KR20020034058A - Hibrid smart antenna system and method for error management - Google Patents

Abstract

PURPOSE: A hybrid smart antenna system and an error processing method are provided to judge whether an error of a signal is generated in a rear terminal of a signal processor in the hybrid smart antenna system and reduce a load of the system. CONSTITUTION: A vector signal receiver(10) receives an x(t) vector signal from an array antenna. A blind type signal processor(20) processes an output signal of the vector signal receiver(10) by a blind method to obtain a first weight, and performs an inner product of the output signal of the vector signal receiver(10) and the first weight. A reference type signal processor(30) processes an output signal of the vector signal receiver(10) by a reference method to obtain a second weight, and performs an inner product of the output signal of the vector signal receiver(10) and the second weight. An error judgment and signal selecting section(40) checks whether errors are generated in output signals of the blind type signal processor(20) and reference type signal processor(30) and outputs a switching control signal. A channel element(60) sets a path of the output signal of the vector signal receiver(10). A switching controller(50) controls an operation of the channel element(60).

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, it requires too much computation to detect the correct direction of the received signal, which makes it difficult to process in real time. In addition, although the method of using the reference signal is simple, although the channel environment is poor, an error occurrence probability is higher than that of the traffic signal due to the characteristics of the pilot signal used as the reference 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, a blind signal processor for processing the 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 reference method signal processor for processing a received signal output from the vector signal receiver by a reference method to obtain a weight, and outputting the resultant signal by internalizing the weighted signal and the received signal; an error of a signal output from each signal processor An error determination and signal selection unit which selects and transmits to the channel element the ones having few errors, and simultaneously outputs a switching control signal for signal processor selection, and a switching control signal issued by the error determination and signal selection unit. Output from the vector signal receiver according to Technical features of the present invention include a switch controller for controlling a switch for setting a signal path, and a switch for setting a path of a signal output from the vector signal receiving unit under control of the switch controller.

In order to achieve the above object, the error processing method in the hybrid smart antenna system according to the present invention,

Processing a vector signal received from an array antenna by a blind or reference signal processor, determining whether an output signal has passed through each signal processor, and whether or not an error occurs in each signal processor according to the determination result. The method consists in selecting a signal processor having a low number.

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 flowchart illustrating an error processing process of an error processor in a hybrid smart antenna system according to the present invention. FIG. 3A is a flowchart illustrating an error processing process in a blind method, and FIG. 3B is a flowchart of an error processor in a reference method. This is a flow chart showing the process.

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

<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)

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, the vector signal receiving unit 10 received from the array antenna The vector signal passes through a hybrid signal processor including a blind signal processor 20 and a reference signal processor 30, and then passes through an error determination and signal selection unit 40. That is, 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 signal processor 20 having a relatively excellent performance is used, so that each signal processor 20 is used. , 30) and then the error determination and signal selection unit 40 checks whether the signal environment is good. The switch controller 50 controls each of the signal processors 20 and 30 in accordance with the error determination and the check result of the signal selector 40, and transmits them to the channel element 60.

3 is a flowchart illustrating a process of an error processor in a hybrid smart antenna system according to the present invention. FIG. 3A is a flowchart illustrating a process of an error processor in a blind method, and FIG. 3B is a process of an error processor in a reference method. A flow chart showing the process.

In the blind method of FIG. 3A, an operation process of an error processor is as follows.

First, when the output signal y1 passing through the signal processor 20 by the blind method is input to the error determination and signal selection unit 40 in step ST11, the error determination and signal selection unit 40 in step ST12 It is checked whether an error occurs in the received blind signal processor 20 output signal y1, 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 the good channel environment, and in step ST15, the signal processor is changed to the reference method 30 using the switch controller 50.

In the reference method of FIG. 3B, an operation process of the error processor is as follows.

First, when the output signal y2 passing through the signal processor 30 by the reference method is input to the error determination and signal selection unit 40 in step ST21, the error determination and signal selection unit 40 in step ST22 It is checked whether an error occurs in the output signal y2 of the received reference signal processor 30, and if the error does not occur 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.

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

As shown therein, the error determination and the signal selection section 40 determine whether an error has occurred when the mobile station transmits at a data rate of 9600 bps, and the total number of bits per second is 192 bits. 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.

First, 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. Generator 300, which is a type of error detection method used for group error detection during data transmission, which performs error checking using a polynomial code for error detection in addition to the minimum bits necessary to represent data; A bit adder 400 which receives data from the quality checker 200 and the generator 300 and outputs the sum to the error determiner 500, and extracts a result value of the bit adder 400 It is configured to include an error determiner 500 for determining the presence or absence of an error in accordance with the result.

The error determination and signal selection unit 40 configured as described above,

The quality checker 200 outputs a 12-bit frame quality check bit. In addition, the base station CRC polynomial generator 300 performs data cyclic redundancy check, 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". .

As described above, the hybrid smart antenna system according to the present invention processes the reverse pilot signal in a hybrid structure combining a method using a reference signal and a blind method not using a reference signal, thereby more actively responding to changes in the channel environment. It is possible to cope with this, and the result is more than the conventional method.

In addition, there is an advantage that can be implemented by adding only additional software (software) to the existing signal processing algorithm without adding additional hardware.

Claims (3)

In the smart antenna system, Received from an array antenna A vector signal receiver for receiving a vector signal; A blind signal processor for processing a received signal output from the vector signal receiver by a blind method to obtain a weight, and outputting the weighted result and the received signal by outputting the resultant signal; A reference type signal processor for processing a received signal output from the vector signal receiver by a reference method to obtain a weight, and outputting the weighted result and the received signal by outputting the resultant signal; An error determination and signal selection unit which checks whether an error of a signal output from each signal processor is checked, transmits a signal having a small error to a channel element, and simultaneously outputs a switching control signal for signal processor selection; A switch controller for controlling a switch for setting a path of a signal output from the vector signal receiving unit according to the switching control signal issued from the error determining and signal selecting 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 CRC by 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 smart antenna system comprising a vector signal receiver, a blind signal processor, a reference signal processor, an error determination and signal selection unit, a switch controller, Processing the vector signal received from the array antenna by a blind or reference signal processor; Determining whether there is an error in the output signal passing through each signal processor; And selecting a signal processor with less error among the signal processors according to the determination result.