RU2197778C2 - Method and device for reducing mobile-station peak-to-mean transmission power ratio - Google Patents

Abstract

FIELD: mobile communications engineering. SUBSTANCE: peak-to-mean power ratio is reduced by extending and modulating transmission data by complex extending sequence. This sequence is generated in response to each pseudonoise sequence so as to obtain plurality of items and so that phase difference between every two sequential complex items were 90 deg. Mobile transmission power is generated only on linear section of power amplifier characteristic. EFFECT: enhanced flexibility of power control. 19 cl, 9 dwg

Description

FIELD OF THE INVENTION
The present invention relates generally to mobile communication systems, in particular to a method of reducing the ratio of peak power to average transmit power of a mobile station in a mobile communication system and device for its implementation.

State of the art
A conventional CDMA mobile communication system (code division multiple access) provides voice communication services, while a 3G mobile communication system provides additional services of high-quality voice communication, high-speed data transmission, motion picture transmission and Internet browsing. In such a mobile communication system, a radio communication line consists of a forward link directed from a base station (BS) to a mobile station (MS) and a reverse link directed from MS to a BS.

 When crossing through zero during expansion and modulation during transmission on the reverse link (frequency change by π), the ratio of peak power to average transmit power of the mobile station (mobile transmission power) increases, which leads to a repeated increase. The repeated increase adversely affects the quality of communication for calls made by other subscribers. Therefore, the ratio of peak power to average power is an important factor in the design and operation of a power amplifier in an MS.

 The re-increase appears due to the fact that the characteristic of the power amplifier of the mobile station contains linear and non-linear parts. When the mobile transmission power increases, the transmission signal of the MS, due to the non-linearity of the characteristic, generates interference in the frequency domain of another user, causing a re-increase phenomenon.

 Repeated enlargement can be prevented by reducing the size of the cell and transmitting the signal from the MS in the cell to the corresponding base station with a low power level. Thus, the mobile transmission power can be flexibly adjusted if the ratio of peak power to average power is limited in a certain range. However, it is economically unprofitable to physically reduce the size of a cell, since then more cells are needed for this area, and each cell requires its own communication equipment.

SUMMARY OF THE INVENTION
Accordingly, it is an object of the present invention to provide an apparatus and method for reducing a ratio of peak power to average transmit power of a mobile station in a mobile communication system.

 Another objective of the present invention is to provide a method for flexible control of mobile transmission power by limiting the ratio of peak power to average mobile transmission power within certain limits.

 Another objective of the present invention is to provide a method for flexible resizing of a cell in a mobile communication system to prevent re-enlargement.

 A further object of the present invention is to provide a method for improving the autocorrelation characteristics of a multipath signal and cross-correlation characteristics with respect to other users.

To solve these and other problems, a device and method are proposed for reducing the ratio of peak power to average power of mobile transmission in a mobile communication system. The device and method expand mobile data with an integrated spreading sequence. The complex extension sequence contains many elements and is generated in response to each element of the PN (pseudo-noise) sequence in such a way that the phase difference between each two consecutive complex elements is 90 ^° .

Brief Description of the Drawings
Figure 1 is a block diagram of a mobile station for implementing a method of expansion and modulation according to one embodiment of the present invention;
FIG. 2 is a block diagram of a first embodiment of OFMN (relative phase shift keying) with π / 2 shown in FIG. 1;
FIG. 3A and 3B are a set of signals and phase changes in complex spreading sequences corresponding to the structure of the FPS generator with π / 2 shown in FIG. 2;
FIG. 4 is a block diagram of a second embodiment of an OFMN generator with π / 2 shown in FIG. 1;
FIG. 5A and 5B show a combination of signals and phase changes in complex spreading sequences in accordance with the structure of the FPS with π / 2 generator shown in FIG. 4;
FIG. 6 is a flowchart of a mobile station in an IS-95 3G system using an extension and modulation method according to the present invention;
FIG. 7 is a flowchart of a mobile station in a W-CDMA (Code Division Multiple Access) system using the spreading and modulation method of the present invention.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
Below, with reference to the accompanying drawings, preferred embodiments of the present invention are described. In the following description, well-known constructions or functions are not described in detail so as not to detract from the essence of the present invention.

The present invention contains the following new and distinctive features:
(1) the power of mobile transmission can be flexibly adjusted by limiting the ratio of peak power to average power within certain limits and, therefore, keeping the power of mobile transmission in the linear portion of the power amplifier characteristic;
(2) prevent phase shift of the complex spreading sequence by 180 ^° (i.e., π) to maintain the mobile transmission power in the linear portion of the power amplifier characteristic;
(3) the phase difference between each two consecutive complex elements of the complex spreading sequence (PN _I and PN _Q ) is 90 ^o (i.e. π / 2) to limit the range of output power of the filters of the group spectrum and thereby reduce the ratio of peak power to average power of mobile transmission;
(4) improve the autocorrelation characteristics of a multipath signal and the cross-correlation characteristics relative to other users by re-expanding the signal that passed through a complex expander, extending the PN ₂ sequence generated by the PN code generator.

In this embodiment of the present invention, it is important that "OFPS (relative phase shift keying) with π / 2" is not a common OFPS and is called so because in the complex extension sequence PN _I + jPN _Q generated in the generator of OFPS with π / 2, during the passage of one element of the extension sequence, the phase changes by π / 2.

Referring to FIG. 1, a flowchart of a mobile station (MS) is shown, which is described here to describe methods for expanding and modulating mobile transmission data to reduce the peak power to average mobile transmission ratio in accordance with embodiments of the present invention. A complex signal including I-data (common-mode data) and Q-data (quadrature data, that is, shifted by π / 2) is supplied as a first input signal to complex expander 2. The PN _I 4 generator generates the PN _I sequence, and the generator The FPSN with π / 2 6 generates the complex extension sequences PN _I and PN _Q , the PN _I sequence being supplied from the PN ₁ generator 4. The complex extension sequences PN _I and PN _Q are supplied as a second input signal to the complex expander 2. This embodiment The present invention is characterized in that there is no transition through zero, since the phase difference between each two consecutive complex elements of the complex spreading sequence (PN _I and PN _Q ) is π / 2. The structure and operation of the OFPS generator with π / 2 6 is described in detail below with reference to FIG. 2 to 5V.

In figure 1, the complex expander 2 includes multipliers 8, 10, 12 and 14, as well as adders 16 and 18 for complex expansion of the complex signal complex expansion sequences PN _I and PN _Q. A detailed description of the operation of the complex expander 2 can be found in Patent Application KR 98-7667.

Multipliers 20-1 and 20-2 multiply the resulting expanded common-mode signal XI and the expanded quadrature signal XQ received from the complex expander 2 by the PN ₂ sequence generated by the PN ₂ 21 generator for additional expansion. In this embodiment of the present invention, the PN ₁ and PN ₂ sequences are independent. It is assumed that PN sequences PN ₁ and PN ₂ may be followed by a PN sequence, which is generated by the user identification code. In this invention, the multiplication of the output of the complex expander 2 by PN _{2 is} not a mandatory feature.

The output signals of the multipliers 20-1 and 20-2 are filtered using the filters of the group spectrum 22-1 and 22-2 and gain control (G _P ) using the gain controllers 24-1 and 24-2, respectively. Then the mixers 26-1 and 26-2 multiply the output signals of the gain controllers 24-1 and 24-2 by the corresponding carriers, cos (2πf _c t) and sin (2πf _c t), for conversion with increasing frequency, and the adder 28 sums the output signals of mixers 26-1 and 26-2.

According to the present invention, the autocorrelation characteristic of a multipath signal and the cross-correlation characteristics with respect to other users are improved by doubling the extension of the input complex signal: once by the sequence PN ₁ , and another time by the sequence PN ₂ . Here, the sequences PN ₁ , PN ₂ , PN _I and PN _Q have the same repetition rate of their elements.

If the phase of the complex extension sequence PN _I + jPN _Q coming from the output of the extension sequence generator changes dramatically (for example, from 0 to 180 ^o ), this will increase the ratio of peak power to average power of mobile transmission, which will lead to a repeated increase and worsen the quality of communication from another user.

However, the configuration of the spreading sequence generator is such that, in this embodiment of the present invention, when generating the complex spreading sequence PN _I + jPN _Q, there is no transition through zero (phase does not change to π).

Figure 2 presents the block diagram of the generator OFPS with π / 2 6, proposed as a generator of the extension sequence according to the present invention. A feature of the OFMN generator with π / 2 6 is that the maximum phase difference between each two successive complex elements of the complex extension sequence PN _I + jPN _Q is π / 2.

An FPS generator with π / 2 6 includes a complex function computation unit 32, a complex multiplier 34, and delay registers 36 and 38. A multiplier 30 multiplies the PN elements of the PN _I sequence by ± π / 2 or ± 3π / 2. It is assumed that the multiplier 30 multiplies each one PN element of the PN _I sequence by any phase in the range of ± π / 2 or ± 3π / 2.

The complex function computation unit 32 generates complex data Re + jIm by converting each phase-shifted PN element coming from the multiplier 30 into the complex function exp (j [•]). The complex multiplier 34 performs complex multiplication of the complex data Re + jIm by the values (complex data) obtained from the delay registers 36 and 38, and outputs a block of PN _I + jPN _Q elements of the complex spreading sequence. The delay register 36 stores the PN _I value during the transit time of one element, and the delay register 38 stores the PN _Q value during the transit time of one element. The initial values (complex data) of the contents of the delay registers 36 and 38 are determined as follows:
(equation 1)
delay register 36 = Re [exp (jθ)]
delay register 38 = Im [exp (jθ)],
where θ can have any value, but preferably π / 4.

Assuming that consecutive elements in sequences PN ₁ and PN ₂ are {1, -1, 1, -1, ...} and {-1, 1, -1, 1, ...}, respectively, and the initial values the delay registers 36 and 38 are equal to 1, then the sequential elements of the complex extension sequence PN _I + jPN _Q generated by the OFPS generator with π / 2 6 are {(-1 + j), (1 + j), (-l + j), (1 + J) ...}, and the consecutive elements of the complex spreading sequence fed to the input of group spectrum filters 22-1 and 22-2 are {(1-j), (1 + j), ( 1-j), (1 + j) ...}. The PN ₁ to PN ₂ sequences can be long codes for identifying a user in a CDMA 3G system.

выраженное в форме комплексного числа (Re+jim) в виде (0+1j). Следовательно, комплексный умножитель 34 создает комплексные данные (-1+j)=(0+j)x(1+j). Здесь (0+j) - комплексные данные, поступающие из блока вычисления комплексной функции 32, а (1+j) - начальные значения содержимого регистров задержки 36 и 38.In FIG. 3A and 3B show the totality of signals and phase changes in the complex spreading sequence PN _I + jPN _Q coming from the output of the OFMN generator with π / 2 6 and the complex spreading sequence coming in at the input of the group spectrum filters 22-1 and 22-2, respectively. Turning to FIG. 1 to 3B, where, for the first PN chip 1 of the sequence PN _1, the output signal of the multiplier 30 in the generator DPSK with π / 6 February shifted by π / 2 since the other input to the multiplier 30 is shifted by π / 2, and the complex data output from the complex function computation unit, are

expressed in the form of a complex number (Re + jim) in the form (0 + 1j). Therefore, the complex multiplier 34 creates complex data (-1 + j) = (0 + j) x (1 + j). Here (0 + j) are the complex data coming from the complex function computation unit 32, and (1 + j) are the initial values of the contents of the delay registers 36 and 38.

 In FIG. 3A, the complex data (-1 + j) are in the second quadrant of the diagram in a system of orthogonal coordinates determined by the real components (Re) and imaginary components (Im) of the complex signal. The real part -1 of the complex data (-1 + j) is stored in the delay register 36 during the transit time of one element, and the imaginary part 1 is stored in the delay register 38 during the transit time of one element.

выраженное в форме комплексного числа (Re+jIm) в виде (0-j). Следовательно, комплексный умножитель 34 создает комплексные данные (1+j)=(0-j)x(-1+j). Здесь (0-j) - комплексные данные, поступающие из блока вычисления комплексной функции 32, а (-1+j) - предыдущие значения регистров задержки 36 и 38.For the second PN element -1 of the PN ₁ sequence, the output signal of the multiplier 30 in the OFDM generator with π / 2 6 is shifted by -π / 2, and the complex data coming from the complex function computation unit 32 are

expressed in the form of a complex number (Re + jIm) in the form (0-j). Therefore, the complex multiplier 34 creates complex data (1 + j) = (0-j) x (-1 + j). Here (0-j) is the complex data coming from the complex function computation unit 32, and (-1 + j) is the previous values of the delay registers 36 and 38.

In FIG. 3A, the complex data (1 + j) are in the first quadrant of the diagram in the orthogonal coordinate system. The real part 1 of the complex data (1 + j) is stored in the delay register 36 during the transit time of one element, and the imaginary part 1 is stored in the delay register 38 during the transit time of one element. Similarly, the complex data coming from the output of the complex multiplier 34 is (-1 + j) for the third PN element 1 of the PN ₁ sequence and (1 + j) for the fourth PN element -1 of the PN ₁ sequence.

In Fig. 3A, a complex extension sequence PN _I + jPN _Q exists in the second and first quadrants of the diagram in the orthogonal coordinate system defined by the real components (Re) and imaginary components (Im) of the complex signal, and the phase difference between each two successive complex elements is π / 2.

The π / 2 phase difference between each two consecutive complex elements is maintained in a complex extension sequence resulting from the repeated extension of the PN ₂ sequence. We turn to figure 1, where the complex extension sequence {(1-j), (1 + j), (1-j), (1 + j). . .} is obtained by multiplying the elements {(-1 + j), (1 + j), (-1 + j), (1 + j) ...} of the complex extension sequence PN _I + jPN _Q by the elements {-1, 1, -1, 1, ...} of the sequence PN ₂ . As shown in FIG. 3B, in the complex spreading sequence supplied to the input of the group spectrum filters 22-1 and 22-2, the phase difference between each two successive complex elements is π / 2, as well as in the complex spreading sequence PN _I + jPN _Q.

 Since the phase difference between each two consecutive complex elements of complex expanding sequences is small, namely π / 2, as can be seen from FIG. 3A and 3B, the ratio of peak power to average mobile transmission power after processing in the group spectrum filters 22-1 and 22-2 decreases, which reduces the effects of a re-increase. The result is improved communication efficiency and quality.

If the predetermined phase value in radians at the input to the multiplier 30 of the OFPS generator with π / 2 6 is −3π / 2, then the complex spreading sequence PN _I + jPN _Q looks like a set of signals shown in FIG. 3A. If the value in radians is −π / 2 or 3π / 2, then the elements of the complex extension sequence PN _I + jPN _Q will appear sequentially at the same positions in the first and second quadrants in turn, starting from the first quadrant in FIG. 3A.

In Fig.4 presents a block diagram of a second variant of the generator OFPS with π / 2 6 shown in Fig.1. As in the first embodiment, the maximum phase difference between each two successive complex elements of the complex extension sequence PN _I + jPN _Q is ± π / 2. The FPSN generator with π / 2 6 according to the second embodiment includes an adder 40, a delay register 42, and an integrated function calculation unit 44. The adder 40 adds the PN element of the PN ₁ sequence with the previous output of the adder 40 stored in the delay register 42. It is preferable that the initial value Delay register 42 was set to 1/2. The complex function computation unit 44 creates a complex extension sequence PN _I + jPN _Q by converting the output of the adder 40 to the complex function exp [j (π / 2 (•))].

Из уравнения (2) следует, что фаза текущего элемента комплексной расширяющей последовательности PN_I+jPN_Q представляет собой сумму фазы предыдущего элемента и произведения текущего элемента последовательности PN_I на π/2.The phase change of the complex extension sequence PN _I + jPN _Q is given by equation (2)
∠ (PN $\genfrac{}{}{0ex}{}{\text{(k)}}{\text{I}}$ + jPN $\genfrac{}{}{0ex}{}{\text{(k)}}{\text{Q /}}$ ) ≡ θ (k)

From equation (2) it follows that the phase of the current element of the complex extension sequence PN _I + jPN _Q is the sum of the phase of the previous element and the product of the current element of the sequence PN _I by π / 2.

Assuming that the consecutive elements of the sequences PN ₁ and PN ₂ are {1, -1, 1, -1, ...} and (-1, 1, -1, 1, ..,}, respectively, and the initial value of the contents of the delay register 42 is 1/2, then the sequential elements of the complex extension sequence PN _I + jPN _Q generated by the OFPS generator with π / 2 6 are [(-1 + j), (1 + j), ( -1 + j), (1 + j) ...}, and the sequential elements of the complex spreading sequence fed to the input of the group spectrum filters 22-1 and 22-2, represent {(1-j), (1 + j ), (1-j), (1 + j) ...}. elnosti PN ₁ to PN ₂ can be long codes for user identification in the 3G CDMA system.

In FIG. 5A and 5B, the signals and phase changes of the complex spreading sequence PN _I + jPN _Q coming from the output of the OFMN generator with π / 2 6 and the complex spreading sequence coming to the input of the group spectrum filters 22-1 and 22-2, respectively, are proved.

, выраженное в форме комплексного числа (Re+jlm) в виде (-1+j), и являются элементом комплексной расширяющей последовательности PN_I+jPN_Q. Здесь (-1+j) находится во втором квадранте диаграммы в ортогональной системе координат, показанной на фиг.5А.Turning to FIG. 1 to 5B, wherein for the first PN chip 1 of the sequence PN _1, the output signal of the adder 40 is 3/2 (= 1 + 1/2 ) and stored in delay register 42 for one transit time element, and the complex data output from the unit computing complex functions 44 are

expressed in the form of a complex number (Re + jlm) in the form (-1 + j), and are an element of the complex extension sequence PN _I + jPN _Q. Here (-1 + j) is in the second quadrant of the diagram in the orthogonal coordinate system shown in FIG. 5A.

, выраженное в форме комплексного числа (Re+jIm) в виде (1+1j). Здесь (1+1j) находится в первом квадранте диаграммы в ортогональных координатах, показанной на фиг.5А. Подобным же образом комплексные данные, поступающие с выхода блока вычисления комплексной функции 44, представляют собой (-1+j) для третьего ПШ элемента 1 последовательности PN₁ и (1+j) для четвертого ПШ элемента -1 последовательности PN₁.For the second PN element -1 of the PN ₁ sequence, the output of the adder 40 is 1/2 (= -1 + 3/2) and is stored in the delay register 42 for the duration of the passage of one element, and the complex data coming from the output of the complex function calculation unit 44 are

expressed in the form of a complex number (Re + jIm) in the form (1 + 1j). Here (1 + 1j) is in the first quadrant of the diagram in orthogonal coordinates shown in FIG. 5A. Similarly, the complex data coming from the output of the complex function calculation block 44 is (-1 + j) for the third PN element 1 of the PN ₁ sequence and (1 + j) for the fourth PN element -1 of the PN ₁ sequence.

In Fig. 5A, a complex extension sequence PN _I + jPN _Q exists in the second and first quadrants of the orthogonal coordinate system defined by the real components (Re) and imaginary components (Im) of the complex signal, and the phase difference between each two successive complex elements is π / 2 .

The π / 2 phase difference between each two consecutive complex elements is maintained in the complex extension sequence obtained by re-expanding the complex extension sequence PN _I + jPN _{Q with the} sequence PN ₂ . (Note that this complex extension sequence can also be re-extended with the original PN sequence or some other PN sequence). We turn to figure 1, where the complex extension sequence {(1-j), (1-j), (1-j), (1 + j) ...} is obtained by multiplying the elements {(-1 + j), (1 + j), (-1 + j, (1 + j) ...} of the complex extension sequence PN _I + jPN _Q to the elements {-1, 1, -1, 1, ...} of the sequence PN ₂ . As shown in FIG. 5B, in the complex spreading sequence supplied to the input of the group spectrum filters 22-1 and 22-2, the phase difference between each two consecutive complex elements is π / 2, as well as in the complex spreading sequence PN _I + jPN _Q.

 Since the phase difference between each two successive complex elements of the complex expanding sequences is small, namely π / 2, as noted in FIG. 5A and 5B, the ratio of peak power to average mobile transmission power after processing in the group spectrum filters 22-1 and 22-2 decreases, thereby preventing a re-increase. As a result, communication efficiency and quality are improved.

 6 is a flowchart of an MS in a 3G IS-95 system that employs an extension and modulation method according to this embodiment of the present invention. Reverse communication channels include a pilot channel, which is always activated, a control channel, a main channel that is taken out of operation in a specific frame, and an additional channel. The pilot channel is not modulated and is used to obtain initial values, time tracking and synchronization of the rake receiver (collecting receiver). This makes it possible to adjust the power in the reverse link in a closed loop. A dedicated control channel transmits an unencrypted bit for fast power control and encoded control information. These two types of information are multiplexed and sent on one control channel. The main channel is used to send PRS frames (radio protocol) and packet data.

Channels are expanded with Walsh codes to form orthogonal channels. The signals of the control channel, as well as the secondary and main channels are multiplied by the corresponding Walsh codes in the multipliers 50, 52 and 54, respectively. The relative gain controllers 56, 58, and 60 adjust the relative gain G _{C of the} output signals of the multipliers 50, 52, and 54, respectively. An adder 62 adds the pilot channel signal to a control channel signal received from the relative gain controller 56. The summed data from the adder 62 is used as the I-channel signal. The adder 64 adds the signal of the additional channel coming from the output of the relative gain controller 58 with the signal of the main channel coming from the output of the relative gain controller 60. The data summed in the adder 64 is used as a Q-channel signal.

As shown in FIG. 1, a signal sent on a pilot channel, a dedicated control channel, a primary channel and an auxiliary channel is a complex signal. The channel of the pilot signal and the control channel when summing form the I-channel, and the main channel and the secondary channel when summing form the Q-channel. The complex signal of the I- and Q-channels is subjected to complex expansion by the complex spreading sequence PN _I + JPN _Q in the complex expander 2 in FIG. 6. The complex extended signal is multiplied by a PN ₂ sequence, that is, a long code to identify the user. The resulting complex spreading sequence is filtered in group spectrum filters 22-1 and 22-2 and transmitted through gain controllers 24-1 and 24-2, mixers 26-1 and 26-2 and adder 28 with a reduced ratio of peak power to average power.

In FIG. 7 is a flowchart of an MS in a W-CDMA system using the spreading and modulation method of the present invention. In FIG. 7, a traffic signal is sent over a dedicated channel for physical data (VKFD), and a control signal is sent over a dedicated channel for control data (VKFD). The VKFD signal is multiplied in the multiplier 70 by the channel formation code C _D with the element repetition rate, and this channel becomes an I-channel. The VKCD signal is multiplied in the multiplier 72 by the channel formation code C _C with the element repetition rate, converted into an imaginary number using an imaginary operand (• j) 74, and this channel becomes a Q-channel. Here, the codes C _D and C _C are mutually orthogonal. Channels I and Q form a complex signal. The complex signal is complexly expanded by the complex spreading sequence PN _I + jPN _Q in complex expander 2 in FIG. 7 and is multiplied by the PN ₂ sequence; that is, a long code for user identification, which is generated in the PN ₂ generator 21. The resulting complex spreading sequence is filtered in the group spectrum filters 22-1 and 22-2 and transmitted through amplification controllers 24-1 and 24-2, mixers 26- 1 and 26-2 and an adder 28 with a reduced ratio of peak power to average power.

According to the above invention, the ratio of peak power to average power of mobile transmission is limited in a certain range by providing a phase difference between each two consecutive elements of the complex spreading sequence equal to 90 ^o . As a result, the power of mobile transmission is generated only on the linear section of the characteristics of the power amplifier, which allows flexible control of the power of mobile transmission and cell size. In addition, the autocorrelation characteristics of the multipath signal and cross-correlation characteristics with other users can be improved by re-expanding the signal that passed through the complex expander with another PN sequence that is generated by the PN code generator.

 Although the invention has been presented and described with reference to specific preferred embodiments, it will be apparent to those skilled in the art that various changes can be made regarding the form and details of its implementation, within the spirit and scope of the invention as defined in the claims.

Claims (20)

1. A method of reducing the ratio of peak power to average transmit power of a mobile station in a mobile communication system, which consists in generating a complex spreading sequence in which the phase difference between each two consecutive complex elements of the PN (pseudo-noise) sequence obtained at the output of the PN generator, is 90 ^o , and expand the data intended for transmission in a mobile station, a comprehensive spreading sequence.  2. The method according to p. 1, characterized in that when generating a complex extension sequence multiply the elements of the PN sequence by a predetermined phase value to obtain phase-shifted elements, convert the phase-shifted elements to complex data when each phase-shifted element is used as a phase and multiplying the transformed complex data by previously transformed complex data to generate a plurality of elements of the complex spreading sequence.  3. The method according to claim 2, characterized in that the conversion uses the complex function exp (j [•]) to convert the phase-shifted elements into complex data.  4. The method according to p. 2, characterized in that the predetermined phase value is in the range from Fπ / 2 to F3π / 2.  5. The method according to p. 1, characterized in that when generating a complex expansion sequence, each element of the PN sequence is added together with the corresponding previously stored element to obtain the summed elements, and the summed elements are converted into complex data to generate many elements of the complex expansion sequence.  6. The method according to p. 2, characterized in that the conversion uses the complex function exp j (π / 2 (•)) to convert the summed elements into complex data.  7. The method according to p. 1, characterized in that it further re-extends the extended data intended for transmission in the mobile station, an independent PN sequence. 8. A device for reducing the ratio of peak power to the average transmit power of a mobile station in a mobile communication system, comprising a complex spreading sequence generator for generating a complex spreading sequence in which the phase difference between each two successive complex PN elements (pseudo-noise) received at the PN output generator is 90 ^o and expander for expanding data to be transmitted to a mobile station integrated expanding sequence.  9. The device according to p. 8, characterized in that the complex extension sequence generator comprises a multiplier for multiplying the PN sequence elements by a predetermined phase value to obtain phase-shifted elements, a complex data generator for converting phase-shifted elements into complex data when used as phase of each phase-shifted element and a complex multiplier for generating a plurality of elements of a complex expanding multiplication sequence of transformed complex clear data on previously converted complex data.  10. The device according to claim 9, characterized in that when converting the phase-shifted elements into complex data, the complex exp function (j [•]) is used.  11. The device according to p. 9, characterized in that the set phase value is in the range from Fπ / 2 to F3π / 2.  12. The device according to p. 8, characterized in that the complex extending sequence generator comprises an adder for adding each element of the PN sequence with the corresponding previously stored element to obtain the summed elements and a complex data generator for generating many elements of the complex expanding sequence by converting the summed elements to complex data.  13. The device according to p. 12, characterized in that when converting the summed elements into complex data, the complex function exp [j (π / 2 (•))] is used.  14. The device according to p. 8, characterized in that it further comprises a re-extender for re-expansion of the extended data intended for transmission in the mobile station, an independent PN sequence.  15. The device according to p. 14, characterized in that the independent PN sequence is identical to the PN sequence. 16. A device for reducing the ratio of peak power to average transmit power of a mobile station in a mobile communication system, comprising means for generating a complex spreading sequence for generating a complex spreading sequence in which the phase difference between each two successive complex PN elements (pseudo-noise) received PN generator is 90 ^o and expansion means for expanding the data to be transmitted to the mobile station, SET JISC spreading sequence.  17. The device according to p. 16, characterized in that the means for generating a complex spreading sequence comprises multiplication means for multiplying elements of the PN sequence by a predetermined phase value to obtain phase-shifted elements, means for generating complex data for converting phase-shifted elements into complex data at using as a phase of each phase-shifted element and means of complex multiplication to generate many elements of a complex expanding sequence and by multiplying the converted complex data previously converted complex data.  18. The device according to p. 17, characterized in that the set phase value is in the range from Fπ / 2 to F3π / 2.  19. The device according to p. 16, characterized in that the means for generating a complex spreading sequence comprises a summing means for adding each element of the PN sequence with the corresponding previously stored element to obtain the summed elements and means for generating complex data for generating a plurality of elements of the complex spreading sequence by converting the summed elements in complex data.  20. The device according to p. 16, characterized in that it further comprises means for re-expansion for re-expansion of the expanded data intended for transmission in the mobile station, an independent PN sequence.

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