KR100717682B1 - Apparatus and method for generating signal according to ifdma, and apparatus for receiving signal - Google Patents

Abstract

Disclosed are a signal generator and a signal receiver according to an interleaved frequency division multiple access (IFDMA) scheme.

The signal generating apparatus generates a plurality of complex symbols by digitally modulating the plurality of data symbols, and rotates the generated plurality of complex symbols at a plurality of phase angles having different values. The signal generating apparatus repeats a plurality of rotated complex symbols a predetermined number of times, and generates a plurality of transmission symbols by rotating the plurality of transmission chips generated by the repetition at a phase angle of a phase sequence orthogonal to each user.

The signal receiving apparatus may have a maximum diversity gain when receiving the plurality of transmission symbols generated as described above.

IFDMA, diversity, PSK

Description

Apparatus and method for signal generation in interleaved frequency division multiple access method, and signal receiver TECHNICAL FIELD

1 is a diagram illustrating a conventional IFDMA transport block.

2 is a block diagram showing a signal transmission apparatus according to an embodiment of the present invention.

3 is a flowchart illustrating a signal transmission method according to an embodiment of the present invention.

4 is a diagram illustrating an IFDMA transport block according to an embodiment of the present invention.

5 is a block diagram showing a signal receiving apparatus according to an embodiment of the present invention.

6 is a diagram illustrating an operation of a signal receiving apparatus according to an embodiment of the present invention.

The present invention relates to a signal generating device and a signal receiving device according to an interleaved frequency division multiple access (IFDMA) method, and in particular, an IFDMA signal generating device and a signal capable of obtaining a maximum frequency diversity gain. It relates to a receiving device.

An IFDMA transmission scheme has been proposed that has the advantages of spread-spectrum transmission and multicarrier transmission. The signal generating apparatus conforming to this IFDMA uses a transport block as shown in FIG.

1 is a diagram illustrating a conventional IFDMA transport block.

As shown in FIG. 1, an IFDMA transport block includes Q symbols repeated a total of L times. The minimum unit constituting the transport block is called a chip, and the IFDMA transport block illustrated in FIG. 1 includes L * Q chips.

The signal generation apparatus conforming to the IFDMA generates a transmission signal vector by multiplying a phase vector orthogonal to each user in the IFDMA transport block of FIG. The signal receiving apparatus conforming to the IFDMA demodulates a specific user's symbol by multiplying the signal vector received from the channel by the phase vector used by the signal generating apparatus.

However, according to the conventionally proposed IFDMA, the maximum frequency diversity gain could not be obtained.

SUMMARY OF THE INVENTION The present invention has been made in an effort to provide an IFDMA signal generating device and a signal receiving device capable of obtaining a maximum frequency diversity gain.

The signal generating device according to an embodiment of the present invention includes a first rotating part, a repeating part, and a second rotating part. The first rotating unit rotates the plurality of complex symbols at a plurality of different phase angles respectively corresponding to the plurality of complex symbols to generate a rotated complex symbol group. The repeater outputs a plurality of transmission chips by repeating the rotated complex symbol group a predetermined number of times. The plurality of transmission chips are rotated by a plurality of phase angles included in a sequence of orthogonal phases for each user to generate a plurality of transmission symbols.

The signal generating apparatus may further include a digital modulator for digitally modulating a plurality of data symbols with M phase angles to generate the plurality of complex symbols.

The first rotation unit may generate the rotated complex symbol group by rotating a k-th complex symbol of the plurality of complex symbols in inverse proportion to the M and at a phase angle proportional to the k.

A signal generation method according to an embodiment of the present invention comprises the steps of generating a plurality of complex symbols by digitally modulating a plurality of data symbols to M phase angles, and corresponding to the plurality of complex symbols respectively Generating a rotated complex symbol group by rotating the plurality of different phase angles, generating the plurality of transmission chips by repeating the rotated complex symbol group a predetermined number of times, and using the plurality of transmission chips as a user. And generating a plurality of transmission symbols by rotating the phase angles of the orthogonal phase sequences.

A signal receiving apparatus according to an embodiment of the present invention includes a receiver, a first reverse rotation unit, an adder, a second reverse rotation unit, and a digital demodulation unit. The receiving unit receives a plurality of transmission symbols, the first reverse rotation unit rotates the plurality of transmission symbols by a phase angle of a phase sequence orthogonal to each user to generate a plurality of chips, and an adder generates the same data among the plurality of chips. The chips corresponding to the symbol are added to generate a plurality of complex symbols. The second reverse rotation unit rotates the plurality of complex symbols at a plurality of different phase angles corresponding to the plurality of complex symbols, respectively, to generate a plurality of reverse rotated complex symbols, and the digital demodulator generates the plurality of reverse symbols. A digital symbol is generated by digitally demodulating the rotated complex symbol.

DETAILED DESCRIPTION Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art may easily implement the present invention. As those skilled in the art would realize, the described embodiments may be modified in various different ways, all without departing from the spirit or scope of the present invention. In the drawings, parts irrelevant to the description are omitted in order to clearly describe the present invention, and like reference numerals designate like parts throughout the specification.

In addition, when a part is said to "include" a certain component, which means that it may further include other components, except to exclude other components unless otherwise stated.

Now, a signal transmission apparatus 100 according to an embodiment of the present invention will be described in detail with reference to FIG. 2.

2 is a block diagram showing a signal transmission apparatus 100 according to an embodiment of the present invention.

As shown in FIG. 2, the signal generating apparatus 100 may include a digital modulator 110, a first rotating unit 120, a symbol repeating unit 130, a second rotating unit 140, a transmitter 150, and an antenna ( 160). Operation of the components included in the signal generating apparatus 100 will be described with reference to FIG. 3.

3 is a flowchart illustrating a signal transmission method according to an embodiment of the present invention.

First, the digital modulator 110 performs M-ary phase shift keying (MPSK) on a binary data symbol using M phase angles and generates a complex symbol (S110). For example, the digital modulator 110 performs binary phase shift keying (BPSK), 4-PSK, 16-PSK, and 64-PSK.

The first rotating unit 120 treats Q complex symbols generated by the digital modulator 110 as one complex symbol group. The complex symbol group {d _k } may be represented by Equation 1 below.

As shown in Equation 1, the k-th complex symbol of the complex symbol group is represented by d _k .

Next, the first rotation unit 120 rotates each of the plurality of complex symbols included in the complex symbol group at different phase angles (S120). The phase angle θ _k used by the first rotating unit 120 to rotate the complex symbol d _k may be expressed by Equation 2 below.

Meanwhile, the plurality of rotated complex symbols generated by the first rotating unit 120 will be referred to as rotated complex symbol groups. The rotated complex symbol group {d _k '} may be represented by Equation 3 below.

The first rotating unit 120 may use a rotation angle determined according to various methods to rotate the complex symbol. The first rotating unit 120 may determine the rotation angle as shown in Equation 4 to obtain the maximum frequency diversity gain.

In Equation 4, M is the number of phase angles used by the digital modulator 110 for digital modulation, and Q is the number of complex symbols included in the complex symbol group (hereinafter referred to as the size of the complex symbol group).

The symbol repeater 130 repeats the rotated complex symbol group {d _k '} L times to generate a transport block as shown in FIG. 4 (S130).

4 is a diagram illustrating an IFDMA transport block according to an embodiment of the present invention.

As shown in FIG. 4, the IFDMA transport block generated by the symbol repeater 130 includes L * Q transmission chips. Meanwhile, among the L rotated complex symbol groups included in the IFDMA transport block, the L _G rotated complex symbol groups may be used as a guard interval. The remaining L _I rotated complex symbol groups except for L _G among the L rotated complex symbol groups are information intervals.

L * Q transmission chips included in the IFDMA transport block may be represented by Equation 5 below.

3 will be described again.

})을 사용자별로 직교하는 위상 수열({

})의 위상각으로 회전시켜 복수의 전송 심볼({

})을 생성한다(S140).The second rotating unit 140 may include a plurality of transmission chips ({

} Orthogonal to each user per phase sequence ({

} To rotate the phase angle of the plurality of transmission symbols ({

}) Is generated (S140).

})은 다음의 수학식 6과 같이 나타낼 수 있다.Phase sequence according to an embodiment of the present invention ({

}) May be expressed as in Equation 6 below.

Here, the user-dependent phase Φ ⁽ⁱ⁾ dependent on the user ⁱ may be expressed by Equation 7 below.

})을 생성한다.The second rotating unit 140 may include a plurality of transmission symbols ({

})

})을 안테나(160)를 통해 송출한다.The transmitter 150 generates a plurality of transmission symbols ({

}) Is transmitted through the antenna 160.

Next, a signal receiving apparatus 200 according to an embodiment of the present invention will be described with reference to FIG. 5.

5 is a block diagram showing a signal receiving apparatus according to an embodiment of the present invention.

As shown in FIG. 5, the signal receiver 200 includes an antenna 210, a receiver 220, a first reverse rotation unit 230, an adder 240, a second reverse rotation unit 250, and a digital demodulator ( 260).

})을 수신한다. 수신부(220)가 수신한 복수의 심볼({

})은 다수의 사용자의 신호 생성 장치(100)로부터의 심볼들이 더해진 것이다. 즉, 전송 심볼(

)에 대한 수신 심볼을

라고 할 때 수신부(220)가 수신하는 심볼(

)은 수학식 9와 같다.The receiver 220 receives a plurality of symbols ({

}) The plurality of symbols received by the receiver 220 ({

}) Is the sum of the symbols from the signal generating apparatus 100 of the plurality of users. That is, the transmission symbol (

For received symbols

When the symbol received by the receiver 220 (

) Is the same as Equation 9.

})을 사용자별로 직교하는 위상 수열({

})의 위상각으로 역회전하여 복수의 칩({

})을 생성한다. 제1 역회전부(230)가 생성하는 복수의 칩({

})은 다음 수학식 10과 같다.Next, the first reverse rotation unit 230 includes a plurality of symbols ({

} Orthogonal to each user per phase sequence ({

} To reverse the phase angle of the

}) The plurality of chips generated by the first reverse rotation unit 230 ({

}) Is shown in Equation 10 below.

}) 중에서 동일한 데이터 심볼에 해당하는 칩들을 더하여 Q개의 복소 심볼({d_k'}, k=0, 1, ..., Q-1)을 생성한다. 덧셈부(240)가 생성하는 Q개의 복소 심볼({d_k'})은 특정 사용자(i)에 해당하는 심볼이다.The adder 240 may include a plurality of chips generated by the first reverse rotation unit 230 ({

}), The chips corresponding to the same data symbol are added to generate Q complex symbols {d _k '}, k = 0, 1, ..., Q-1. The Q complex symbols {d _k '} generated by the adder 240 are symbols corresponding to the specific user i.

})은 제1 역회전부(230) 및 덧셈부(240)를 거치면서 특정 사용자에 해당하는 심볼로 변화되는데, 이는 위상 수열({

})이 사용자별로 직교하기 때문이다.The plurality of symbols received by the receiver 220 ({

}) Is changed into a symbol corresponding to a specific user while passing through the first reverse rotation unit 230 and the adder 240, which is a phase sequence ({

}) Because it is orthogonal per user.

The operation of the receiver 220, the first reverse rotation unit 230, and the adder 240 will be described with reference to FIG. 6.

6 is a view showing the operation of the signal receiving apparatus 200 according to an embodiment of the present invention. FIG. 6 is a diagram illustrating a signal receiving apparatus 200 when L _G = 1, L _I = 4, and Q = 3.

As shown in FIG. 6, the receiver 220 receives 15 received symbols Y ₀ ,..., Y ₁₄ . In FIG. 15, although the transmission symbols of the user i are stored in the reception buffer of the receiver 220 for convenience, the reception symbols of the plurality of user's signal generation apparatuses 100 are added to the reception buffer of the receiver 220. (Y ₀ , ..., Y ₁₄ ) is stored.

First inverse rotation unit 230 generates a plurality of chips _{(c 0, ..., c 14} ) from performing an operation, such as the equation (10) the plurality of received symbol _{(Y 0, ..., Y 14} ) . In addition, the adder 240 performs operations as shown in Equations 11 to 13 to generate the complex symbols d ₀ ′, d ₁ ′, and d ₂ ′. In this case, the first reverse rotation unit 230 and the addition unit 240, the received symbol (Y _0, Y _1, Y ₂₎ on it for not performing the operations received symbol (Y _0, Y _1, Y ₂₎ is protected This is because it corresponds to a section.

As such, the adder 240 generates a plurality of complex symbols by adding chips corresponding to the same data symbol among the plurality of chips generated by the first reverse rotation unit 230.

The plurality of complex symbols generated by the adder 240 are symbols rotated at specific phase angles in order to obtain diversity gain. Therefore, the second reverse rotation unit 250 reversely rotates the plurality of complex symbols generated by the adder 240 at the phase angles used by the transmitter. The plurality of complex symbols generated by the second reverse rotation unit 250 performing reverse rotation will be referred to as reverse rotated complex symbols. In particular, when the transmitter uses the phase angle as shown in Equation 4, the second reverse rotation unit 250 performs the reverse rotation at the phase angle as shown in Equation 4.

The plurality of reverse rotated complex symbols generated by the second reverse rotation unit 250 are digitally modulated symbols. Accordingly, the digital demodulator 260 digitally demodulates the plurality of reverse rotated complex symbols generated by the second reverse rotater 250 to generate a final data symbol.

The embodiments of the present invention described above are not implemented only through the apparatus and the method, but may be implemented through a program for realizing a function corresponding to the configuration of the embodiment of the present invention or a recording medium on which the program is recorded. Implementation may be easily implemented by those skilled in the art from the description of the above-described embodiments.

Although the embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and various modifications and improvements of those skilled in the art using the basic concepts of the present invention defined in the following claims are also provided. It belongs to the scope of rights.

According to an embodiment of the present invention, an IFDMA signal generation device generates an IFDMA transmission symbol with a plurality of complex symbols rotated at a plurality of phase angles having different values, respectively, thereby obtaining better diversity gain than in the prior art. have.

Claims (12)

A first rotation unit configured to rotate a plurality of complex symbols at a plurality of different phase angles corresponding to the plurality of complex symbols to generate a rotated complex symbol group; A repeater for outputting a plurality of transmission chips by repeating the rotated complex symbol group a predetermined number of times; And a second rotation unit configured to generate the plurality of transmission symbols by rotating the plurality of transmission chips at a plurality of phase angles included in orthogonal phase sequences for each user. The method of claim 1, And a digital modulator for digitally modulating a plurality of data symbols with M phase angles to generate the plurality of complex symbols. The method of claim 2, The first rotating unit generates the rotated complex symbol group by rotating a k-th complex symbol of the plurality of complex symbols in inverse proportion to the M and at a phase angle proportional to the k. The method of claim 3, The first rotating unit may phase-angle the k-th complex symbol among the plurality of complex symbols.

Rotate to generate the rotated complex symbol group, Wherein Q is the number of complex symbols included in the rotated complex symbol group. The method according to any one of claims 1 to 4, The second rotating part of the plurality of transmission chips

Recall the fourth transfer chip

A signal generating device for rotating at a phase angle proportional to and proportional to a user number. The method of claim 5, The second rotating unit is the

Phase angle of the first transmission chip

Rotate with I is the user number, Q is the number of complex symbols included in the rotated complex symbol group, Wherein L is the number of times the repeater repeats the rotated complex symbol group. Digitally modulating the plurality of data symbols with M phase angles to generate a plurality of complex symbols; Generating a rotated complex symbol group by rotating the plurality of complex symbols at a plurality of different phase angles respectively corresponding to the plurality of complex symbols; Generating a plurality of transmission chips by repeating the rotated complex symbol group a predetermined number of times; And generating a plurality of transmission symbols by rotating the plurality of transmission chips at phase angles of orthogonal phase sequences for each user. The method of claim 7, wherein Generating the rotated complex symbol group And generating a rotated complex symbol group by rotating a k-th complex symbol of the plurality of complex symbols in inverse proportion to the M and at a phase angle proportional to the k. The method of claim 8, Generating the plurality of transmission symbols Of the plurality of transmission chips

Recall the fourth transfer chip

And generating the plurality of transmission symbols by rotating at a phase angle proportional to and proportional to a user number. A receiver which receives a plurality of transmission symbols; A first reverse rotation unit rotating the plurality of transmission symbols by a phase angle of a phase sequence orthogonal to each user to generate a plurality of chips; An adder configured to generate a plurality of complex symbols by adding chips corresponding to the same data symbol among the plurality of chips; A second reverse rotation unit configured to reversely rotate the plurality of complex symbols by a plurality of different phase angles respectively corresponding to the plurality of complex symbols to generate a plurality of reverse rotated complex symbols; And a digital demodulator for digitally demodulating the plurality of reversely rotated complex symbols to generate data symbols. The method of claim 10, The digital demodulator performs digital demodulation using M phase angles, The second reverse rotation unit generates the plurality of reverse rotated complex symbols by rotating a k th complex symbol of the plurality of complex symbols inversely proportional to the M and at a phase angle proportional to the k. The method of claim 11, The first reverse rotation unit is among the plurality of transmission symbols.

Recall the first transmission symbol

A signal receiving device that rotates in reverse with a phase angle proportional to and proportional to a user number.

Images