WO2012053859A2

WO2012053859A2 - Apparatus and method for transceiving data

Info

Publication number: WO2012053859A2
Application number: PCT/KR2011/007890
Authority: WO
Inventors: 임종수
Original assignee: 한국전자통신연구원
Priority date: 2010-10-22
Filing date: 2011-10-21
Publication date: 2012-04-26
Also published as: WO2012053859A3

Abstract

The invention relates to a data-transmitting apparatus which symbol-maps a plurality of input data signals to generate a plurality of modulated data symbols, converts the plurality of modulated data symbols into real signals of a time domain in a frequency domain and angle-modulates the real signals, controls the sizes of sine signals for the real signals which are angle-modulated to gains varying in accordance with a control signal, and transmits the real signals.

Description

Data transmitting and receiving device and method

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus and method for transmitting and receiving data, and in particular, a peak-to-average power ratio in a communication system for transmitting data using an orthogonal frequency-division multiplexing (OFDM) scheme. And a data transmission / reception apparatus and method for controlling a PAPR).

Orthogonal frequency-division multiplexing (OFDM) can be implemented through a simple equalizer, but has strong characteristics of multipath fading, so it can be used in a wireless local area network (WLAN), a wireless metropolitan area network (WLAN). WMAN), digital audio broadcast (DAB), digital video broadcast (Digital Video Broadcast, DVB) and other wireless communication systems such as have been adopted and used.

However, because OFDM uses a large number of carriers, in-phase signals are combined to generate a high average-to-average power ratio (PAPR), and the high PAPR results in the power amplifier of the OFDM transmitter. The operating point is located in the nonlinear region, resulting in nonlinear distortion of the signal. Therefore, in an OFDM system, the power amplifier is back-off to reduce the effect of PAPR. If the power amplifier is not sufficiently backed off, the frequency spectrum of the system is widened and the distortion caused by inter-frequency modulation is reduced. And result in a decrease in system performance.

It is essential to reduce the PAPR for the power efficiency and miniaturization of the OFDM transmitter. However, the lower the PAPR, the lower the reception performance.

In addition, in the case of visible light wireless communication using VLC, it is effective to reduce the PAPR to 0 dB. However, in the case of non-infrared light communication, the PAPR needs to be increased for reception performance. That is, the performance of the system can be improved when the PAPR can be adjusted according to the reception environment in the OFDM system.

As a method for lowering PAPR in an OFDM system, various methods, such as a block coding technique and a clipping technique, have been proposed, but these methods cannot ultimately lower the PAPR to 0 dB. Is not acceptable.

The present invention has been made in an effort to provide an apparatus and method for transmitting and receiving data capable of controlling PAPR according to a reception environment.

According to an embodiment of the present invention, an apparatus for transmitting data is provided. The data transmission apparatus includes a symbol mapping unit, a normalization and real signal conversion unit, an angular modulation unit, a PAPR control and power normalization unit, and a signal transmission unit. The symbol mapping unit generates a plurality of modulation data symbols by symbol mapping the input signal. A normalization and real signal converter converts the plurality of modulated data symbols into a real signal in the time domain in the frequency domain. An angular modulator angulates the real signal. The PAPR control and power normalization unit controls the magnitude of the sine component of each modulated real signal according to the first gain, and power normalizes the sine and cosine components of the real signal. The signal transmitter converts the power normalized real signal into a radio frequency signal and transmits the signal.

The PAPR control and power normalization unit may vary the first gain according to an input control signal.

The normalization and real signal converter may include a normalization unit for power normalizing the plurality of modulation data symbols such that an average power of the plurality of modulation data symbols is 1.

The normalization and real signal converters include an inverse fast Fourier transform unit for inverse fast Fourier transform on a plurality of input signals, and a plurality of conjugated complex symbols generated by conjugate complex-converting the plurality of modulation data symbols and the plurality of modulation data symbols. It may include an input signal processing unit for outputting to the inverse fast Fourier transform unit.

The angular modulator may include a phase controller for controlling the magnitude of the real signal in accordance with a second gain, and a modulator for angularly modulating the real signal into a cosine signal and a sine signal.

The PAPR control and power normalization unit includes: a PAPR controller for controlling the magnitude of a sine component of the angularly modulated real signal according to the first gain, and multiplying a cosine component of the real signal by a set value for power normalization to baseband I signal. And a second multiplier for generating a baseband Q signal by multiplying the set value by a sine component of the real signal whose magnitude is controlled according to the first gain.

When the first gain is 1, the PAPR may be zero.

According to another embodiment of the present invention, an apparatus for receiving data is provided. The data receiving apparatus includes a received signal processor, a power compensator, an angular demodulator, a normalized and real signal inverse transformer, a symbol demapping unit, and a parallel-serial converter. The received signal processor outputs a phase signal in a digital signal corresponding to the received data. The power compensator compensates for the magnitude of the phase signal corresponding to the magnitude controlled by the data transmission apparatus for PAPR control. An angular demodulator angulates the phase signal. The normalized and real-signal inverse transform unit converts each demodulated phase signal into a plurality of data symbols in the frequency domain in the time domain through fast Fourier transform. The symbol demapping unit generates a plurality of data signals by symbol demapping the plurality of data symbols. The parallel-serial converter converts the plurality of data signals into serial data signals to restore the received data.

The reception signal processor may include: a multiplier for multiplying a signal multiplied by a baseband Q signal by the data transmission device with the received data, and an analog for converting an output signal of the multiplier into a digital signal and outputting the phase signal from the digital signal. It may include a digital converter.

The power compensator includes a multiplier for compensating power by multiplying the phase signal by a first set value, and a PAPR controller for outputting a sine signal of the phase signal by dividing a power compensated phase signal by the first gain. It may include.

A sine signal and a cosine signal are generated through each modulation in the data transmission apparatus, and magnitude control for PAPR is performed on the sine signal, and the first setting value is estimated for the cosine signal generated in the data transmission apparatus. Value and an estimated value for the sine signal having the magnitude control.

The normalized and real-signal inverse transform unit may include a fast Fourier transform unit for generating a plurality of data symbols by performing fast Fourier transform on a plurality of input signals, a serial-parallel converter for converting each demodulated phase signal from a serial signal to a parallel signal; And a signal processor for outputting some of the plurality of data symbols to the demapping unit.

According to another embodiment of the present invention, a method for transmitting data by a data transmission device is provided. The data transmission method may include: generating a plurality of modulation data symbols by symbol mapping an input signal, converting the plurality of modulation data symbols into a real signal in a time domain in a frequency domain, and angularly modulating the real signal; Controlling the magnitude of the sinusoidal signal with respect to the angularly modulated real signal according to the set gain, and converting the angularly modulated real signal into a radio frequency signal and transmitting the same.

The controlling may include varying the gain according to an input control signal.

According to another embodiment of the present invention, a method for receiving data by a data receiving apparatus is provided. The data receiving method may include generating a phase signal corresponding to a real signal from a digital signal corresponding to received data, compensating for the magnitude of the phase signal corresponding to a magnitude controlled by a data transmission device for PAPR control, Angular demodulating a phase signal, converting the angulated demodulated phase signal into a plurality of data symbols in a frequency domain in the time domain, and symbol demapping the plurality of data symbols to generate a plurality of data signals Restoring the data.

According to the embodiment of the present invention, since the PAPR can be varied from 0 dB depending on the reception environment, problems caused by high PAPR, such as distortion caused by cross-frequency modulation and nonlinear distortion caused by a power amplifier, etc. Can be improved. In addition, a service considering both PAPR and reception performance, which is in inverse relationship, can be enabled according to a reception environment without changing a transmitter specification. For example, in the case of visible light wireless communication using lighting, the control may prevent flicker by controlling the PAPR to 0 dB, and in the case of communication using wireless light rather than infrared light, the PAPR may be increased to improve reception performance.

1 is a diagram illustrating an OFDM transmitter according to an embodiment of the present invention.

2 is a flowchart illustrating a data transmission method of an OFDM transmission apparatus according to an embodiment of the present invention.

3 is a diagram illustrating an NRSC shown in FIG. 1.

4 is a diagram illustrating an example of modulated data symbols symbol-mapped by digital modulation in the symbol mapping unit of FIG. 1.

FIG. 5 is a diagram illustrating an example of modulated data symbols normalized in the NRSC of FIG. 1.

FIG. 6 is a diagram illustrating each modulator shown in FIG. 1.

7 is a diagram illustrating a phase magnitude distribution of an input signal of each modulator.

8 is a diagram illustrating a phase magnitude distribution of an output signal of each modulator.

FIG. 9 is a diagram illustrating a PCPN shown in FIG. 1.

10 is a diagram illustrating an OFDM receiver according to an embodiment of the present invention.

11 is a flowchart illustrating a data receiving method of an OFDM receiver according to an embodiment of the present invention.

FIG. 12 is a diagram illustrating an example of a received signal processor illustrated in FIG. 10.

FIG. 13 is a diagram illustrating another example of the reception signal processor illustrated in FIG. 10.

FIG. 14 is a diagram illustrating the power compensator shown in FIG. 10.

FIG. 15 is a diagram illustrating each demodulator shown in FIG. 10.

FIG. 16 is a diagram illustrating an NRSDC shown in FIG. 10.

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.

Throughout the specification and claims, when a part is said to "include" a certain component, it means that it can further include other components, without excluding other components unless specifically stated otherwise.

An apparatus and method for transmitting and receiving data according to an embodiment of the present invention will now be described in detail with reference to the accompanying drawings.

1 is a diagram illustrating an OFDM transmitter according to an embodiment of the present invention, and FIG. 2 is a flowchart illustrating a data transmission method of an OFDM transmitter according to an embodiment of the present invention.

Referring to FIG. 1, the OFDM transmitter 100 may include a serial to parallel converter (SPC) 110, a symbol mapper 120, and a normalization and real signal converter. Real Signal Converter, NRSC (130), Angle Modulation unit (140), Peak to Average Power Ratio (PAPR) control and power normalization unit (PAP Control & Power Normalize unit, PCPN) 150 and signals Transmitter 160 is included.

2, when a plurality of serial data signals corresponding to bit data are input, the SPC 110 converts the plurality of serial data signals into a plurality of parallel data signals (S210).

The symbol mapping unit 120 performs symbol mapping on a plurality of parallel data signals through digital modulation such as Binary Phase Shift Keying (BPSK), Quadrature Amplitude Modulation (QAM), 16-QAM, 64-QAM, etc. To generate (S220).

The NRSC 130 normalizes the average power to 1 for a plurality of modulated data symbols (S240), and performs an inverse fast Fourier transform (IFFT) on the normalized symbols to perform modulation data symbols in the frequency domain. Is converted into a real signal in the time domain (S240). The NRSC 130 converts the real signal in the time domain into a serial signal (S250).

Each modulator 140 modulates the size of the real signal by modulating each real signal normalized by the NRSC 130 (S260). As each modulation method, a phase modulation method may be used.

The PCPN 150 controls the PAPR by adjusting the magnitude of the sine component of each modulated signal according to the input gain value (S270) and normalizes the power (S280).

Next, the signal transmitter 160 multiplies the real component of the power normalized signal by A, multiplies the imaginary component of the power normalized signal by B, and adds the two components to convert the power normalized signal into a radio frequency signal. In this case, A may be cos (2πf _c t) or sin (2πf _c t), and B may be cos (2πf _c t) or sin (2πf _c t), which may be different from A. f _c is the radio frequency. In FIG. 1, A is cos (2πf _c t) and B is sin (2πf _c t). Alternatively, the signal transmitter 160 may multiply the imaginary component of the power normalized signal by -B. The signal transmitter 160 transmits a radio frequency signal (S290). The radio frequency signal transmitted from the OFDM transmitter 100 may be defined as an OFDM signal.

Next, the OFDM transmitter 100 will be described in detail with reference to FIGS. 3 to 9.

3 is a diagram illustrating an NRSC shown in FIG. 1, FIG. 4 is a diagram illustrating an example of modulated data symbols symbol-mapped by digital modulation in the symbol mapping unit of FIG. 1, and FIG. 5 is a diagram of an NRSC of FIG. 1. FIG. 1 shows an example of a normalized modulated data symbol.

Referring to FIG. 3, the NRSC 130 includes a normalizer 131, an input signal processor 133, an IFFT unit 135, a parallel to serial converter (PSC) 137, and a multiplier 139. ).

The symbol mapping unit 120 modulates a plurality of parallel data signals to represent positions in constellations according to modulation schemes such as binary phase shift keying (BPSK), quadrature amplitude modulation (QAM), 16-QAM, and 64-QAM. Mapping to a symbol, the modulation data symbol may be as shown in FIG.

In order to normalize the modulation data symbol, the normalization unit 131 obtains an average value by taking an absolute value of the modulation data symbol, squares it, obtains a square root of the obtained average value, and divides the modulation data symbol by the square root, thereby obtaining an average power of 1. Can be normalized to

For example, the symbol mapping unit 120 locates a plurality of parallel data signals in constellations according to modulation schemes such as binary phase shift keying (BPSK), quadrature amplitude modulation (QAM), 16-QAM, and 64-QAM. A modulation data symbol is mapped to the modulation data symbol to be represented, and the modulation data symbol may be as shown in FIG. 4.

If the modulation data symbol is equal to FIG. 4, the average value is 10 (=

) To the modulated data symbol

By multiplying the modulated data symbols can be normalized, the normalized modulated data symbols can be shown as shown in FIG.

The input signal processor 133 converts the normalized modulated data symbol into an input signal X (0), of the IFFT unit 135, in order to convert the modulated data symbol normalized by the normalizer 131 into a real signal in the time domain. X (1),... , X (N-1), X (N), X (N + 1),... , X (2N-1)]. Here, N (exponential power of 2) represents the number of modulation data symbols, and if the number of modulation data symbols is N, the size of the IFFT may be 2N.

That is, the input signal processing unit 133 may input the input signals X (0), X (1),... Of the IFFT unit 135. , X (N-1), X (N), X (N + 1),... , N (modulated data) symbols are used for X (2N-1), and the input signals X (N), X (N + 1),... Of the IFFT unit 135 are used. , X (2N-1)] is used by conjugate conjugated N modulation data symbols. The 0th modulation data symbol is 0, so that the modulation data symbols inputted to the input signals X (0) and (X (N)] become 0. That is, the input signals X (1), ..., X ( N-1)] using N data symbols and conjugate signal complex modulation of the modulation data symbol of the input signal [X (2N-k)] with the input signals [X (N + 1), ..., X (2N-1)]. Can be used, where k is N + 1, N + 2, ..., 2N-1.

Input signal to IFFT unit 135 [(X (0), X (1), ..., X (N-1), X (N), X (N + 1), ..., X (2N-1)] Is input, the IFFT unit 135 inputs the input signal [(X (0), X (1), ..., X (N-1), X (N), X (N + 1), ..., X (2N). -1)], where the modulated data symbols are the real-time signals [(X '(0), X' (1), ..., X '(N-1), X' (N) in the frequency domain). ), X '(N + 1), ..., X' (2N-1)].

The PSC 137 converts a real time signal in a time domain from a parallel signal to a serial signal.

The multiplier 139 is used for a series real signal.

Normalize by multiplying

6 is a diagram illustrating each modulator illustrated in FIG. 1, FIG. 7 is a diagram illustrating a phase magnitude distribution of an input signal of each modulator, and FIG. 8 is a diagram illustrating a phase magnitude distribution of an output signal of each modulator.

Referring to FIG. 6, each modulator 140 includes a phase controller 141 and a modulator 143.

The phase controller 141 receives a normalized real signal from the NRSC 130 as an input signal IN. The phase controller 141 adjusts the magnitude of the input signal IN by varying the gain G1 such that the magnitude of the input signal IN is in the range of −π / 2 to π / 2. Where π is the circumference.

For example, when the magnitude of the input signal IN of the phase controller 141 is equal to that of FIG. 8, the phase controller 141 may have the magnitude of the input signal IN in a range of −π / 2 to π / 2, The size of the input signal IN may be adjusted by multiplying the input signal IN by a gain 0.4. Then, as shown in FIG. 8, the phase magnitude of the input signal IN may be in the range of −π / 2 to π / 2.

The modulator 143 angulates the real signal adjusted by the phase controller 141 into a cosine signal and a sine signal [cos (IN), sin (IN)].

FIG. 9 is a diagram illustrating a PCPN shown in FIG. 1.

Referring to FIG. 9, the PCPN 150 includes a PAPR controller 151 and

multipliers

153 and 155. The

multipliers

153 and 155 may operate as a power normalizer for power normalization.

The cosine signal [cos (IN)], which is an output signal of the modulator 143, is denoted as a (t) in FIG. 9 for convenience of description.

The cosine signal [a (t)], which is the output signal of the modulator 143, is input to the multiplier 153 without passing through the PAPR controller 151, and the sine signal [sin (IN)], which is the output signal of the modulator 143, is It is input to the PAPR controller 151.

The PAPR controller 151 controls the gain G2 according to the input control signal, and adjusts the magnitude of the sine signal sin (IN) input according to the gain G2. In this case, the control signal may include a gain value to be controlled.

That is, the PAPR controller 151 controls the PAPR by adjusting only the magnitude of the sine component of each modulated signal. The sine signal b (t) adjusted by the PAPR controller 151 is input to the multiplier 155.

In general, the PAPR in one OFDM symbol is represented by Equation (1). In general, a guard interval is inserted into a time-domain serial signal output from the NRSC 130, and the guard interval and a signal corresponding to one modulation data symbol are combined to be called an OFDM symbol.

[Equation 1]

Here, E {.} Represents an expected value, and T represents a period of one OFDM symbol.

In this case, the PAPR (dB) according to the embodiment of the present invention may be expressed as Equation 2 and Equation 2.

[Equation 2]

[Equation 3]

In Equation 3, Gain represents the gain G2 of the PAPR controller 151, and when Gain is 1, the PAPR becomes 0 dB.

In particular, as can be seen from Equation 3, the PAPR varies depending on the gain. That is, since it is possible to control the gain G2 using the control signal according to the reception environment, the control of the PAPR may be possible accordingly.

For example, the gain G1 of the phase controller 141 shown in FIG. 6 is 0.4, the size of the IFFT is 2048, and for 16QAM modulation, the PAPR is the gain G2 of the PAPR controller 151 as shown in Table 1 below. ) May vary.

TABLE 1

The cosine signal a (t) and the scaled sine signal b (t) are multiplied by the value of C for power normalization. C is the same as Equation 4.

[Equation 4]

That is, the multiplier 153 multiplies the cosine signal [a (t)] by C to power normalization, and the multiplier 155 multiplies the sine signal [b (t)] by C to normalize power.

If the power normalized cosine signal is called a baseband I signal, and the power normalized sine signal is called a baseband Q signal, respectively,

and

Multiply by and add to convert to a radio frequency signal.

10 is a diagram illustrating an OFDM receiver according to an embodiment of the present invention, and FIG. 11 is a flowchart illustrating a data reception method of an OFDM receiver according to an embodiment of the present invention.

Referring to FIG. 10, the OFDM receiver 200 includes a received signal processor 210, a power compensator 220, an angle demodulation unit 230, and a normalized and real signal inverse transform unit. -Converter (NRSDC) 240, a symbol demapping unit 250, and a PSC 260. The OFDM receiver 200 performs the reverse operation of the OFDM transmitter 100.

Referring to FIG. 11, when the reception signal processor 210 receives an OFDM signal as received data, the received signal processor 210 multiplies the real component of the OFDM signal by A 'and multiplies the imaginary component of the power normalized signal by B', and then converts the analog signal through analog-to-digital conversion. In operation S1110, a bandpass analog signal is converted into a plurality of baseband digital signals. Here, A 'and B' may be the same as A and B of the OFDM receiver 100, and B 'may be -B. A 'may be cos (2πf _c t) or sin (2πf _c t), and B' may be cos (2πf _c t) or sin (2πf _c t), which may be different from A '. f _c is the radio frequency.

The power compensator 220 compensates for the size adjusted by the PAPR controller 151 with respect to the plurality of baseband digital signals (S1120).

Each demodulator 230 demodulates each of a plurality of baseband digital signals whose magnitude is compensated by the power compensator 220 (S1130).

The NRSDC 240 converts each demodulated signal from a serial signal to a parallel signal (S1140) and performs a Fast Fourier Transform (FFT) on the converted parallel signal, so that parallel data symbols in the frequency domain are performed in the parallel signal in the time domain. Convert to (S1150).

The symbol demapping unit 250 demaps the parallel data symbols in the frequency domain output from the NRSDC 240 through digital demodulation such as BPSK, QAM, 16-QAM, and 64-QAM to generate a plurality of parallel data signals. (S1160).

The PSC 270 converts a plurality of parallel data signals output from the symbol demapping unit 260 into a plurality of serial data signals and outputs the converted serial data signals (S1170), thereby restoring an OFDM signal to a data signal.

Next, the OFDM receiver 200 will be described in detail with reference to FIGS. 12 to 16.

FIG. 12 is a diagram illustrating an example of a received signal processor illustrated in FIG. 10, and FIG. 13 is a diagram illustrating another example of a received signal processor illustrated in FIG. 10.

Referring to FIG. 12, the reception signal processor 210 includes a

multiplier

211 and 213, a low pass filter (LPF) 215 and 217, and an analog to digital converter (ADC) 219. It includes.

The multiplier 211 multiplies the received OFDM signal by A ', converts it to a cosine signal or a sine signal, and outputs the result to the LPF 215. In FIG. 12, A ′ is shown to be cos (2πf _c t). In this case, the signal output from the multiplier 211 may be a cosine signal.

The multiplier 213 multiplies the received OFDM signal by B ', converts it to a cosine signal or a sine signal, and outputs the result to the LPF 217. In FIG. 12, B ′ is illustrated as sin (2πf _c t), and the signal output from the multiplier 211 may be a sine signal.

Here, A 'may be cos (2πf _c t) or sin (2πf _c t), and B' may be cos (2πf _c t) or sin (2πf _c t), which may be different from A '.

The

LPFs

215 and 217 respectively filter cosine signals and sinusoidal signals input from the

multipliers

211 and 213, and pass only signals of a desired band in the input signal.

The ADC 219 converts the cosine signal and the sine signal passed through the

LPFs

215 and 217 into a digital signal through analog-to-digital conversion, and then outputs a phase value from any one of the digital signals. The ADC 219 may output a phase value from the digital signal generated by multiplying the OFDM signal by a signal multiplied by the baseband Q signal by the OFDM transmitter 100 between A 'and B'.

Unlike this, referring to FIG. 13, the received signal processor 210 ′ may further include a switching unit 212 as compared to the received signal processor 210 illustrated in FIG. 12.

The switching unit 212 multiplies the received OFDM signal so that the signal multiplied by the baseband Q signal (cos (2πf _c t) or sin (2πf _c t)) is multiplied by the OFDM signal in the OFDM transmitter 100. 211) or to the multiplier 213. For example, when the baseband Q signal is multiplied by sin (2πf _c t) and converted into a radio frequency signal in the OFDM transmitter 100, the switching unit 212 may output the OFDM signal to the multiplier 213. have.

On the other hand, in the OFDM transmitter 100, when the signal multiplied by the baseband Q signal [cos (2πf _c t) or sin (2πf _c t)] is multiplied by a negative sign, the ADC 219 outputs a phase value. You can multiply (phase) by the minus sign.

FIG. 14 is a diagram illustrating the power compensator shown in FIG. 10.

Referring to FIG. 14, the power compensator 220 includes a multiplier 221 and a PAPR controller 223.

The multiplier 221 multiplies D by a phase value output from the reception signal processor 210 or 210 'to compensate for power and outputs the power to the PAPR controller 223. In this case, D may be represented as in Equation 5.

[Equation 5]

Here, T means a period of the OFDM symbol.

Denotes an estimate of the cosine signal (a (t) in FIG. 9) in the OFDM transmitting apparatus 100,

Denotes an estimate of a sine signal (sin (IN (t)) in FIG. 9) in the OFDM transmitter 100. FIG. Gain also represents the gain G3 of the PAPR controller 223.

And

Since the IFFT signal is a random signal cannot be accurately obtained. Therefore, the error can be reduced by averaging over and over again, and the estimate according to the gain G1 of the phase controller 141 of FIG. 6 of the OFDM transmitter 100 may be as shown in Table 2.

TABLE 2

The PAPR controller 223 divides the power-compensated signal by the multiplier 221 by the gain G3 of the PAPR controller 223 and outputs a sine signal [sin (phase)]. It is equal to the gain G2 of the PAPR controller 151 of the gain G3 of the PAPR controller 223. For example, if the gain G1 of the phase controller 141 of FIG. 6 is 0.4 and the gain G3 of the PAPR controller 223 is 2, D is 1.179. Dividing the phase multiplied by 1.179 by 2 produces a sine signal [sin (phase)].

FIG. 15 is a diagram illustrating each demodulator shown in FIG. 10.

Referring to FIG. 15, each demodulator 230 includes a demodulator 231 and a phase controller 233.

The demodulator 231 obtains the inverse sine of the sine signal [sin (phase)] output from the power compensator 220, that is, the inverse sine value [Asin (phase)], and then outputs it to the phase controller 233. do.

The inverse sine (z) of the sine signal sin (z) may be obtained as in Equation 6.

[Equation 6]

Here j is a complex imaginary unit and satisfies j ² = 1.

The phase controller 233 has a gain G4 and outputs a phase value by dividing the inverse value [Asin (phase)] from the demodulator 231 by the gain G4. Here, the gain G4 is equal to the gain G1 of the phase controller 141 of each modulator 140.

FIG. 16 is a diagram illustrating an NRSDC shown in FIG. 10.

Referring to FIG. 16, the NRSDC 250 includes a multiplier 251, an SPC 253, an FFT unit 255, and a signal processor 257.

The multiplier 251 multiplies and normalizes a real signal output from each demodulator 230 to SPC 253.

In order to FFT the normalized signal, the SPC 253 converts the normalized signal by the multiplier 251 into a parallel signal and outputs it to the FFT unit 255.

The parallel signals converted by the SPC 253 are input signals P (0), P (1),... Of the FFT unit 255. , P (N-1), P (N), P (N + 1),... , P (2N-1)], the FFT unit 255 enters the input signals P (0), P (1),... , P (N-1), P (N), P (N + 1),... , P (2N-1)] is FFTed. Then, the input signals P (0), P (1),... , P (N-1), P (N), P (N + 1),... , P (2N-1)] are the data symbols X (0), X (1), ... in the frequency domain in the time domain. , X (N-1), X (N), X (N + 1),... , X (2N-1)].

The signal processor 257 stores data symbols [(X (0), X (1), ..., X (N-1), X (N), X (N + 1), ..., X (2N-) in the frequency domain. 1)] and outputs a signal in the frequency domain [(X (0), X (1), ..., X (N-1)] to the symbol demapping unit 260. At this time, the signal processing unit 257 outputs data. The symbols [(X (0), X (1), ..., X (N-1)] may be output as they are to the symbol demapping unit 260. The signal processing unit 257 may output data symbols [X] in the frequency domain. Complex conjugate conversion of (N + 1), ..., X (2N-1)], and then relocate the data symbol at the position of X (2N-k) and output it to the symbol demapping unit 260. Here, k is N + 1, N + 2, ..., 2N-1 For example, in the case of the symbol [X (2N-1)] in the frequency domain after FFT, the signal processing unit 257 Can be rearranged to the position of X (1) after complex conjugate conversion of the symbol X (2N-1) in the frequency domain.

The symbol demapping unit 260 demaps each data symbol into a plurality of parallel data signals in a constellation diagram according to a demodulation scheme corresponding to the symbol mapping unit 120 of the OFDM transmitter 100, and a plurality of parallel data. The signal is output to the PSC 270. The PSC 270 then recovers the data by converting the plurality of parallel data signals into a plurality of serial data signals.

The embodiments of the present invention described above are not only implemented through the apparatus and the method, but may also 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.

Claims

In the device sending the data,

A symbol mapping unit for generating a plurality of modulation data symbols by symbol mapping the input signal;

A normalization and real signal converter for converting the plurality of modulated data symbols into a real signal in a time domain in a frequency domain;

An angular modulator for angularly modulating the real signal;

A PAPR control and power normalization unit for controlling the magnitude of the sine component of each modulated real signal according to a first gain and power normalizing the sine and cosine components of the real signal;

A signal transmitter for converting the power normalized real signal into a radio frequency signal for transmission

Data transmission device comprising a.
In claim 1,

And the PAPR control and power normalization unit varies the first gain according to an input control signal.
In claim 1,

The normalization and real signal converter,

And a normalizer for power normalizing the plurality of modulation data symbols such that an average power of the plurality of modulation data symbols is one.
In claim 1,

The normalization and real signal converter,

An inverse fast Fourier transform unit for inverse fast Fourier transform on a plurality of input signals, and

An input signal processor for outputting a plurality of conjugate complex symbols generated by conjugate complex-conversion the plurality of modulation data symbols and the plurality of modulation data symbols to the inverse fast Fourier transform unit

Data transmission device comprising a.
In claim 4,

The input signal processor,

When the number of the plurality of modulation data symbols is N, N modulation data symbols are positioned at positions 0 to N-1 th input signals, and the plurality of conjugated complexes are positioned at positions N to (2N-1) th input signals. Place the symbol,

Position the complex conjugate symbol of the (2N-k) th input signal at the position of the (N + 1) th to (2N-1) input signal,

Wherein N is a positive number and k is a value from N + 1 to 2N-1.
In claim 1,

The angle modulator,

A phase controller for controlling the magnitude of the real signal in accordance with a second gain, and

And a modulator for angularly modulating the real signal into a cosine signal and a sine signal.
In claim 1,

The PAPR control and power normalization unit,

A PAPR controller for controlling the magnitude of the sinusoidal component of the angularly modulated real signal according to the first gain;

A first multiplier for generating a baseband I signal by multiplying a cosine component of the real signal by a set value for power normalization, and

And a second multiplier for generating a baseband Q signal by multiplying a sine component of the real signal whose magnitude is controlled according to the first gain by the set value.
In claim 7,

And a PAPR of 0 when the first gain is 1.
In claim 7,

The signal transmitter,

Generating the radio frequency signal by multiplying the baseband I signal by a second set value, multiplying the baseband Q signal by a third set value, and adding

The second set value is one of a sine function and a cosine function of radio frequency,

And the third set value is different from the second set value among a sine function and a cosine function of the radio frequency.
On the device receiving the data,

A reception signal processor for outputting a phase signal from a digital signal corresponding to the reception data;

A power compensator for compensating the magnitude of the phase signal corresponding to the magnitude controlled by the data transmission apparatus for PAPR control;

An angle demodulation unit for demodulating the phase signal,

A normalized and real-signal inverse transform unit for converting each demodulated phase signal into a plurality of data symbols in a frequency domain in a time domain through a fast Fourier transform;

A symbol demapping unit configured to generate a plurality of data signals by symbol demapping the plurality of data symbols, and

A parallel-serial converter converting the plurality of data signals into a serial data signal to restore the received data

Data receiving apparatus comprising a.
In claim 10,

The received signal processor,

A multiplier for multiplying the received data by a signal multiplied by a baseband Q signal in the data transmission apparatus, and

And an analog to digital converter for converting the output signal of the multiplier into a digital signal and outputting the phase signal from the digital signal.
In claim 10,

The power compensator,

A multiplier for power compensation by multiplying the phase signal by a first set value; and

And a PAPR controller having a first gain and dividing a power compensated phase signal by the first gain to output a sine signal of the phase signal.
In claim 12,

In the data transmission apparatus, a sine signal and a cosine signal are generated through each modulation, and magnitude control for PAPR is performed on the sine signal.

And the first set value is determined by an estimated value for a cosine signal generated by the data transmitter and an estimated value for a sine signal in which the magnitude control is performed.
In claim 10,

The normalization and real signal inverse transform unit,

A fast Fourier transform unit for generating a plurality of data symbols by performing fast Fourier transform on a plurality of input signals;

A serial-to-parallel converter for converting each demodulated phase signal from a serial signal to a parallel signal, and

And a signal processor to output a part of the plurality of data symbols to the demapping unit.
In a method in which a data transmitting apparatus transmits data,

Symbol mapping the input signal to generate a plurality of modulated data symbols;

Converting the plurality of modulated data symbols into a real signal in a time domain in a frequency domain;

Angularly modulating the real signal;

Controlling the magnitude of the sinusoidal signal for each angularly modulated real signal in accordance with the set gain, and

Converting the angularly modulated real signal into a radio frequency signal and transmitting the radio frequency signal

Data transmission method comprising a.
The method of claim 15,

The controlling step,

And varying the gain in accordance with an input control signal.
The method of claim 15,

Power normalizing the sine and cosine components of the real signal before the controlling step.

The data transmission method further comprising.
The method of claim 15,

The converting step,

Inverse fast Fourier transform for a plurality of input signals,

Setting a plurality of conjugated complex symbols obtained by conjugate complex complex conversion of the plurality of modulation data symbols and the plurality of modulation data symbols as a plurality of input signals for inverse fast Fourier transform,

Position the plurality of modulation data symbols at positions 0 through N-1 of the input signal, and position the plurality of conjugated complex symbols at positions of N to (2N-1) th input signals, wherein the (2N-k) th Positioning a conjugated complex symbol of the input signal at a position of the (N + 1) to (2N-1) th input signal, and

Inverse fast Fourier transform for the plurality of input signals,

N is a positive number and k is a value from N + 1 to 2N-1.
In the method for the data receiving device to receive data,

Generating a phase signal corresponding to a real signal from a digital signal corresponding to the received data,

Compensating for the magnitude of the phase signal corresponding to the magnitude controlled by the data transmission device for PAPR control;

Angular demodulating the phase signal,

Converting each demodulated phase signal into a plurality of data symbols in the frequency domain in the time domain, and

Symbol demapping the plurality of data symbols to generate a plurality of data signals to restore the received data

Data receiving method comprising a.
The method of claim 19,

The converting step,

Converting each demodulated phase signal from a serial signal to a parallel signal,

Fast Fourier transforming a plurality of conjugated complex signals generated by conjugate complex converting the parallel signal and the parallel signal, and

Selecting a portion of the fast Fourier transformed data symbols as the plurality of data symbols.