KR100763485B1 - Radio relay apparatus of cdma having a rejection function of pn pollution - Google Patents

Abstract

A radio relay apparatus of CDMA(Code Division Multiple Access) having rejection function of PN(Pseudo-Noise) pollution is provided to transmit only desired base station signals to a service location within an area where multiple base station signals are existed, thereby preventing system resources from being reduced and improving communication quality. A radio relay apparatus of CDMA(Code Division Multiple Access) having rejection function of PN(Pseudo-Noise) pollution comprises the followings: a receiving antenna(100) for receiving high frequency signal; a band pass filter(110) for filtering band pass of received signals; a low noise amplifier(120) for receiving the filtered signal and amplifying the received signal; a frequency down converting unit(130) for downing the amplified signals to an intermediate frequency band; a relation signal detecting unit(140); a signal control unit(150); a non-desire signal generating unit(160); a non-desire signal deleting unit(170); a frequency up converting unit(180); a power amplifier(190); and a transmitting antenna(200).

Description

Radio relay apparatus of CDMA having a rejection function of PN pollution

1 is a block diagram showing a downlink structure of a conventional code division multiple access wireless relay device;

2 is a block diagram illustrating a downlink structure of a code division multiple access type wireless relay apparatus having a conventional PN pollution cancellation function.

3 is a block diagram illustrating a downlink structure of a code division multiple access wireless relay device having a PN pollution cancellation function according to the present invention.

4 is a diagram illustrating energy distribution in a correlation signal detection unit of a code division multiple access wireless relay device having a PN pollution cancellation function according to the present invention.

5 is a diagram illustrating the removal of a pilot signal in an undesired signal removal unit of a code division multiple access type wireless relay device having a PN pollution cancellation function according to the present invention.

Figure 6 is a flow chart illustrating in detail the process of removing the undesired signal of the code division multiple access wireless relay device having a PN pollution cancellation function according to the present invention.

** Description of the symbols for the main parts of the drawings **

10, 20, 100: Receive antenna 11, 21, 110: Bandpass filter

12, 29, 190: power amplifier 13, 30, 200: transmit antenna

22, 120: low noise amplifier 23, 130: frequency down converter

24 correlator 25 control unit

26: pseudo pilot generator (# 1 ~ #n) 27, 170: undesired signal removal unit

28, 180: frequency up-conversion unit 140: correlation signal detector

141: integrator 150: signal control unit

160: undesired signal generator 171: synthesizer

The present invention relates to a code division multiple access (CDMA) type wireless relay apparatus using the same transmission / reception frequency, and more particularly to a Pseudo-Noise Pollution (PN Pollution) occurring in a region where a plurality of base station signals are mixed. The present invention relates to a code division multiple access (CDMA) wireless relay device having a removal function.

In this case, PN pollution means that a terminal receiving the mixed radio waves in a region where a plurality of base station signals are mixed receives a plurality of pilot channels having similar signal strengths, thereby increasing the amount of interference, thereby causing frequent pilot channels. Due to the discovery and handover, the call quality is degraded and the base station load is increased.

A general wireless repeater is a device used to reduce a radio wave shadow area and improve call quality. FIG. 1 is a diagram illustrating a downlink structure of a conventional code division multiple access wireless repeater.

As shown in FIG. 1, the code division multiple access wireless relay device receives a signal from a base station or another repeater, amplifies it, and then receives a signal from a mobile station or another repeater in a downlink and a service area transmitted to a shadow area. It has an uplink to amplify it and then transmit it to the base station.

Hereinafter, since PN pollution to be solved in the present invention occurs only in downlink, only the operation of downlink will be described.

In a case where a general wireless relay device is installed in a region where a plurality of base station signals are mixed, when a high frequency signal to be relayed in a shaded area is received through the reception antenna 10 and then input to the band pass filter 11, the band pass The filter 11 band-passes the received signal and transmits the received signal to the power amplifier 12. Thereafter, the power amplifier 12 amplifies the signal filtered by the band pass filter 11 and radiates it to the service area through the transmission antenna 13. In this case, the mobile station in the service area receiving the amplified signal from the wireless relay device receives a mixed signal of a plurality of base station signals, thereby degrading call quality such as call drop due to PN pollution. Inevitably, the mobile station requests a frequent handover by receiving a plurality of pilot channels having similar signal strengths, which causes the base station system resource utilization to be inhibited by allocating unnecessary channels.

FIG. 2 is a block diagram illustrating a downlink structure of a code division multiple access wireless relay device having a conventional PN pollution cancellation function. As shown in FIG. 2, the code division multiple access wireless relay device having a PN pollution cancellation function receives a signal from a base station or another relay device, amplifies it, and transmits the signal to a shadow area. It has a downlink that receives a signal from a mobile station or another repeater in a service area, amplifies it, and transmits the signal to a base station.

Hereinafter, since PN pollution to be solved in the present invention occurs only in downlink, only the operation of downlink will be described.

When a code division multiple access wireless repeater having a conventional PN pollution cancellation function is installed in a region where a plurality of base station signals are mixed, a high frequency signal to be relayed in a sound region is received by a reception antenna (20). When the signal is received through the band pass filter 21 and then input to the band pass filter 21, the band pass filter 21 band-pass filters the received signal and transmits the received signal to the low noise amplifier 22. Thereafter, the low noise amplifier 22 amplifies the signal filtered by the band pass filter 21 and transfers it to the frequency downconversion unit 23. Here, the frequency down converter 23 receives the signal amplified by the low noise amplifier 22 and lowers the frequency to the base band.

The signal having the frequency lowered to the base band by the frequency downconversion unit 23 is passed through the correlator 24 and the control unit 25 to the pseudo pilot generators (# 1 to #n) 26, which are the pseudo pilots. Generator (# 1 ~ #n) 26 generates a reference pseudo pilot for each base station search for each frequency in advance to the correlator 24, the correlator 24 is a pseudo pilot generator (# 1 ~ #n) Compute correlation between the reference pseudo pilot for searching each frequency received from (26) and the signal received by the frequency downconversion unit 23 to detect time information and magnitude information of the base station signal in the received signal. To the control unit 25. The controller 25 transmits time information and size information for each frequency detected by the correlator 24 to a pseudo pilot generator (# 1 to #n) 26, and the pseudo pilot generator (# 1 to #n). 26 generates a signal corresponding to the time and magnitude information received from the controller 25 for each frequency and transmits the signal to the undesired signal removing unit 27.

The undesired signal removing unit 27 synthesizes the signal received from the frequency downconverting unit 23 and the signal received from the pseudo pilot generators (# 1 to #n) 26 to form a base station other than the desired base station. Remove the signal of and transmit it to the frequency up-conversion unit 28. The frequency up-conversion unit 28 of the frequency up-conversion unit 28 through the power amplifier 29 to increase the frequency in a high frequency band in order to radiate the signal received from the undesired signal removal unit 27 to the service area The signal is amplified and radiated to the service area through the transmission antenna 30.

However, the conventionally proposed technique increases the complexity of the system to be implemented because PN pollution is to be processed for each input frequency and increases the system price as the frequency of use increases.

In addition, since the system delay time due to the processing time increases due to the processing in the baseband, there is a problem in that call drop occurs due to a failure of handoff when used in an actual wireless relay section.

In order to solve the above problems, the present invention can significantly reduce the system delay time by performing signal processing in the intermediate frequency band, all by using the correlation between the base stations without generating a separate PN signal By integrating the signals in the frequency band, the signals of other base stations except for the desired base station are removed in the same way regardless of the used frequency, and ultimately, only the signals of the desired base station are relayed to improve the system resource utilization efficiency of the base station to which the mobile station is connected. The purpose is to provide a wireless relay device that maximizes.

In order to achieve the above object, a code division multiple access wireless relay apparatus having a PN pollution elimination function according to the present invention has the exception of a signal of a desired base station in an environment in which a plurality of base station signals are mixed. It is designed to remove the signal of the base station. Accordingly, the communication quality and the capacity of the base station can be improved while overcoming the problems caused by the PN pollution or installation limitations of the conventional code division multiple access wireless relay. It relates to a wireless repeater for increasing the.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

3 is a block diagram illustrating a downlink structure of a code division multiple access wireless relay device having a PN pollution cancellation function according to the present invention.

As shown in FIG. 3, in the wireless relay device for removing PN pollution occurring in a city center where a plurality of base station signals are mixed,

A reception antenna (100) for receiving a high frequency signal to be relayed to the shadow area;

A band pass filter (110) for band-pass filtering the signal received through the reception antenna (100);

A low noise amplifier (120) for receiving and amplifying the signal filtered by the band pass filter (110);

A frequency down converter 130 which receives the signal amplified by the low noise amplifier 120 and lowers the frequency to an intermediate frequency band;

A correlation signal detector 140 which obtains a pilot distribution map, which is an energy distribution of an input signal by taking a predetermined time integration operation on the signal frequency-converted from the frequency down-converter 130;

A signal controller 150 for controlling operation information of other base station signals except for a desired base station signal with respect to time information and size information of a pilot distribution map detected by the correlation signal detector 140;

An undesired signal generator 160 for generating an undesired signal out of phase for removing a pilot channel of another base station with respect to the signal received from the signal controller 150;

A non-desired signal removing unit 170 for synthesizing and removing the antiphase signal generated by the undesired signal generation unit 160 and the signal from the frequency downconverting unit 130;

A frequency up-conversion unit 180 for converting a received signal from which a signal of another base station is removed by the undesired signal removal unit 170 into a high frequency to radiate to a service area;

A power amplifier 190 for amplifying the signal of the frequency up-conversion unit 180;

And a transmission antenna (200) for radiating the amplified signal of the power amplifier (190) to a service area. The code division multiple access wireless relay device having a PN pollution cancellation function is configured.

Next, the operation process of each component of the code division multiple access wireless relay device having the PN pollution removal function according to the present invention will be described in detail.

When the high frequency signal to be relayed to the shadow area is received through the reception antenna 100 of the wireless relay device and then input to the band pass filter 110, the band pass filter 110 through the reception antenna 100 The received signal is bandpass filtered and transmitted to the low noise amplifier 120.

The low noise amplifier 120 is a signal that is filtered by the band pass filter 110 has a low power level due to the attenuation and the effect of noise, and therefore must be amplified, and is a signal that already includes a lot of noise from the outside. Therefore, the noise is minimized to lower the noise figure of the entire receiver for high frequency amplification. In addition, by receiving the signal amplified by the low noise amplifier 120, the frequency downconversion unit 130 lowers the frequency to an intermediate frequency (IF, Intermediate Frequency) band and collects only the desired frequency channels to increase frequency selectivity. .

The correlation signal detector 140 receiving the frequency-converted signal by the frequency down-conversion unit 130 performs an integral calculation on the frequency-converted signal to obtain an energy distribution of the input signal. The energy becomes a pilot distribution map to be immediately obtained.

FIG. 4 is a pilot distribution map showing a distribution of energy obtained by an integration operation in a correlation signal detector of a code division multiple access wireless relay device having a PN pollution cancellation function according to the present invention. ).

As shown in FIG. 4, the signal transmitted from the frequency down-conversion unit 130 is integrated in the integrator 141 of the correlation signal detector 140 to represent the plurality of base station signals as a magnitude of time, and thus a received signal. Time information (PN Offset) and size information of the base station signals within are detected by using a correlation characteristic of a code division multiple access (CDMA) signal from a received signal.

The signal controller 150 separates operation information of other base station signals except for a desired base station signal with respect to time information and size information of a pilot distribution map detected by the correlation signal detector 140 to generate an undesired signal generator. Forward to 160.

The undesired signal generation unit 160 appropriately applies an adaptive weighting value for components of a pilot channel input from the frequency downconversion unit 130 based on time information and size information of base stations received from the signal control unit 150. Thus, an antiphase signal having the same amplitude is generated for other base station signals except the base station.

The non-desired signal removing unit 170 synthesizes an antiphase signal having the same amplitude generated by the non-desiring signal generating unit 160 and a signal received by the frequency downconverting unit 130 to perform pilots of other base stations except for the desired base station. Pilot) Remove the signal.

FIG. 5 illustrates the removal of pilot signals of other base stations except for the desired base station in an undesired signal removal unit of a code division multiple access wireless relay device having a PN pollution cancellation function according to the present invention. will be.

As shown in FIG. 5, the signal A received by the frequency downconverter 130 and the signal B generated by the undesired signal generator 160 are synthesized using the synthesizer 171 to generate an undesired signal. Only the signal C of the base station desired to be removed is left to transmit.

In addition, the frequency upconversion unit 180 receiving the received signal of the base station from which the other base station signal is removed by the non-desired signal removing unit 170 increases the frequency in the high frequency band to radiate to the service area, and the power amplifier ( In 190, the signal of the frequency up-conversion unit 180 is amplified and radiated to the service area through the transmission antenna 200.

FIG. 6 is a flowchart illustrating an undesired signal removal process of a code division multiple access wireless relay device having a PN pollution cancellation function according to the present invention.

As shown in FIG. 6, when a plurality of base station signals are input through a reception antenna of a code division multiple access wireless relay device having a PN pollution cancellation function (S1), a band pass filter and a low noise amplifier are passed through. The frequency downconversion unit downconverts the frequency (S2).

Integrating a plurality of base station signals in the integrator of the correlation signal detection unit (S3), extracting time information and magnitude information of the plurality of base station signals using a pilot distribution map indicating energy distribution (S4), The signal controller separates the desired base station signal and the undesired base station signal (S5).

By applying an adaptive weighting value to the frequency down-converted signal S2 with respect to the separated non-desired base station signal, a non-desired signal represented by an inverse phase of the same amplitude is generated (S6).

Finally, the generated undesired signal and the frequency down-converted signal S2 are synthesized by a synthesizer to remove signals of the undesired base station for signals input from a plurality of base stations (S7), so that only signals of the desired base station are frequencyd. The signal is upconverted and transmitted to the transmission antenna through the power amplifier (S8). In this case, the signal of the non-desired base station is removed, and the signal is removed from the undesired base station.

As described above, although the preferred embodiment of the code division multiple access wireless relay apparatus having the PN pollution elimination function according to the present invention has been described, the present invention is not limited thereto. Without departing from the gist of the invention as claimed in the claims, any person of ordinary skill in the art will have a technical spirit of the present invention to the extent that various modifications can be made.

As described above, the code division multiple access wireless relay apparatus having a PN pollution cancellation function according to the present invention can transmit only a desired base station signal to a service area even in a region where a plurality of base station signals are mixed. Therefore, it is possible to effectively reduce the shadow area and improve the call quality while overcoming the problem of poor call quality and base station system resources caused by PN Pollution, which the conventional wireless relay system has. have.

In addition, the code division multiple access wireless relay device having a PN pollution removal function according to the present invention is a frequency-divided process of the conventional wireless relay device having a PN pollution function. There is an effect that can solve the problem of call drop due to increased cost and increased system delay time.

Claims (3)

In the wireless relay device for removing PN Pollution (PN Pollution) generated in the city center where a plurality of base station signals are mixed, A receiving antenna for receiving a high frequency signal to be relayed to the shadow area; A bandpass filter for bandpass filtering the signal received through the reception antenna; A low noise amplifier receiving and amplifying the signal filtered by the band pass filter; A frequency down converter configured to receive a signal amplified by the low noise amplifier and lower the frequency to an intermediate frequency band; A correlation signal detector which obtains a pilot distribution map for an input signal by taking a predetermined time integration operation on the frequency-converted signal from the frequency down-converter; A signal control unit controlling operation information of other base station signals except for a desired base station signal with respect to time information and size information of a pilot distribution map detected by the correlation signal detection unit; An undesired signal generator for generating an undesired undesired signal for canceling a pilot channel of another base station with respect to the signal received from the signal controller; A non-desired signal removing unit for synthesizing and removing an antiphase signal generated by the undesired signal generation unit and a signal from the frequency downconversion unit; A frequency up-converter for converting a received signal from which a signal of another base station is removed by the undesired signal remover into a high frequency to radiate to a service area; A power amplifier for amplifying the signal of the frequency upconversion unit; A transmission antenna for radiating the amplified signal of the power amplifier to a service area; Code division multiple access wireless relay device with PN Pollution cancellation function. The method of claim 1, The correlation signal detector detects time information and size information of a base station in a received signal by using a correlation of a code division multiple access (CDMA) signal from a signal of the frequency downconverter. Code division multiple access wireless repeater with removal function. The method of claim 1, The undesired signal generator generates a signal of the undesired base station under the control of the signal controller, and the undesired base station uses a component of a pilot channel that is commonly included in the received signal provided by the frequency downconverter. Code division multiple access wireless repeater having a PN pollution cancellation function, characterized in that for generating a signal of.

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