KR100960470B1 - Apparatus And Method For Multi-Angle of arrival Scan And Beam Forming In Smart Antenna System - Google Patents

Abstract

The present invention provides a multi-incident angle scan in a smart antenna system that can utilize a practical path diversity by forming a beam signal through a corresponding incident angle scan when a plurality of angles of incidence are provided in each path in the smart antenna system to obtain a final signal. A beam forming apparatus and a method thereof.

The present invention forms a beam signal through a multi-incident angle scan for a multipath signal received at different incidence angles through each array antenna of the smart antenna system, thereby realizing practical path diversity and finally obtaining The signal-to-noise ratio (SNR) of the signal can be improved, and the system load can be reduced by eliminating the need to calculate the smart antenna weight for each path.

In addition, the present invention can be directed to a single beam signal for the same direction incidence angle on different paths by performing the rake coupling before performing the incident angle scan for the signal received through each array antenna in the smart antenna system More efficient multi-incident angle scans are possible, including fewer scans.

Description

Apparatus And Method For Multi-Angle of Arrival Scan And Beam Forming In Smart Antenna System}

1 is a view schematically showing a coupling structure of a conventional smart antenna and rake receiver.

2 is a diagram illustrating a multiple-incidence angle scan and beamforming apparatus in a smart antenna system according to an embodiment of the present invention.

3 is a flow chart illustrating multiple incident angle scan and beamforming operations of FIG.

4 is a diagram illustrating a multiple-incident angle scan and beamforming apparatus in a smart antenna system according to another embodiment of the present invention.

FIG. 5 is a flow chart illustrating multiple incident angle scan and beamforming operations of FIG. 4. FIG.

6 is a diagram illustrating a multiple-incidence angle scan and beamforming apparatus in a smart antenna system according to another embodiment of the present invention.

FIG. 7 is a flow chart illustrating multiple incident angle scan and beamforming operations of FIG. 6. FIG.

Explanation of symbols on the main parts of the drawings

21-1 ~ 21-n, 41-1 ~ 41-n, 61-1 ~ 61-n: Explorer 22-1 ~ 21-L: Finger

23-1 to 23-3, 43-1 to 43-3: Incidence angle scanner 24, 44, 65: Adder                 

25, 42-1 to 42-n, 62-1 to 62-n: Rake combiner 63-1 to 63-n: Multiplier

64: incident angle scan & weight calculator

The present invention relates to a smart antenna system, and in particular, when each path has a plurality of angles of incidence, a beam signal is formed through a corresponding angle of incidence scan to obtain a final signal, thereby enabling practical path diversity to be utilized. A multi-incidence angle scanning and beamforming apparatus and method thereof are provided.

In general, in a code division multiple access (CDMA) mobile communication system, a base station performing wireless communication with a mobile terminal uses one antenna per sector to receive a signal of a corresponding terminal, or an antenna Two antennas are used to take advantage of the multiplicity, and recently, a smart antenna system is used to remove interference signals from other directions by forming a beam signal in the direction of a terminal using an antenna array. have.

Here, the beam forming method of the smart antenna system includes a beam signal forming method in a spreading chip unit and a beam signal forming method in a modulation symbol unit. Switched Beam Former that applies the beam closest to the receiving path by using a few fixed beams, and an Adaptive Beam Former that adapts to the direction of each path according to the method of determining ) In two ways.

In addition, the smart antenna system described above has a structure in which a rake receiver is coupled after forming one beam signal for each multipath as illustrated in FIG. 1.

That is, when a multipath signal is received through each array antenna, the corresponding searchers 11-1 to 11-n have one finger 12-1 to each path. 12-L) is arranged to search the code phase of the multipath received signal received through the array antenna, and then the searched code phase is transmitted to each of the fingers 12-1 to 12-L.

Then, each of the fingers 12-1 to 12-L reproduces the spreading code used for generating the subscriber signal and performs the despreading process. At this time, the smart antenna weight calculator 14 for each path By calculating and outputting the smart antenna weights, the signals of each path are multiplied by the smart antenna weights using the multipliers 13-1 to 13-n, and the adder 15 is added to the signals of each path multiplied by the smart antenna weights. By using this method, one beam signal for the corresponding path is formed and delivered to the rake combiner 16.

Thereafter, the rake combiner 16 combines beam signals output from each of the fingers 12-1 to 12-L, that is, multi-path beam signals, to obtain a final signal.                         

However, the above-described smart antenna system assumes that each of the multipaths has one angle of arrival (Angle Of Arrival), and after forming a beam signal through the process of multiplying the smart antenna weight for each path, the coupling at the rake receiver However, in the actual system, since there are multiple angles of incidence in each multipath, path diversity cannot be utilized, and a smart antenna is required for each path, resulting in increased complexity of hardware implementation. Doing.

That is, assuming that a signal incident simultaneously with an array antenna in an arbitrary path of the conventional smart antenna system, that is, the radio wave has two incident angles of 'a' and 'b', the conventional beam forming method uses the incident angle ' It is not possible to form a beam signal directed at the same time a 'and' b ', in this case, there is a problem that the signal loss is very large because the beam formation is not directed to the correct angle of incidence.

As shown in FIG. 1, the number of smart antenna weights is required as the product of the number of antenna arrays and the number of multipaths, and a complex multiplier for multiplying the weights with the received input signal requires the number of corresponding smart antenna weights. This is complicated and also requires a lot of load on the system because the smart antenna weights have to be calculated for each multipath.

The present invention is to solve the problems described above, the object is to form a beam signal through a multi-incident angle scan for the signal of the multi-path received with different incidence angle through each array antenna of the smart antenna system By acquiring the final signal, it is possible to utilize the actual path diversity while improving the signal-to-noise ratio of the final signal, and also to reduce the system load.

Another object of the present invention is to perform a rake coupling prior to performing an incident angle scan on a signal for each path in a smart antenna system so that the system can be directed to one beam signal for the same direction incident angle on different paths. It is to enable more efficient multi-incident angle scan, such as reducing the overall number of scans.

A feature of the present invention for achieving the above object is a plurality of searchers for detecting the time delay of the signal received through each array antenna and delivering the signal received for each path; A plurality of fingers connected one-to-one with each searcher to scan an incident angle of a received signal transmitted from a corresponding searcher to form one beam signal for a corresponding path; The present invention provides a multi-incidence angle scan and beamforming apparatus in a smart antenna system including a rake coupler for correcting beam signals formed for each path by the fingers by a corresponding time delay and then combining them to obtain a final signal.                     

Here, each finger is implemented by the number of incidence angles for each path, and forms a beam signal for each incidence angle by applying the beamforming coefficients found by scanning the incidence angle of the received signal transmitted from the corresponding searcher to the received signal. An angle of incidence scanner; And an adder for adding beam signals formed by each incident angle scanner to form a beam signal for each path and transferring the beam signals to the rake combiner.

Another feature of the present invention is a plurality of searchers for detecting the time delay of the signal received through each array antenna and for transmitting the signal received for each path; A plurality of rake combiners connected one-to-one with each searcher to combine the received signals for each path received from the corresponding searchers by a corresponding time delay, and then combine and deliver the received signals for each path; The number of incidence angles of the received signals for each path is implemented, and the beamforming coefficients found by scanning the incidence angles of the received signals for each path transmitted from the respective rake combiners are applied to the corresponding received signals. An incident angle scanner for forming a signal; The present invention provides a multiple incident angle scan and beam forming apparatus in a smart antenna system including an adder configured to add beam signals for each incident angle formed by each incident angle scanner to obtain a final signal.

이며, 이때, 'θ'는 기본 벡터의 파라미터, 'd'는 안테나 간의 간격, 'T'는 행렬의 전치(transpose)를 의미함.)In the above-described multiple incident angle scan and beamforming apparatus in the smart antenna system, the incident angle scanner is characterized in that the beamforming coefficient is found by selecting the weight of the signal-to-noise ratio using the weight of the Butler matrix. In addition, by scanning the θ value from the base vector at predetermined intervals, the beamforming coefficient is found by finding the θ value that maximizes the signal-to-noise ratio.

Where 'θ' is the parameter of the base vector, 'd' is the spacing between antennas, and 'T' is the transpose of the matrix.)

Still another aspect of the present invention provides a plurality of searchers for determining a time delay of a signal received through each array antenna and transmitting a signal received for each path; A plurality of rake combiners connected one-to-one with each searcher to combine the received signals for each path received from the corresponding searchers by a corresponding time delay, and then combine and deliver the received signals for each path; A beamforming unit which adds the weight vectors found through each incident angle scan in advance and then applies them to the received signal transmitted from each rake combiner to form beam signals for each path; The present invention provides a multi-incident angle scan and beamforming apparatus in a smart antenna system including an adder for adding a beam signal for each path formed by the beamforming unit to obtain a final signal.

The beamforming unit may include: an incident angle scan & weight calculator configured to generate and transfer a beamforming coefficient to be applied when forming a beam signal by adding weight vectors found through the incident angle scans of each multipath; The multiplier is connected one-to-one with each rake combiner to form and transmit a beam signal for each path by applying a beamforming coefficient transmitted from the incident angle scan & weight calculator to the received signal for each path transmitted from a corresponding rake combiner. Characterized in that it comprises a.

On the other hand, another feature of the present invention, the process of finding the time delay of the signal received through each array antenna and transmitting the signal received for each path; A multi-incidence angle scan in the smart antenna system comprising applying a beamforming coefficient obtained through the incident angle scan of the received signal for each path to a corresponding received signal to form a beam signal, and then using the same to obtain a final signal. And a beam forming method.

The process of forming a beam signal through the incident angle scan and obtaining a final signal may include: finding a beamforming coefficient by searching for an incident angle of a received signal for each path; Applying the found beamforming coefficients to the received signal for each path to form a beam signal for each incident angle, and then adding the beamforming coefficients to form a beam signal for each path constituting a multi-path; And correcting the beam signals for each path by a corresponding time delay and then combining the beam signals to obtain a final signal.

In addition, the process of obtaining the final signal by forming a beam signal through the incident angle scan, the step of correcting and combining the received signals for each path by a corresponding time delay; Finding a beamforming coefficient by scanning an incident angle of the received signals for each path combined; And applying a beamforming coefficient to a received signal for each path to form a beam signal for each incident angle, and then adding the beamforming coefficients to obtain a final signal.

Another method may include forming a beam signal through the incident angle scan to obtain a final signal, including correcting and combining received signals for each path by a corresponding time delay; Finding a weight vector corresponding to each incidence angle through the incidence angle scan of each path, and generating the beamforming coefficients by adding them together; And multiplying the received signal for each path by the beamforming coefficients to form a beam signal for each path, and then adding them to obtain a final signal.

Hereinafter, in the smart antenna system according to the present invention, the beam signal is formed by scanning a plurality of angles of arrival received through each path to form a beam signal, thereby fully utilizing path diversity. With reference to the accompanying drawings, an embodiment of the multiple incident angle scan and beam forming apparatus and method thereof in the smart antenna system will be described in detail as follows.

FIG. 2 is a diagram illustrating a multiple incident angle scan and beam forming apparatus in a smart antenna system according to an exemplary embodiment of the present invention, which indicates a plurality of incident angles received for each path in a smart antenna system having multiple paths. The structure which scans using the scanners 23-1 to 23-3 is shown.

That is, as shown in Figure 2, the smart antenna system according to an embodiment of the present invention is largely a plurality of searchers (21-1 ~ 21-n), fingers (22-1 ~ 22-L) and rake coupler ( 25), each of the searchers 21-1 to 21-n determine the time delay through the code phase search of the CDMA signal received through the corresponding array antenna and distinguish each of the multiple paths. The received signal is transmitted to the corresponding fingers 22-1 to 22-L.

Each finger 22-1 to 22-L scans an angle of incidence with respect to the received signal transmitted from the searchers 21-1 to 21-n to form one beam signal for a corresponding path, thereby forming a rake combiner 25 For this purpose, as many angles of incidence scanners 23-1 to 23-3 and one adder 24 corresponding to the number of incidence angles (assuming three incidence angles) are provided for each path. . Here, each incident angle scanner 23-1 to 23-3 scans an incident angle with respect to a received signal transmitted from the searchers 21-1 to 21-n, finds a beamforming coefficient for forming a beam signal, and corresponds to a corresponding beam. By applying the forming coefficient to the received signal, one beam signal is formed and output for each incident angle, and the adder 24 adds beam signals formed by each incident angle scanner 23-1 to 23-3 to each path. One beam signal is formed per star and transmitted to the rake combiner 25.

The rake combiner 25 corrects the beam signals output from each of the fingers 12-1 to 12-L, that is, the beam signals formed for each path by a delayed time, and combines the signals according to a maximum gain combining or equal gain combining scheme. In this case, considering the time delay of each path found by the searchers 21-1 to 21-n, the beam signals transmitted first are temporarily stored in a memory such as a buffer and then combined with beam signals transmitted later. Acquire the final signal.

(여기서, 'θ'는 기본 벡터의 파라미터, 'd'는 안테나 간의 간격, 'T'는 행렬의 전치(transpose)를 의미함)를 이용하는 방법이 있는데, 여기서 버틀러 행렬을 이용하는 방법은 빔포밍 계수를 찾기 위 해 버틀러 행렬의 가중치를 사용하여 신호 대 잡음비(SNR)가 최대값이 나오는 가중치를 선별하여 빔포밍 계수를 찾는 방법으로, 예를 들어 배열 안테나가 4개이고, 입사각이 2개일 경우에 안테나의 가중치를

의 벡터에서

의 값을 아래의 표 1과 같이 'Set 1' 부터 'Set 4'까지 바꿔가면서 SNR의 최대값 2개를 빔포밍 계수로 찾는다.In addition, the above-described incidence angle scanners 23-1 to 23-3 find a beamforming coefficient by finding an incidence angle, and a method using a Butler matrix and a basic vector.

(Where 'θ' is the parameter of the fundamental vector, 'd' is the spacing between the antennas, and 'T' is the transpose of the matrix), where the Butler matrix uses the beamforming coefficients. In order to find the beamforming coefficients by using the weight of the Butler matrix to find the maximum value of the signal-to-noise ratio (SNR), for example, 4 array antennas and 2 angles of incidence The weight of

In the vector of

Change the value of from 'Set 1' to 'Set 4' as shown in Table 1 below, and find the maximum two SNRs as the beamforming coefficients.

θ ₁ θ ₂ θ ₃ θ ₄ Set 1 π / 4 -π π / 4 -π / 2 Set 2 0 π / 4 -π / 2 -3π / 4 Set 3 -3π / 4 -π / 2 π / 4 0 Set 4 -π / 2 π / 4 -π π / 4

를 이용하는 방법은 θ값을 기설정된 간격으로 스캔하여 SNR 값이 최대가 되는 θ값을 찾아 빔포밍 계수를 찾는 방법으로, 이는 기본 벡터의 'θ'에 기설정된 값을 대입하면서 SNR이 최대가 되는 2개의 θ값을 찾아 빔포밍 계수를 찾는다.Another way, base vector

In this method, the θ value is scanned at predetermined intervals to find the beamforming coefficient by finding the θ value that maximizes the SNR value. This method substitutes a predetermined value to 'θ' of the base vector and maximizes the SNR value. The beamforming coefficients are found by finding two values of θ.

In addition, the method of combining the signals in the above-described rake combiner 25 will be described in more detail, the maximum gain combining is a method of combining while applying a weight so that the SNR of the signal after combining the signals of the multi-path to the maximum, equal Gain combining means a method of combining by applying the same weight. For example, if the 'a' signal of path 1 is combined with the 'a' signal of path 2, the ratio is 1: 1 and the gain is equal to the gain. When the 'a' signal is combined with a weight of 0.4, and the SNR is the maximum combination, this is the maximum gain combination.

A multi-incident angle scan and beamforming operation in a smart antenna system according to an embodiment of the present invention having the above-described configuration will be described with reference to FIG. 3 as follows.

First, when a signal having a plurality of incidence angles is received through each array antenna constituting the smart antenna system (step S31), each of the searchers 21-1 to 21-n receives the signals received through the corresponding array antenna. After determining the time delay, each of the multiple paths are distinguished using the corresponding time delay information (step S32), and the time delay information for each of these divided paths is informed to the rake combiner 25 so that they can be used in signal combining. In addition, the received signal of each path is transmitted to the corresponding fingers 22-1 to 22-L (step S33).

Then, the received signals transmitted from the searchers 21-1 to 21-n in each of the incident angle scanners 23-1 to 23-3 provided with the number of incident angles on each of the fingers 22-1 to 22-L. The beamforming coefficients for beam signal formation are found by searching for and scanning the incident angle of (step S34), and one beam signal is formed for each incident angle by applying the found beamforming coefficients to the received signal (step S35).

Subsequently, in the adder 24 provided in each finger 22-1 to 22-L, the multipath is added by adding beam signals formed by the incident angle scanners 23-1 to 23-3 provided in the same finger. One beam signal is formed for each path constituting the path and transmitted to the rake combiner 25 (step S36), and the rake combiner 25 outputs each path output from each finger 22-1 to 22-L. The final signal is obtained by correcting the time delays reported by the searchers 21-1 to 21-n by combining the maximum gains or the equal gains (step S37).

Thus, according to the embodiment of the present invention, when a plurality of incidence angles exist in one path constituting the multi-path in the smart antenna system, after forming a beam signal for each path through the corresponding incident angle scan in time By combining and correcting the delay, it is possible to take advantage of the path diversity by converting it into a form having a plurality of incidence angles in one path as a whole.

On the other hand, Figure 4 is a view showing a multi-incidence angle scan and beam forming apparatus in a smart antenna system according to another embodiment of the present invention, which is one rake coupler (42-1) for each array antenna, unlike FIG. 42-n), and each rake coupler 42-1 to 42-n is connected to each searcher 41-1 to 41-n at the front end of each incident angle scanner 43-1 to 43-3. By implementing a one-to-one correspondence, each rake combiner 42-1 to 42-n combines the received signals of the multipath using the time delay information found by the corresponding searchers 41-1 to 41-n. The combined signals are formed as beam signals for each incident angle by the incident angle scanners 43-1 to 43-3, and then added by the adder 44 to obtain a final signal.

That is, as shown in Figure 4, the smart antenna system according to another embodiment of the present invention is largely a plurality of searchers (41-1 ~ 41-n), rake coupler (42-1 ~ 42-n) and the incident angle scanner (Assuming three incident angles) (43-1 to 43-3), wherein each searcher (41-1 to 41-n) is a code of a CDMA signal received through a corresponding array antenna. By detecting the time delay through phase search, each multipath is distinguished, and the received signal of each path is transmitted to the corresponding Rake combiners 42-1 to 42-n.

Each rake combiner 42-1 to 42-n corrects received signals for each path transmitted from the corresponding searchers 41-1 to 41-n by a delayed time, and combines them according to a maximum gain combining or equal gain combining scheme. Each of the incident angle scanners 43-1 to 43-3 is transferred to each of the incident angle scanners 43-1 to 43-3. It is stored temporarily in and combined with the received signals later.

Each incidence angle scanner 43-1 to 43-3 scans the incidence angle of the received signal for each path coupled by the respective rake combiners 42-1 to 42-n, respectively, and calculates the beamforming coefficients found in each path. One beam signal is formed for each incident angle to be applied to the received signal and transmitted to the adder 44. In this case, the adder 44 beams for each incident angle formed by the incident angle scanners 43-1 to 43-3. The final signal is obtained by adding the signals.

A multi-incident angle scan and beamforming operation in a smart antenna system according to another embodiment of the present invention having the above-described configuration will be described with reference to FIG. 5 as follows.

First, when a signal having a plurality of incidence angles is received through each array antenna constituting the smart antenna system (step S51), each searcher (41-1 to 41-n) of the signal received through the corresponding array antenna After determining the time delay, each of the multiple paths is distinguished using the corresponding time delay information (step S52), and together with the received signal of each path to use the time delay information for each of the divided paths in the signal combination The transfer is made to the corresponding rake couplers 42-1 to 42-n (step S53).

Then, in each rake coupler 42-1 to 42-n, the corresponding searchers 41-1 to 41-n inform the received signals of each path transmitted from the corresponding searchers 41-1 to 41-n. After correcting the time delay and combining maximum gain or equal gain, it is transmitted to each of the incident angle scanners 43-1 to 43-3 (step S54).

Subsequently, each incident angle scanner 43-1 to 43-3 searches for the incident angle of the received signal for each path transmitted from the rake combiners 42-1 to 42-n to scan the beamforming coefficients for forming the beam signal. (Step S55), the beamforming coefficients thus found are applied to the received signal to form one beam signal for each incident angle (Step S56), in which the adders 44 each incidence angle scanner 43-1 to 43-. The final signal is obtained by adding the beam signals for each incident angle formed by 3) (step S57).

'의 신호가 i 번째 레이크 결합기의 결합 신호로 출력되며, 이렇게 각 레이크 결합기에 의해 결합된 신호를 입사각 스캔을 통해 얻은 빔포밍 계수인 스마트 안테나 가중치 벡터를 적용하여 빔 신호를 형성한 후에 이를 모두 가산하여 최종 신호를 획득하게 된다. 즉, A 라는 신호가 있고, 여기에 빔포밍 계수 B1, B2, B3가 있다고 가정하면, 'B1*A + B2*A + B3*A'의 방식으로 빔 신호 형성 및 최종 신호를 획득하게 된다.For example, assume that the signal received by the j-th finger from the i-th array antenna is 'h _ij s + n _ij ', where 'h _ij ' is a channel variable representing signal distortion such as fading and attenuation of a wireless channel. 's' is the transmission signal, and 'n _ij ' is the sum of noise and interference signal) .The Rake combiner combines signals received in multiple paths using methods such as maximum gain combining or equal gain combining. If you do equal gain combination,

'Is output as the combined signal of the i-th rake combiner, and the signals combined by each rake combiner are formed by applying the smart antenna weight vector, the beamforming coefficient obtained through the incident angle scan, to form a beam signal and then adding them all together. To obtain the final signal. That is, assuming that there is a signal A, and the beamforming coefficients B1, B2, and B3 are present, the beam signal formation and the final signal are obtained in the manner of 'B1 * A + B2 * A + B3 * A'.

6 is a diagram illustrating a multiple incident angle scan and beam forming apparatus in a smart antenna system according to another embodiment of the present invention, which is different from FIG. 4 in one incident angle scan & weight calculator 64. The weight vectors found through the incidence angle scan of P are summed in advance, multiplied by the signals combined by the respective Rake couplers 62-1 to 62-n, and then added to the adder 65 to obtain a final signal.

That is, as shown in Figure 6, the smart antenna system according to another embodiment of the present invention is largely a plurality of searchers (61-1 ~ 61-n) and rake couplers (62-1 ~ 62-n) and one And an angle of incidence scan & weight calculator 64 of each of the searchers 61-1 to 61-n, which finds the time delay through the code phase search of the CDMA signal received through the corresponding array antenna. By distinguishing the multiple paths, the received signals of each path are transmitted to the corresponding Rake couplers 62-1 to 62-n.

Each Rake combiner 62-1 to 62-n corrects received signals for each path transmitted from the corresponding searchers 61-1 to 61-n by a delayed time, and combines them according to a maximum gain combining or equal gain combining scheme. At this time, considering the time delay for each path found by the searchers 61-1 to 61-n, the received signals are temporarily stored in the same memory as the buffer and then combined with the received signals. do.

The incident angle scan & weight calculation unit 64 finds weight vectors-as many as the number of incident angles-through the incident angle scans of each path, and adds the weight vectors in advance, and multiplies them by the multipliers 63-1 to 63-n. Multiply by the signal output from each rake combiner (62-1 ~ 62-n) by using to form a beam signal for each path to pass to the adder 65, where the adder 65 is the incident angle scan & weight The final signal is obtained by adding the beam signals of each path formed by the calculator 64 and the multipliers 63-1 to 63-n.

A multi-incident angle scan and beamforming operation in a smart antenna system according to another embodiment of the present invention having the above-described configuration will be described with reference to FIG. 7 as follows.

First, when a signal having a plurality of incidence angles is received through each array antenna constituting the smart antenna system (step S71), each of the searchers 61-1 to 61-n receives the signal received through the corresponding array antenna. After determining the time delay, each of the multiple paths is distinguished using the corresponding time delay information (step S72), and together with the received signal of each path to use the time delay information for each of these divided paths in signal combining The transfer is made to the corresponding rake couplers 62-1 to 62-n (step S73).

Then, in each rake coupler 62-1 to 62-n, the received signals for each path transmitted from the corresponding searchers 61-1 to 61-n are searched at the corresponding searchers 61-1 to 61-n. After correcting the known time delay, the maximum gain combining or equal gain combining is output to the corresponding multipliers 63-1 to 63-n (step S74).

At this time, the incident angle scan & weight calculator 64 finds weight vectors corresponding to each incident angle through the incident angle scan of each path, and adds one weight vector, that is, one beamforming coefficient, to be applied in actual beam signal formation. After generation (step S75), the beamforming coefficients thus generated are transferred to the respective multipliers 63-1 to 63-n, so that the signals output from the respective rake combiners 62-1 to 62-n, i.e., each By multiplying the received signal by the path by the same beamforming coefficients to form one beam signal for each path (step S76), the adder 65 in the incident angle scan & weight calculator 64 and multiplier 63-1 The final signal is obtained by adding the beam signals of each path formed by ˜63-n) (step S77). For example, if there is a signal A, and the beamforming coefficients B1, B2, and B3 are present, the beam signal formation and the final signal are obtained in the manner of (B1 + B2 + B3) * A.

Thus, according to the above-described embodiment of the present invention, when a plurality of incidence angles exist in one path constituting the multipath in the smart antenna system, the incidence angle scan & weight calculator 64 determines the number of incidence angles through the incidence angle scan. After finding the weight vectors, the sum is pre-sumed and used to form the beam signal. Thus, the complexity of hardware can be minimized by using only one smart antenna weight vector, that is, one beamforming coefficient, in forming the beam signal. .                     

In addition, the embodiments according to the present invention are not limited to the above-described embodiments, and various alternatives, modifications, and changes can be made within the scope apparent to those skilled in the art.

As described above, the present invention forms a beam signal through a multi-incident angle scan for a multi-path signal received with different angles of incidence through each array antenna of the smart antenna system, thereby enabling practical path diversity to be utilized. It is possible to improve the signal-to-noise ratio (SNR) of the finally obtained signal, and to reduce the system load by eliminating the process of calculating the smart antenna weight for each path.

In addition, the present invention can be directed to a single beam signal for the same direction incidence angle on different paths by performing the rake coupling before performing the incident angle scan for the signal received through each array antenna in the smart antenna system More efficient multi-incident angle scans are possible, including fewer scans.

Claims (11)

delete A plurality of searchers for detecting a time delay of a signal received through each array antenna and delivering a signal received for each path; A plurality of fingers connected one-to-one with each searcher to scan an incident angle of a received signal transmitted from a corresponding searcher to form one beam signal for a corresponding path; In the multiple-incident angle scan and beamforming apparatus of the smart antenna system comprising a rake combiner for correcting the beam signals formed by the fingers for each path by a corresponding time delay and then combine to obtain a final signal, Each finger is implemented by the number of incidence angles for each path, and forms a beam signal for each incidence angle by applying the beamforming coefficients found by scanning the incidence angle of the received signal transmitted from the corresponding searcher to the received signal. An incident angle scanner; And an adder configured to add beam signals formed by each incident angle scanner to form a beam signal for each path, and to deliver the beam signal to the rake coupler. A plurality of searchers for detecting a time delay of a signal received through each array antenna and delivering a signal received for each path; A plurality of rake combiners connected one-to-one with each searcher to combine the received signals for each path received from the corresponding searchers by a corresponding time delay, and then combine and deliver the received signals for each path; The number of incidence angles of the received signals for each path is implemented, and the beamforming coefficients found by scanning the incidence angles of the received signals for each path transmitted from the respective rake combiners are applied to the corresponding received signals. An incident angle scanner for forming a signal; And an adder configured to add beam signals for respective incident angles formed by the incident angle scanners to obtain a final signal. The method of claim 2 or 3, The incident angle scanner is a multi-incidence angle scanning and beam forming apparatus of the smart antenna system, characterized in that the weight of the signal-to-noise ratio is selected by using the weight of the Butler matrix to find the beamforming coefficients. The method of claim 2 or 3, And the incident angle scanner scans the θ values from the basic vectors at predetermined intervals to find a beamforming coefficient by finding a θ value that maximizes the signal-to-noise ratio. Where the base vector is

Where 'θ' is the parameter of the base vector, 'd' is the spacing between antennas, and 'T' is the transpose of the matrix. A plurality of searchers for detecting a time delay of a signal received through each array antenna and delivering a signal received for each path; A plurality of rake combiners connected one-to-one with each searcher to combine the received signals for each path received from the corresponding searchers by a corresponding time delay, and then combine and deliver the received signals for each path; A beamforming unit which adds the weight vectors found through each incident angle scan in advance and then applies them to the received signal transmitted from each rake combiner to form beam signals for each path; And an adder configured to add a beam signal for each path formed by the beamformer to obtain a final signal. The method of claim 6, The beamforming unit includes: an incident angle scan & weight calculator configured to generate and transfer a beamforming coefficient to be applied when forming a beam signal by adding weight vectors found through the incident angle scans of each multipath; The multiplier is connected one-to-one with each rake combiner to form and transmit a beam signal for each path by applying a beamforming coefficient transmitted from the incident angle scan & weight calculator to the received signal for each path transmitted from a corresponding rake combiner. Multiple incident angle scan and beam forming apparatus in a smart antenna system comprising a. delete delete delete delete

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