KR20000074534A - Apparatus and method for pn acquisition of mobile station in cdma system - Google Patents

Abstract

PURPOSE: A method and device for acquiring pseudo noise(PN) of a mobile station in a code division multiple access(CDMA) mobile communication system, is provided to de-spread/accumulatively add/square received signals, according to an orthogonal spreading section of a data symbol in a transmission terminal or according to integral sections by the times of positive numbers of the orthogonal spreading section, and to remove orthogonal noise components de-spread at a point that PN codes generated in a base station and the mobile station become coincident by an accumulative adding operation of a correlator. So that PN acquiring performance can be improved. CONSTITUTION: An integral section is set up by the times of positive numbers of an orthogonal section of a data symbol in a transmission terminal for signals received at an optional point, and the received data are de-spread/accumulatively added/squared to calculate a correlation detection energy(a first step). If the detection energy is smaller than a preset threshold, a pseudo noise(PN) code generated in a mobile station is applied a phase-delay by one chip, and the first step is re-performed(a second step).

Description

Apparatus and method for acquiring P-N of mobile station in code division multiple access mobile communication system {APPARATUS AND METHOD FOR PN ACQUISITION OF MOBILE STATION IN CDMA SYSTEM}

The present invention relates to a mobile station in a code division multiple access mobile communication system, and more particularly, to an apparatus and method for capturing a pseudo noise sequence of a mobile station.

In general, spread-spectrum communication is a method in which an information signal to be transmitted is spread with a much wider bandwidth and then despreaded to the original bandwidth. The spreading methods include a direct sequence method, a frequency hopping method, a time hopping method, and a hybrid method. Code division multiple access (hereinafter, referred to as CDMA) commercially available mobile communication systems use the spread-band communication technique of the direct sequence method. That is, when a base station of a code division multiple access system transmits a spread signal by multiplying an information signal by a high data rate pseudo-noise sequence (hereinafter referred to as a PN sequence), the mobile station of the system generates the base station. The information signal is restored by multiplying the received signal in synchronization with the PN sequence to despread it. At this time, the mobile station performs an initial synchronization acquisition operation of matching the start position of the base station generated PN sequence with the start position of the mobile station generated PN sequence.

Meanwhile, in a code division multiple access mobile communication system, an initial synchronous acquisition operation of a mobile station may be divided into an acquisition operation and a tracking operation. The capturing operation is an operation of calculating a detection energy according to a correlation between a base station generated PN sequence value and a mobile station generated PN sequence value received at an arbitrary time point and comparing the calculation result with a threshold value. Can be divided. At this time, if the calculation result is less than the threshold value, the mobile station shifts the phase of the mobile station generation PN sequence, and then continues to acquire. However, if the calculation result is larger than the threshold value, since the starting position of the mobile station generation PN sequence is within a predetermined limit error, the mobile station further refines the operation of calculating the detection energy and comparing the threshold value to find the correct synchronization. That is, the mobile station performs a tracking operation. The capturing operation may be classified into a serial search method and a parallel search method.

On the other hand, in the CDMA mobile communication system, communication channels of each mobile station using the same frequency band are distinguished by channel modulation by different orthogonal codes. In addition, several channels transmitted on a forward link from a single base station to a plurality of mobile stations are distinguished by having orthogonality with each other. The received signal of a specific mobile station is made up of the sum of the signal from the base station (hereinafter referred to as a 'service base station') of the cell where the mobile station is currently located and the signal from other base stations. In particular, during the initial synchronous acquisition operation, the received signal of the mobile station may be represented by a pilot signal of the serving base station and a signal of other base stations modeled as orthogonal noise components and additive white gauge noise (AWGN). Equation 1 shows an input signal of a mobile station receiving end during an initial synchronization acquisition operation of the mobile station.

In this case, the left side of Equation 1 denotes a received signal of a mobile station, and the right side P (t) represents a pilot signal of a serving base station. Denotes an orthogonal noise component, and the right side Ioc denotes a reception signal from other base stations. And the orthogonal noise component Denotes a channel coded data symbol for other mobile stations in the same cell, Denotes an orthogonal code for channel-dividing the data symbols. And i is the number of channels transmitted from the service base station except for the pilot signal.

And the pilot signal is Walsh orthogonal code to a symbol consisting of a continuous '+1' Orthogonal codes, such as multiplied by orthogonal spreading (Othogonal Spreading), and can be a PN Spreading (PN Spreading) signal by the base station generated PN code. At this time, since each sequence of the pilot signal is not modulated during orthogonal spreading, each sequence value of the pilot signal is equal to each sequence value of the base station generated PN code. The orthogonal noise component is a transmission signal for other mobile stations in the same cell, and a channel-coded random '+1' or '-1' data symbol is multiplied by a corresponding orthogonal code for channel division to obtain orthogonal spreading ( Othogonal Spreading), which can be a PN spread signal by a base station generated PN code. In other words, the pilot signal and the quadrature noise component may be analyzed in FIG. 1A or 1B to be described later.

1A is a diagram illustrating an example of a process of spreading a pilot signal.

As shown, consecutive '1' symbols 11a are Walsh orthogonal codes. Orthogonal codes such as (12a) are multiplied and orthogonally spread to form an orthogonal diffusion chip sequence 13a. In the case of the Walsh orthogonal code, the orthogonal diffusion section 110 is a 64 chip section. Walsh Ortho Code The characteristic of (12a) is that the sequence consists only of '+1'. This allows orthogonal spreading chip sequence 13a to be a Walsh orthogonal code. It has the same chip sequence value as (12a). Each sequence value of the orthogonal spreading chip sequence 13a is multiplied by each sequence value of the base station generated PN code 14a to be PN-spread to form a pilot signal 15a. At this time, since each sequence of the orthogonal spreading chip sequence 13a is '1', each sequence value of the pilot signal P (t) 15a is equal to each sequence value of the base station generated PN codes 14a and P (t). same. In the description of FIG. 1A, the symbols of consecutive '1's are orthogonally spread over the orthogonal spreading section 110, and each sequence of the orthogonal spreading chip sequence 13a is each sequence of the base station generated PN code 14a. The value is multiplied to PN spread to become the pilot signal 15a.

1B is a diagram illustrating an example of a diffusion process of orthogonal noise components.

Channel coded data symbols with random '+1' or '-1' values (11b) is the Walsh orthogonal code Orthogonal Diffusion Chip Sequence ㆍ (13b). Generally, orthogonal codes are characterized in that one row has the same number as '+1' and '-1'. Walsh Ortho Code Orthogonal If (12b) is multiplied, each data symbol 11b is a Walsh orthogonal code in a spreading chip sequence 13b. It spreads over the same orthogonal diffusion section 110 as in (12b). As illustrated, the orthogonal spreading chip sequence 13b is orthogonally modulated according to a value of '+1' or '-1' of the data symbol 11b. Each sequence value of the orthogonal spreading chip sequence 13b is multiplied by each sequence value of the base station-generated PN code 14a to spread PN to obtain orthogonal noise. ㆍ ㆍ (15b). In the description of FIG. 1B, '+1' or '-1' of the channel-coded random data symbol 11b is orthogonally spread by the orthogonal diffusion section 110, and each sequence of the orthogonal spreading chip sequence 13b. Is multiplied by each sequence value of the base station-generated PN code 14a to obtain PN spreading, resulting in orthogonal noise 15b. That is, as shown in the orthogonal noise 15b is each data symbol '+1' or '-1' of (11b) may be expressed as a PN spread signal over the orthogonal diffusion section 110.

On the other hand, conventionally, in the synchronous acquisition operation of the received pilot signal of the PN acquisition circuit provided in the mobile station, not only the reception signal from other base stations but also the orthogonal noise component influenced the PN code detection probability. That is, the determination of whether or not the initial synchronization acquisition of the PN acquisition circuit is performed by comparing the detected energy and the threshold value according to the correlation between the base station generated PN code and the mobile station generated PN code during the set integration period. Although the base station-generated PN code and the mobile station-generated PN code included in the pilot signal are actually synchronized, there is no guarantee that the PN acquisition circuit can necessarily detect the PN code due to the influence of the noise component described above. Similarly, despite the fact that the synchronization does not coincide, the PN capture circuit can generate a false alarm due to the influence of the noise component described above. That is, the magnitude of the noise component received at the mobile station affects the PN code detection probability.

2 is a diagram illustrating a PN acquisition circuit in a code division multiple access mobile communication system. The operation of the conventional PN capture circuit will be described below.

During the initial synchronization acquisition operation of a mobile station (not shown), the despreader 210 inputs a pilot signal, an orthogonal noise component, and signals from other base stations and a mobile station generated PN code generator of Equation 1 input at an arbitrary time point. The despreading operation is performed by multiplying the mobile station generated PN code generated from 240 over the set integral period. The despreader 210 outputs the result of the despreading operation to the correlator 220. The correlator 220 accumulates and squares the output of the despreader 210 during the integration period. As a result, the correlator 220 calculates a detection energy according to a correlation between the base station generated PN code of the pilot signal and the mobile station generated PN code within the integration section. At this time, the orthogonal noise component and the received signal from other base stations among the received signals become noise components with respect to the base station generated PN code of the pilot signal. The controller 230 compares the output of the correlator 220 with a threshold. If the detected energy in the integral section is greater than the threshold value, the controller 230 determines that the capture operation is successful and performs control of the tracking operation of the PN capture circuit. The description of the tracking operation is not the main concern of the present invention and thus will be omitted. When the detection energy in the integral section is less than the threshold, the mobile station-generated PN code generator 240 delays the mobile station-generated PN code by one chip. The conventional PN acquisition circuit performs despreading, cumulative addition, square, and comparison operations between the base station generated PN code of the newly input pilot signal and the phase delayed mobile station generated PN code within the set integral period.

3 is a view showing the operation of the conventional PN acquisition circuit seen from the viewpoint of the integral section in the CDMA mobile communication system. Hereinafter, the operation of the conventional PN capture circuit will be described in detail with reference to FIGS. 1A to 2.

Reference numeral 200 denotes a correlation start point of the integration section 270 at a predetermined point in the initial synchronization acquisition operation of the mobile station. At this point, it is assumed that the base station generated PN code P (t) 14a of the pilot signal 15a and the mobile station generated PN code have a phase difference of two chips as shown by the reference numeral 350.

As described above with reference to Figs. 1A to 2, conventionally orthogonal noise in a received signal during initial synchronization acquisition operation of a mobile station. ㆍ ㆍ Received signal from 15b and other base stations The pilot signal Base station generation PN code of (15a) It becomes a noise component with respect to (14a).

That is, the despreader 210 performs the despreading operation of multiplying each sequence value of the mobile station generated PN code and each sequence value of the base station generated PN code 14a of the pilot signal 15a during the set integration period 370. The correlator 220 accumulates and squares the output of the despreader 110, that is, each sequence value of the orthogonal spreading chip sequence 13a of FIG. 1A during the integration period 370, and thus detects energy according to the correlation. Calculate The controller 230 compares the detected energy with a threshold. At this time, since the detected energy is less than the threshold value, the controller 230 commands a one-chip phase delay of the mobile station generated PN sequence generator 240. Reference numeral 330 denotes one chip phase delay of the mobile station generated PN code because the mobile station PN code generator 240 stops operating for one clock. As a result, the despreader 210 starts the sequence signal of the phase-delayed mobile station generated PN code by one chip and newly inputs the pilot signal 15a from the correlation start point CS 320 to the integration section 380 again. A despreading operation of multiplying each sequence value of the base station generated PN code 14a is performed.

On the other hand, the despreader 210 at the correlation starting point 200 is the orthogonal noise of FIG. ㆍ ㆍ The despreading operation of multiplying each sequence value of the mobile station-generated PN code by each sequence value of the orthogonal noise 15b is performed during the integration section 370 set also for (15b). Due to this orthogonal noise ㆍ ㆍ 15b is despread to orthogonal spread chip sequence ㆍ Is converted to (13b). And the orthogonal diffusion chip sequence described above. ㆍ 13b is input to the correlator 220. At this time, since the PN capture circuit (not shown) of the conventional mobile station does not designate the integral section 370 as an integer multiple of the orthogonal diffusion section 110 and the orthogonal diffusion section 110, the orthogonal diffusion chip sequence ㆍ 13b is not removed from the correlator 220. Therefore, it can be seen that the orthogonal noise component from the service base station (not shown) becomes the noise component for the base station generated PN code 14a of the pilot signal 15a during the initial synchronization acquisition operation of the mobile station. However, if the integration section 370 is designated as the orthogonal diffusion section 110, the correlator 220 during the integration section 370 during the initial synchronization acquisition when the starting position of the mobile station generated PN code and the base station generated PN code 14a coincide. Data symbol during cumulative addition operation 12b becomes a constant having a constant value. Due to this, the orthogonal spreading chip sequence is determined by the property of the orthogonal code in which the row has the same number as '+1' and '-1'. ㆍ 13b will be removed during the cumulative add operation of the correlator 220. Similarly, even if the integral section 370 is designated as an integer multiple of the orthogonal diffusion section 110, the orthogonal diffusion chip sequence is determined by the nature of the orthogonal code at the time of initial synchronization acquisition. ㆍ 13b is removed during the cumulative addition operation of the correlator 220.

On the other hand, the despreader 210 multiplies the sequence delayed mobile station generated PN code by one chip and each sequence value of the newly input base station generated PN code 14a from the correlation starting point CS 320 to the integration period 380. Perform a spread operation. Correlator 220 is orthogonal diffusion chip sequence ㆍ Each sequence value of (13b) is cumulatively added and squared during the integration period 380. However, even in this case, since the two PN codes have a phase difference of one chip as shown by reference numeral 360, the controller 230 commands a one-chip phase delay of the mobile station generated PN code generator 240. Reference numeral 340 denotes a one-chip phase delay of the mobile station generated PN code because the mobile station PN code generator 240 stops operating for one clock. As a result, the despreader 210 starts the base station generated PN code of the phase-delayed mobile station generated PN code by one chip and the newly inputted pilot signal 15a from the correlation start point CS 325 to the integration period 390 again. A despreading operation is performed to multiply each sequence value in 14a. However, since the synchronization of the two PN codes from this time, the detection energy according to the correlation in the comparison operation of the controller 230 is larger than the threshold value. However, even when the synchronization between the base station-generated PN code 14a and the mobile station-generated PN code coincides with each other as described above, the orthogonal noise 15b is not removed from the correlator 220 and thus becomes a noise component with respect to the pilot signal 15a. At this time, although the base station-generated PN code 14a and the mobile station-generated PN code are synchronized with each other from the point of time of the reference numeral 327, the set integral section of the correlator 220 is influenced by the influence of the orthogonal noise 15b. The cumulative addition and the squared result may be smaller than the threshold. This causes the PN code detection probability of the PN acquisition circuit to fall.

On the other hand, in the PN acquisition circuit of the conventional mobile station, as shown, the correlation end point CE 310 and the correlation start point CS 320 before and after the phase delay time of the actual mobile station generation PN code generator 240 are shown. It can be seen that there is at least one chip difference. That is, in the conventional PN acquisition circuit, after the despreader 210 performs the despreading operation during the corresponding integration period, the mobile station generation PN code generator 240 performs a phase delay operation on the sequence of the first mobile station generation PN code generated. Did not perform. In addition, the conventional PN acquisition circuit does not perform the despreading operation from the sequence of the base station-generated PN code 14a first input after the one-chip phase delay operation of the mobile station-generated PN code generator 240. That is, it is orthogonal noise component ㆍ ㆍ This is because it is not necessary to coincide with the initial synchronization acquisition time and the orthogonal spread start time of the channel coded data symbol by considering (15b) as noise. In addition, this is because the integral section for despreading, cumulative addition, and the like for the received signal input to the conventional PN acquisition circuit is not made in an integer multiple of the orthogonal diffusion section 110 and the orthogonal diffusion section 110.

Accordingly, an object of the present invention is to provide a mobile station PN acquisition apparatus and method for removing orthogonal noise components of a service base station in a code division multiple access mobile communication system.

Another object of the present invention is to despread, accumulate add, and square the received signal in an integral division unit of an orthogonal diffusion section of a data symbol or an integer multiple of the orthogonal diffusion section with respect to a received signal in a code division multiple access method mobile communication system. The present invention provides a mobile station PN acquisition apparatus and method for removing despread orthogonal noise components by a cumulative addition operation of a correlator when the synchronization between a base station generated PN code and a mobile station generated PN code coincides.

Another object of the present invention is to despread, accumulate add, and square the received signal in an integral division unit of an orthogonal spreading section of a data symbol or an integer multiple of the orthogonal spreading section for a received signal in a code division multiple access mobile communication system. By setting one chip interval between the correlation end point of the previous integration section and the correlation start point of the integration section for the received signal inputted at the new point of time, the start point of the integrative and orthogonal diffusion sections coincide with each other is despreaded. The present invention provides a mobile station PN capture device and method in which a quadrature noise component is removed during a cumulative addition operation.

In order to achieve the above object, according to the present invention, a mobile station P-N acquisition apparatus in a code division multiple access type mobile communication system multiplies a received signal input at an arbitrary time point with a mobile station-generated P-encode, and transmits the received signal. A despreader for despreading by an integral division unit of an integer multiple of an orthogonal spreading section for a data symbol in a correlator, a correlator that calculates a correlation detection energy by cumulative adding and squaring the despreaded received signal in the integral section unit; A controller for instructing a chip phase delay for the mobile station generated P-en code when the correlation detection energy is smaller than a threshold value, and outputting the mobile station generated P-en code by one chip phase delay by a command of the controller; It is characterized in that it consists of a mobile station generated P-encode generator.

In the present invention, a P-N acquisition method of a mobile station in a code division multiple access method uses an integral interval in units of integer multiples of orthogonal spreading intervals of data symbols at a transmitting end with respect to a received signal input at an arbitrary point in time. A first step of calculating the correlation detection energy by despreading, cumulative addition, and squaring, and if the detection energy is less than a threshold, a phase of one chip phase delay of the mobile station-generated P-en code and the control operation of the first step again. Characterized in that the second process to perform.

1A is a diagram illustrating an example of a process of spreading a pilot signal.

1B is a diagram illustrating an example of a diffusion process of orthogonal noise components.

2 is a diagram illustrating a PN acquisition circuit in a code division multiple access mobile communication system.

3 is a view showing the operation of the conventional PN acquisition circuit seen from the perspective of the integral section in the CDMA mobile communication system.

4 is a diagram illustrating the operation of a PN acquisition circuit according to an embodiment of the present invention in terms of an integral section in a CDMA mobile communication system.

5 is a flowchart illustrating a PN capture method according to an embodiment of the present invention.

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 the following description of the present invention, detailed descriptions of related well-known functions or configurations are omitted when it is determined that the detailed description may unnecessarily obscure the subject matter of the present invention.

4 is a diagram illustrating the operation of a PN acquisition circuit according to an embodiment of the present invention in terms of an integration section in a CDMA mobile communication system. Hereinafter, a description will be given with reference to FIGS. 1 to 3.

In the initial synchronization acquisition operation of a mobile station (not shown), the received signal may be represented by a pilot signal of a serving base station and a quadrature noise component and a signal from other base stations. At this time, the pilot signal and the orthogonal noise component are the base station generated PN code of FIG. 14a and the orthogonal noise of FIG. 1b ㆍ ㆍ 15b can be displayed.

PN acquisition circuit according to an embodiment of the present invention is orthogonal noise when the mobile station acquires the initial synchronization ㆍ ㆍ 15b is removed during the cumulative addition operation of the correlator 220. This increases the PN code detection probability of the PN acquisition circuit, thereby improving the PN acquisition performance.

The despreader 210 is a base station-generated PN code inputted in units of an integral section 450 that is equal to the length of the orthogonal spreading section 400. (14a) and orthogonal noise ㆍ ㆍ The despreading operation is performed on 15b. The correlator 220 outputs the despreader 210, that is, each sequence value of the orthogonal spreading chip sequence 13a of FIG. 1A and the orthogonal spreading chip sequence of FIG. 1B. ㆍ (13b) is cumulatively added and squared during the integration period 450 to calculate the detection energy according to the correlation.

The controller 230 compares the detected energy with a threshold. At this time, since the detected energy is less than the threshold value, the controller 230 commands a one-chip phase delay of the mobile station generated PN code generator 240. The time point 'D' 401 denotes one chip phase delay of the mobile station generated PN code because the mobile station PN code generator 240 stops operating for one clock. As a result, the despreader 210 receives the sequence values of the phase-delayed mobile station generated PN codes by one chip and newly input base station generated PN codes from the correlation starting point CS 410 to the integral section 455 again. (14a) and orthogonal noise ㆍ ㆍ The despreading operation is performed on 15b.

The correlator 220 outputs the despreader 210, that is, each sequence value of the orthogonal spreading chip sequence 13a and the orthogonal spreading chip sequence. ㆍ Cumulative addition and square (13b) over the integration period (455) to calculate the detection energy according to the correlation. The controller 230 compares the detected energy with a threshold. At this time, since the detection energy is still smaller than the threshold value due to the one-chip phase difference between the two PN codes, the controller 230 commands the one-chip phase delay of the mobile station generated PN code generator 240. The point in time 'D' 402 means that the mobile station PN code generator 240 stops operating for one clock so that one chip phase delay of the mobile station generated PN code is performed. This causes the despreader 210 to newly input the base station generated PN code for each sequence value of the phase delayed mobile station generated PN code by one chip from the correlation start point CS 420 to the integration period 460 again. (14a) and orthogonal noise ㆍ ㆍ The despreading operation is performed on 15b.

The correlator 220 outputs the despreader 210, that is, each sequence value of the orthogonal spreading chip sequence 13a and the orthogonal spreading chip sequence. ㆍ (13b) is cumulatively added and squared during the integration period 460 to calculate the detection energy according to the correlation. The controller 230 compares the detected energy with a threshold. Since the synchronization of the two PN codes is consistent from this time, in the comparison operation of the controller 230, the detection energy according to the correlation is greater than the threshold value.

However, as described above, since the integration section 460 is the same as the orthogonal diffusion section 400, the despread orthogonal noise ㆍ ㆍ Orthogonal Diffusion Chip Sequence of (15b) ㆍ 13b is removed by the cumulative addition operation of the correlator 220 in the integration section 460 in which the two PN codes are synchronized. That is, since the starting point of the integrating period 460 and the orthogonal diffusion section 400, which are synchronized, coincides with each other, the data symbol is used during the integration period 460. The value '+1' of (12b) is maintained. This allows orthogonal spreading chip sequences according to the nature of orthogonal codes. ㆍ 13b is removed during the cumulative addition of the correlator 220 described above. Therefore, the PN acquisition circuit according to the embodiment of the present invention has orthogonal noise at the time when the mobile station acquires initial synchronization. ㆍ ㆍ It can be seen that the PN capturing performance can be improved by removing 15b during the cumulative addition operation of the correlator 220. In addition, even if the integral section is an integer multiple of the orthogonal diffusion section 400, orthogonal noise at the time when the mobile station acquires initial synchronization. ㆍ ㆍ It can be seen that 15b is removed during the cumulative addition operation of the correlator 220.

On the other hand, in the embodiment of the present invention, between the correlation end point CE 405 and the correlation start point CS 410 and the correlation end point CE 415 and the correlation end point CS 420 are actual mobile station PN code generator 240. It can be seen that the phase delay time of 'D' (401) is one chip interval. This coincides with the starting point of the integrating period 460 and the orthogonal diffusion section 400 that are synchronized, and thus, the data symbol during the integration period 460. This is to keep the value of (12b) constant. This results in orthogonal noise at the time of mobile station acquisition of initial synchronization. ㆍ ㆍ 15b is removed during the cumulative addition operation of the correlator 220. As shown in the figure, the correlation end point CE 425 and the correlation start point CS 430 and the correlation end point CE 435 and the correlation end point CS 440 before and after the phase delay point of the actual mobile station generation PN code generator 240. If there is a difference of at least one chip, the starting point of the integration period 475 and the orthogonal diffusion section 400, which are synchronized, do not coincide. This results in orthogonal noise at the time of mobile station acquisition of initial synchronization. ㆍ ㆍ It can be seen that 15b is not removed during the cumulative addition operation of the correlator 220.

5 is a flowchart illustrating a PN capturing method according to an embodiment of the present invention. Hereinafter, a description will be given with reference to FIGS. 1 to 4.

In step 510, an integral section is set in units of integer multiples of an orthogonal diffusion section of a data symbol at a transmitting end, and a correlation detection energy is calculated by despreading, cumulative addition, and square. In operation 520, it is determined whether the detected energy is greater than a preset threshold. If the detected energy is less than the predetermined threshold in step 530, the mobile station-generated PN code is delayed by one chip and the operation in step 510 is performed again. However, at this time, a correlation between the end point of the correlation between the previous integration section and the start point of the correlation between the integration sections for the received signal input at the new time point is set as one chip section.

1 to 5, the PN capturing apparatus and method according to an embodiment of the present invention is a unit of an orthogonal diffusion section or an integer multiple of the orthogonal diffusion section of a data symbol at a transmitting end with respect to a received signal input at an arbitrary point in time. Calculate the correlation detection energy by setting the integrating section with despreading, cumulative addition and square. If the detected energy is less than the predetermined threshold value, the mobile station-generated PN code is delayed by one chip, and at this time, between the correlation end point of the previous integration section and the correlation start point of the integration section for the received signal input at the new time point. Leave it as a chip section. As a result, the starting point of the orthogonal spreading section for the data symbol at the transmitter and the synchronization unit coincide with each other, and the despread noise component is removed during the cumulative addition operation of the correlator due to the nature of the orthogonal code. As a result, the PN code detection probability of the PN capture circuit is increased to improve the PN capture performance.

As described above, the PN capturing apparatus and method of a mobile station according to the embodiment of the present invention integrate an interval in the unit of an orthogonal diffusion section or an integer multiple of the orthogonal diffusion section of a data symbol at a transmitting end with respect to a received signal input at an arbitrary point in time. Calculate the correlation detection energy by setting In this case, the correlation end point of the previous integration section and the correlation start point of the integration section for the received signal inputted at the new point of time are set as 1 chip intervals, and the orthogonal diffusion section for the data symbol at the transmitter and the integration section where synchronization is matched is performed. Match the start point. As a result, the despread orthogonal noise component is removed during the cumulative addition operation of the correlator due to the nature of the orthogonal code. As a result, the PN code detection probability of the PN capture circuit is increased to improve the PN capture performance.

Claims (4)

A mobile station P-N acquisition apparatus in a code division multiple access mobile communication system, A despreader for multiplying a received signal input at an arbitrary time point by a mobile station-generated P-encode and despreading the received signal in integral units of integral multiples of an orthogonal spreading period for a data symbol at a transmitting end; A correlator configured to calculate a correlation detection energy by accumulating and adding the squared sum of the despread received signals in units of the integral section; A controller for instructing a chip phase delay for the mobile station generated P-en code when the correlation detection energy is less than a threshold; And a mobile station generated P-EN code generator for outputting the mobile station generated P-EN code by one chip phase delay by a command of the controller. The method of claim 1, The mobile station generated P-en generator performs one chip phase delay operation on the first generated mobile station generated P-N sequence after the despreading operation of the integral section unit for the received signal at a predetermined time of the despreader, And the despreader performs the despreading operation from the first generated mobile station generated P-EN sequence after the one-chip phase delay operation of the mobile station generated P-EN code generator. In the P-N acquisition method of a mobile station in a code division multiple access mobile communication system, A first step of calculating the correlation detection energy by despreading, cumulative adding, and squaring an integral section by setting an integral section in units of integer multiples of an orthogonal diffusion section of a data symbol at a transmitting end with respect to a received signal input at an arbitrary time point; And a second process of delaying the phase of the mobile station-generated P-encode by one chip and performing the control operation of the first process if the detected energy is less than the threshold value. 4. The method of claim 3, wherein And a period between the correlation end point of the previous integration section and the correlation start point of the integration section for the received signal inputted at the new time point is one chip section.