KR100558113B1 - Space-Time Array Receive System and Method Using Fading Rate Indicator - Google Patents

Abstract

The present invention adaptively compensates for the distortion caused by a fading channel by using the Doppler frequency estimation of the fading channel and the data rate of the received signal when applying a space-time array receiving system to a CDMA wireless communication system. The present invention relates to a technique for providing high performance. In general, in a CDMA mobile communication system, data and pilot information are simultaneously transmitted as a method for coherent demodulation of a forward link. In this case, in order to compensate for distortion caused by fading of the channel at the terminal, the pilot information is correlated for a predetermined period to estimate the fading channel information, and has been used to compensate the data information. In the present invention, however, this method is modified to use the Doppler frequency estimation and the data rate of the received signal in the reverse link of the base station system to which the smart antenna is applied. A more accurate estimation method is presented.

Array antenna, Doppler frequency estimator, correlation length selector

Description

Space-Time Array Receive System and Method Using Fading Rate Indicator

1 is a detailed block diagram of a space-time array receiving system using a chip level beamforming algorithm applying a systolic array structure for real-time calculation of beamforming weight vectors for a specific channel according to an embodiment of the present invention. Degree,

2 is a diagram of a space-time array receiving system applying a chip level decision-directed beamforming algorithm using a systolic array structure for real-time calculation of a beamforming weight vector for a specific channel according to an embodiment of the present invention. Detailed block diagram,

3 is a configuration diagram showing in detail the configuration of the finger shown in FIG.

4 is an exemplary reverse link structure of a space-time arrangement system;

5 is a block diagram of a Doppler frequency estimator of a fading channel and a correlation length selector of a channel estimator;

6 is a signal flowchart of a Doppler frequency estimator of a fading channel and a correlation length selector of a channel estimator.

         ※ Explanation of code about main part of drawing ※

100: array antenna 110: RF / IF / ADC stage

120: digital beamforming network 130: weighted vector estimator

140: correlation length selection unit 150: Doppler frequency estimation unit

160: demodulator 161, 162: finger and RAKE synthesizer

170: reference signal generator 180: microprocessor

The present invention relates to a fading adaptive ultra-high performance ST array receiving system and method thereof in a CDMA wireless communication system, and more specifically, to a distortion phenomenon caused by a fading channel using a Doppler frequency estimation of a fading channel and a data rate of a received signal. To provide a system and method for adaptively compensate for providing high performance.

In general, in the CDMA wireless communication system proposed by Qualcomm, the pilot channel is correlated for a certain period to compensate for the distortion caused by the fading channel in the terminal, and the fading channel information is estimated and used to compensate the data information. (Qualcomm Incorporated, Mobile Demodulator Architecture for A Spread Spectrum Multiple Access Communication System, US Patent 5764687, June 1998).

Thus, until now, the channel is estimated by correlating the pilot channel only for a predetermined period of time in order to compensate for the distortion of the channel regardless of the amount of change in the fading channel according to the moving speed of the terminal. However, in a fast fading environment generated as the terminal moves at a high speed, a shorter correlation length of the pilot channel is selected. In a slow fading environment generated as a lower speed moves, a longer channel length is selected to estimate a more accurate channel. Needs to be. Also, in the IS-95 CDMA system, which mainly provided voice-oriented services, the reception power of all terminals received from the base station was constant, but in the base station providing high-speed data services such as the IMT-2000 system, voice signals (low speed data) and video Signals (high speed data) can be received simultaneously. In this case, since the reception power of the video signal is higher than the reception power of the audio signal, in the case of low-speed data (low reception power), it is necessary to correlate for a long period when estimating the channel to obtain accurate estimates, In this case, accurate estimates can be obtained even if they are correlated for a short period. In addition, the existing prior patent "spread spectrum receiver" (patent holders are Takashi Kitase and Kazuyuki Miya, patent name KR98-12990, "spread spectrum receiver", March 1998) is a forward link of a general CDMA system A method of adaptively estimating a channel by estimating the Doppler frequency at a link from a base station to a mobile station is applied. The prior art for adaptively compensating for distortion of a data signal due to fading by estimating Doppler in a mobile station of such a CDMA system includes a Doppler frequency estimator for estimating Doppler frequency and a filter circuit having a partial correlation result through weighting. The method of compensating correlation results is adopted.

Therefore, in order to solve the problems described above, the present invention relates to the correlation of the pilot channel in order to compensate for the distortion caused by the fading channel in the reverse link of the CDMA wireless communication system employing the array antenna, for a predetermined period of time. An object of the present invention is to provide a system and method for adaptively selecting and correlating a correlation length of a pilot channel by using a change amount of a fading channel obtained through Doppler frequency estimation and a data rate of a received signal.

According to the present invention devised to achieve the above object, a plurality of digital beam forming network for forming a beam by multi-spatially filtering the received signal received from a plurality of antennas digitally converted received signal by multi-path signal for each multipath signal; A plurality of demodulators for demodulating output signals of the plurality of digital beamforming networks; A pilot channel correlator for estimating a fading channel using a pilot channel in the plurality of demodulators; A Doppler frequency estimator for estimating a Doppler frequency of a fading channel by receiving the output of the pilot channel correlator; A microprocessor providing data rate information of the received signal and controlling the flow of the signal; A correlation length selector which receives a Doppler frequency estimate estimated from the Doppler frequency estimator and a data rate of a received signal as an input to determine a correlation length of a pilot channel correlator; A reference signal generator configured to receive outputs of a plurality of fingers and generate a reference signal; And a plurality of weight vector estimators for receiving the output of the reference signal generator and the received signal, estimating a weight vector, and providing the weight vector to the digital beamforming network. An array receiving system is provided.

In addition, a plurality of digital beamforming network for forming a beam by multi-spatially filtering the received signal received from the plurality of antennas and the digitally converted received signal for each multipath signal by multiplying the weight vector; A plurality of demodulators for demodulating output signals of the plurality of digital beamforming networks; A pilot channel correlator for estimating a fading channel using a pilot channel in the plurality of demodulators; A Doppler frequency estimator for estimating a Doppler frequency of a fading channel by receiving the output of the pilot channel correlator; A microprocessor providing data rate information of the received signal and controlling the flow of the signal; A correlation length selector which receives a Doppler frequency estimate estimated from the Doppler frequency estimator and a data rate of a received signal as an input to determine a correlation length of a pilot channel correlator; A rake synthesizer configured to receive outputs of the plurality of demodulators and synthesize symbols; A hard limiter for symbol estimation which determines a sign of a symbol synthesized by the rake synthesizer; A reference signal generator which receives the output of the hard limiter and the output of a plurality of fingers to apply a beamforming algorithm and generates a reference signal for each multipath signal; And a plurality of weight vector estimators for receiving the output of the reference signal generator and the received signal, estimating a weight vector, and providing the weight vector to the digital beamforming network. An array receiving system is provided.

In addition, a first step of forming a beam by performing a spatial filtering by multiplying a weight vector for each multipath signal received from a plurality of antennas and digitally converted received signal; A second step of demodulating the output signal of the first step; Estimating a fading channel using a pilot channel in the plurality of demodulators; A fourth step of receiving the output of the third step and estimating the Doppler frequency of the fading channel; A fifth step of providing data rate information of the received signal and controlling the flow of the signal; A sixth step of determining a correlation length of a pilot channel correlator by receiving the estimated value of the fourth step and a data rate of the received signal; A seventh step of receiving outputs of a plurality of fingers and generating a reference signal; An eighth step of receiving the output of the seventh step and estimating a weight vector; And a ninth step of providing the estimated value of the eighth step as an input of the digital beamforming network. A space-time array receiving method using a chip level and temporal reference beamforming algorithm is provided.

More preferably, the eighth step may include: a first substep of receiving the outputs of the plurality of demodulators and synthesizing the symbols; A second substep of determining a sign of the synthesized symbol of the first substep; A third substep of receiving the output of the second substep and the outputs of the plurality of fingers and generating a reference signal for each multipath signal; And a fourth sub which receives the output of the third sub-step and the received signal and estimates a weight vector through an adaptive beamforming algorithm such as decision-directed (MMSE-DD), LMS-DD, NLMS-DD, and RLS-DD. And a ninth step of providing an estimated value of the eighth step as an input of the digital beamforming network. A method for receiving a space-time array using a chip level and temporal reference beamforming algorithm is provided. .

In addition, a first step of forming a beam in the computer by spatially filtering the received signal received from the plurality of antennas digitally converted received signal by multiplying the weight vector for each multipath signal; A second step of demodulating the output signal of the first step; Estimating a fading channel using a pilot channel in the plurality of demodulators; A fourth step of receiving the output of the third step and estimating the Doppler frequency of the fading channel; A fifth step of providing data rate information of the received signal and controlling the flow of the signal; A sixth step of determining a correlation length of a pilot channel correlator by receiving the estimated value of the fourth step and a data rate of the received signal; A seventh step of receiving outputs of a plurality of fingers and generating a reference signal; The weight vector using the adaptive beamforming algorithm such as Minimum Mean Square Error (MMSE), Least Mean Square (LMS), Normalized LMS (NLMS), and Recursive Least Square (RLS) by receiving the output and the received signal of the seventh step. Estimating an eighth step; And a ninth step of providing the estimated value of the eighth step as an input of the digital beamforming network, a computer-readable recording medium having recorded thereon a program capable of executing the program.

More preferably, the eighth step may include: a first substep of receiving the outputs of the plurality of demodulators and synthesizing the symbols; A second substep of determining a sign of the synthesized symbol of the first substep; A third substep of receiving the output of the second substep and the outputs of the plurality of fingers and generating a reference signal for each multipath signal; And a fourth to estimate the weight vector using an adaptive beamforming algorithm such as decision-directed (MMSE-DD), LMS-DD, NLMS-DD, and RLS-DD. A computer-readable recording medium is provided which includes a sub-step, and a program capable of executing what is included in the ninth step of providing the estimated value of the eighth step as an input of the digital beamforming network.

In the present invention, an apparatus and method for estimating more accurate channel information by modifying a method proposed by Qualcomm by adaptively selecting a correlation length of a pilot channel according to a change amount of a fading channel and a data rate of a received signal are proposed. .

Applying the adaptive beamforming technique using an array antenna to a base station increases power efficiency and reduces unnecessary interference by ultimately transmitting and receiving radio waves according to the spatial distribution of users, ultimately reducing communication quality and service radius per base station. It can be an effective way to increase subscriber capacity.

Adaptive beamforming algorithms include minimum mean square error (MMSE), minimum mean square (LMS), and recursive least square (RLS). All of them require some kind of reference signals in their adaptive optimization process. In general, the reference signal refers to a signal that contains complete information or knowledge of a signal of interest in advance, and the perfect reference signal may be divided into a spatial reference signal and a temporal reference signal. In this case, the spatial reference signal refers to the angle of arrival of the desired signal information, and the temporal reference signal may be spread signals used in a pilot signal or a CDMA transmission terminal (terminal) correlated with the desired signal.

In the CDMA wireless communication system, since the spreading code sent from the terminal can be known accurately, adaptive beamforming using a reference signal can be applied well. In general, adaptive beamforming in a CDMA wireless communication system is described by Ralph T. Compton, Jr., Adaptive Array in a Spread Spectrum Communication System, Proc. Of The IEEE, Vol. 66, No. 3, pp. 289-298, March 1978).

In the present invention, a reference signal generation model based on Ralph T. Compton's reference signal generation model is applicable to an existing CDMA mobile communication system and used in a chip level beamforming technique.

Hereinafter, a "fading adaptive ultra-high performance S-T array receiver and its method" according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings. 1 is a detailed block diagram of a space-time array receiving system using a chip level beamforming algorithm applying a systolic array structure for real-time calculation of beamforming weight vectors for a specific channel according to an embodiment of the present invention. It is also. Referring to FIG. 1, the space-time array receiving system includes an array antenna 100, an RF / IF / ADC stage 110, a digital beamforming network 120, a weight vector estimator 130, and a correlation length selector 140. ), A Doppler frequency estimator 150, a finger 161, a rake synthesizer 162, a reference signal generator 170, and a microprocessor 180, which will be described in detail as follows.

First, the baseband signal passing through the array antenna 100 and the RF / IF / ADC stage 110 is input to the weight vector estimator 130 and is referred to as the digital beamforming network 120 or a spatial filter. ) Is multiplied by a weight vector obtained from a snapshot signal received in the past, and then summed into one signal sequence 190.

Signals for each path are de-spreaded at each of the fingers 161 in the demodulator based on finely adjusted path delay profile information, and these path signals are de-spreaded by the RAKE synthesizer 162. Synthesized in The synthesized signal is recovered through a de-interleaver, a channel decoder, and passed through a data decompressor. The pilot channel data and the traffic channel data are despread at the finger 161 of the demodulator and used for channel estimation and data demodulation, respectively, and the PN code output from the pseudo noise (PN) code generator of the finger 161 is the reference. It is fed back to the input of the signal generator 170 and used to generate a reference signal. The reference signal generator 170 uses the PN code transmitted from the finger 161 as a reference signal by synchronizing with the received signal, and transmits it to the weight vector estimator 130.

The complex weight vector of the digital beamforming network 120 receives the output of the reference signal generator 170 and the received signal as input, and the weight vector estimator 130 performs an adaptive control process using a systolic array structure in real time. Is updated. The number of the digital beamforming network 120 and the weight vector estimator 130 is determined according to the number of the fingers 161 in the demodulator, and the complex weight vector of each weight vector estimator 130 is independently Is updated. In addition, the microprocessor 180 controls the flow of data communication and control signals between the blocks.

Figure 2 is a space applying a chip-level decision-directed (DD) beamforming algorithm applying a systolic array structure for the real-time calculation of the beamforming weight vector for a particular channel in accordance with an embodiment of the present invention. Detailed block diagram of a timed array reception system. Referring to FIG. 2, FIG. 2 differs from FIG. 1 in the method of generating a reference signal necessary for weight vector estimation only, and is identical to FIG. 1 in all other parts. This will be described in more detail as follows.

First, signals for each path are de-spreaded at each finger 261 in the demodulator based on finely adjusted path delay profile information, and these path signals are RAKE synthesizer 262. Synthesized in The synthesized signal passes through a data decompressor via a de-interleaver and a channel decoder, and a symbol is determined while passing through a hard limiter 263. The symbol determined by the hard limiter 263 is fed back to the reference signal generator 270. The pilot channel data and the traffic channel data are despread at the finger 261 of the demodulator and used for channel estimation and data demodulation. The PN code output from the PN code generator of the finger 261 is input to the reference signal generator 270. It is fed back to the output and used to generate the reference signal. In the reference signal generator 270, the symbol determined by the hard limiter 263 is re-spread using the PN code transmitted from the finger 261, and then synchronized with the received signal and used as a reference signal, and the weight vector estimator 230 is used. To pass). In the present invention, a method of estimating a weight vector using a reference signal obtained through the above method is referred to as a decision-directed beamforming algorithm.

3 is a detailed block diagram illustrating the configuration of the finger illustrated in FIGS. 1 and 2. Referring to FIG. 3, the finger 300 despreads the reception spread spectrum signals 190 and 290 for each channel and performs a code tracking loop. I / Q correlator (also referred to as 310, or channel estimator), traffic channel I / Q correlator 320, access channel I / Q correlator 330, signaling channel I for pilot channel detection for processing of 350 / Q correlator 340, fast-late I / Q correlator 351, 352, comparator 357, loop filter 356, NCO (Numerical Controlled Oscillator) 355, deskew It includes a 360 and a lock detector (370), which will be described in detail as follows.

The I / Q correlator 310 for detecting the pilot channel receives the correlation length from the correlation length selector 140 or 240 to detect data of the pilot channel from the spread spectrum signals 190 and 290 to obtain channel estimation information. The Doppler frequency estimator 150 and 250 and the traffic, access and signaling I / Q correlators 320, 330 and 340, respectively. The fast I / Q correlator 351 performs a correlation function by an integral section defined by a local PN code Tc (chip duration) / 2 ahead of an on-time PN code, and the late I / Q correlator 352. Correlates with the local PN code Tc / 2 behind the on-time PN code. When the correlation function is completed as much as the correlation length, the data of I and Q are squared and added to obtain energy (354). Energy is obtained for each of the fast path and the late path, and the difference between the two energies is obtained, and then these energy differences are applied to the loop filter 356 to obtain the average of the energy obtained in units of integral sections. The output of the loop filter 356 is used to control the NCO 355. The NCO 355 generates a controlled clock according to the input value, which controls the PN code generator 353.

As shown in FIG. 3, in the present invention, the structure of the existing demodulator is maintained as it is, except that the PN code information is fed back from the demodulator and used as a reference signal generator input.

4 is an exemplary diagram conceptually showing a structure of a reverse link of a fading adaptive space-time arrangement system according to an embodiment of the present invention. The structure of the reverse link is described in detail with reference to FIG. 4 as follows. In the IS-95 CDMA system, which mainly provided voice-oriented services, the reception power of all the terminals 410, 420, and 430 received by the base station 400 is constant, but the base station provides high-speed data service like the IMT-2000 system. Received power of each terminal received at 400 may vary according to the received data rates received from the terminals 410, 420, and 430. For example, when the terminal 410 is a voice signal (low data rate) and the terminal 430 is a video signal (high data rate), generally, the reception power of each terminal received from the base station 400 is greater than that of the terminal 410. do. Therefore, in the case of low-speed data, an accurate estimate may be obtained by correlating for a long period during channel estimation, whereas in the case of high-speed data, an accurate estimate may be obtained even by correlating for a short period.

5 is a block diagram of the Doppler frequency estimator 520, the channel estimators 310 and 510, and the correlation length selector 500 of the fading channel illustrated in FIGS. 1 and 2. Referring to FIG. 5, the Doppler frequency estimator 520 receives the fading channel information and the current fading channel information, which are output from the channel estimator 510 using the pilot channel and stored in the buffer 530, and are faded. Estimate the Doppler frequency of the channel.

과 n+1 번째 채널 추정값

이 각각 수학식 1과 같을 때 페이딩 채널의 도플러 주파수에 해당하는 순간 주파수 차는 다음의 수학식 2에서부터 수학식 4를 통해서 구할 수 있다.Referring to the Doppler frequency estimation method proposed in the present invention in detail. N- th channel estimate of the channel estimator 510

And n + 1th channel estimate

As shown in Equation 1, the instantaneous frequency difference corresponding to the Doppler frequency of the fading channel can be obtained from Equation 2 to Equation 4 below.

,

,

,

를 나타내고,

와

는 각각 페이딩 채널의 크기와 위상을 의미한다.Where I ( n ) and Q ( n ) , I ( n +1) and Q ( n +1) are respectively

,

,

,

Indicates,

Wow

Denotes the size and phase of the fading channel, respectively.

In the equation (1) is multiplied by the I (n) and Q n +1 for the second channel estimate (n +1) of the n-th channel estimation values, n of Q (n) and the n +1 th channel estimated value of the second channel estimation value I ( Multiply n + 1) to obtain Equation 2.

은 I²(n) + Q²(n)을 의미하므로 구하고자 하는 순간 주파수 차는 다음의 수학식 4로 구할 수 있다.here,

Since I ² (n) + Q ² (n) means that the instantaneous frequency difference to be obtained can be obtained by the following equation (4).

Using the Doppler frequency obtained from Equation 4 and the data rate of the received signal received from the microprocessors 180 and 280, the correlation length selector 500 averages the correlation lengths selected in the past and the correlation lengths currently selected. As shown in FIG. 5, the correlation length N _p of the channel estimator 510 is determined.

6 is a signal flowchart of a Doppler frequency estimator of a fading channel and a correlation length selector of a channel estimator. This will be described in detail with reference to FIG. 6 as follows. First, the received signal is input to the channel estimator 600, and the received received signal performs a correlation function with the local PN code by the selected correlation length in the past (610), and through this, the data rate information and the Doppler frequency of the received signal are In estimating 620, the correlation length of the channel estimator is selected 630 to update the correlation length selected in the past. This series of steps is performed 660 recursively. In addition, the received signal input to the channel estimator performs a correlation function with a local PN code, and as a result, the estimated channel information 650 is used to compensate for the distortion of the traffic channel (640).

While the invention has been described above based on the preferred embodiments thereof, these embodiments are intended to illustrate rather than limit the invention. It will be apparent to those skilled in the art that various changes, modifications, or adjustments to the above embodiments can be made without departing from the spirit of the invention. Therefore, the protection scope of the present invention will be limited only by the appended claims, and should be construed as including all such changes, modifications or adjustments.

As described above, the present invention correlates a pilot channel for a certain period in order to compensate for distortion caused by a fading channel in a terminal (terminal) of a conventional CDMA mobile communication system, estimates fading channel information, and uses it to compensate the data. Unlike the method, the power of the optimal directional beam formation is achieved by using a method of adaptively correlating the pilot channel by using the amount of fading channel variation obtained through Doppler frequency estimation and the data rate of the received signal in the base station system using the array antenna. In addition to increasing efficiency, unnecessary interference can be reduced, and distortions caused by fading channels can be more accurately compensated, thereby improving communication quality and increasing service radius and subscriber capacity per base station.

Claims (17)

A finger used in a fading adaptive space-time array receiving system including a reference signal generator for generating a reference signal and delivering the same to a weight vector estimator, A pilot channel I / Q correlator receiving the spread spectrum signal and the correlation length to detect data of the pilot channel to obtain channel estimation information; A fast I / Q correlator which receives the spread spectrum signal and the channel estimation information and performs a correlation function by an integral section determined by a local PN code Tc / 2 ahead of an on-time PN code; A late I / Q correlator receiving the spread spectrum signal and the channel estimation information and performing a correlation function with a local PN code that is Tc / 2 behind a regular PN code; A loop filter obtaining energy from the result values of the fast I / Q correlator and the late I / Q correlator, and then calculating the average of the energy obtained in units of integration intervals from these energy differences; A NCO (Numerical Controlled Oscillator) controlled using the result of the loop filter; And A PN code generator for generating a PN code using the output clock of the NCO and feeding the PN code back to the I / Q correlators and the reference signal generator; Finger used in a fading adaptive space-time array receiving system, characterized in that made. delete A Doppler frequency estimator for receiving the estimated fading channel information and the currently output fading channel information by using the pilot channel and estimating the Doppler frequency through a series of processes; And A correlation length selector which receives the past and present instantaneous frequency difference values of the Doppler frequency estimator and data rate information of the received signal and adaptively determines the correlation length by averaging the correlation lengths selected in the past and the currently selected correlation lengths; ; Including, The correlation length determination is performed recursively, and the estimated fading channel information is used to compensate for the distortion of the traffic channel. The correlation length selection and the Doppler frequency estimation used in the fading adaptive space-time array receiving system. Device. The method of claim 3, wherein In adaptively determining the correlation length in the correlation length selector, the Doppler estimated for each data rate using a table in which the correlation length is determined in advance with respect to the data rate of each received signal and the Doppler frequency of a finite sample. A correlation length selection and Doppler frequency estimator for use in a fading adaptive space-time array receiving system, comprising comparing a frequency and a table to select a correlation length corresponding to the nearest Doppler frequency. A fading adaptive space-time array receiving system with a finger according to claim 1, comprising: A plurality of digital beamforming networks configured to form a beam by multiplying a received signal received from a plurality of antennas by digital multiplication by multiplying a weight vector for each multipath signal and transmitting the beam to the finger; A Doppler frequency estimator for estimating a Doppler frequency of a fading channel by receiving a result of the finger; A correlation length selector which receives a Doppler frequency estimate estimated from the Doppler frequency estimator and a data rate of a received signal, and adaptively determines a correlation length applied in a correlation function performed by the finger; A reference signal generator which receives the output of the finger and generates a reference signal; And A plurality of weight vector estimators receiving the output of the reference signal generator and the received signal and providing them to the digital beamforming network; Fading adaptive space-time array receiving system characterized in that it comprises a. A fading adaptive space-time array receiving system with a finger of claim 1, comprising: A plurality of digital beamforming networks configured to form a beam by multiplying a received signal received from a plurality of antennas by digital multiplication by multiplying a weight vector for each multipath signal and transmitting the beam to the finger; A Doppler frequency estimator for estimating a Doppler frequency of a fading channel by receiving a result of the finger; A correlation length selector which receives a Doppler frequency estimate estimated from the Doppler frequency estimator and a data rate of a received signal, and adaptively determines a correlation length applied in a correlation function performed by the finger; A rake synthesizer receiving the output of the finger to synthesize a symbol; A hard limiter for symbol estimation which determines a sign of a symbol synthesized by the rake synthesizer; A reference signal generator which receives the output of the hard limiter and the output of a finger to apply a beamforming algorithm and generates a reference signal for each multipath signal; And A plurality of weight vector estimators receiving the output of the reference signal generator and the received signal and providing them to the digital beamforming network; Fading adaptive space-time array receiving system characterized in that it comprises a. The method according to claim 5 or 6, The Doppler frequency estimator receives the fading channel information and the currently output fading channel information estimated using the pilot channel and estimates the Doppler frequency through a series of processes. system. The method of claim 7, wherein The correlation length selector receives the past and present instantaneous frequency difference values of the Doppler frequency estimator and data rate information of the received signal and adaptively calculates the correlation length by averaging the correlation lengths selected in the past and the currently selected correlation lengths. Determining a fading adaptive space-time array receiving system. The method of claim 8, In adaptively determining the correlation length in the correlation length selector, the Doppler estimated for each data rate using a table in which the correlation length is determined in advance with respect to the data rate of each received signal and the Doppler frequency of a finite sample. A fading adaptive space-time array receiving system, comprising comparing a frequency and a table to select a correlation length corresponding to the nearest Doppler frequency. A first step of forming a beam by spatially filtering the received signals received from the plurality of antennas by digital multiplication by multiplying a weight vector for each multipath signal; A second step of receiving the output value of the first step, estimating a fading channel using a pilot channel, performing a correlation function, and generating a PN code; A third step of estimating the Doppler frequency of the fading channel by receiving the result value of the second step; A fourth step of receiving the estimated Doppler frequency estimate and the data rate of the received signal and adaptively determining a correlation length applied in the correlation function in the second step; A fifth step of receiving a result value of the second step and generating a reference signal; And A sixth step of receiving the reference signal and the received signal and estimating a weight vector; Fading adaptive space-time array receiving method comprising a. The method of claim 10, The second step, Receiving a spread signal and a correlation length to detect data of a pilot channel to obtain channel estimation information; A sub-step of receiving the spread spectrum signal and the channel estimation information and performing a correlation function by an integral section determined by a local PN code Tc / 2 before the on-time PN code; A sub-step of receiving the spread spectrum signal and the channel estimation information and performing a correlation function with a local PN code that is Tc / 2 behind a timely PN code; A sub-step of obtaining energy from the result of the correlation function, and then calculating an average of the energy obtained in units of integration intervals from these energy differences; And A sub step of controlling a NCO (Numerical Controlled Oscillator) using the average energy value and generating a PN code for use as a reference signal generator input using an output clock of the NCO; Fading adaptive space-time array receiving method comprising a. The method of claim 10, In the third step, the fading adaptive space-time array is received by estimating the Doppler frequency through a series of processes by receiving the estimated fading channel information and the currently output fading channel information using the pilot channel. Way. The method of claim 12, In the fourth step, the correlation length is adaptively obtained by averaging past and present instantaneous frequency difference values of the estimated Doppler frequencies and data rate information of a received signal and averaging the correlation lengths selected in the past and the correlation lengths currently selected. Fading adaptive space-time array receiving method characterized in that it determines. The method of claim 13, In adaptively determining the correlation length, the Doppler frequency estimated for each data rate is compared with the estimated Doppler frequency for each data rate using a table in which the correlation length is determined in advance for the data rate of each received signal and the Doppler frequency of a finite sample. And selecting a correlation length corresponding to the nearest Doppler frequency. delete delete delete

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