JP2009044338A - Ofdm receiver and ofdm receiving method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To effectively cancel distortion components of a received OFDM signal based on frequency deviation between transmission and reception with simple structure. <P>SOLUTION: This OFDM receiver is provided with a distortion compensation part which compensates the distortion components superimposed on a base band OFDM signal on the basis of a pilot signal multiplexed to the base band OFDM signal, wherein the distortion compensation part is provided with: an OFDM main signal component extraction part which passes the base band OFDM signal through a filter to extract OFDM main signal components; and a distortion compensation signal generation part which performs discrete Fourier transform of the base band OFDM signal to be converted into a frequency component signal, extracts frequency components of the pilot signal of the frequency component signal to rearrange the frequency components at a position where the frequency is zero, performs inverse Fourier transform of the rearranged pilot signal components to be converted into a time signal, and generates a distortion compensation signal for compensating the distortion components superimposed on the pilot signal converted into the time signal on the basis of the known pilot signal. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an OFDM receiving apparatus and an OFDM receiving method. In particular, an RF processing unit that receives and preprocesses an RF band OFDM signal to generate a baseband OFDM signal, and a distortion component superimposed on the baseband OFDM signal based on a pilot signal multiplexed on the baseband OFDM signal The present invention is suitable for application to an OFDM receiving apparatus and an OFDM receiving method that include a distortion compensating unit that compensates for OFDM and a demodulating unit that OFDM-demodulates the distortion-compensated OFDM signal.

  The OFDM communication system is used in a wireless LAN system (IEEE802.11a) and terrestrial digital broadcasting. Further, as a wireless communication system for a home network in a home, high-speed transmission using the OFDM system in the millimeter wave band is used. Technology development is underway. At present, since the frequency of 10 GHz or less is tight, there are high expectations for general use of the millimeter wave band in the future.

  OFDM communication is a technique for transmitting information using multicarriers, and has a characteristic that it is not easily affected by fading in a multipath environment because it transmits a number of subcarriers with guard times. On the other hand, in OFDM communication, if the orthogonality between subcarriers is lost during reception demodulation, the reception error rate is greatly degraded. Path delay due to multipath can be prevented to some extent by providing a guard time, but if the frequency of the carrier wave fc deviates more than expected, the reception error rate is greatly affected. This will be described in detail below.

  FIG. 10 is a diagram for explaining the prior art, and shows a basic configuration of an OFDM communication apparatus. FIG. 10A is a block diagram of an OFDM transmission apparatus, which includes an OFDM modulation unit 10 and an RF amplification unit 20. In the figure, transmission I and Q data are converted by a symbol mapper 11 into N complex symbol sequences for modulating each subcarrier, and the converted complex symbol sequences are converted by a serial / parallel converter (S / P) 12. The signal is converted into a parallel signal and further subjected to batch inverse Fourier transform by a discrete Fourier inverse transform unit (IFFT) 13 to generate N ODFM symbol sample values. Further, the generated N ODFM symbol sample values are converted into serial (time) signals by a parallel-serial converter (P / S) 14 to generate a complex baseband OFDM signal, and the output thereof is converted into a real number unit ( RE) is converted to a real number by 15 and added to the RF amplification unit 20. The RF amplification unit 20 multiplies the real part of the complex baseband OFDM signal by the carrier wave (fc) and passes the output through the BPF 23 to generate an RF band OFDM signal. This is amplified by an RF amplifier (RFA) 24 and transmitted from an antenna.

  FIG. 10B is a block diagram of the ODM receiving apparatus, and the ODM receiving apparatus includes an RF front end unit (RFFE) 30 and an OFDM demodulating unit 40. In the figure, an OFDM signal in an RF band received by an antenna is amplified by a low noise amplifier (LNA) 31, and then separated into I and Q signal components and the frequency is down-converted by mixers 34a and 34b to form a complex baseband OFDM signal. And is sampled by the sampling unit 35 to generate a complex signal sequence. Further, the complex signal sequence is converted into N parallel signals by a serial-parallel converter (S / P) 41, and discrete Fourier transform (FFT) is performed on the converted N sample values, thereby A complex symbol sequence that modulates a subcarrier is extracted. The extracted complex symbol sequence is converted into a serial signal sequence by a parallel / serial conversion unit (P / S) 43, and these are determined by a data determination unit 44 to demodulate received data.

In this way, in OFDM communication, the OFDM signal in the RF band up-converted by the local oscillator (fc) 21 on the transmission side is down-converted by the local oscillator (fc) 32 unique to the reception side to perform OFDM demodulation. / 32 oscillation accuracy and synchronization performance of the synchronization circuit are not sufficient, or an error (phase noise) occurs between the two frequencies fc due to the Doppler effect accompanying movement of the communication device.

  As a result of uniformly superimposing such phase noise on all subcarriers, intercarrier interference (ICI) is caused between all subcarriers. In this case, if the demodulated symbols are only the desired symbols. Instead, it receives interference from symbols transmitted on all other subcarriers in the same OFDM symbol.

Conventionally, when canceling phase noise using a pilot signal having a known amplitude / phase characteristic, the pilot signal is extracted in order to extract an optimum C / N pilot signal according to the reception level of the reception IF signal. A transmission signal processing apparatus that adaptively changes the pass bandwidth of an extraction filter is known (Patent Document 1).
JP 2006-140608 A JP 2002-152158 A

  The present invention has been made in view of the above-described problems of the prior art. An object of the present invention is to provide an OFDM receiving apparatus and OFDM receiving method capable of effectively canceling distortion of a received OFDM signal based on a frequency deviation between transmission and reception with a simple configuration. It is to provide.

  An OFDM receiver according to a first aspect of the present invention is based on an RF processing unit that receives and preprocesses an RF band OFDM signal to generate a baseband OFDM signal, and a pilot signal multiplexed on the baseband OFDM signal. An OFDM receiver comprising: a distortion compensation unit that compensates for distortion components superimposed on the baseband OFDM signal; and a demodulation unit that performs OFDM demodulation on the distortion-compensated OFDM signal, wherein the distortion compensation unit includes the baseband OFDM An OFDM main signal component extraction unit that extracts the OFDM main signal component by passing the signal through a filter, and converts the baseband OFDM signal into a frequency component signal by discrete Fourier transform, and extracts the frequency component of the pilot signal The frequency component is rearranged at the position of frequency 0, and the rearranged pilot is Distortion compensation signal generation for generating a distortion compensation signal for compensating for a distortion component superimposed on a pilot signal converted to a time signal based on a known pilot signal by converting the signal component into a Fourier signal by inverse Fourier transform And a distortion cancellation unit that cancels the distortion component superimposed on the extracted OFDM main signal component by the generated distortion compensation signal. According to the present invention, the distortion component superimposed on the pilot signal can be efficiently detected and the distortion component superimposed on the OFDM main signal component can be collectively compensated in time series, so that the distortion compensation processing and the circuit configuration are simple.

An OFDM receiver according to a second aspect of the present invention is based on an RF processing unit that receives and preprocesses an RF band OFDM signal and generates a baseband OFDM signal, and a pilot signal multiplexed on the baseband OFDM signal. An OFDM receiver comprising: a distortion compensation unit that compensates for distortion components superimposed on the baseband OFDM signal; and a demodulation unit that performs OFDM demodulation on the distortion-compensated OFDM signal, wherein the distortion compensation unit includes the baseband OFDM A Fourier transform unit for transforming the signal into a frequency component signal by performing discrete Fourier transform, and an OFDM main signal component for extracting a portion related to the OFDM main signal from the converted frequency component signal and converting it into a time signal by inverse discrete Fourier transform An extraction unit and a portion related to the pilot signal in the converted frequency component signal are extracted. The pilot signal component is rearranged at a position of frequency 0, and the rearranged pilot signal component is converted into a time signal by Fourier inverse transform, and converted into the time signal based on a known pilot signal. A distortion compensation signal generation unit that generates a distortion compensation signal for compensating the superimposed distortion component, and a distortion cancellation unit that cancels the distortion component superimposed on the extracted OFDM main signal component by the generated distortion compensation signal Are provided. In the present invention, since the filter circuit is not used, the OFDM main signal component and the pilot signal component can be separated with high accuracy.

  An OFDM receiver according to a third aspect of the present invention is based on an RF processing unit that receives and pre-processes an RF band OFDM signal to generate a baseband OFDM signal, and a pilot signal multiplexed on the baseband OFDM signal. An OFDM receiver comprising: a distortion compensation unit that compensates for distortion components superimposed on the baseband OFDM signal; and a demodulation unit that performs OFDM demodulation on the distortion-compensated OFDM signal, wherein the distortion compensation unit includes the baseband OFDM An OFDM main signal component extracting unit for extracting an OFDM main signal component by passing a signal through a first filter; and extracting a component related to a pilot signal by passing the baseband OFDM signal through a second filter; The pilot signal component is frequency-converted until the signal component reaches the position of frequency 0, and the known A distortion compensation signal generator for generating a distortion compensation signal for compensating for a distortion component superimposed on the pilot signal frequency-converted based on a pilot signal; and a distortion component superimposed on the extracted OFDM main signal component And a distortion canceling unit that cancels using the generated distortion compensation signal. In the present invention, since all signal processing is performed on the time axis, the circuit configuration is simple.

  An OFDM receiver according to a fourth aspect of the present invention is based on an RF processing unit that receives and pre-processes an RF band OFDM signal to generate a baseband OFDM signal, and a pilot signal multiplexed on the baseband OFDM signal. An OFDM receiver comprising: a distortion compensation unit that compensates for distortion components superimposed on the baseband OFDM signal; and a demodulation unit that performs OFDM demodulation on the distortion-compensated OFDM signal, wherein the distortion compensation unit includes the baseband OFDM An OFDM main signal component extraction unit that extracts the OFDM main signal component by passing the signal through the first filter, and the frequency of the baseband OFDM signal until the pilot signal component included in the baseband OFDM signal is at a position of frequency 0 The frequency-converted signal is passed through the second filter and the pilot signal is applied And a distortion compensation signal generator for generating a distortion compensation signal for compensating a distortion component superimposed on the extracted pilot signal based on a known pilot signal, and the extracted OFDM main signal component And a distortion cancellation unit that cancels the superimposed distortion component using the generated distortion compensation signal. In the present invention, since the pilot signal component is first down-converted, the pilot signal component can be extracted with a relatively simple LPF.

  An OFDM reception method according to a fifth aspect of the present invention receives and pre-processes an RF band OFDM signal to generate a baseband OFDM signal, and the baseband OFDM signal is based on a pilot signal multiplexed on the baseband OFDM signal. In an OFDM reception method for compensating for a distortion component superimposed on a signal and OFDM demodulating the distortion-compensated OFDM signal, the distortion compensation unit extracts the OFDM main signal component by passing the baseband OFDM signal through a filter. The baseband OFDM signal is subjected to discrete Fourier transform to be converted into a frequency component signal, and the frequency component of the pilot signal is extracted, and the frequency component is rearranged at the position of frequency 0, and the rearranged pilot signal is The components are Fourier transformed and converted to a time signal, based on a known pilot signal. Generating a distortion compensation signal for compensating for the distortion component superimposed on the pilot signal converted into the time signal, and canceling the distortion component superimposed on the extracted OFDM main signal component by the generated distortion compensation signal. To do.

  As described above, according to the present invention, the distortion of the received OFDM signal based on the frequency deviation between transmission and reception can be effectively canceled with a simple configuration, and thus this type of OFDM receiving apparatus can be provided in a small size and at low cost.

  Hereinafter, a plurality of embodiments of the present invention will be described in detail with reference to the accompanying drawings. Note that the same reference numerals denote the same or corresponding parts throughout the drawings. FIG. 1 is a block diagram of an OFDM transmission apparatus according to an embodiment, and shows a case where a pilot signal is added to an OFDM main signal (data signal) for transmission. The basic configuration of the OFDM modulation unit 10 and the RF amplification unit 20 may be the same as that described with reference to FIG. The configuration of this OFDM transmitter is commonly used in the description of OFDM receivers according to the first to fourth embodiments described below.

  In FIG. 1, (N + P) bit strings composed of N transmission data and P (for example, 1) pilot data are converted into (N + P) complex symbol strings by a symbol mapper 11 and then serial-parallel converted. The parallel signal is converted by the unit 12 and the inverse inverse Fourier transform is performed by the discrete Fourier inverse transform unit (IFFT) 13, thus generating (N + P) ODFM symbol sample values. These are converted into a serial (time) signal by the parallel-serial converter 14, and then the real part of the obtained complex baseband OFDM signal is multiplied by the carrier wave (fc) to generate an RF band OFDM signal. This is amplified by an RF amplifier (RFA) 24 and transmitted from an antenna.

An example of pilot signal arrangement is shown in the inset (a). Here, pilot signal PL is placed at a position of frequency fp that is at least one sample (basic frequency f ₀ minutes) or more away from the portion of OFDM main signal (data signal) having center frequency fc. Inset (b) shows another pilot signal arrangement example. Here, pilot signal component PL and guard band GB are arranged at the position of center frequency fc of the entire band including pilot signal PL. The guard band GB is for facilitating (reliable) band separation by a digital filter or the like, and the guard band GB is not necessarily provided. Further, in the following description of each embodiment, the case of the frequency arrangement of the inset (a) will be described, but the case of other frequency arrangements can be processed in the same way.

  FIG. 2 is a block diagram of the OFDM receiver according to the first embodiment. A distortion compensation signal generated by generating a distortion component superimposed on an OFDM main signal component (data signal portion) based on a received pilot signal and a known pilot signal. 1 shows a first embodiment of a distortion compensator that compensates for The basic configuration of the RF front end unit 30 and the OFDM demodulation unit 40 may be the same as that described in FIG. In the figure, 50A is a distortion compensation unit according to the first embodiment, 51 is a digital low pass filter (LPF), 52 is a delay circuit, 53 is a high-speed discrete Fourier transform unit (FFT), 54 is a 0 shift unit, and 55 is a discrete unit. A Fourier inverse transform unit (IFFT), 56 is a distortion compensation signal generation unit (1 / α), and 60 is a multiplication unit.

  FIG. 3 is a diagram for explaining the operation of the OFDM receiver according to the first embodiment. Hereinafter, the operation of the distortion compensator 50A according to the first embodiment will be described with reference to FIGS. The input baseband OFDM signal {FIG. 3 (a)} is divided into two systems, one of which is passed through the LPF 51 to extract only the OFDM main signal component {FIG. 3 (b)} excluding the pilot signal component. The extracted OFDM main signal component is temporarily held in the delay circuit 52 in order to match the delay caused by the pilot signal processing with the processing time.

The other of the baseband OFDM signals is converted into a frequency component signal by FFT 53, and then a pilot signal component and a guard band component {FIG. 3 (c)} are extracted, and the frequency of the pilot signal component becomes 0 Hz. In this way, 0 shift (rearrangement) {(FIG. 3 (d)} is performed. In addition, by inserting “0” into each frequency component in the range above the guard band portion, IFFT processing is performed. The number of points is adjusted to the required number of IFFT points in the next IFFT 55. When this is Fourier-transformed by the IFFT 55, a time signal (DC signal) {FIG. 3 (e)} for the pilot signal PL is obtained.

  This pilot signal PL receives inter-carrier interference (ICI) from all other subcarriers based on the frequency deviation substantially uniformly. Conversely, each of the other subcarriers also receives from all the other subcarriers including the pilot signal. Inter-carrier interference is received almost uniformly. Therefore, the distortion compensation signal generation unit 56 obtains the distortion component α of the received pilot signal based on the known pilot signal level, and multiplies the OFDM main signal component by the inverse (1 / α), for example, to determine the OFDM main signal component. Remove distortion components.

  FIG. 4 is a block diagram of an OFDM receiver according to the second embodiment, and shows a second embodiment of the distortion compensator according to the present invention. In the figure, 50B is a distortion compensation unit according to the second embodiment, 57 is a discrete Fourier transform unit (FFT), 58 is a 0 insertion unit, 55a and 55b are discrete Fourier inverse transform units (IFFT), and 54 is a 0 shift unit. , 56 are distortion compensation signal generators (1 / α), and 60 is a multiplier.

  FIG. 5 is a diagram for explaining the operation of the OFDM receiver according to the second embodiment. Hereinafter, the operation of the distortion compensator 50B according to the second embodiment will be described with reference to FIGS. The input baseband OFDM signal {FIG. 5 (a)} is converted into a frequency component signal by FFT 57, and the OFDM main signal component {FIG. 5 (b)} is taken out from one of the signals and at the frequency position of the upper pilot signal component. “0” is inserted and converted into an OFDM main signal on the time axis {FIG. 5 (c)} by IFFT 55a.

  From the other side of the FFT 57, the pilot signal component and the guard band component {FIG. 5 (d)} are extracted, and these are shifted by 0 ((FIG. 5 (e)}) so that the frequency of the pilot signal component becomes 0 Hz. At the same time, by inserting “0” into the frequency component in the range above the guard band component, the number of points in the IFFT processing is adjusted to the required number of IFFT points in the next IFFT 55b. When inverse conversion is performed, a time signal (DC level) {FIG. 5 (f)} for the received pilot signal PL subjected to inter-carrier interference distortion is obtained.

  FIG. 6 is a block diagram of an OFDM receiving apparatus according to the third embodiment, and shows a third embodiment of the distortion compensator according to the present invention. In the figure, 50C is a distortion compensation unit according to the third embodiment, 51 is a digital low-pass filter (LPF), 52 is a delay circuit, 61 is a digital bandpass filter (BPF), and 62 is a frequency digital down converter (DDC). , 56 are distortion compensation signal generators (1 / α), and 60 is a multiplier.

  FIG. 7 is a diagram for explaining the operation of the OFDM receiver according to the third embodiment. Hereinafter, the operation of the distortion compensator 50C according to the third embodiment will be described with reference to FIGS. The input baseband OFDM signal {FIG. 7 (a)} is divided into two systems, one of which is passed through the LPF 51, and only the OFDM main signal component {FIG. 7 (b)} excluding the pilot signal component is extracted. The extracted OFDM main signal component is temporarily held in the delay circuit 52 in order to match the delay caused by the pilot signal processing with the processing time.

The other part of the baseband OFDM signal is passed through the BPF 61 to extract only the part composed of the pilot signal component and the guard band component {FIG. 7 (c)} so that the frequency of the pilot signal component becomes 0 Hz. The DDC 62 performs down-conversion {FIG. 7 (d)}. Accordingly, “0” is inserted into each frequency component in the range above the guard band component. Further, when this signal is viewed on the time axis, a time signal {FIG. 7 (e)} for the received pilot signal PL having a constant DC level over one symbol period is obtained.

  This received pilot signal PL is substantially uniformly subjected to inter-carrier interference (ICI) from all other subcarriers based on the frequency deviation, and conversely, each of the other subcarriers also includes the remaining other subcarriers including the pilot signal. The inter-carrier interference from is received almost uniformly. Therefore, the distortion compensation signal generation unit 56 obtains the distortion component α of the received pilot signal based on the known pilot signal level, and multiplies the received OFDM main signal component by the inverse number (1 / α), for example, to obtain the OFDM main signal. The distortion component superimposed on the component is removed.

  FIG. 8 is a block diagram of an OFDM receiver according to the fourth embodiment, and shows a fourth embodiment of the distortion compensator according to the present invention. In the figure, 50D is a distortion compensation unit according to the fourth embodiment, 51a is a digital low pass filter (LPF), 52 is a delay circuit, 62 is a frequency digital down converter (DDC), 51b is a digital low pass filter (LPF), Reference numeral 56 denotes a distortion compensation signal generator (1 / α), and reference numeral 60 denotes a multiplier.

  FIG. 9 is a diagram for explaining the operation of the OFDM receiver according to the fourth embodiment. Hereinafter, the operation of the distortion compensator 50D according to the fourth embodiment will be described with reference to FIGS. The input baseband OFDM signal {FIG. 9 (a)} is divided into two systems, one of which is passed through the LPF 51a to extract only the OFDM main signal component {FIG. 9 (b)} excluding the pilot signal component, and a delay circuit 52.

  For the other of the baseband OFDM signals, first, the DDC 62 performs down-conversion {FIG. 9 (c)} so that the frequency of the pilot signal component becomes 0 Hz, and passes these through the digital LPF 51b and the pilot signal component and the guard band component. And extract. When this signal is viewed on the time axis, a time signal {FIG. 9 (d)} for the received pilot signal PL having a constant DC level over one symbol period is obtained, and this received pilot signal PL has a frequency deviation. The inter-carrier interference (ICI) from all other subcarriers based on is substantially uniformly received. Therefore, the distortion compensation signal generation unit 56 obtains the distortion component α of the received pilot signal based on the known pilot signal level, and multiplies the received OFDM main signal component by the inverse number (1 / α), for example, to obtain the OFDM main signal. The distortion component superimposed on the component is removed.

  In addition, although several embodiment of the said invention was described, it cannot be overemphasized that the change of the structure of each part, control, a process, and these combinations can be performed within the range which does not deviate from this invention.

1 is a block diagram of an OFDM transmission apparatus according to an embodiment. It is a block diagram of the OFDM receiver by 1st Embodiment. It is operation | movement explanatory drawing of the OFDM receiver by 1st Embodiment. It is a block diagram of the OFDM receiver by 2nd Embodiment. It is operation | movement explanatory drawing of the OFDM receiver by 2nd Embodiment. It is a block diagram of the OFDM receiver by 3rd Embodiment. It is operation | movement explanatory drawing of the OFDM receiver by 3rd Embodiment. It is a block diagram of the OFDM receiver by 4th Embodiment. It is operation | movement explanatory drawing of the OFDM receiver by 4th Embodiment. It is a figure explaining a prior art.

Explanation of symbols

10 OFDM modulator 20 RF amplifier (RFA)
30 RF front end (RFFE)
40 OFM Demodulation Unit 50 Distortion Compensation Unit 54 0 Shift Unit 56 Distortion Compensation Signal Generation Unit 58 0 Insertion Unit 60 Multiplication Unit 62 Digital Down Converter (DDC)

Claims (5)

An RF processing unit that receives and preprocesses an RF band OFDM signal to generate a baseband OFDM signal, and compensates for distortion components superimposed on the baseband OFDM signal based on a pilot signal multiplexed on the baseband OFDM signal In an OFDM receiver comprising a distortion compensation unit that performs and a demodulation unit that OFDM-demodulates the distortion-compensated OFDM signal, the distortion compensation unit includes:
An OFDM main signal component extracting unit that extracts the OFDM main signal component by passing the baseband OFDM signal through a filter;
The baseband OFDM signal is subjected to discrete Fourier transform to be converted into a frequency component signal, the frequency component of the pilot signal is extracted from the baseband OFDM signal, the frequency component is rearranged at the position of frequency 0, and the rearranged pilot signal component A distortion compensation signal generator for generating a distortion compensation signal for compensating for a distortion component superimposed on the pilot signal converted into the time signal based on a known pilot signal by performing Fourier inverse transform on ,
An OFDM receiving apparatus comprising: a distortion canceling unit that cancels a distortion component superimposed on the extracted OFDM main signal component by using the generated distortion compensation signal. An RF processing unit that receives and preprocesses an RF band OFDM signal to generate a baseband OFDM signal, and compensates for distortion components superimposed on the baseband OFDM signal based on a pilot signal multiplexed on the baseband OFDM signal In an OFDM receiver comprising a distortion compensation unit that performs and a demodulation unit that OFDM-demodulates the distortion-compensated OFDM signal, the distortion compensation unit includes:
A Fourier transform unit for transforming the baseband OFDM signal into a frequency component signal by performing discrete Fourier transform;
An OFDM main signal component extraction unit that extracts a portion related to the OFDM main signal from the converted frequency component signal and converts it into a time signal by discrete Fourier inverse transform;
Extracting a portion related to the pilot signal from the converted frequency component signal and rearranging the pilot signal component at a position of frequency 0, and converting the rearranged pilot signal component into a time signal by Fourier inverse transform; A distortion compensation signal generator for generating a distortion compensation signal for compensating for a distortion component superimposed on the pilot signal converted into the time signal based on a known pilot signal;
An OFDM receiving apparatus comprising: a distortion canceling unit that cancels a distortion component superimposed on the extracted OFDM main signal component by using the generated distortion compensation signal. An RF processing unit that receives and preprocesses an RF band OFDM signal to generate a baseband OFDM signal, and compensates for distortion components superimposed on the baseband OFDM signal based on a pilot signal multiplexed on the baseband OFDM signal In an OFDM receiver comprising a distortion compensation unit that performs and a demodulation unit that OFDM-demodulates the distortion-compensated OFDM signal, the distortion compensation unit includes:
An OFDM main signal component extracting unit that extracts the OFDM main signal component by passing the baseband OFDM signal through a first filter;
A component related to a pilot signal is extracted by passing the baseband OFDM signal through a second filter, and the pilot signal component is frequency-converted until the extracted pilot signal component reaches a position of frequency 0, and a known pilot signal A distortion compensation signal generator for generating a distortion compensation signal for compensating for a distortion component superimposed on the frequency-converted pilot signal based on
An OFDM receiving apparatus comprising: a distortion canceling unit that cancels a distortion component superimposed on the extracted OFDM main signal component by using the generated distortion compensation signal. An RF processing unit that receives and preprocesses an RF band OFDM signal to generate a baseband OFDM signal, and compensates for distortion components superimposed on the baseband OFDM signal based on a pilot signal multiplexed on the baseband OFDM signal In an OFDM receiver comprising a distortion compensation unit that performs and a demodulation unit that OFDM-demodulates the distortion-compensated OFDM signal, the distortion compensation unit includes:
An OFDM main signal component extracting unit that extracts the OFDM main signal component by passing the baseband OFDM signal through a first filter;
The baseband OFDM signal is frequency-converted until the pilot signal component included in the baseband OFDM signal reaches the position of frequency 0, and the component related to the pilot signal is extracted by passing the frequency-converted signal through the second filter. And a distortion compensation signal generator for generating a distortion compensation signal for compensating for a distortion component superimposed on the extracted pilot signal based on a known pilot signal;
An OFDM receiving apparatus comprising: a distortion canceling unit that cancels a distortion component superimposed on the extracted OFDM main signal component by using the generated distortion compensation signal. An RF band OFDM signal is received and preprocessed to generate a baseband OFDM signal, and a distortion component superimposed on the baseband OFDM signal is compensated based on a pilot signal multiplexed on the baseband OFDM signal. In an OFDM receiving method for OFDM demodulating a compensated OFDM signal,
The distortion compensator is
Passing the baseband OFDM signal through a filter to extract an OFDM main signal component;
The baseband OFDM signal is subjected to discrete Fourier transform to be converted into a frequency component signal, the frequency component of the pilot signal is extracted from the baseband OFDM signal, the frequency component is rearranged at the position of frequency 0, and the rearranged pilot signal component Is converted into a time signal by inverse Fourier transform, and a distortion compensation signal for compensating for a distortion component superimposed on the pilot signal converted into the time signal based on a known pilot signal is generated,
An OFDM receiving method, wherein a distortion component superimposed on the extracted OFDM main signal component is canceled by the generated distortion compensation signal.

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