡이 오차보정 필터(412)에 의해 보정됨을 나타낸다.here,

Is the impulse response of the target response filter 513. In [Equation 3] above

silver

this

As you converge to

Convergence, indicating that the transfer function distortion of the m-th channel receiver 210 is corrected by the error correction filter 412.

On the other hand, the error correction coefficient vector to minimize the cost function is calculated as shown in Equation 6 below.

은 탭 계수 벡터이고 μ는 적응 상수이다. 또한,

는

에 대한

의 복소 미분 벡터를 뜻하며 하기의 [수학식 7]과 같이 나타낼 수 있다.here,

Is the tap coefficient vector and μ is the adaptive constant. Also,

Is

For

Denotes the complex differential vector of and can be expressed as shown in Equation 7 below.

과

은 각각

의 실수부와 허수부이며, 미분 벡터의 i번째 실수부와 허수부는 하기의 [수학식 8], 및 [수학식 9]와 같다.here,

and

Are each

Are the real part and the imaginary part of, and the i real part and the imaginary part of the differential vector are as shown in Equations 8 and 9 below.

은 전체 임펄스 응답과 기준 응답의 차이이다.Where sign (.) Is a sign function

Is the difference between the overall impulse response and the reference response.

을 오차보정기(410) 입력에서의 오차보정 비트에 대한 임펄스 응답으로 두면

는 하기의 [수학식 10]과 같이 나타낼 수 있다.And,

Is the impulse response to the error correction bits at the error corrector 410 input.

Can be expressed as shown in Equation 10 below.

과

은 각각

의 실수와 허수부이며, 이로부터

는 하기의 [수학식 11]과 같이 표현된다.here,

and

Are each

Mistakes and imaginary numbers, from which

Is expressed by Equation 11 below.

이 최고값을 가지며 다른 값보다 훨씬 큰 점을 가질 때, 즉

일 때 상기의 [수학식 11]은 하기의 [수학식 12]와 같이 표현된다.here,

When you have this highest value and a point that is much larger than the other values

Where Equation 11 is expressed as Equation 12 below.

Accordingly, the error correction coefficient is decomposed into 2L + 1 independent equations and is expressed as Equation 13 below.

의 크기와 위상은 1과

으로 가정한다.here,

The magnitude and phase of 1 and

Assume

In addition, since the error correction bits are not correlated with each other, the ensemble average may be obtained as shown in Equation 14 below.

은 오차보정 신호이며, 이로부터 오차보정 계수는 하기의 [수학식 15]와 같이 구해진다.here,

Is an error correction signal, and the error correction coefficient is obtained from Equation 15 below.

Here, if the sign function and the ensemble mean operator are removed and converted to Stochastic gradient, the error correction coefficient is finally obtained as shown in Equation 16 below.

So far, we have discussed in detail how to obtain the error correction coefficient. After that, the power control method of the error correction signal will be described.

The power of the error correction signal must be controlled so that the error correction signal to noise ratio (hereinafter referred to as CSNR) remains constant. Noise in CSNR means antenna signal and thermal noise, and this CSNR control is essential for real-time error correction.

If the power of the error correction signal is much larger than the received signal power received through the antenna, the gain of the receiver depends on the error correction signal, thereby increasing the quantization error. On the other hand, if the power of the error correction signal is too small compared to the received signal, there is a problem that the algorithm performance for calculating the error correction coefficient is degraded.

Therefore, in the error correction, the CSNR needs to be fixed, and the power of the error correction signal is fixed at the input of the error corrector 410. Since the gain of the receiver is continuously changed rapidly by an automatic gain control (AGC) circuit in the gain controller 220, the gain of the receiver changes rapidly in time unless the error correction signal power at the error corrector 410 is properly controlled. In this case, the error corrector 410 having a relatively slow convergence rate cannot follow this change, and it is difficult to remove the error correction signal from the interference canceller. Therefore, power control of the error correction signal is an essential element in error correction of the receiver.

Referring to the power control of the error correction signal according to the present invention formally.

When the narrowband assumption is applied, the received signal at the input of the m th error corrector 410 may be expressed as Equation 17 below.

는 오차보정 신호이며

은 그 크기를 나타낸다. 또한,

는 안테나 수신 신호와 잡음의 합이다. 오차보정 신호와 수신 신호 및 잡음의 합은 서로 상관성이 없으므로 오차보정기(410) 입력에서의 신호 전력은 하기의 [수학식 18]과 같다.here,

Is the error correction signal

Indicates its size. Also,

Is the sum of the antenna received signal and noise. Since the sum of the error correction signal, the received signal, and the noise does not correlate with each other, the signal power at the input of the error corrector 410 is expressed by Equation 18 below.

은 오차보정 신호 전력이고

은 안테나 수신 신호 및 잡음의 합 전력이다.here,

Is the error correction signal power

Is the sum power of the antenna received signal and noise.

The error correction signal power-to-noise ratio (CSNR) is defined as in Equation 19 below.

이고

으로 M개의 수신 채널에 대한 평균값을 의미한다.here,

ego

This means the average value for M reception channels.

는 이득 제어기(220)의 자동이득제어에 의해 고정값을 갖도록 제어되므로 CSNR은 하기의 [수학식 20]과 같이 오차보정 신호만을 제어하여 조정된다.And the total received signal power

Since is controlled to have a fixed value by the automatic gain control of the gain controller 220, the CSNR is adjusted by controlling only the error correction signal as shown in Equation 20 below.

는 오차보정 신호 전력을 제어하기 위해 사용되는 가변 증폭기(330) 이득의 로그값이며,

는 이득 제어기(220)의 자동이득제어에 의해 계산된 수신기의 이득

에 대한 로그값의 시간 증분이다.here,

Is the logarithm of the gain of the variable amplifier 330 used to control the error correction signal power,

Is the gain of the receiver calculated by the automatic gain control of the gain controller 220.

The time increment of the log value for.

는 기준 오차보정 신호 전력

와 추정된 오차보정 신호 전력

과의 차이이며, ρ는 수렴 속도를 결정하는 상수이다. 그리고,

는 오차보정 신호 전력이 기준 전력에 수렴한 후에 출렁거림을 제거한다.Also,

Is the reference error correction signal power

And estimated error correction signal power

And ρ is a constant that determines the speed of convergence. And,

Eliminates rumble after the error correction signal power has converged to the reference power.

The power of the error correction signal spatially averaged using Equations 17 to 20 is estimated as Equation 21 below.

은 오차보정 신호

의 전력이고

는

의 샘플이다. 또한,

로서

는

의 샘플을 의미한다.here,

Is error correction signal

Is the power of

Is

Is a sample. Also,

as

Is

Means the sample.

The present invention described above is capable of various substitutions, modifications, and changes without departing from the technical spirit of the present invention for those skilled in the art to which the present invention pertains. It is not limited by the drawings.

As described above, the present invention has an effect of correcting an error between channels of a multichannel receiver in an array antenna system by applying a zero-forcing equalization algorithm to the multichannel receiver so that each receiving channel has the same transfer function characteristic. .

In addition, the present invention has an effect of correcting frequency nonlinearity in a multichannel receiver channel in an array antenna system by compensating for signal distortion due to nonlinear frequency response of each receiver.

In addition, the present invention by controlling the power of the error correction signal when the error correction of the receiver, there is an effect that can minimize the interference on the system of the error correction signal.

Claims (8)

In the base station system having an error correction function of a multi-channel receiver, An array antenna unit for combining the error correction signal from the error correction signal generator with the received signal received from the outside and transmitting the combined error correction signal to the multi-channel receiver; The multi-channel receiver for signal processing and outputting a received signal combined with an error correction signal received from the array antenna unit; An error correction signal generator for generating an error correction signal and transmitting the error correction signal to the array antenna unit and the error correction unit; Compensate the error of the received signal by calculating an error correction coefficient by using the received signal combined with the error correction signal received from the multi-channel receiver and the error correction signal received from the error correction signal generator, and combining the received signal with the received signal. The error correction unit for removing the error correction signal; And Beam forming unit for receiving an error-corrected received signal from the error correction unit to form an antenna beam Base station system having an error correction function of a multi-channel receiver comprising a. The method of claim 1, The error correction signal generator, An error correction signal generator for generating an error correction signal; A digital / analog converter for converting the digital error correction signal from the error correction signal generator into an analog error correction signal; A variable amplifier for amplifying the error correction signal from the digital / analog converter under the control of the multi-channel receiver; A frequency mixer for upconverting the frequency of the error correction signal amplified by the variable amplifier; And Image removal filter for removing noise of the error correction signal frequency up-converted by the frequency mixer Base station system having an error correction function of a multi-channel receiver comprising a. The method of claim 2, The error correction signal generator, An error correction bit generator for generating an error correction bit signal that is a real value; A pulse shaping filter for pulse shaping the error correction bit signal generated by the error correction bit generator; And Target response filter for determining the transfer function of the entire channel of the multi-channel receiver by receiving the error correction bit signal pulse-formed from the pulse shaping filter Base station system having an error correction function of a multi-channel receiver comprising a. The method according to any one of claims 1 to 3, The error correction part, The base station system having an error correction function of a multi-channel receiver, characterized in that it comprises an error corrector of the number corresponding to the number of channels of the multi-channel receiver. The method of claim 4, wherein Each error corrector, The received signal combined with the error correction signal received from the multi-channel receiver, the error correction bit signal received from the error correction signal generator, and the error correction filtering value received from the error correction filter are applied to a zero-forcing adaptive algorithm. An error correction coefficient calculator for estimating tap coefficients of the error correction filter; And The error correction filter for compensating for distortion of a transfer function of a corresponding channel by using a received signal in which the tap coefficient received from the error correction coefficient calculator and the error correction signal received from the multi-channel receiver are combined. Base station system having an error correction function of a multi-channel receiver comprising a. In the error correction method of a multi-channel receiver in a base station system, An error correction signal generation step of generating an error correction bit signal and generating an error correction signal through filtering; A signal processing step of combining the error correction signal with a received signal received from the outside and processing the signal; An error correction step of estimating an error correction coefficient using the signal-processed received signal and the error correction signal to correct an error of the received signal; And Error correction signal power control step of controlling the power of the error correction signal to remove the error correction signal coupled to the received signal Error correction method of a multi-channel receiver in a base station system comprising a. The method of claim 6, The error correction step, Generating a cost function by applying a received signal in which the output signal of the target response filter and the error correction signal are combined to the zero-forcing algorithm to find the tap coefficient vector of the error correction filter; Performing a complex derivative process to find a complex error correction coefficient vector that minimizes the cost function; And Calculating the error correction coefficient by converting the complex error correction vector obtained from the derivative process into a stochastic gradient. Error correction method of a multi-channel receiver in a base station system comprising a. The method according to claim 6 or 7, The error correction signal power control step, The error correction method of the multi-channel receiver in the base station system, characterized in that the power of the error correction signal is kept constant by reversing the error correction signal power control with the automatic gain control of the multi-channel receiver.

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