KR100369632B1 - Hibrid smart antenna system and method for error management - Google Patents

Abstract

The present invention relates to a smart antenna system for a base station used to increase the capacity of a channel in the next generation mobile communication, and in particular, by extracting the optimal weight for forming a beam pattern by a hybrid method combining a reference method and a blind method, The present invention relates to a hybrid smart antenna system and an error processing method that allow an antenna system to more actively cope with changes in a channel environment and increase a capacity of a base station.

The present invention prevents improper signal search due to a wrong pilot signal when the channel environment is poor, and uses a signal search method using an easy-to-use reference signal processing method instead of using a blind calculation method where the channel environment is good. It reduces the load on the system and provides a hybrid approach that combines only real-time processing speed, which is an advantage of reference signal processing, and better performance in poor signal environments, which is an advantage of blind signal processing.

In addition, it is determined that the error occurs in the signal at the rear of the signal processor of the receiving system. If an error occurs, it is determined that the channel environment is poor. If the error does not occur, the blind channel processor is used. Use a signal processor.

Description

Hybrid smart antenna system and method for error management

The present invention relates to a new structure of a smart antenna system for a base station used to increase channel capacity in a next generation mobile communication (IMT-2000 system), and refers to an optimal weight reference method for forming a beam pattern. The present invention relates to a hybrid smart antenna system and an error processing method that enable a smart antenna system to more actively cope with changes in a channel environment and increase a capacity of a base station by extracting a hybrid method combining a and a blind method.

In general, the smart antenna method refers to a method in which each element in the array antenna automatically adjusts the antenna to an optimal direction based on information obtained by receiving an input signal. In addition, the smart antenna scheme is commonly referred to as an adaptive antenna array.

The configuration of the system using the conventional smart antenna scheme described above is a plurality of smart antenna 100, that is, the array antenna (100-1, 100-n) of the adaptive arrangement, a plurality of multipliers 110 as shown in FIG. And a signal processor 130 and a channel element 140 for processing the signal after selecting the adder 120 and the algorithm.

As shown in the drawing, each signal received by the array antenna 100 is compared with a reference antenna. It has a phase difference of and the equation is as follows.

here, " Is the angle of incidence of the signal and s (t) is the reference signal.

The weight vector obtained through the signal processor 130 is an input signal. Dot product with vectors Find the signal.

Referring to FIG. 1, the conventional operation will be briefly described. The array input vector signals x1 to xn received from the smart antenna 100, that is, the plurality of antennas 100-1 to 100-n having an adaptive arrangement. They are applied to each of the multipliers (110-1 ~ 110-n) and is multiplied by the weight (w1 ~ wn) of the complex number that is adaptively adjusted by the signal processor 130 is output. The output signal is applied to the summer 120, and the output signal applied to the summer 120 is combined to obtain an array output y, thereby gaining a direction in which a desired signal comes in the form of a receive beam. And null in the direction from which the interference signal comes, enabling spatially selective reception. Therefore, the conventionally proposed smart antenna system serves to increase the capacity of the system by reducing the interference between the channels in the CDMA mobile communication system.

Therefore, the above-described conventional smart antenna base station (BTS) provides a maximum gain in the direction of a desired mobile station (MS) and forms a beam pattern having a minimum gain in the direction of another mobile station. As a method of increasing the capacity of a base station, a signal processing algorithm for obtaining an optimal weight using a received signal is required to form a beam pattern. For this reason, the conventional smart antenna system has proposed a blind method that does not use a reference signal and a method that uses a reference signal such as a pilot signal to obtain a weight.

However, since the blind method does not use the reference signal and requires too much computation to detect the correct direction of the received signal, real-time processing is difficult, and the method using the reference signal is simple even though the method is simple. If the environment is poor, the nature of the pilot signal used as a reference signal has a problem that the error probability is higher than the traffic signal.

Accordingly, the present invention has been proposed to solve the conventional problems as described above, and an object of the present invention is to determine whether an error occurs in a signal at the rear end of a signal processor of a hybrid smart antenna system, and as a result, a bad channel occurs when an error occurs. By using a blind signal processor that prevents improper signal search due to a bad pilot signal in the environment, and using a reference signal processor that is simple to use and has high speed in real time when no error occurs, The purpose is to reduce the load.

Hybrid smart antenna system according to the present invention to achieve the above object,

Received from an array antenna A vector signal receiver for receiving a vector signal, and a blind signal processor for processing a received signal output from the vector signal receiver in a blind manner to obtain a weight, and outputting the weighted result of the received signal and the received signal; A hybrid type signal processor comprising a reference type signal processor configured to obtain a weight by processing the received signal output from the vector signal receiving unit by a reference method, and output the resultant signal by internalizing the weighted signal and the received signal; An error determination and signal selection unit which checks whether an error signal is outputted from the controller and selects a signal having a small error, and transmits it to the channel element, and simultaneously outputs a switching control signal for signal processor selection; According to the switching control signal from And a switch controller for controlling a switch for setting a path of a signal output from the vector signal receiver, and a switch for setting a path of a signal output from the vector signal receiver according to the control of the switch controller. It features.

In order to achieve the above object, an error processing method in a hybrid smart antenna system according to the present invention includes determining whether an error occurs in an output signal passing through a signal processor by a blind method or a reference method, and the determination result value. Processing the vector signal or operating a timer using a signal processor of a corresponding method (blind / reference),

After the timer is operated, any threshold of the timer is determined, and if the threshold is not exceeded, the signal processor (blind / reference) of the corresponding method is used continuously, and if the threshold is exceeded, the switch controller is used. And the step of changing the signal processor to a signal processor different from the above-described method (reference / blind).

1 is a block diagram showing a block configuration of a typical smart antenna system,

2 is a block diagram showing a block configuration of a hybrid smart antenna system according to the present invention,

3 is a block diagram showing the detailed block configuration of the error determination and signal selection unit according to the present invention;

4 is a flowchart illustrating an error processing procedure of an error determination and signal selection unit in a hybrid smart antenna system according to the present invention. FIG. 4A is a flowchart illustrating a process of error determination and signal selection unit in a blind method, and FIG. 4B is a reference. In the case of the method, it is a flowchart illustrating a process of an error determination and a signal selection unit.

<Explanation of symbols for the main parts of the drawings>

10: vector signal receiving unit 15: switch

20 blind signal processor

30: reference type signal processor

40: error determination and signal selection unit

50: switch controller

60 channel element (CE) 70 hybrid signal processor

200: quality checker

300: Generator

400: beat adder

500: error determiner

Hereinafter, a preferred embodiment of the hybrid smart antenna system and the error processing method of the present invention according to the above technical concept will be described in detail with reference to the accompanying drawings.

2 is a block diagram showing a block configuration of a hybrid smart antenna system according to the present invention.

As shown here, received from an array antenna A vector signal receiving unit 10 for receiving a vector signal and a received signal output from the vector signal receiving unit 10 are processed by a blind method to obtain a weight, and the weight and the received signal are internally output to output the result signal. A reference type signal processor for processing a blind signal processor 20 and the received signal output from the vector signal receiver 10 by a reference method to obtain a weight, and outputting the weighted result of the weighted signal and the received signal. 30 and check whether the signal output from each of the signal processors 20 and 30 is error, and then select the ones having few errors and transmit them to the channel element 60, and at the same time, a switching control signal for signal processor selection. According to the error determination and signal selection unit 40 for outputting the switching control signal output from the error determination and signal selection unit 40 A switch controller 50 for controlling a switch 15 for setting a path of a signal output from the signal receiver 10 and a signal output from the vector signal receiver 10 under the control of the switch controller 50. The operation configuration of the hybrid smart antenna system according to the present invention having the configuration described above is as follows. First, the vector signal receiving unit 10 receives the signal from the array antenna. The vector signal passes through a hybrid signal processor 70 including a blind signal processor 20 and a reference signal processor 30, and then passes through an error determination and signal selection unit 40. In this case, when the signal environment is good, the reference type signal processor 30 having a high performance speed is used, and when the signal environment is poor, the blind type signal processor 20 having relatively high performance is processed. After passing through the signal processors 20 and 30, the error determination and signal selection unit 40 checks whether or not the signal environment is good. In this case, the error determination and the signal selection unit 40 check results. According to the switch controller 50 to control the switch 15 to selectively use each of the signal processor 20, 30. Next, the signal according to the channel environment through the switch 15 The processor selects a processor to process the input vector signal and transmit the same to the channel element 60.

3 is a block diagram illustrating a detailed block configuration of an error determination and signal selection unit according to the present invention.

As shown in the figure, a cyclic redundancy check (CRC) using a quality checker 200 outputting a 12-bit frame quality check bit and a 12-bit frame quality check bit output from the quality checker 200. A generator 300 for performing the operation, a bit adder 400 for adding data output from the quality checker 200 and the generator 300 to the error determiner 500, and the bit adder 400. It is composed of an error determiner 500 for extracting a result value output from the) and to determine the presence or absence of an error according to the result.

An operation configuration of an error determination and signal selection unit according to the present invention having the above configuration, that is, a determination process of whether an error occurs is described in more detail as follows.

First, when the error determination and signal selection unit 40 determines whether an error has occurred or not, when the mobile station transmits at a data rate of 9600 bps, the total number of bits per second is 192 bits. In this case, the 192 bits are composed of 172 bits of information bits, 12 bits of frame quality checking bits, and 8 bits of encoder tail bits.

The quality checker 200 outputs a 12-bit frame quality check bit. In addition, it is a type of error detection method used for cyclic redundancy check (CRC) of a base station and cyclic redundancy check in data transmission, and it uses a polynomial code for error detection in addition to the minimum bits necessary to represent data. Inspecting method) The cyclic redundancy check is performed in the polynomial generator 300, and the bit adder 400 calculates the data through the quality check bit and the CRC and transmits the data to the error determiner 500. The error determiner 500 checks the output value calculated by the bit adder and determines that there is no error if the data value is "0", and determines that an error has occurred if the value is "1". On the other hand, the error determination and signal selection process of the error determination and signal selection unit having the above configuration comprises the steps of: processing the vector signal received from the array antenna with a blind or reference signal processor; Determining whether there is an error of one output signal, and selecting a signal processor with less error in each signal processor according to the determination result, detailed operation description thereof is as shown in FIG.

4 is a flowchart illustrating an error processing procedure of an error determination and signal selection unit in a hybrid smart antenna system according to the present invention. FIG. 4A is a flowchart illustrating a process of error determination and signal selection unit in a blind method, and FIG. 4B is a reference. In the case of the method, it is a flowchart illustrating a process of an error determination and a signal selection unit.

The operation of the error determination and signal selection unit in the blind method of FIG. 4A is as follows. As shown in FIG. 4, when a signal passing through the blind signal processor is input to the error determination and signal selection unit (ST11), the received signal is received. Checking whether an error has occurred (ST12), transmitting a received signal to a channel element when an error occurs in the check result (ST16), and if an error does not occur in the received signal as a result of the check, a timer Activating (ST13), and after operation of the timer, determining an arbitrary threshold value and checking whether the timer has exceeded an arbitrary threshold value (ST14); And selecting and processing the reference method signal processor through step ST15 and, if the check result is equal to or less than an arbitrary threshold value, the channel element. An input signal is transmitted (ST16). The process of the error determination and signal selection unit according to the present invention having the above-described configuration will be described in detail as follows. First, in step ST11, the signal processor 20 according to the blind method is performed. When the output signal y1 that has passed through is inputted to the error determination and signal selection unit 40, the error determination and signal selection unit 40 receives the output signal of the blind signal processor 20 of the received blind method in step ST12. It is checked whether an error of y1) occurs, and if an error occurs as a result of the determination, it is transmitted to the channel element of step ST16. If no error occurs as a result of the check, in step ST13, a timer is operated to prevent frequent signal processor changes due to transient changes in the channel.

If the timer is activated in step ST13, an arbitrary threshold value is determined in step ST14, and if an error occurs before the result timer exceeds an arbitrary threshold value, it is determined excessively. The blind signal processor 20 continues to be used. If the timer exceeds the threshold, it is determined that the mobile station has entered a good channel environment, and in step ST15, the signal processor is changed to the reference method 30 using the switch controller 50.

The operation of the error determination and signal selection unit in the reference method of FIG. 4B is as follows. As shown in FIG. 4, when a signal passing through the reference type signal processor is input to the error determination and signal selection unit (ST21), the received signal is received. Checking whether an error occurs in step ST22, transmitting a received signal to a channel element when an error occurs in the check result (ST26), and if an error does not occur in the received signal as a result of the check, a timer Activating (ST23), and after operation of the timer, determining an arbitrary threshold value and checking whether the timer has exceeded an arbitrary threshold value (ST24); Selecting and processing a blind signal processor through the step ST25 and, if the check result is equal to or less than a threshold value, An input signal is transmitted (ST26). The process of error determination and signal selection according to the present invention having the above-described configuration will now be described in detail. First, in step ST21, the signal processor 30 according to the reference method is performed. When the output signal y2 having passed through is inputted to the error determination and signal selection unit 40, the error determination and signal selection unit 40 receives the output signal ( It is checked whether an error of y2) occurs. If no error occurs as a result of the check, it is determined that the current channel environment is good and the reference method is continued. If an error occurs as a result of the check in step ST22, the timer is operated in step ST23 to prevent frequent signal processor changes due to excessive changes in the channel.

When the timer is activated in step ST23, the threshold value of the timer is determined in step ST24, and if the error does not occur before the result timer exceeds a certain threshold value, it is determined excessively and continues to use the reference signal processor 30. In addition, if the timer exceeds the threshold value, it is determined that the mobile station has entered the bad channel environment, and in step ST25, the signal processor is changed to the blind system 20 using the switch controller 50.

As described above, the hybrid smart antenna system according to the present invention determines whether an error occurs in a signal at the rear of the signal processor of the hybrid smart antenna system, and as a result, if an error occurs, it is unsuitable due to an incorrect pilot signal in a poor channel environment. By using a blind signal processor that can prevent a signal search, and by using a reference signal processor that is simple to use and fast in real time when no error occurs, the system load can be reduced. .

In addition, as described above, by processing the reverse pilot signal in a hybrid structure combining a method using a reference signal and a blind method not using a reference signal, a smart antenna system that can cope more actively with changes in the channel environment can be implemented. In addition, it can be implemented in software in the existing signal processing algorithm without the addition of additional hardware has the advantage that can increase the economics.

Claims (3)

In the smart antenna system, Received from an array antenna A vector signal receiver for receiving a vector signal; A hybrid signal processor for processing a received signal output from the vector signal receiving unit selectively using a blind method or a reference method according to a channel environment, obtaining a weight, and outputting the weighted value and the received signal to output the resultant signal. Wow; An error determination and signal selection unit which checks whether an error of the signal outputted from the signal processor is error and transmits the selected one to the channel element with a small error, and simultaneously outputs a switching control signal for signal processor selection; A switch controller controlling a switch for setting a path of a signal output from the vector signal receiving unit according to the switching control signal output from the error determination and signal selection unit; And a switch configured to set a path of a signal output from the vector signal receiver under the control of the switch controller. The method of claim 1, wherein the error determination and signal selection unit, A quality checker for outputting a 12-bit frame quality check bit; A generator for performing a cyclic redundancy check (CRC) using a 12-bit frame quality check bit output from the quality checker; A bit adder for adding and outputting data output from each of the quality checker and the generator; And an error determiner which determines whether there is an error by retrieving the data output from the bit adder. In the error processing method in a smart antenna system, Determining whether an error occurs in the output signal passing through the signal processor by the blind method or the reference method; Processing the vector signal or starting a timer using a signal processor of a corresponding method (blind / reference) according to the determination result value; After the timer is operated, any threshold of the timer is determined, and if the threshold is not exceeded, the signal processor (blind / reference) of the corresponding method is used continuously, and if the threshold is exceeded, the switch controller is used. And changing the signal processor to a signal processor different from the above method (reference / blind).