KR100330217B1 - The pich power measurement means for terminal in asynchronous cdma communication system - Google Patents

Abstract

The present invention provides a mobile communication system for wireless communication between a base station to which a mobile terminal belongs, and a base station adjacent thereto and the mobile terminal by an asynchronous code division multiple access scheme, wherein each base station uses a scramble code previously assigned to each base station. A first pilot channel signal spreading the spread pilot symbols in a first antenna symbol pattern and a second pilot channel signal spreading the spread pilot symbols in a second antenna symbol pattern through the at least two antennas Respectively, the first pilot channel signal is composed of a frame having a plurality of slots, each slot is spread with the first antenna symbol pattern having the same sign, and the second pilot channel signal is a plurality of slots Each slot pair of the plurality of slot pairs When the opposite symbols are spread in a second antenna symbol pattern composed of slots, and the mobile station receives a pilot channel signal combined with the spread first and second pilot channel signals from each base station through an antenna, It relates to a power measuring device of the mobile terminal for measuring the transmission power of each base station. To this end, the power measuring device may be configured to generate a scramble code generator that generates the same scramble code as the scramble code allocated to each of the base stations, and the received pilot channel signal by the scramble code output from the scramble code generator. A multiplier despreading, and accumulating the pilot channel signal despread in the multiplier for each slot period corresponding to each of the pilot symbols to obtain an amplitude value of the signal, and calculating the amplitude value at each end of each slot period. An integrator to output the power, a power supply of the signal obtained by powering the amplitude value output from the integrator, and a power value of the signal output from the power supply and inputting the power value for one slot period A delay delay unit, and a power value currently output from the power supply unit and the delay unit And an adder for adding the previously output power value, and a switch connected to the adder at the end of every two slot cycles.

Description

Pilot signal power measuring device of a terminal in asynchronous code division multiple access communication system {TH PICH POWER MEASUREMENT MEANS FOR TERMINAL IN ASYNCHRONOUS CDMA COMMUNICATION SYSTEM}

The present invention relates to a power measurement apparatus in a mobile terminal for measuring power of a pilot channel signal transmitted from antennas of a base station to which a mobile terminal belongs and an adjacent base station in an asynchronous code division multiple access mobile communication system. In particular, a base station using transmit diversity spreads pilot symbols through a plurality of antennas by spreading pilot symbols by a scramble code pre-assigned to the base station and spreading the spread pilot symbols into a plurality of antenna symbol patterns. When the mobile terminal receives a pilot channel signal combined with the plurality of spread pilot channel signals from each base station through an antenna for a power measurement device in the mobile terminal for measuring the respective transmission power of the base station will be.

Currently, most mobile communication systems use a method in which a base station and a mobile terminal transmit and receive data using one antenna. In this case, when the transmitting channel experiences fading, a plurality of data groups are damaged, which causes a significant decrease in communication quality. This problem of deterioration of communication quality can be solved by using diversity transmission that transmits data using at least two antennas. That is, the performance of the mobile communication system in the fading environment as described above can improve the transmission / reception performance of data by using diversity. Therefore, in the next generation mobile communication method, it is recommended to use transmit diversity in which a base station divides data into two antennas in order to maximize data transmission / reception capability.

In Europe, the next generation mobile communication system (hereinafter referred to as 3GPP) also stipulates that the base station can use transmit diversity in order to maximize the reception capability of the mobile terminal. However, since the mobile terminal is small in size, it cannot be provided with a plurality of antennas. When installing a plurality of transmit and receive antennas in the mobile terminal, the diversity gain that can be obtained is limited as the distance between the installed antennas is limited. In addition, when it is necessary to install a plurality of antennas in the mobile terminal as described above, it is disadvantageous in terms of the size and price of the mobile terminal. For this reason, the next generation mobile communication system recommends the use of transmit diversity only at the base station.

FIG. 1 shows a signal in which a signal is transmitted from an antenna of a base station to a mobile terminal 16 in a mobile communication system in which base stations 13 and 15 using a transmit diversity function and a base station 14 having only one antenna are mixed. It is a figure which shows the form. As shown in FIG. 1, the mobile terminal 16 receives signals not only from the base station 13 to which the mobile terminal belongs, but also from antennas of the base station and neighboring base stations 14 and 15. In general, the strength of a signal transmitted from an antenna of neighboring base stations is weaker than that of a signal transmitted from an antenna of a base station to which a mobile station belongs. However, as the mobile terminal approaches the neighboring base station, the strength of the signal received from the base station to which the mobile terminal belongs is weakened while the strength of the signal received from the neighboring base station increases. Therefore, the mobile station must measure the power of pilot channel signals transmitted from antennas of base stations adjacent to the base station as well as the base station to which the mobile terminal belongs to determine whether to handover.

2 is a diagram illustrating an antenna symbol pattern structure used to distinguish each antenna when a base station simultaneously transmits pilot channel signals using two antennas. In 3GPP, one frame of a physical channel has a length of 10 msec, and all 15 timeslots. Each timeslot is spread to 256 chips by the scramble code generated in the scramble code generator, not shown in the figure. Pilot symbols are also spread to 256 chips per symbol by the scramble code. Referring to FIG. 2, one frame of the antenna symbol pattern has a length of 10 msec, and is composed of 15 time slots. The pilot symbols spread to 256 chips per symbol by the scramble code are spread to respective pilot channel signals by the antenna symbol patterns. The first antenna symbol pattern is composed of 15 slots all having the same code, whereas the second antenna symbol pattern is composed of a plurality of slot pairs of two adjacent slots having opposite signs. That is, 2nd, 3rd, 6th, 7th, 10th, 11th, 14th, and 15th slots have opposite signs.

3 is a diagram illustrating a structure in which a pilot channel signal is spread using two antenna symbol patterns of FIG. 2 and transmitted through two antennas when a base station simultaneously transmits pilot channel signals using transmit diversity. Referring to FIG. 3, unmodulated pilot symbols (all symbols consisting of 1s) are spread by an orthogonal variable spreading factor code in a multiplier 301. The pilot symbols spread and output from the multiplier 301 are spread to I / Q scramble code output from the scramble code generator 304, and to 256 chips per symbol in the multiplier 302 and multiplier 303, respectively. Here, the I / Q scramble code is a digital data sequence previously assigned to each base station. The I / Q signals spread and output from the multiplier 302 and the multiplier 303 are respectively multiplied by the multiplier 307 and the multiplier 308 with the symbol pattern output from the first antenna symbol pattern 305. Spread to pilot channel signal. In addition, the I / Q signals spread and output from the multiplier 302 and the multiplier 303 are respectively multiplied by the multiplier 309 and the multiplier 310 by the symbol pattern output from the second antenna symbol pattern 306. It is spread with two pilot channel signals. The I / Q signals spread as the first pilot channel signals in the multiplier 307 and the multiplier 308 are respectively exclusive ORed in the exclusive logical combiner 311, and are frequency-modulated by a modulator not shown in the drawing. Transmitted by the antenna 313. In addition, the I / Q signals spread from the multiplier 309 and the multiplier 310 as the second pilot channel signal are exclusive ORed in the exclusive logical combiner 312, and are frequency-modulated by a modulator not shown in the drawing to form a second antenna. 314 is sent.

However, as described above, the base station simultaneously transmits pilot channel signals spread by two antenna symbol patterns through two antennas. Therefore, when the mobile station wants to measure the power of the pilot channel signal using the conventional IS-95 method, it is necessary to separate pilot channel signals transmitted simultaneously from two antennas of the base station through the antenna of the mobile station. That is, the pilot channel signal received by the mobile terminal is a signal in which the first pilot channel signal spread by the first antenna symbol pattern and the second pilot channel signal spread by the second antenna symbol pattern are combined. In order to separate the first and second pilot channel signals from the received pilot channel signal, at least two slots must be accumulated. If the power of the first pilot channel signal transmitted from the first antenna is measured, the mobile station uses the first antenna symbol pattern, that is, AA and FIG. 2 in units of two slots within one frame of the received pilot channel signal. Despread in two slot units together. In this way, the mobile station can remove the second pilot channel signal transmitted from the second antenna of the base station from the received pilot channel signal. However, this method results in failure to measure the power of the second pilot channel signal transmitted from the second antenna. Therefore, when the second antenna transmits a pilot channel signal having a larger power, the mobile station makes an erroneous handoff decision based on the power of the first pilot channel signal received from the first antenna.

Meanwhile, as shown in FIG. 5, the mobile terminal receives a pilot channel signal combined with the spread first and second pilot channel signals from two antennas of a base station through an antenna, and the mobile terminal receives the pilot channel signal. In order to separate the first and second pilot channel signals, a first and second antenna symbol patterns may be multiplied by the received pilot signal to despread. That is, referring to FIG. 5, the pilot channel signal received through the antenna of the mobile terminal is despread by the scramble code generated by the scramble code generator 505. In order to separate the first pilot channel signal from the despread pilot channel signal, the first antenna symbol pattern generated by the first antenna symbol pattern generator 510 in the mobile terminal is multiplied by the received pilot channel signal. In addition, to separate the second pilot channel signal, the second antenna symbol pattern generated by the second antenna symbol pattern generator 511 in the mobile terminal is multiplied by the received pilot channel signal. Accordingly, the pilot channel signal received through the antenna of the mobile terminal is separated into a first pilot channel signal and a second pilot channel signal using the method. The separated first and second pilot channel signals are integrated in the integrators 512, 513, 514, and 515 in units of two slots. The integral values output from the integrator are squared in the powers 520, 521, 522, and 523 and are exclusive OR in the exclusive logical sums 524, 525, respectively. That is, the power of each of the pilot channel signals transmitted from the two antennas of the base station is obtained. As a result, when the exclusive logical sum of the power of the pilot channel signals for the two antennas in the exclusive logical summator 526, the mobile terminal is connected to the pilot channel signals of the entire base station regardless of the reception power ratio of each antenna in two slot units. Power measurement is possible. However, in this scheme, since the pilot channel signal received through the antenna of the mobile terminal is a signal in which the first and second pilot channel signals are combined, the signal must be separated into the first and second pilot channel signals. To this end, the hardware configuration is complicated because two antenna symbol patterns are generated and then despreading is performed. In addition, in FIG. 5, an integral limit of the integrator 512 and the integrator 513 must be accumulated twice as many as 256 chips corresponding to one symbol period, that is, multiples of 512 chips, and the limit is frequency error or fading. Etc., may adversely affect accurate power measurement.

Accordingly, an object of the present invention is to provide a power measuring apparatus in a mobile terminal for measuring power of a base station to which a mobile terminal belongs and a pilot channel signal transmitted from an adjacent base station in an asynchronous code division multiple access mobile communication system.

Another object of the present invention is to transmit a plurality of antennas through a plurality of antennas when a plurality of antennas transmit pilot channel signals spread by a plurality of antenna symbol patterns as well as a base station to which the mobile terminal belongs. The present invention provides a power measuring apparatus for measuring a transmission power of each base station when receiving a pilot channel signal in which a plurality of pilot channel signals spread by an antenna symbol pattern are combined.

It is still another object of the present invention to provide an apparatus capable of determining whether adjacent base stations are using transmit diversity for transmitting data through a plurality of antennas.

In order to achieve the above object according to the present invention, in a mobile communication system for wireless communication in asynchronous code division multiple access method between a base station to which a mobile terminal belongs, and an adjacent base station and the mobile terminal, each base station is a pilot symbol to the A first pilot channel signal spreading with a scramble code pre-assigned to a base station, spreading the spread pilot symbols in a first antenna symbol pattern, and a second pilot channel signal spreading the spread pilot symbols in a second antenna symbol pattern Is transmitted through the at least two antennas, and the first pilot channel signal is composed of a frame having a plurality of slots, and each of the slots is spread to the first antenna symbol pattern having the same code. 2 pilot channel signal is composed of a frame having a plurality of slots, Each slot pair of the plurality of slot pairs is spread with a second antenna symbol pattern composed of slots opposite to each other, and the mobile terminal combines the spread first and second pilot channel signals from each base station through an antenna. In the power measurement apparatus of the mobile terminal for measuring the transmission power of each base station when receiving the pilot channel signal,

A scramble code generator for generating a scramble code identical to the scramble code previously assigned to each base station;

A multiplier for despreading the received pilot channel signal by a scramble code output from the scramble code generator;

An integrator that accumulates the pilot channel signal despread by the multiplier for each slot period corresponding to each of the pilot symbols to obtain an amplitude value of the signal, and outputs the amplitude value at each end of the slot period;

A power squarer that squares the amplitude value output from the integrator to obtain a power value of the signal;

A delay unit for inputting a power value of the signal output from the squarer and delaying the power value for one slot period;

An adder for adding a power value currently output from the power supply and a power value output before the power value input from the delay unit;

And a switch connected to the adder at the end of every two slot periods.

1 is a diagram illustrating a form in which a signal is transmitted from a base station using a transmit diversity technique to a terminal.

2 is a diagram illustrating an antenna symbol pattern spread to distinguish two antennas;

3 is a diagram illustrating a process of diversity transmission of a pilot channel signal through two antennas at a base station;

4 is a diagram illustrating a structure of a terminal for code division multiple access communication in a code division multiple access communication system;

5 is a diagram illustrating a structure of a power measuring device in a terminal that obtains and sums power of pilot channel signals transmitted from two antennas, respectively;

6 is a diagram showing the structure of a power measurement device in a terminal according to the present invention;

DETAILED DESCRIPTION A detailed description of preferred embodiments of the present invention will now be described with reference to the accompanying drawings. It should be noted that reference numerals and like elements among the drawings are denoted by the same reference numerals and symbols as much as possible even though they are shown in different drawings. In the following description of the present invention, if it is determined that a detailed description of a related known function or configuration may unnecessarily obscure the subject matter of the present invention, the detailed description thereof will be omitted.

6 is a diagram illustrating a structure of a power measurement device for measuring the power of a pilot channel signal according to an embodiment of the present invention. The power measuring device of FIG. 6 is included in each of the digital data receivers of FIG. 4.

4 and 6, the mobile station receives a pilot channel signal combined with the first and second pilot channel signals through an antenna. The received pilot channel signal is converted into an I / Q digital signal through the RF processor 402 and the A / D converter 403 of FIG. The converted I / Q signals are despread in the multipliers 601 and 602 by the I / Q scramble code generated by the scramble code generator 605. The I / Q signals despread and output from the multipliers 601 and 602 are input to the integrators 607 and 608. The integrators 607 and 608 accumulate the despread I / Q signals in units of 256 chips during each slot period corresponding to each of the pilot symbols and output I / Q signals indicating the amplitude of the pilot channel signal. The I / Q signals output from the integrators 607 and 608 are input to the multipliers 609 and 610 via switches 614 and 615 connected at the end of each slot period. The squarers 609 and 610 and the adder 616 square and add the amplitudes of the signals input from the integrators 607 and 608 to obtain power of the pilot channel signals over each slot period. The signal representing the power of the pilot channel signal of one slot period output from the adder 616 is delayed for one slot period by the delayer 617. The adder 618 is added with a signal representing the power of the pilot channel signal of the subsequent slot period output by the adder 616 and a signal representing the power input from the delayer 617. Signals or information indicating power of two slot periods output from the adder 618 are input to a processor (not shown in the drawing) through a switch 619 connected at the end of every two slot periods, and the information is then transmitted to a base station. Is sent to. That is, the information output from the exclusive logical summator 618 is easily summed up by the sum of the power over two slots of the pilot channel signals transmitted from the two antennas of the base station, to those skilled in the art. Can be understood.

Meanwhile, even though the first antenna symbol pattern generator 606, the multiplier 603, and the multiplier 604 of FIG. 6 are not provided, the first antenna symbol pattern generator 606, the multiplier 603, and the multiplier 604 may be omitted because they have the same effect in actual implementation of the present invention. It can be easily understood by those who have.

Accordingly, a feature of the present invention is a scramble code in which each base station pre-assigns pilot symbols to each base station in a mobile communication system in which a base station to which a mobile terminal belongs and communicates with an adjacent base station and a mobile terminal in an asynchronous code division access method. The at least two antennas and a first pilot channel signal spreading the spread pilot symbols in a first antenna symbol pattern and a second pilot channel signal spreading the spread pilot symbols in a second antenna symbol pattern. Respectively, the first pilot channel signal comprises a frame having a plurality of slots, each slot is spread over the first antenna symbol pattern having the same code, and the second pilot channel signal is divided into a plurality of slots. A slot having slots, wherein each slot pair of the plurality of slot pairs In the case of receiving a pilot channel signal combined with the spread first and second pilot channel signals from each base station through an antenna of the mobile station, the opposite code is spread into a second antenna symbol pattern composed of slots. The present invention relates to a power measurement apparatus of a mobile terminal that measures transmission power of each base station at any time without separating the pilot channel signal into the first and second pilot channel signals. To this end, the mobile terminal despreads the pilot channel signal received by combining the first pilot channel signal and the second pilot channel signal through an antenna without separating the received pilot channel signal. The despread pilot channel signal is accumulated in the integrator for one slot period corresponding to one pilot symbol. The integral value output in one slot period from the integrator is squared in the square. The squared value output from the squarer is delayed for one slot period in the delayer. An adder adds a square value currently output from the squarer and a square value output before the square value input from the delayer. Accordingly, the present invention is characterized in that it comprises a delay for delaying the square value output from the squarer for one slot period, and a switch for outputting the value output from the adder in two slot periods.

Now, a process of measuring transmission power of pilot channel signals transmitted from two antennas of a base station according to an embodiment of the present invention will be described in detail.

Assuming that the total power transmitted from the two antennas of the base station is 1, the power ratio of the pilot channel signals received by the terminal may be expressed as 1- x : x . In this case, x has a value between 0 and 1, and if x is 0, the base station transmits through one of the two antennas.

The mobile terminal receives a pilot channel signal combined with first and second pilot channel signals from a base station through an antenna. The received pilot channel signal is separated into an I / Q signal and despread in 256 chips by the scramble code in the multiplier 601 and the multiplier 602 of FIG. 6. The despread I / Q signal is integrated for each slot period in the integrator 612 to obtain the amplitude of the pilot channel signal. Therefore P (power) A (amplitude) ² relationship, and since the pilot channel signal is a signal in which the first and second pilot channel signals are combined, the 1st, 4th, 5th, 8th, 9th, 12th, 13th in one frame of the signal. In each of the slot periods the amplitude of the signal + Corresponds to Meanwhile, in each of the 2, 3, 6, 7, 10, 11, 14, and 15th slot periods within one frame of the pilot channel signal, the amplitude of the signal is - This is because the second pilot channel signal has the opposite sign in the slots. In this case, since the result of the 15th slot is not used, the 256 chips corresponding to the 15th slot in one frame of the pilot channel signal may not be despread. To obtain the power of the pilot channel signal, the multiplier 613 squares the amplitude of the signal input from the integrator 612. Thus, a signal representing power in each of the 1st, 4th, 5th, 8th, 9th, 12th, and 13th slot periods within one frame of the signal is 1 + 2 And a signal representing power in each of the 2nd, 3rd, 6th, 7th, 10th, 11th, 14th, and 15th slot periods within one frame of the signal is 1-2 Becomes Accordingly, when the two adjacent slots are terminated, the current power output from the multiplier 613 and the immediately previous power value delayed for one slot period from the delayer 617 are added to 1 + 2. + 1 + (-2 ) = 2 As a result, it is possible to measure the total power of the first and second pilot channel signals received through the antenna of the mobile terminal irrespective of the value of the power ratio of the two antennas of the base station. Therefore, the power of the entire base station can be measured regardless of the transmission type of the base station (whether the antenna diversity is used or not, if x is 0) and the power ratio of the two antennas received by the mobile station.

Meanwhile, in the detailed description of the present invention, specific embodiments have been described, but various modifications are possible without departing from the scope of the present invention. For example, the first antenna symbol pattern generator may be changed to a second antenna symbol pattern generator. In addition, the positions of the scramble code generator and the antenna symbol pattern generator used to despread the received pilot channel signal may be configured differently. Meanwhile, even when there are three or more antenna symbol patterns, the power of the base station can be measured by the same method as the present invention. Therefore, the scope of the present invention should not be limited to the described embodiments, but should be defined not only by the scope of the following claims, but also by the equivalents of the claims.

As described above, in the present invention, when the spreading pilot channel signals are transmitted to at least two antennas in two antenna symbol patterns of the base station, the mobile station does not separate the pilot channel signals received at the same time. A device for measuring power. Therefore, the mobile station can measure the power of the entire base station without despreading the received pilot channel signal with the antenna symbol pattern, thereby realizing a power measurement device having a simple hardware configuration.

Claims (12)

In a mobile communication system in which a mobile station belongs to a base station to which a mobile station belongs, and a wireless communication between a base station adjacent to the mobile station and an asynchronous code division multiple access method, each base station spreads pilot symbols with a scramble code previously assigned to each base station, The first pilot channel signal spreading the spread pilot symbols in the first antenna symbol pattern and the second pilot channel signal spreading the spread pilot symbols in the second antenna symbol pattern are respectively transmitted through the at least two antennas. The first pilot channel signal is composed of a frame having a plurality of slots, each slot is spread to the first antenna symbol pattern having the same sign, and the second pilot channel signal is a frame having a plurality of slots. Each slot pair of the plurality of slot pairs is opposite to each other The base station is spread with a second antenna symbol pattern composed of slots, and the mobile station receives a pilot channel signal combined with the spread first and second pilot channel signals from each base station through an antenna. In the power measuring device of the mobile terminal for measuring each transmission power, A scramble code generator for generating a scramble code identical to the scramble code previously assigned to each base station; A multiplier for despreading the received pilot channel signal by a scramble code output from the scramble code generator; An integrator that accumulates the pilot channel signal despread by the multiplier for each slot period corresponding to each of the pilot symbols to obtain an amplitude value of the signal, and outputs the amplitude value at each end of the slot period; A power squarer that squares the amplitude value output from the integrator to obtain a power value of the signal; A delay unit for inputting a power value of the signal output from the squarer and delaying the power value for one slot period; An adder for adding a power value currently output from the power supply and a power value output before the power value input from the delay unit; And a switch coupled to the adder at the end of every two slot periods. The power measuring apparatus of claim 1, further comprising a switch located between the integrator and the squarer and connected only when one slot is terminated. The apparatus of claim 1, further comprising an antenna symbol pattern generator positioned between the scramble code generator and the integrator and generating the first antenna symbol pattern or the second antenna symbol pattern. The apparatus of claim 1, wherein the pilot symbol is spread to 256 chips by the scramble code. The apparatus of claim 1, wherein the integrator accumulates 256 chips of the despread pilot channel signal. The power measuring device of claim 1, wherein the first and second antenna symbol patterns comprise 15 slots. The method of claim 1, wherein the first antenna symbol pattern is composed of fifteen slots in which one frame has the same reference sign, and the second antenna symbol pattern is the second, third, six, seven, ten, eleven of one frame. And the 14th and 15th slots comprise slots having opposite signs. The power measuring device of claim 1, wherein the fifteenth slot in one frame of the pilot channel signal is not despread. In a mobile communication system in which a base station to which a mobile station belongs and wirelessly communicates between an adjacent base station and the mobile station in an asynchronous code division multiple access scheme, the base station spreads pilot symbols with a scramble code previously assigned to each base station, Diversity of the first pilot channel signal spreading the spread pilot symbols in the first antenna symbol pattern and the second pilot channel signal spreading the spread pilot symbols in the second antenna symbol pattern through the at least two antennas, respectively The first antenna symbol pattern is composed of a frame having 15 slots, each slot is a symbol pattern having the same sign, and the second antenna symbol pattern is composed of a frame having 15 slots. Each slot pair of the plurality of slot pairs excluding the fifteenth slot A symbol pattern composed of slots having opposite signs, and when the mobile station receives a pilot channel signal combined with the spread first and second pilot channel signals from each base station through an antenna, transmission of each of the base stations In the power measuring device of the mobile terminal for measuring the power, A scramble code generator for generating a scramble code identical to the scramble code previously assigned to each base station; A multiplier for despreading the received pilot channel signal by a scramble code output from the scramble code generator; An integrator for accumulating the pilot channel signal despread by the multiplier for each slot period corresponding to each of the pilot symbols to obtain an amplitude value of the signal, and outputting the amplitude value at each end of the slot period; A power squarer that squares the amplitude value output from the integrator to obtain a power value of the signal; A delay unit for inputting a power value of the signal output from the squarer and delaying the power value for one slot period; An adder for adding a power value currently output from the power supply and a power value output before the power value input from the delay unit; And a switch coupled to the adder at the end of every two slot periods. In a mobile communication system in which a mobile station belongs to a base station to which a mobile station belongs, and a wireless communication between a base station adjacent to the mobile station and an asynchronous code division multiple access method, each base station spreads pilot symbols with a scramble code previously assigned to each base station, The first pilot channel signal spreading the spread pilot symbols in the first antenna symbol pattern and the second pilot channel signal spreading the spread pilot symbols in the second antenna symbol pattern are respectively transmitted through the at least two antennas. The first pilot channel signal is composed of a frame having a plurality of slots, each slot is spread to the first antenna symbol pattern having the same sign, and the second pilot channel signal is a frame having a plurality of slots. Each slot pair of the plurality of slot pairs is opposite to each other The base station is spread with a second antenna symbol pattern composed of slots, and the mobile station receives a pilot channel signal combined with the spread first and second pilot channel signals from each base station through an antenna. In the power measuring device of the mobile terminal for measuring each transmission power, A scramble code generator for generating a scramble code identical to the scramble code previously assigned to each base station; A multiplier for despreading the spread pilot channel signal from each base station by an I / Q scramble code output from the scramble code generator; An integrator for inputting the despread I / Q pilot channel signal from the multiplier, accumulating the I / Q signal for each slot period corresponding to each of the pilot symbols, and outputting each of the slot periods; A multiplier for inputting respective I / Q integrals output from the integrator and square the I / Q integrals; A first adder for inputting respective I / Q squared values output from the squarer and adding the I / Q squared values to obtain a power value of the signal; A delay unit for inputting the power value output from the first exclusive logical summ and delaying the power value for one slot period; A second adder configured to add the power value currently output from the first exclusive logical sum and the power value output before the power input from the delay unit; And the switch connected to the second adder only at the end of two slot cycles. In a mobile communication system in which a mobile station belongs to a base station and a wireless communication system between an adjacent base station and the mobile station by an asynchronous code division multiple access method, each base station receives pilot symbols spread by a scramble code pre-assigned to the base station. A first symbol pattern each of which is spread by a plurality of antenna symbol patterns and transmitted through at least two antennas, wherein the antenna symbol patterns are composed of a plurality of slots per frame and the slots are all composed of the same code And a plurality of slot patterns each having a plurality of slots and having a second symbol pattern composed of a plurality of slot pairs having opposite signs, and wherein the mobile terminal has a plurality of pilot channels spread from the base stations through an antenna. When receiving a pilot channel signal combined with the signal, the In the power measuring device of the mobile terminal for measuring the transmission power of each base station, A scramble code generator for generating a scramble code identical to the scramble code previously assigned to each base station; A multiplier for despreading the received pilot channel signal by the scramble code output from the scramble code generator; An integrator for accumulating the pilot channel signal despread by the multiplier for each slot period corresponding to each of the pilot symbols to obtain an amplitude value of the signal, and outputting the amplitude value at each end of the slot period; A power squarer that squares the amplitude value output from the integrator to obtain a power value of the signal; A delay unit for inputting a power value of the signal output from the squarer and delaying the power value for one slot period; An exclusive logical sum that exclusively ORs the power value currently output from the power supply and the power value previously outputted from the power value input from the delay unit; And a switch coupled to the exclusive logical sum at the end of every two slot periods. In an asynchronous code division multiple access mobile communication system including base stations using transmit diversity, the base station to which the mobile terminal belongs and the base stations adjacent to the base station are composed of 15 symbols per frame, and the first symbol pattern is all The second symbol pattern is composed of symbols having the same sign, and the second symbol pattern is configured to spread pilot channel signals by the plurality of symbol patterns each having a plurality of symbol pairs opposite to each other, and thereafter at least the spread pilot channel signal. A power measurement apparatus for transmitting diversity through two antennas and measuring a total transmission power of the base stations by the mobile terminal using the pilot channel signals, A scramble code generator for generating a scramble code identical to the scramble code pre-assigned to each base station under control of a controller; A multiplier for multiplying the scramble code output from the scramble code generator and the pilot channel signal to despread the pilot channel signals transmitted from the antennas of the respective base stations; An integrator that accumulates the pilot channel signal despread and output from the multiplier for each slot period; A power squarer that obtains a power value of the signal by squared an integral value during each slot period output from the integrator; A delay unit for inputting a power value currently output from the squarer and delaying the power value for one slot period; An adder for adding a power value currently output from the power supply and a power value output before the power value input from the delay unit; And a switch connected to the adder only at the end of two symbol periods.