KR20050118027A - Apparatus and method for generating dummy pilot signal in hard hand-over of mobile telecommunication - Google Patents

Abstract

The present invention provides a hard handover for extracting and using a base station classification PN synchronization from a base station CDMA RF signal when a beacon device that supports hard handover in a synchronous CDMA wireless network generates a dummy pilot signal. A dummy pilot signal generator for and a method thereof,

According to the present invention, when generating a dummy pilot signal in a beacon device, a large number of gates are not needed by using a serial search method when acquiring a short pseudo noise code from an RF CDMA signal, and an oscillator is used. Compensating for the drift of the Short PN code due to the frequency shift due to the stability of), and the output dummy pilot signal satisfies the performance of the base station-level frequency stability (≤ ± 0.05ppm). In the conventional method of generating a dummy pilot signal, the inconvenience of having to receive the EVEN CLOCK and the reference clock from the base station is eliminated.

Description

Apparatus and Method for Generating Dummy Pilot Signal in Hard Hand-over of Mobile Telecommunication}

The present invention relates to an apparatus and method for generating a dummy pilot signal for hard handover in mobile communication, and more particularly, to a dummy pilot signal of a beacon device supporting hard handover in a synchronous CDMA wireless communication network. The present invention relates to an apparatus and method for generating a dummy pilot signal for hard handover in mobile communication, which extracts and uses a base station identification PN synchronization from a base station CDMA RF signal.

In the mobile communication, the base station provides a service in a cell manner, and the terminal should service the call so as not to be disconnected even when the mobile station moves between cells or base stations. In this way, the service between the base stations is seamlessly called "handover".

In general, handover in mobile communication is divided into a hard handover and a soft handover. Soft handover refers to the allocation of a call channel to the same frequency allocation as the neighboring base station during handover between base stations, and hard handover occurs when another FA is allocated from the neighboring base station at the time of handover while the terminal is talking. . At this time, the beacon (Beacon) is a device that supports the FA so that the call is not broken in hard handover between different base stations.

1 is a diagram illustrating hard handover between base stations.

In FIG. 1, when the terminal moves from the base station A area to the base station B while moving to the base station B area, the terminal does not know whether the base station B is in the area of the base station B if there is no signal of the base station B. This is because the terminal has an RF H / W that processes one frequency. Therefore, the terminal continuously enters the base station B area until the signal of the base station A is disconnected, and eventually the call is disconnected.

However, when a dummy pilot signal is transmitted from the FA2 of the base station B to the terminal, the terminal knows that it is entering the base station B area. Therefore, when the pilot energy of FA2 of base station B becomes sufficiently strong, the terminal performs hard handover to base station B, and the call is not disconnected. At this time, when the dummy pilot signal of FA2 is generated by the base station B, the base station B should have the same time offset of the short PN code for identifying the base station of the pilot channel of the FA1 of the base station B.

On the other hand, the frequency hard handoff phenomenon mainly occurs in the urban boundary line and the outdoor / in-building boundary area where the frequency number FA used by the base station is different. In case the FA between base stations is different at the boundary between the city center and the city center, beacon equipment is installed in the city center base station so that the number of FAs is the same between the city base station and the city center base station so as to induce smooth handoff between the base station cells.

In the existing beacon method, two methods were used.

First, in FIG. 1, the base station B couples the FA1 RF signal at the base station and transmits the frequency by changing the frequency to FA2. In this method, all channels of Pilot, Sync, Paging, and Traffic used in FA1 are transmitted from FA2, which overloads the final amplifier. Also, due to the delay of the RF path, the pilot signals of FA1 and FA2 cannot be exactly the same time offset of the Short PN code.

Second, the base station B of FIG. 1 provides Even CLK, which is a base station synchronization signal to the beacon equipment, when the user inputs a short PN, the beacon equipment generates a dummy pilot signal by time offsetting the short PN code according to the user's setting. . This method has a disadvantage in that the base station always provides Even CLK and a reference clock to the beacon.

Meanwhile, in the case of beacon equipment that accommodates the above two methods, when the FA1 is coupled to FA2, the RF signal is coupled by a direction coupler connected to the base station main (BTS_MAIN) antenna cable when transformed to FA2. The coupled RF signal is input to the RF hopping unit to change the frequency. The converted RF signal is output through a high power amplifier (HPA) through a duplexer filter and a diversity antenna (ANT_DIV).

In addition, when generating a dummy pilot signal by receiving the EVEN_CLK transmitted from the base station, the base station short pien of the PN generation unit receives the EVEN_CLK and the reference clock through the EVEN_CLK and the reference clock port. (Short PN) Used as a synchronization and beacon system reference clock. The PN generator generates a pilot signal having an appropriate time offset based on the user's PN setting based on EVEN_CLK. The pilot signal is converted to an RF frequency through an RF hopping unit and output to a diversity antenna (ANT_DIV) port through a high power amplifier (HPA) and a duplexer filter.

In the existing beacon equipment, the method of transforming the RF signal has the advantage that the equipment is very simple, while there are sync, paging, and traffic channels other than the pilot channel. This provides a load to the final output stage amplifier, which outputs about 5 dB higher than the amplifier transmitting only the pilot channel, and the time offset of the short PN is not accurate due to the delay of the RF path. There is a disadvantage. In addition, the method of generating a pilot by receiving a conventional clock (EVEN_CLK) from the outside has the advantage that the equipment is relatively simple, while the base station has to provide the EVEN_CLK and the reference clock of the Short PN code.

On the other hand, in the case of "an improved beacon device capable of hard handoff" of the previously filed domestic application No. 20-2000-0020362, the pilot searcher is used to match the short PN code with a matched filter. The fast synchronization can be obtained, and the interface with the base station is simple since the dummy pilot signal does not receive a synchronous clock signal such as EVEN_CLK from the outside. However, implementing the pilot searcher as a matched filter consumes a lot of gates, and it is possible to obtain an initial short PN code using only the pilot searcher, but due to the stability of its own oscillator. There is a disadvantage in that there is no drift compensation method of the Short PN code due to the frequency shift. In addition, there is no scheme for the output dummy pilot signal to have a base station-level frequency stability (≤ ± 0.05ppm), and by using a delay for delaying the I and Q signals output from the pilot I and Q generators for a predetermined time. The disadvantage is the need for First In First Out (FIFO) memory.

In order to solve the above problems, the present invention provides a mobile communication system for extracting a base station classification PN synchronization from a base station CDMA RF signal when a beacon device supporting hard handover in a synchronous CDMA wireless communication network generates a dummy pilot signal. An object of the present invention is to provide a dummy pilot signal generating apparatus and method for hard handover.

In order to achieve the above object, the present invention, when the beacon equipment that supports hard handover in the synchronous code division multiple access wireless communication network generates a dummy pilot signal to extract the base station identification PN synchronization from the CD signal of the base station A dummy pilot signal generating device for hard handover, comprising: a beacon device for receiving a CDM RF signal from the base station and outputting the dummy pilot signal; A directional coupler for coupling the CD signal of the base station to the beacon device; A hybrid combiner for outputting a mobile communication signal by combining the dummy pilot signal outputted from the beacon device with the CDA RF signal; And a base station antenna for radiating the mobile communication signal output from the hybrid combiner as a wireless signal.

In addition, according to the second object of the present invention, when the beacon equipment supporting hard handover in the synchronous code division multiple access wireless communication network generates a dummy pilot signal, it extracts the PN synchronization for the base station classification from the CD signal of the base station A dummy pilot signal generating device for hard handover, comprising: a beacon device for receiving a CDM RF signal from the base station by wire and outputting the dummy pilot signal; A directional coupler for coupling the CD signal of the base station to the beacon device; A base station antenna for radiating the CD signal as a radio signal; A duplexer which combines the CD signal of the base station with the dummy pilot signal of the beacon device and outputs a mobile communication signal; A reception antenna feeding cable configured to transfer the CD signal of the base station to the duplexer; And a receiving diversity antenna for radiating the mobile communication signal into the air.

In addition, according to a third object of the present invention, when the beacon equipment supporting hard handover in the synchronous code division multiple access wireless communication network generates a dummy pilot signal, the PN synchronization for base station classification is extracted from the CD signal of the base station. A dummy pilot signal generating device for hard handover, comprising: a beacon device for wirelessly receiving a CDM RF signal of the base station and wirelessly radiating a mobile communication signal including the dummy pilot signal; A reception beacon antenna for wirelessly receiving the CD signal; And a transmission beacon antenna for wirelessly transmitting the dummy pilot signal as a mobile communication signal.

In addition, according to a fourth object of the present invention, a method for generating a dummy pilot signal for hard handover in which a dummy pilot signal of a beacon device is synchronized with a base station using a CDA RF signal transmitted from a base station, the transmission from the base station A first step of correlating a short PN code generated by the beacon device with a received CD signal to recognize a starting point of the short PN code of the base station; A second step of compensating for a delay of a trigger pulse time for generating a transmission pilot signal for compensating a system time delay and a transmission and propagation delay by using the periodicity of the short PN code; And a third step of periodically checking the CD-ALF signal transmitted from the base station to compensate for the delay of the trigger pulse time for the transmission pilot, and the dummy pilot signal generation method for hard handover. .

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

First of all, in adding reference numerals to the components of each drawing, it should be noted that the same reference numerals are used as much as possible even if displayed on different drawings.

In addition, in describing the present invention, when it is determined that the detailed description of the related well-known configuration or function may obscure the gist of the present invention, the detailed description thereof will be omitted.

2 illustrates a configuration of a dummy pilot signal generator for hard handover according to a first embodiment of the present invention.

The dummy pilot signal generator 200 according to the first embodiment of the present invention is a method of interworking a beacon apparatus of the present invention with a base station that does not support transmit / receive diversity, and moves with a base station controller (not shown). The base station 210 transmits and receives a communication signal, and is installed in a region where the strength of the CDMA RF signal transmitted from the base station 210 is weak, interworking with the base station 210, the CD from the base station 210 Beacon device 220 for receiving a CDMA RF signal and outputting a dummy pilot signal, Directional coupler for coupling the CDA RF signal of the base station 210 to the beacon device 220 (D) / C: Directional Coupler, 230); A hybrid coupler 240 for combining a dummy pilot signal output from the beacon device 220 with a CDA RF signal to output a mobile communication signal; And a base station antenna 250 that radiates the mobile communication signal output from the hybrid combiner 240 as a wireless signal.

In addition, the beacon apparatus 220 may include a beacon module 222 for converting a CDMA RF signal into a dummy pilot signal, a high power amplifier 224 for amplifying the dummy pilot signal at high power, and an amplified dummy pilot signal. And a band pass filter 226 for filtering a signal of a corresponding band.

That is, in the dummy pilot signal generating apparatus 200 according to the first embodiment of the present invention, the beacon apparatus 220 is a CDMA RF transmitted from the base station 210 using the directional coupler 230. Coupling the signal, the coupled CDA RF (CDMA RF) signal is input to the beacon device 220, the beacon device 220 is the base station 210 using the CDA RF (CDMA RF) signal Outputs a dummy pilot signal identical to the short PN code of the PD code, and the dummy pilot signal output from the beacon device 220 is outputted from the CDM RF (CDMA) output from the base station 210 using the hybrid combiner 240. Coupled with the RF) signal and outputs a mobile communication signal, the combined mobile communication signal is radiated through the base station antenna 250.

However, when the output of the beacon device 220 is combined with the base station output, the phenomenon that the output of the base station 210 and the beacon device 220 is attenuated by 3 dB while using the hybrid combiner 240.

3 illustrates a configuration 300 of a dummy pilot signal generator for hard handover according to a second embodiment of the present invention.

Although the dummy pilot signal generator 300 according to the second embodiment of the present invention does not support transmit antenna diversity, a method of interworking a beacon apparatus of the present invention with a base station supporting receive antenna diversity, In the configuration of FIG. 2, the receiving antenna feed cable Rx1 is added to the base station 210 to transmit the CDA RF signal of the base station 210 to the receiving diversity antenna 320, and beacons. Duplexer (310) for combining the dummy pilot signal of the device 220 and the CDMA RF signal transmitted through the receive antenna feed cable (Rx1), and the CD received from the base station 210 It has a configuration including a receiving diversity antenna (320) for radiating an RF (CDMA RF) signal to the air through the beacon device 220 as a mobile communication signal containing a dummy pilot signal.

Beacon device 220 is a CDMA RF transmitted from the base station 210 by using a directional coupler (D / C, 230) in the antenna feed cable (TX / RX0) of the base station 210 The signal is coupled, and the coupled CDA RF signal is input to the beacon device 220. The beacon apparatus 220 transmits a dummy pilot signal identical to the Short PN code of the base station 210 using the CDMA RF signal. The dummy pilot signal output from the beacon apparatus 210 is coupled to the duplexer 310 through the receiving antenna feed cable Rx1 of the base station 210 to radiate to the air through the receiving diversity antenna 320 as a mobile communication signal. do.

4 illustrates a configuration 400 of an apparatus for generating a dummy pilot signal for hard handover according to a third embodiment of the present invention.

In the dummy pilot signal generating apparatus 400 according to the third exemplary embodiment of the present invention, when the base station 210 and the beacon apparatus 410 cannot be connected by wire, the CD MAP (CDMA) transmitted by the base station antenna 250 may be used. A method of receiving an RF signal using the reception beacon antenna 420 in the beacon apparatus 410, and wirelessly receives a CDMA RF signal transmitted from the base station 210 and converts it into a dummy pilot signal. Wireless transmission of a beacon device 410 for wireless transmission as a mobile communication signal, a reception beacon antenna 420 for wirelessly receiving a CDMA RF signal, and a dummy pilot signal as a mobile communication signal. It has a configuration including a beacon antenna 430.

The beacon apparatus 410 receives the CDA RF signal of the base station 210 through the reception beacon antenna 420, and the received CDA RF signal is transmitted to the beacon apparatus 410. Is entered. The beacon apparatus 410 transmits a dummy pilot signal identical to the short PN code of the base station 210 using the CDA RF signal. The pilot dummy signal is radiated to the air wirelessly as a mobile communication signal through the transmission beacon antenna 430.

5 is a block diagram schematically illustrating the internal configuration of the beacon apparatus.

The beacon apparatus 500 according to the embodiment of the present invention includes an NMS terminal apparatus 502, a first band pass filter (504), a 2-way splitter 506, and a first RF amplifier 508. ), A second BPF 510, a first mixer 512, a first synthesizer 514, a first low pass filter 516, a second RF amplifier 518, a SAW filter 520 ), A third RF amplifier 522, a first variable attenuator 524, a second synthesizer 526, a quadrature demodulator 528, a second LPF 530, an analog to digital converter 532, Baseband processor 534, voltage controlled oscillator 536, system clock phase lock loop (PLL) 538, digital to analog converter 540, third LPF 542, quadrature modulator 544, a third synthesizer 546, a third BPF 548, a fourth RF amplifier 550, a second variable attenuator 552, a fourth synthesizer 554, a second mixer 556, a fourth The BPF 558, the fifth RF amplifier 560, the high power amplifier 562, the cavity BPF 564, and the like are included.

Since the function of each part in the internal configuration of the beacon device 500 is already known technology, its detailed description is omitted.

The beacon apparatus 500 may receive a CDA RF signal transmitted from the base station 210. In this case, the CDA RF signal includes a pilot channel, a synchronization channel, a paging channel, a call channel, and the like. The CDMA RF signal input to the beacon apparatus 500 may pass through the first BPF 504 and then pass through the 2-Way distributor 506 to be used for the NMS. Distribution to the first RF amplifier 508.

The distribution signal of the CDA RF signal input to the first RF amplifier 508 passes through the second BPF 510 for image removal after amplification is performed. The amplified signal passing through the second BPF 510 is input to the first mixer 512. The signal passing through the second BPF 510 is mixed in the first mixer 512 together with the signal supplied from the first synthesizer 514.

The mixer output signal output from the first mixer 512 passes through the first LPF 516. The output of the first LPF 516 has only an IF frequency signal. That is, the CDMA RF signal is converted to the IF frequency. The output signal of the first LPF 516 passes through the SAW filter 520 after the amplification is performed through the second RF amplifier 518. The SAW filter 520 is used to remove a plurality of adjacent CDA RF signals output from the base station 210 and to receive only one CDA RF signal.

The CDMA signal passing through the SAW filter 520 is input to the first variable attenuator 524 via the third RF amplifier 522. The first variable attenuator 524 controls the reception gain according to a control signal applied from the baseband processor 534. The first variable attenuator 524 adjusts the gain so that the CDMA RF signal, which changes frequently, is at a constant power level according to the reception gain control signal. The constant level signal output from the first variable attenuator 524 is input to the quadrature phase demodulator 528. The quadrature phase demodulator 528 converts a CDA (CDMA) signal having an IF frequency into an I / Q baseband CDMA signal using a signal input from the second synthesizer 526.

The I / Q baseband CDMA signal output from the quadrature phase demodulator 528 passes through the second LPF 530 to remove the image signal. The CDMA signal passing through the second LPF 530 is input to the AD converter 532. The AD converter 532 converts the CDMA signal into digital data and performs sampling at a rate eight times higher than 1.2288 Mbps. The digital CDMA signal converted into digital data through the AD converter 532 is input to the baseband processor 534.

The baseband processor 534 receives the system clock from the system clock PLL unit 538 and receives an output setting of the user. In addition, the baseband processor 534 controls the first variable attenuator 524 to perform reception gain control, and generates a reference frequency of the beacon apparatus 500 to reduce the frequency error with the base station 210. Control oscillator 536 is controlled. In addition, the baseband processor 534 performs transmission power control, so that a dummy pilot signal having a short PN code identical to a received pilot signal may be output from the beacon apparatus 500. Generate a Q signal.

The dummy pilot I / Q signal output from the baseband processor 534 is input to the DA converter 540 and converted into an analog I / Q signal. The analog I / Q signal output from the DA converter 540 passes through the third LPF 542, thereby removing the image signals. The pilot I / Q signal passing through the third LPF 542 is input to the quadrature phase modulator 544 and converted into an IF signal.

The output of quadrature phase modulator 544 passes through third BPF 548 to eliminate image signals outside the pass band. The output signal of the third BPF 548 is amplified via the fourth RF amplifier 550 and then input to the second variable attenuator 552. In this case, the second variable attenuator 552 is used to adjust the output level of the dummy pilot signal. The output of the second variable attenuator 552 is input to the second mixer 556 and converted into an RF signal.

The output of the second mixer 556 passes through the fourth BPF 558 to remove the image signals, and is then input to the fifth RF amplifier 560 to perform signal amplification. The output of the fifth RF amplifier 560 is input to the high output amplifier 562 to amplify to a high output. After the high power amplification is performed, the out-of-band image and the spurious are removed through the cavity BPF 564 and then output as a dummy pilot signal.

6 is a block diagram schematically illustrating an internal configuration of the baseband processor 534.

The baseband processor 534 includes a reception level adjuster 602, a transmission gain adjuster 604, a correlator 606, a phase distortion adjuster 608, a correlation energy value calculation and a PN code clock control unit 610, a short PN code, It has a configuration including a trigger pulse generator 612, a pilot signal generator 614 and the like.

The reception level adjuster 602 performs a reception gain control so that a predetermined power level is received by inspecting a predetermined section of the received digital I / Q signal using the received digital I / Q signal.

The transmission gain adjuster 604 performs transmission gain control according to the user's setting. In addition, the transmission gain adjuster 604 measures the pilot level of the received CDMA signal using the received level strength received from the receive level adjuster 602 and the correlation value received from the correlator 606, and uses the received pilot level. Transmit gain control of the output Dummy Pilot signal.

The phase distortion adjuster 608 has a phase distortion of the received pilot due to the phase difference between the base station 210 and the beacon apparatus 500, and the I / Q correlation integral value output from the correlator 606 and the previous state. By comparing the correlation integral of, it is determined that the clockwise rotation and the counterclockwise rotation are performed, and the voltage control of the reference oscillator is performed to be positioned at a predetermined point without rotation. Through this continuous control process, the CDMA center frequency received by the base station 210 and the reception selection center frequency of the beacon apparatus 500 coincide with each other.

The correlator 606 is composed of a multiplier and an integrator therein. The multiplier multiplies the generated I / Q Short PN code with the received digital CDMA I / Q signal. The digital value passed through the multiplier is entered into the integrator. The integrator integrates the digital values over a period of time. Multiplication and integration are performed independently of I / Q, respectively, and output independent I / Q integrals.

The correlation energy value calculation and the PN code clock control unit 610 calculates the correlation energy value using the I / Q integral value output from the correlator 606, and uses the correlation energy value thus obtained to generate the short PN. Correlation position determination and PN code clock control are performed.

The short PN code and the trigger pulse generator 612 generate an I / Q short PN code for use in the receiver, and also generate a trigger pulse signal of the Short PN code for generating a pilot signal. Here, the I / Q short PN code generates an I / Q PN code suitable for the CDMA scheme. The trigger pulse signal of the Short PN code to generate the pilot signal is the period of the Short PN code (1 / 1.2288 Mcps * 2 ¹⁵ 26.67 ms). This trigger pulse generates the trigger pulse signal taking into account the time delay caused by the beacon equipment system delay and processing delay.

The pilot signal generator 614 is a device that generates a dummy pilot signal for use in the transmitter of the beacon apparatus 500. The same PN as that generated by the base station 210 may be generated by using the trigger pulse signal generated in FIG. 6. The pilot signal generation generates a signal that satisfies the IS-95 standard, and the pilot signal has a period (26.67 ms) of I / Q of the pilot signal outputted because the short PN code has a period (26.67 ms). It is a data memory device that stores one cycle (26.27 ms) of I / Q data using such periodicity. Therefore, when the pilot signal is transmitted, the address of the memory is adjusted every 26.67 ms by receiving the trigger pulse generated in FIG. 6.

The base station synchronization scheme of the dummy pilot signal of the beacon apparatus 500 using the CDMA RF signal transmitted from the base station 210 is divided into three steps.

First, the process of recognizing the starting point of the short-PN code (starting point of PN # 0) of the base station by correlating the short PN code generated by the CDMA RF signal transmitted from the base station, and second, the system using the periodicity of the short PN code. Compensating for the delay of the transmission pulse signal generation trigger pulse time to compensate for the time delay and the transmission and propagation delay; and third, periodically checking the CDMA RF signal transmitted from the base station to determine the delay of the trigger pulse time for the transmission pilot. The process of compensation is made.

First, a process of recognizing the starting point (starting point of PN # 0) of the short-PN code of the base station by correlating the short PN code generated by the CDMA RF signal transmitted from the base station will be described.

7 is a diagram illustrating a receiver PN code generation and a receiver PN code trigger pulse generated in FIG. 6.

In FIG. 7, the case of 'all zero' does not appear when the PN sequence is to be known using 15 flip-flops. Due to the nature of the PN sequence, if all flip-flops are 'all zero', then the PN sequence will continue to have a '0'. So, if you do not add zero, PN Sequence has 32767 cycles. Therefore, you must add 'zero' at the end of the PN Sequence. In both I and Q, 14 'zero's come out at the end of the sequence, and 32678 chips can be generated by adding' zero 'to them.

If 14 "0s" are generated during the creation of the receiver I / Q Short-PN Sequence, additionally insert "0". Then, at the beginning of the I / Q Short-PN Sequence, that is, at the beginning of Short-PN # 0, The trigger pulse of the receiver PN sequence is generated.

8 illustrates a PN offset of an input CDMA signal and an output PN offset correction.

In FIG. 8, the CDMA signal input with an arbitrary time offset correlates and slews the Short-PN code generated in the AFC under the OFF state to find the position of PN # 0.

The PN reference point of the CDMA signal input in FIG. 8 indicates the input time of the RF input port of the beacon apparatus 500, and the receiver PN sequence trigger pulse indicates the point where the beacon apparatus 500 recognizes the starting point of PN # 0. have. Here, time delay I represents the time delay of the baseband processor 34 and the processing time delay of the baseband processor 534 at the RF input port.

Second, a process of compensating for a delay of a trigger pulse time for generating a transmission pilot signal for compensating system time delay and transmission and propagation delay by using a periodicity of a short PN code will be described.

When the beacon apparatus 500 finds the starting point of the PN # 0 of the base station 210, the pilot signal must be transmitted by compensating for the time delay of the beacon apparatus 500. Elements of the time delay of the beacon apparatus 500 are the time delay of the receiver, the time delay of the baseband processing, and the time delay of the transmitter. In order to compensate for this time in the beacon apparatus 500, time compensation is performed using the fact that the pilot signal is periodic.

The time compensation is applied to the trigger pulse for transmitting the pilot signal in FIG. 8. In order to time-align between the CDMA signal received at the RF input port and the output of the pilot signal of the beacon apparatus 500, a time delay II is delayed to generate a transmit pilot signal.

Third, a process of periodically checking the CDMA RF signal transmitted from the base station 210 to compensate for the delay of the trigger pulse time for the transmission pilot will be described.

Although the time delay between the CDMA signal input to the baseband processing unit 534 and the pilot signal of the beacon output is compensated, the CDMA signal and the beacon output are generated due to the difference in stability between the system clock of the beacon apparatus 500 and the system clock of the base station 210. The time delay between the pilot signals of is to be changed.

Therefore, such compensation correlates the short PN code of the beacon apparatus 500 with the CDMA signal inputted at regular intervals to obtain an energy value and continuously compensate. In order to reduce the shaking of the time delay during compensation, the beacon apparatus 500 performs 8 Over Sampling or more during analog / digital conversion, and the control resolution of the trigger pulse time delay for the transmission pilot is performed by 1/24 Chip. In this case, AFC is performed for the stability of the system clock of the beacon apparatus 500. For reference, Qualcomm's handsets are doing 4 Over Sampling during analog / digital conversion.

9 illustrates a conceptual diagram for generating a dummy pilot signal of the baseband processor 534.

In FIG. 9, the pilot data are all "0", and since the Walsh is also "0" in IS-95, it is modulated to a Walsh "0" of 1.2288 bps. At this time, the output is divided into two and modulated with the PN code generated from the I / Q Short PN generator based on the trigger pulse supplied from the outside, and the sequence period of the I / Q Short PN code is 2 ¹⁵ lengths (ie, 32768 Chip).

The data modulated by the PN code is input to the FIR filter after gain adjustment is made through a scaler. The FIR filter removes harmonic signals except for baseband signals that are compatible with IS-95. The FIR filter outputs after performing 4 Over Interpolation.

Therefore, the beacon apparatus 500 has one period (1 / 1.2288 Mcps * 32768) because the transmission digital I / Q pilot signal has periodicity due to the periodicity of the PN code. 26.67ms) of I / Q pilot signals are stored in the data memory to generate I / Q pilot signals with periodic repetition.

10 is a block diagram illustrating an internal configuration of a data memory for generating an I / Q pilot signal.

As shown in Fig. 10, the trigger pulse signal is divided into I pilot data and Q pilot data by the address latch and address counting unit and stored in the data memory. In FIG. 10, the I pilot data is stored from address 0 to 131071 every 0.25 chip time delay in the storage area of the I pilot data, and the Q pilot data from address 0 to 131071 every 0.25 chip time delay in the storage area of the Q pilot data. Is stored.

Meanwhile, the following describes a method of linking the output frequency stability of the base station with the output frequency stability of the beacon device.

The output frequency stability standard of the beacon apparatus 500 is ± 0.05 ppm or less, and should ensure the same frequency stability as the base station. In order to consider this frequency stability, the oscillator used as the reference oscillator of the beacon device 500 should be used in consideration of the temperature stability and the stability according to the biennial change rate. At this time, if you use the oscillator (OCXO grade) of the design degree in the beacon device 500, the price becomes very expensive. In order to solve such a price problem, the beacon device 500 used a voltage controlled oscillator (TCXO), and implemented the AFC function to enable the beacon device 500 according to the performance of the base station reference oscillator using the input CDMA signal. In addition, due to the high frequency stability of the beacon apparatus 500, the control is performed with a resolution of 10 bits or more when controlling the voltage of the reference oscillator. For example, in a Qualcomm terminal, the AFC resolution is 8 bits.

Next, the base station output level and the beacon apparatus output level interworking scheme will be described.

In a conventional beacon device that generates a dummy pilot, the output level is fixed by the user. If the base station increases or decreases the overall output level, since the service area of the base station is changed, the output of the beacon device must be changed as well, but the existing beacon device has a disadvantage that the base station pilot power is not changed. To compensate for this problem, the base station output level and the output level of the beacon device are interlocked as follows.

The CDMA RF signal input to the RF port is composed of a pilot channel, a synchronization channel, a paging channel, and a plurality of call channels. In addition, the power of the input CDMA RF signal is constantly changing according to the number of call subscribers. Even if it changes in the base station output signal, if the pilot channel power is constant, the service area of the base station remains constant. Therefore, if the power of the pilot channel is known in the input CDMA RF signal, the pilot signal power control of the beacon output signal is possible.

That is, the beacon apparatus 500 recognizes the reception level of the CDMA RF signal while performing AGC (Automatic Gain Controlling). In addition, since the baseband processor 534 integrates through the correlator 606 to obtain a correlation value and the correlation value varies linearly with the number of communication channels, the pilot power ratio is calculated from the total power. Then, the pilot channel power is calculated from the CDMA RF signal power and the transmission dummy pilot power is controlled.

When the output level is increased or decreased by the base station 210 as a whole, the power of the pilot channel is increased or decreased, and the beacon apparatus 500 controls the output level of the beacon apparatus by sensing the rate of change of the power of the pilot channel.

As described above, the present invention provides a hard hand for mobile communication in which a beacon device supporting hard handover in a synchronous CDMA wireless communication network extracts and uses a base station classification PN synchronization from a base station CDMA RF signal when generating a dummy pilot signal. An over dummy pilot signal generating apparatus and method can be realized.

The above description is merely illustrative of the technical idea of the present invention, and those skilled in the art to which the present invention pertains may make various modifications and changes without departing from the essential characteristics of the present invention.

Therefore, the embodiments disclosed in the present invention are not intended to limit the technical idea of the present invention but to describe the present invention, and the scope of the technical idea of the present invention is not limited by these embodiments.

The protection scope of the present invention should be interpreted by the following claims, and all technical ideas within the equivalent scope should be interpreted as being included in the scope of the present invention.

As described above, according to the present invention, when generating a dummy pilot signal in a beacon device, a lot of gates are not required by using a serial search method when acquiring a short pseudo noise code synchronization from an RF CDMA signal. Compensates for the drift of the Short PN code due to the frequency shift caused by the stability of the oscillator, and the output dummy pilot signal has a base station-level frequency stability (≤ ± 0.05 ppm). Compared to the method of generating a dummy pilot signal by receiving the reference clock and the EVEN_CLK, the base station interface is very simple because it does not receive a separate EVEN CLOCK and the reference clock.

1A is a diagram illustrating hard handover between base stations;

2 is a view showing the configuration of a dummy pilot signal generator for hard handover according to a first embodiment of the present invention;

3 is a view showing the configuration of a dummy pilot signal generator for hard handover according to a second embodiment of the present invention;

4 is a view showing the configuration of a dummy pilot signal generator for hard handover according to a third embodiment of the present invention;

5 is a block diagram schematically illustrating an internal configuration of a beacon device;

6 is a block diagram schematically showing the internal configuration of the baseband processing unit 534,

7 is a diagram illustrating a receiver PN code generation and a receiver PN code trigger pulse generated in FIG. 6;

8 is a diagram illustrating a PN offset of an input CDMA signal and an output PN offset correction;

9 is a conceptual diagram for generating a dummy pilot signal of the baseband processor 534,

10 is a block diagram illustrating an internal configuration of a data memory for generating an I / Q pilot signal.

※ Explanation of codes for main parts of drawing

200: first embodiment dummy pilot signal generator 210: base station

220: beacon device 222: beacon module

224: high power amplifier 226: bandpass filter

230: directional coupler 240: hybrid coupler

250 antenna

300: second embodiment dummy pilot signal generator 310: duplexer

320: reception diversity antenna Rx1: reception antenna feed cable

400 embodiment 3 dummy pilot signal generator 410 beacon apparatus

420: reception beacon antenna 430: transmission beacon antenna

500: beacon apparatus 502: NMS terminal apparatus

504: First BPF 506: 2-Way Splitter

508: first RF amplifier 510: second BPF

512: first mixer 514: first synthesizer

516: First LPF 518: Second RF Amplifier

520 SAW filter 522: third RF amplifier

524: first variable attenuator 526: second synthesizer

528: quadrature demodulator 530: second LPF

532 AD converter 534 baseband processing unit

536: voltage controlled oscillator 538: system clock PLL

540: DA converter 542: third LPF

544: Quadrature Modulator 546: Third Synthesizer

548: third BPF 550: fourth RF amplifier

552: second variable attenuator 554: fourth synthesizer

556: second mixer 558: fourth BPF

560: fifth RF amplifier 562: high power amplifier

564: Cavity BPF 602: Receive Level Adjuster

604: transmission gain adjuster 606: correlator

608: phase distortion regulator 610: correlation energy value calculation and PN code clock control unit

612: Short PN code and trigger pulse generator 614: pilot signal generator

Claims (21)

In a synchronous Code Division Multiple Access (CDMA) wireless communication network, a beacon device that supports hard handover generates a dummy pilot signal when a beacon device generates a dummy pilot signal. In the apparatus for generating a dummy pilot signal for hard handover to extract and use a PN (Pseudo Noise) synchronization from a CDMA RF signal, A beacon apparatus that receives a CDA RF signal from the base station by wire and outputs the dummy pilot signal; A directional coupler (D / C) for coupling a CDA RF signal of the base station to the beacon device; A hybrid coupler for outputting a mobile communication signal by combining the dummy pilot signal output from the beacon device with the CDA RF signal; And And a base station antenna for radiating the mobile communication signal output from the hybrid combiner as a radio signal. The method of claim 1, The beacon device is configured to couple the CDA RF signal transmitted from the base station using the directional coupler; The coupled CDA RF signal is input to the beacon device, The beacon device outputs the dummy pilot signal identical to the short PN code of the base station by using the CDA RF signal, The dummy pilot signal output from the beacon device is combined with the CDA RF signal output from the base station using the hybrid combiner, and the combined mobile communication signal is radiated through the base station antenna. The dummy pilot signal generator for hard handover, characterized in that the. The method according to claim 1 or 2, The beacon device includes a beacon module for converting the CDA RF signal to the dummy pilot signal, a high power amplifier for amplifying the dummy pilot signal at high power, and the amplified dummy pilot signal in a corresponding band. A dummy pilot signal generator for hard handover, comprising: a bandpass filter for filtering a signal. CDMA Code Division Multiple Access (CDMA) Base station CDMA when a beacon device that supports hard handover in a wireless communication network generates a dummy pilot signal In the apparatus for generating a dummy pilot signal for hard handover which extracts and uses a PN (Pseudo Noise) synchronization from a base station (RF) signal, A beacon apparatus that receives a CDA RF signal from the base station by wire and outputs the dummy pilot signal; A directional coupler (D / C) for coupling a CDA RF signal of the base station to the beacon device; A base station antenna for radiating the CDA RF signal as a wireless signal; A duplexer which combines a CDA RF signal of the base station and a dummy pilot signal of the beacon device to output a mobile communication signal; A receiving antenna feeding cable (Rx1) for transmitting a CDA RF signal of the base station to the duplexer; And And a receiving diversity antenna for radiating the mobile communication signal into the air. The method of claim 4, wherein The beacon device couples the CDA RF signal transmitted from the base station using the directional coupler in the antenna feed cable TX / RX0 of the base station, The coupled CDMA RF signal is input to the beacon device, and the beacon device uses the same CDMA RF signal as the short PN code of the base station. Transmit the dummy pilot signal, The dummy pilot signal output from the beacon device and the CDA RF signal transmitted through the receiving antenna feed cable Rx1 of the base station are combined and output as a mobile communication signal through a duplexer. And the mobile communication signal is radiated into the air through the receiving diversity antenna. The method according to claim 4 or 5, The beacon device includes a beacon module for converting the CDA RF signal to the dummy pilot signal, a high power amplifier for amplifying the dummy pilot signal at high power, and the amplified dummy pilot signal in a corresponding band. A dummy pilot signal generator for hard handover, comprising: a bandpass filter for filtering a signal. CDMA Code Division Multiple Access (CDMA) Base station CDMA when a beacon device that supports hard handover in a wireless communication network generates a dummy pilot signal In the apparatus for generating a dummy pilot signal for hard handover which extracts and uses a PN (Pseudo Noise) synchronization from a base station (RF) signal, A beacon apparatus wirelessly receiving a CDA RF signal of the base station and wirelessly radiating a mobile communication signal including the dummy pilot signal; A reception beacon antenna wirelessly receiving the CDA RF signal; And And a transmission beacon antenna for wirelessly transmitting the dummy pilot signal as a mobile communication signal. The method of claim 7, wherein The beacon device wirelessly receives a CDA RF signal of the base station through the reception beacon antenna, The received CDMA RF signal is input to the beacon device, and the beacon device uses the same CDMA RF signal as the short PN code of the base station. Transmits a dummy pilot signal, And the pilot dummy signal is radiated to the air wirelessly as the mobile communication signal through the transmission beacon antenna. The method according to claim 7 or 8, The beacon device includes a beacon module for converting the CDA RF signal to the dummy pilot signal, a high power amplifier for amplifying the dummy pilot signal at high power, and the amplified dummy pilot signal in a corresponding band. A dummy pilot signal generator for hard handover, comprising: a bandpass filter for filtering a signal. The method according to any one of claims 1, 4 and 7, The beacon apparatus receives the user's output setting, performs reception gain control, controls generation of a reference frequency of the beacon apparatus to reduce frequency error with the base station, performs transmission power control, and is received. And a baseband processor configured to generate a dummy pilot I / Q signal so that a dummy pilot signal having the same short PN code as the pilot signal can be output. Dummy pilot signal generator for over. The method of claim 10, The baseband processing unit, A reception level adjuster configured to inspect a predetermined period of the digital I / Q signal using an input digital I / Q signal to perform reception gain control to receive a predetermined power level; A transmission gain adjuster which performs transmission gain control according to a user's setting; Internally composed of a multiplier and an integrator, the multiplier performs a multiplication of the generated I / Q Short PN code and the received digital CDMA I / Q signal, and the digital value passed through the multiplier A correlator which is input and integrates digital values over a predetermined interval in the integrator, and multiplication and integration are performed independently of I / Q and output independent I / Q integral values; Due to the phase difference between the base station and the beacon device, there is a phase distortion of the received pilot. The I / Q correlation integral value output from the correlator and the correlation integral value of all states are compared in clockwise and counterclockwise directions. A phase distortion adjuster which determines to rotate and performs voltage control of the reference oscillator to be positioned at a predetermined point without rotating; The correlation energy value is calculated using the I / Q integral value output from the correlator, and the correlation position determination and PN code clock control of the short PN generated by itself are performed using the correlation energy value. An energy value calculation and a PN code clock control unit; A short PN code and a trigger pulse generator for generating an I / Q short PN code for use in a receiver and generating a trigger pulse signal of a short PN code for generating a pilot signal; And A device for generating a dummy pilot signal for use in a transmitter of the beacon device, the hard hand comprising a pilot signal generator for generating the same PN as the PN generated by the base station using a trigger pulse signal Dummy pilot signal generator for over. The method of claim 11, The transmission gain adjuster measures a pilot level of the received CDM RF signal by using the reception level strength received by the reception level adjuster and the correlation value received by the correlator, and outputs the dummy output using the received pilot level. A dummy pilot signal generator for hard handover, characterized in that to perform transmission gain control of a pilot signal. The method of claim 11, In the short PN code and the trigger pulse generator, the I / Q short PN code generates an I / Q PN code suitable for a CDMA scheme, and short PN code for generating the pilot signal. The trigger pulse signal of the PN code is generated every cycle of the short PN code, and the trigger pulse generates the trigger pulse signal in consideration of the time delay caused by the system delay and the processing delay of the beacon device. A dummy pilot signal generator for hard handover. The method of claim 11, The pilot signal generation generates a signal that meets the IS-95 standard, The pilot signal generator stores one period of I / Q data using periodicity, and when transmitting the pilot signal, a hard pulse is received by adjusting a memory address every 26.67 ms by receiving a trigger pulse. Dummy pilot signal generator. The method of claim 11, The pilot signal generator is divided into I pilot data and Q pilot data by an address latch and an address counting unit when a trigger pulse signal is input. The I pilot data is stored in the storage area of the I pilot data from address 0 to 131071 every 0.25 chip time delay, and the Q pilot data is stored in the storage area of the Q pilot data from address 0 to 131071 every 0.25 chip time delay. The dummy pilot signal generator for hard handover, characterized in that for storing. A method of generating a dummy pilot signal for hard handover by synchronizing a dummy pilot signal of a beacon device with a base station using a CDA RF signal transmitted from a base station, A short PN code generated by the beacon device itself is correlated with a CDA RF signal transmitted from the base station, and a starting point (PN # # of the short-PN code of the base station) is correlated. A first step of recognizing the starting point of zero); A second step of compensating for a delay of a trigger pulse time for generating a transmission pilot signal for compensating a system time delay and a transmission and propagation delay by using a periodicity of the short PN code; And And a third step of periodically checking a CDMA RF signal transmitted from the base station and compensating for a delay of the trigger pulse time for the transmission pilot. . The method of claim 16, The first step is, When performing PN sequence using 15 flip-flops, 'all zero' does not appear. If all flip-flops are 'all zero' due to the nature of the PN sequence, the PN sequence is continuously outputted with '0' and no '0' is added. In the situation, the PN sequence has a 32767 cycle, and adds '0' to the end of the PN sequence. In I and Q, 14 '0's come out at the end of the sequence, and' 0 'is added to generate 32678 chips, and the receiver I / Q short-PN sequence If 14 "0s" are generated during generation, an additional "0" is inserted, and thereafter, a trigger pulse of a receiver PN sequence is generated at a start point of an I / Q short-PN sequence. Dummy pilot signal generation method for hard handover. The method of claim 17, The PN offset and the PN offset correction of the CDMA RF signal are inputted with an arbitrary time offset under an AFC OFF state. The CDMA RF signal correlates and slews the short-PN code generated by itself to locate PN # 0. The PN reference point of the CDA RF signal indicates an input time point of an RF input port of the beacon device, and the receiver PN sequence trigger pulse indicates a point where the beacon device recognizes the start point of PN # 0. The time delay I represents a time delay of the baseband processor and a processing time delay of the baseband processor at an RF input port. The method of claim 16, In the second step, if the starting point of the PN # 0 of the base station is found, to compensate for the time delay of the beacon device to transmit a pilot signal, Factors of the time delay of the beacon apparatus include a time delay of the receiver, a time delay of the baseband processing, a time delay of the transmitter, Compensating time by using the periodicity of the pilot signal in order to compensate for the time in the beacon device, The time compensation is applied to a trigger pulse for generating a transmitter pilot signal, and time delayed by a time delay to align time between the CDDMA RF signal received at the RF input port and the output of the pilot signal of the beacon device. And generating a transmission pilot signal by delaying the delay. The method of claim 16, The third step may be based on a difference in stability between the system clock of the beacon device and the system clock of the base station, even if the time delay between the CDA RF signal and the pilot signal of the beacon output is compensated for. Due to this, the time delay between the CDA RF signal and the pilot signal of the beacon output is changed, and thus the short PN of the beacon device and the CDA RF signal input at regular intervals. Correlate the code to get the energy value to reward continuously In order to reduce the shake of the time delay during compensation, the beacon device performs more than 8 oversampling during analog / digital conversion, and the control resolution of the trigger pulse time delay for the transmission pilot is performed with a 1/24 chip. , A method for generating a dummy pilot signal for hard handover, comprising performing AFC for stability of a system clock of the beacon device. The method of claim 16, When the output level of the base station and the output level of the beacon device is linked, Since the CDMA RF signal input to the RF port is composed of a pilot channel, a synchronization channel, a paging channel, and a plurality of call channels, AGC (Automatic Gain Controlling) in the beacon device so that the power of the pilot channel is constant. Recognize the reception level of the CDA RF (CDMA RF) signal, integrate through a correlator in the baseband processor to obtain a correlation value, and the correlation value varies linearly with the number of communication channels. Therefore, the pilot power ratio is calculated from the total power, the pilot channel power is calculated from the power of the CDA RF signal, and the dummy pilot signal for hard handover, characterized in that to control the transmission dummy pilot power. How it happens.