JP5654558B2 - Transceiver - Google Patents

Description

  The present invention relates to a transmitter / receiver that modulates data with a predetermined carrier wave and transmits the data and demodulates the modulated data to acquire data.

  Conventionally, data is modulated by a predetermined modulation method, and data assigned to a predetermined carrier wave is transmitted, and data after modulation is received from the modulated data and demodulated to obtain data before modulation. There is a transceiver to acquire

  When this transmitter / receiver is connected to the transmitter / receiver via a wired transmission path, a transmitter / receiver system is configured. Depending on the overall topology of the system, it is assigned to a carrier of a specific frequency by frequency selective fading. While the data is being transmitted through the wired transmission path, the SN ratio of the carrier wave may be small. For this reason, the data assigned to the carrier wave may be difficult to be received by the other party.

  Therefore, conventionally, a special communication sequence is executed between the transceivers, a dedicated packet is transmitted from the transceiver to the sender transceiver, and the transmission path state evaluation result in the sender transceiver is determined. A technique for changing communication parameters (for example, carrier frequency) of a transceiver is used (see Patent Document 1).

  However, in order to send a dedicated packet to the transmitter / receiver and change the communication parameters of the transmitter / receiver according to the evaluation result of the transmission path state in the transmitter / receiver, the dedicated packet is generated. This requires a dedicated circuit for outputting the data and a dedicated circuit for evaluating the transmission path state, which increases costs.

  In addition, when a dedicated packet is transmitted, the transmission / reception state of the transmission source transmitter / receiver is evaluated, and a dedicated communication sequence for changing communication parameters according to the evaluation result is executed, the data after modulation is transmitted. Transmission efficiency is degraded.

JP 2004-343551 A

  An object of the present invention is a transceiver that can easily realize high-quality data transmission without hindering the original function of transmitting modulated data even when the S / N ratio in a carrier wave of a specific frequency decreases. Is to provide.

  A transceiver according to an aspect of the present invention provides a plurality of modulated data signals modulated in a predetermined modulation scheme and given a predetermined order as a signal order with respect to a plurality of subcarriers having different frequencies. A first signal generation unit that generates a first multicarrier modulation signal by assigning a first order that is the order of magnitudes of carrier frequencies; and the plurality of modulated data signals in an order opposite to the first order. A second signal generation unit that generates a second multicarrier modulation signal by assigning the subcarriers to each subcarrier in a second order, and a transmission unit that transmits the first multicarrier modulation signal and the second multicarrier modulation signal. Receiving each of the first multi-carrier modulation signal and the second multi-carrier modulation signal, and each modulation data included in the first multi-carrier modulation signal Comprising a No., between each modulated data signal included in the second multi-carrier modulated signal, and a receiving unit for obtaining an average signal representing an average of the modulated data signal to each other sequentially are equal in the signal sequence.

It is the figure which showed typically an example of the transmission / reception system constructed | assembled using the transmitter / receiver which concerns on 1st Embodiment according to this invention. It is the block diagram which showed an example of the functional module of the transmitter / receiver which concerns on 1st Embodiment. It is the figure which showed an example of the frame structure of the signal produced | generated by a framing circuit. It is the figure which showed an example of the relationship between the frequency of the subcarrier to which each modulation data signal is allocated, and the characteristic of each subcarrier. It is a figure for demonstrating the effect when a notch band arises when transmitting each modulation | alteration data signal from a transmitter / receiver. It is the block diagram which showed an example of the functional module of the transmitter / receiver which concerns on 2nd Embodiment according to this invention. It is a figure for demonstrating the basic process of the transmitter / receiver which concerns on 2nd Embodiment.

  Embodiments according to the present invention will be described below with reference to the drawings. In addition, the structure which attached | subjected the same code | symbol in each figure shows that it is the same structure, The description is abbreviate | omitted.

(First embodiment)
FIG. 1 is a diagram schematically showing an example of a transmission / reception system constructed using the transceiver according to the first embodiment of the present invention.

  As shown in FIG. 1, the transmission / reception system is configured by combining a plurality of transceivers A. In this system, a plurality of transceivers A are connected to each other through a transmission line L. The system is configured such that data can be transmitted through a transmission line L by designating a destination transceiver from a certain transceiver A.

  FIG. 2 is a block diagram illustrating an example of a functional module of the transceiver according to the first embodiment. As shown in FIG. 2, the transceiver A includes a CPU (Central Processing Unit) and the like, and includes a control circuit 100 that comprehensively controls the transceiver A, a transmission block 1, and a reception block 2 (reception unit). And.

  The transmission block 1 includes a modulator 10, a first acquisition unit 11, a selector 12, an OFDM (Orthogonal Frequency-Division Multiplexing) modulator 13, a framing circuit 14, an oversample circuit 150, a waveform shaping circuit 15 having a filter 151, a digital analog A conversion circuit (DAC) 16 and an analog front end (FE) circuit 17 (transmission unit) are provided.

  The control circuit 100, the selector 12, and the OFDM modulator 13 constitute an example of a first signal generation unit. The first signal generation unit receives a plurality of modulated data signals X0 to X15 representing a plurality of data having a predetermined number of bits modulated by a predetermined modulation method (for example, 16QAM described later). Hereinafter, the order of the modulated data signals X0 to X15 is referred to as a signal order, and m of Xm is a signal number representing the signal order.

  Then, the first signal generation unit assigns the modulated data signals in the signal order to the plurality of subcarriers having different frequencies from each other in the first order which is the order of the frequency of each subcarrier. One multicarrier modulation signal is generated. The first order is, for example, the order in which the subcarrier frequency is small (in order of increase).

  For example, as shown in FIG. 4A, when the subcarrier frequencies are represented by f0 to f15 on the horizontal axis (the larger the subscript value, the larger the frequency), the modulation data signals X0 to X15 in the signal order are Each is assigned to subcarriers of frequencies f0 to f15. Hereinafter, the numerical values of the subscripts f0 to f15 are referred to as subcarrier numbers.

  The control circuit 100, the selector 12, the first acquisition unit 11, and the OFDM modulator 13 constitute an example of a second signal generation unit. The second signal generation unit receives a plurality of modulated data signals, assigns each modulated data signal in the signal order to each subcarrier in a second order which is the reverse order of the first order, and generates a second multicarrier. A modulation signal is generated. The second order is, for example, the order in which the subcarrier frequency is large (in order of decreasing). For example, as shown in FIG. 4B, the modulated data signals X0 to X15 in the signal order are allocated to subcarriers having frequencies f15 to f0, respectively.

  Note that the first order may be the order in which the subcarrier frequency is large (in order of decreasing), and the second order may be the order in which the subcarrier frequency is small (in order of increasing).

  The reception block 2 includes an analog front-end (FE) circuit 20, an analog-digital conversion circuit (ADC) 21, a waveform shaping circuit 22 having a down-sample circuit 220 and a filter 221, a guard interval (GI) removal circuit 23, and a synchronization circuit. 24, an OFDM demodulator 25, a selector 26, a second acquisition unit 27, an averaging circuit 28 (average signal acquisition unit), an equalizer 29, and a demodulator 30.

  The reception block 2 receives the first multicarrier modulation signal and the second multicarrier modulation signal. The reception block 2 then modulates the modulated data signal representing the same data (same information) for each modulated data signal included in the first multicarrier modulated signal and each modulated data signal included in the second multicarrier modulated signal. An average signal representing an average between the two (modulated data signals having the same signal number) is acquired (see FIGS. 4C and 4D).

  The control circuit 100, the OFDM demodulator 25, and the selector 26 constitute an example of a first signal acquisition unit. When the first multicarrier modulation signal and the second multicarrier modulation signal are transmitted from the transmitter / receiver, the first signal acquisition unit transmits the subcarrier frequency from each subcarrier of the first multicarrier modulation signal. Each modulated data signal is acquired in ascending order (first order). Then, each modulated data signal is acquired in the order of the signals by the first signal acquisition unit and transmitted to the averaging circuit 28.

  The control circuit 100, the OFDM demodulator 25, the selector 26, and the second acquisition unit 27 constitute an example of a second signal acquisition unit. When the first multicarrier modulation signal and the second multicarrier modulation signal are transmitted from the transmitter / receiver (for example, one of the transmitter / receiver A shown in FIG. 1), the second signal acquisition unit Each modulation data signal included in the multicarrier modulation signal is acquired in order of increasing subcarrier frequency (second order). Then, each modulated data signal is acquired in the order of the signals and transmitted to the averaging circuit 28.

  Further, in the reception block 2, the averaging circuit 28 includes the modulated data signal acquired by the first signal acquisition unit (that is, the OFDM demodulator 25) and the second signal acquisition unit (that is, the OFDM demodulator 25 and the second signal). An average signal representing an average with the modulated data signal acquired by the acquisition unit 27) is acquired. Then, since both the first and second signal acquisition units output the modulated data signals in the order of the signals, the averaging circuit 28 is arranged in the order in which the modulation data signals are output from the first and second signal acquisition units. By sequentially performing the averaging process, the modulated data signals having the same signal number are averaged.

  Hereinafter, the function of each component of the transceiver A will be described. In the transmission block 1, the modulator 10 receives an input of a data bit string and modulates the data with a predetermined modulation method (for example, 16QAM), thereby obtaining a modulated data signal representing the modulated data bit string.

  For example, when the modulator 10 modulates a bit string of data with 16 QAM (16 Quadrature Amplitude Modulation), each of the amplitude and phase of the carrier has four types of values. As a result, 16 types of modulated data signals can be obtained by combinations of amplitude and phase.

  When a data bit string is modulated by 16QAM, the modulated data signal is composed of an I signal (In-Phase signal) representing a real number and a Q signal (Quadrature signal) representing an imaginary number.

  The first acquisition unit 11 receives a plurality of modulated data signals output from the modulator 10 and sequentially stores them in a memory such as a buffer in the order in which each modulated data signal is received. Accordingly, if the modulated data signal is output from the modulator 10 in the order of the modulated data signal X1, the modulated data signal X2,..., The modulated data signal Xn, for example, the first acquisition unit 11 The signals are stored in the order of modulated data signal X1, modulated data signal X2,..., Modulated data signal Xn.

  When the first acquisition unit 11 stores a predetermined number of modulation data signals (for example, the number of subcarriers used by the OFDM modulator 13 and the OFDM demodulator 25), the first acquisition unit 11 stores each modulation data signal in the order of reception of each modulation data signal. Take out in the reverse order. As a result, the modulation data signal stored in the first acquisition unit 11 in the order of the modulation data signal X1, the modulation data signal X2,... The modulation data signal Xn becomes the modulation data signal Xn, the modulation data signal Xn−1. ... Are obtained in the order of modulated data signal X1. That is, the 1st acquisition part 11 outputs a modulation | alteration data signal in the reverse order to the order received.

  The selector 12 includes contacts a and b, and when the modulated data signal obtained by the modulator 10 is input to the OFDM modulator 13, the contact b is closed (contact a is opened). When the modulated data signal is input to the first acquisition unit 11, the contact a is closed (contact b is opened). The selector 12 is switched between a contact point a and a contact point b by a switching signal output from the control circuit 100.

  The OFDM modulator 13 modulates each modulated data signal using a plurality of subcarriers having different frequencies, and generates a multicarrier modulated signal in which each modulated data signal is assigned to each subcarrier.

  The OFDM modulator 13 accepts each modulated data signal sequentially output by the modulator 10 by the number of subcarriers, and serial / parallel converts the received modulated data signal. Then, the OFDM modulator 13 performs inverse fast Fourier transform (IFFT) on the modulated data signal having the same number of parallel signals as the number of subcarriers.

  Thereby, the OFDM modulator 13 can generate each time-domain multicarrier modulation signal by assigning each modulation data signal in the frequency domain to each subcarrier in ascending order of frequency of each subcarrier.

  The processing of the OFDM modulator 13 described above can be expressed by the following equation (1).

但し、ｎは時間インデックス、ｋは変調器１０により得られた素数シンボル信号の周波数インデックスをそれぞれ示す。

Here, n is a time index, and k is a frequency index of a prime symbol signal obtained by the modulator 10.

  The framing circuit 14 receives the multicarrier modulation signal from the OFDM modulator 13, copies the rear half of the received multicarrier modulation signal, and adds it as a guard interval before the multicarrier modulation signal.

  The waveform shaping circuit 15 performs waveform shaping of the multicarrier modulation signal. In other words, in the waveform shaping circuit 15, the oversample circuit 150 samples the multicarrier modulation signal using a sampling frequency that is at least twice the sampling frequency used by the digital-analog conversion circuit 16, and performs a predetermined thinning process or Completion processing is performed.

  Further, in the waveform shaping circuit 15, the filter 151 is provided as a low-pass filter. The filter 151 passes only a frequency component smaller than a certain frequency, and removes high-frequency noise mixed in the multicarrier modulation signal. Remove.

  The digital-analog conversion circuit 16 converts the multicarrier modulation signal input as a digital signal into an analog signal form. The analog front end circuit 17 performs waveform shaping and amplification of a multicarrier modulation signal in the form of an analog signal. Thus, the multicarrier modulation signal that has been subjected to waveform shaping by the analog front-end circuit 17 is transmitted to the transmission line L.

  In the reception block 2, the analog front end circuit 20 receives the multicarrier modulation signal transmitted through the transmission line L, and performs waveform shaping and amplification of the multicarrier modulation signal. The analog-digital conversion circuit 21 converts a multicarrier modulation signal input in the form of an analog signal into a digital signal.

  The waveform shaping circuit 22 performs waveform shaping of the multicarrier modulation signals α and β converted into a digital signal form. The down-sampling circuit 220 of the waveform shaping circuit 22 decimates the multicarrier modulation signal oversampled by the analog-digital conversion circuit 21. The filter 221 is composed of a low-pass filter, and removes high-frequency noise mixed in the multicarrier modulation signal during transmission. The guard interval removal circuit 23 removes the guard interval added to the head of the multicarrier modulation signal.

  The synchronization circuit 24 outputs to the guard interval removal circuit 23 a timing signal for the guard interval removal circuit 23 to remove the guard interval added to the head of the multicarrier modulation signal.

  The OFDM demodulator 25 acquires each modulated data signal included in the multicarrier modulation signal converted into a digital signal form by the analog-digital conversion circuit 21.

  The OFDM demodulator 25 performs fast Fourier transform (FFT) on the time-domain multicarrier modulation signal, and acquires each modulation data signal in the frequency domain in the form of a parallel signal. Then, the OFDM demodulator 25 converts each modulated data signal acquired in the form of a parallel signal into a serial signal form by performing parallel / serial conversion.

  Thereby, the OFDM demodulator 25 acquires each modulation data signal from the multicarrier modulation signal in ascending order of the frequency of each subcarrier (first order).

  The selector 26 includes contacts a and b. When the modulated data signals obtained by the OFDM demodulator 25 are input to the averaging circuit 28, the contact b is closed (contact a is opened). When each modulated data signal is input to the second acquisition unit 27, the contact a is closed (contact b is opened). The selector 26 is switched between a contact point a and a contact point b by a switching signal output from the control circuit 100.

  The second acquisition unit 27 receives a plurality of modulated data signals acquired by the OFDM demodulator 25 and sequentially stores them in a memory such as a buffer in the order of receiving each modulated data signal. Thereby, if the modulated data signal is output from the OFDM demodulator 25 in the order of the modulated data signal Xn, the modulated data signal Xn−1,..., The modulated data signal X1, for example, Each modulated data signal is stored in the order of the modulated data signal Xn, the modulated data signal Xn-1,..., And the modulated data signal X1.

  When the second acquisition unit 27 stores a predetermined number of modulation data signals (for example, the number of subcarriers used by the OFDM modulator 13 and the OFDM demodulator 25), the second acquisition unit 27 stores each modulation data signal in the order of reception of each modulation data signal. Take out in the reverse order. Thereby, in the second acquisition unit 27, the modulation data signal stored in the order of the modulation data signal Xn, the modulation data signal Xn−1,..., The modulation data signal X1 is converted into the modulation data signal X1, the modulation data signal X2, ... obtained in the order of the modulated data signal Xn. That is, the second acquisition unit 27 outputs the modulated data signal in the reverse order to the received order.

  The equalizer 29 equalizes the average signal obtained by the averaging circuit 28 with a preset equalization coefficient. The demodulator 30 demodulates the equalized average signal by a demodulation method corresponding to the modulation method in the modulator 10.

  The transceiver A having such a configuration performs, for example, the following basic processing. In the following description, the initial state represents a state where both the selector 12 and the selector 26 are closed.

(Basic processing when becoming sender)
In the transmitter / receiver A holding the initial state, when there is a data transmission instruction specifying the transmitter / receiver, the control circuit 100 demodulates the data by a predetermined number of bits by the modulator 10, Each modulated data signal is sequentially generated in the order of the signals.

  In the initial state, the selector 12 is in the closed state of the contact b, so that the modulated data signal sequentially generated by the modulator 10 reaches the first acquisition unit 11 and reaches the OFDM modulator 13 through the contact b. To do.

  Under the control of the control circuit 100, the OFDM modulator 13 assigns the modulation data generated in the order of the signals to the subcarriers in ascending order of the subcarrier frequency, thereby generating a multicarrier modulation signal (first multicarrier). Modulation signal) S1 is generated and output to the framing circuit 14.

  At the same time, the control circuit 100 sequentially stores the modulated data signals sequentially generated by the modulator 10 in the first acquisition unit 11 in the order of the signals. When the first acquisition unit 11 stores modulation data signals for the number of subcarriers used by the OFDM modulator 13 and the OFDM demodulator 25, the first acquisition unit 11 converts each modulation data signal into each modulation data. The signals are rearranged in the reverse order of the signal reception order (the reverse of the signal order) and output.

  When the output of the multicarrier modulation signal S1 from the OFDM modulator 13 is completed, the control circuit 100 places the selector 12 in the closed state of the contact 12a, and outputs the modulated data signals rearranged in the reverse order to the signal order. The first acquisition unit 11 outputs the signal to the OFDM modulator 13 through the contact a.

  Then, according to control from the control circuit 100, the OFDM modulator 13 outputs the modulated data signals X15 to X0 sequentially output from the first acquisition unit 11 in ascending order (increase in order of subcarrier frequencies). In order). Then, since each modulation data signal 15 to X0 is rearranged in the reverse order to the signal order by the first acquisition unit 11, each modulation data signal X15 to X0 has a frequency as shown in FIG. Allocated to f0 to f15, a multicarrier modulation signal (second multicarrier modulation signal) S2 is generated.

  That is, the modulated data signals in the signal order are assigned to the subcarriers in the second order opposite to the first order to generate a multicarrier modulated signal (second multicarrier modulated signal) S2. Then, the OFDM modulator 13 outputs a multicarrier modulation signal (second multicarrier modulation signal) S <b> 2 to the framing circuit 14.

  By the processing of the control circuit 100 described above, the multicarrier modulation signal S1 and the multicarrier modulation signal S2 are alternately output to the framing circuit 14. The framing circuit 14 adds a guard interval G before the multicarrier modulation signal S1 when the multicarrier modulation signal S1 is input, and before the multicarrier modulation signal S2 when the multicarrier modulation signal S2 is input. A guard interval G is added.

  FIG. 3 is a diagram illustrating an example of a frame configuration of a signal generated by the framing circuit 14. As shown in FIG. 3, the signal S includes a multicarrier modulation signal S1 and a multicarrier modulation signal S2 alternately. As shown in FIG. 3, a guard interval G is added by a framing circuit 14 before each multicarrier modulation signal S1 and each multicarrier modulation signal S2.

  The signal S generated by the framing circuit 14 is subjected to waveform shaping by the waveform shaping circuit 15, converted to an analog signal by the digital-analog conversion circuit 16, then subjected to waveform shaping by the analog front-end circuit 17, and then to the transmission line L. Is output.

(Basic processing when it becomes the receiving side)
In the transmitter / receiver A that holds the initial state, when the signal S is received from the transmitter / receiver, the control circuit 100 causes the analog front end circuit 20 to shape the waveform of the received signal S.

  The control circuit 100 converts the waveform-shaped signal S into a digital signal form by the analog-digital conversion circuit 21, shapes the waveform by the waveform shaping circuit 22, and then outputs the waveform to the guard interval removal circuit 23.

  The control circuit 100 causes the synchronization circuit 24 to output a timing signal for the guard interval removal circuit 23 to remove the guard interval G from the signal S. For example, the control circuit 100 outputs a timing signal from the synchronization circuit 24 when a portion corresponding to the guard interval G in the signal S is digitized by the analog-digital conversion circuit 21.

  As a result, the signal S is converted from an analog signal into a digital signal and the guard interval G is removed, and the signal S is sequentially input to the OFDM demodulator 25.

  When the signal S is sequentially input to the OFDM demodulator 25, first, since the multicarrier modulation signal S1 is input to the OFDM demodulator 25, the control circuit 100 uses the OFDM demodulator 25 to change the multicarrier modulation signal S1 from The modulation data signals X0 to X15 assigned to the subcarriers are acquired in order of increasing frequency of the subcarriers (first order) (see FIG. 4A).

  At this time, since the transmitter / receiver A maintains the initial state in which the selector 26 is closed, the modulated data signals X0 to X15 obtained from the multicarrier modulation signal S1 by the OFDM demodulator 25 are converted into the contacts b of the selector 26. To the averaging circuit 28.

  The control circuit 100 sequentially stores each modulation data signal input to the averaging circuit 28 in a memory such as a buffer in the input order of each modulation data signal. Thereby, the modulation circuit 28 stores the modulated data signals X0 to X15 acquired from the multicarrier modulation signal S1 in the order of input of the modulated data signals (the signal order) (FIG. 4C). In X0 to X15).

  Thereafter, the control circuit 100 places the selector 26 in a closed state a and waits for the OFDM demodulator 25 to acquire the modulation data signal from the multicarrier modulation signal S2.

  When the multicarrier modulation signal S2 is input to the OFDM demodulator 25, the control circuit 100 modulates the subcarrier frequency from the multicarrier modulation signal S2 in ascending order (first order) by the OFDM demodulator 25. Data signals X0 to X15 are acquired. Then, since the modulated data signals X0 to X15 in the signal order are assigned to the subcarriers in the descending order of the frequency of each subcarrier (second order), the multicarrier modulation signal S2 is modulated data signal X0. ˜X15 are acquired by the OFDM demodulator 25 in the reverse order of the signal order. (See FIG. 4 (b)).

  At this time, since the selector 26 is kept closed, each modulation data signal acquired from the multicarrier modulation signal S2 by the OFDM demodulator 25 is input to the second acquisition unit 27 through the contact a of the selector 26. Is done.

  In the second acquisition unit 27, the modulation data signals acquired from the multicarrier modulation signal S2 are rearranged in the order opposite to the input order of the modulation data signals, that is, the signal order. When the rearrangement by the second acquisition unit 27 ends, the control circuit 100 sequentially outputs the rearranged modulated data signals from the second acquisition unit 27 to the averaging circuit 28.

  The averaging circuit 28 sequentially stores each modulation data signal output from the second acquisition unit 27 in a memory such as a buffer in the order of input of each modulation data signal. Accordingly, the averaging circuit 28 sequentially stores the modulated data signal modulated data signals X0 ′ to X15 ′ acquired from the multicarrier modulated signal S2 and rearranged in order by the second acquiring unit 27 (FIG. 4 (c), see X0 ′ to X15 ′).

  The averaging circuit 28 stores each modulation data signal acquired from the first multicarrier modulation signal S1 and each modulation acquired from the second multicarrier modulation signal S2 and rearranged by the second acquisition unit 27. When the data signal storage is completed, the following processing is performed.

  The averaging circuit 28 is acquired from the modulated data signals X0 to X15 acquired and stored from the first multicarrier modulation signal S1 and the second multicarrier modulation signal S2, and is rearranged by the second acquisition unit 27. The stored modulation data signals X0 ′ to X15 ′ are averaged between the modulation data signals in the same input order (modulation data signals having the same signal number), and the modulation data signals representing the same data are averaged. An average signal is acquired (see FIG. 4D).

  The basic processing of the transceiver A shown above will be further described with reference to FIG. 4A and 4B are diagrams showing the relationship between the frequency of subcarriers to which each modulated data signal is allocated and the characteristics of each subcarrier. Here, the S / N ratio is illustrated as the characteristic of each subcarrier. 4C and 4D are diagrams showing the relationship between the signal number of each modulated data signal and the SN ratio of each modulated data signal.

  In FIG. 4, f0 to f15 indicate the frequencies of subcarriers 0 to 15 with subcarrier numbers 0 to 15, respectively. FIG. 4 shows that the frequency of each subcarrier increases sequentially as the frequency of the subcarrier changes from f0 to f15.

  Further, in FIG. 4, X0 to X15 are modulation data signal identification information for identifying each modulation data signal. FIG. 4 shows that each modulation data signal is modulation data generated later as the modulation data signal identification information changes from X0 to X15.

  When the multicarrier modulation signal S1 obtained by the OFDM modulator 13 is output to the transmission line L and reaches the reception side, for example, the frequency spectrum shown in FIG. 4A is obtained on the reception side.

  In this frequency spectrum, it can be seen that the SN ratio decreases as the subcarrier number increases, that is, as the subcarrier frequency increases. Therefore, it can be seen that the modulated data signal assigned to each subcarrier is more likely to be attenuated during transmission through the transmission line L as the frequency of the subcarrier increases.

  In the multicarrier modulation signal S1, as described above, the modulated data signals in the signal order are assigned to the subcarriers in the order of the frequency of each subcarrier (first order). That is, in the multicarrier modulation signal S1, as shown in FIG. 4A, the modulation data signals X0 to X15 are allocated to subcarriers 0 to 15 (frequency f0 to f15).

  As can be seen from FIG. 4 (a), the modulation data signal assigned to the subcarrier tends to attenuate as the frequency of the subcarrier increases. Therefore, as the modulation data signal is generated in a new order, the modulation data signal is attenuated during transmission. easy.

  On the other hand, when the multicarrier modulation signal S2 obtained by the OFDM modulator 13 is output to the transmission line L and reaches the reception side, for example, the frequency spectrum shown in FIG. 4B is obtained on the reception side.

  In this frequency spectrum, since the characteristics of the transmission line L are the same as in FIG. 4A, it can be seen that, as in FIG. 4A, the SN ratio decreases as the subcarrier frequency increases. Therefore, it can be seen that the modulated data signal assigned to each subcarrier is more likely to be attenuated during transmission through the transmission line L as the frequency of the subcarrier increases.

  In the multicarrier modulation signal S2, as described above, each modulated data signal is assigned to each subcarrier in descending order of frequency of each subcarrier. That is, in the multicarrier modulation signal S2, as shown in FIG. 4B, the modulation data signals X0 to X15 are assigned to the subcarriers 15 to 0 (frequency f15 to f0).

  As can be seen from FIG. 4B, the smaller the subcarrier frequency, the less likely the modulated data signal assigned to the subcarrier is attenuated. Therefore, the newer the order in which the modulated data signals are generated, the more attenuated during transmission. Hateful.

  As described above, when the multicarrier modulation signal S1 arrives at the reception side, the frequency spectrum shown in FIG. 4A is obtained, while when the multicarrier modulation signal S2 arrives at the reception side, The frequency spectrum shown in 4 (b) is obtained.

  In this way, in the multicarrier modulation signal S2, the modulation data assigned to the subcarriers in the reverse order of the multicarrier modulation signal S1 is processed by the second acquisition unit 27 in the same order as the multicarrier modulation signal S1, that is, The signals are extracted in the order of the signals.

  As a result, when the modulation data signals X0 to X15 acquired from the multicarrier modulation signal S1 and the modulation data signals X0 ′ to X15 ′ acquired from the multicarrier modulation signal S2 are stored in the averaging circuit 28, The frequency spectrum shown in FIG. 4C is obtained.

  In FIG. 4C, the signal number increases as the order of input to the averaging circuit 28 is later.

  The averaging circuit 28 averages the modulated data signals X0 to X15 and the modulated data signals X0 ′ to X15 ′ in the order output from the first and second signal acquisition units, thereby obtaining the modulated data signals having the same signal number. Averaging each other to generate an average signal.

  4C, the averaging circuit 28 acquires an average level between the signal level of the modulated data signal X0 and the signal level of the modulated data signal X0 ′ as an average signal. The averaging circuit 28 performs the same processing for the modulated data signals X1 to X15 and the modulated data signals X1 'to X15'.

  As a result, the SN ratio of a certain subcarrier is lower than the threshold value (the SN ratio indicated by the broken line in FIG. 4) at which the modulated data signal can be demodulated by 16QAM due to the characteristics of the transmission path or the generation of impulse noise. The signal level of the modulated data signal assigned to the subcarrier having a small S / N ratio exceeds the threshold due to the modulated data signal assigned to the subcarrier having a small S / N ratio even if the S / N ratio is small. It is supplemented to the extent (see FIG. 4D).

  The transceiver A has the following advantages. FIG. 5 is a diagram for explaining the effect when a notch band is generated when each modulated data signal is transmitted from the transceiver A.

  As shown in FIG. 5A, it is assumed that a notch band is generated in subcarriers 1 to 7 having frequencies f1 to f7 in the middle of transmission of multicarrier modulation signal S1.

  In the multicarrier modulation signal S2, each modulation data signal is assigned to each subcarrier in the reverse order of the multicarrier modulation signal S1. Therefore, the modulation data signals X1 to X7 allocated to the subcarriers of the frequencies f1 to f7 that are in the notch band in the multicarrier modulation signal S1 are notches in the multicarrier modulation signal S2, as shown in FIG. Allocated to subcarriers 8 to 14 of frequencies f8 to f14 that are not bands.

  Each modulation data signal assigned to the multicarrier modulation signal S2 is averaged by the second acquisition unit 27 in a state reverse to the order in which the second acquisition unit 27 received the modulation data. 28. Each modulation data signal assigned to the multicarrier modulation signal S 1 is also stored in the averaging circuit 28.

  Therefore, as shown in FIG. 5C, in the averaging circuit 28, the modulation data signals X1 to X7 transmitted in the notch band of the multicarrier modulation signal S1 and the band that is not the notch band of the multicarrier modulation signal S2 The modulated data signals X1 ′ to X7 ′ transmitted in the above are stored at least.

  Then, the averaging circuit 28 acquires an average signal between each modulated data signal transmitted in the notch band and each modulated data signal transmitted in the band having no notch band.

  As a result, even if a notch band occurs in the middle of transmission of the multicarrier modulation signal S1 through the transmission line L, the signal level of each modulation data signal existing in the notch band is demodulated by 16QAM. Can be complemented to the extent that it does not fall below the threshold (S / N ratio indicated by the broken line in FIG. 5).

(Second Embodiment)
Next, a transceiver according to the second embodiment of the present invention will be described with reference to FIGS. In the transmitter / receiver A1 shown in FIG. 6, the transmission block 1A includes a spreader (spreading processing unit) 18 adjacent to the modulator 10 in the subsequent stage of the modulator 10, and generates a spreading code to the spreader 18. The transmitter / receiver A shown in FIG. 2 is different from the transmitter / receiver A shown in FIG.

  In the transceiver A1 shown in FIG. 6, the reception block 2A includes a despreader (despreading processing unit) 31 adjacent to the averaging circuit 28 in the subsequent stage of the averaging circuit 28, and generates a spreading code. The transmitter / receiver A shown in FIG. 2 is different from the transmitter / receiver A shown in FIG.

  Since other configurations are the same as those of the transmitter / receiver A shown in FIG.

  FIG. 6 is a block diagram showing an example of a functional module of a transceiver according to the second embodiment of the present invention. The spreader 18 performs spreading processing by multiplying each modulated data signal by a spreading code having a number of digits equal to the number of subcarriers used by the OFDM modulator 13 and the OFDM demodulator 25. Then, the spreader 18 acquires the modulated data signal (hereinafter referred to as the spread modulated data signal) subjected to the spread processing by the number of subcarriers.

  The spreading code generation unit 19 generates, for example, an orthogonal code (Walsh code) as a spreading code having the same number of digits as the number of subcarriers. When the number of subcarriers used by the OFDM modulator 13 and the OFDM demodulator 25 is 16, the spread code generator 19 is a 16-digit orthogonal code, for example, [c0, c1, c2,. c15] is generated. Here, each value of c0, c1, c2,..., C15 is a value that is appropriately set according to the difference of users.

  The spread code generator 19 outputs this type of orthogonal code to the spreader 18. The spreader 18 receives the orthogonal code output from the spread code generator 19 and multiplies each modulated data signal sequentially output from the modulator 10.

  As a result, the spreader 18 acquires the spread modulation data signal by the number of subcarriers (for example, 16). When the modulated data signal is represented by X0, the spreader 18 uses a spread modulation data signal c0X0, a spread modulation data signal c1X0, a spread modulation data signal c2X0..., A spread modulation data signal c15X0. Get. Hereinafter, this order from the spread modulation data signal c0X0 to the spread modulation data signal c15X0 is referred to as a signal order in the transceiver A1 shown in FIG.

  The spreader 18 converts these spread modulation data signals into a first acquisition unit in the order of spread modulation data signal c0X0, spread modulation data signal c1X0, spread modulation data signal c2X0..., Spread modulation data signal c15X0, that is, in signal order. 11 and the selector 12.

  Thereby, from the transmission block 1A, the first multicarrier modulation signal in which the spread modulation data signals c0X0 to c15X0 in the signal order are assigned to the subcarriers in ascending order of the frequency of the subcarriers (first order). S1 and the spread modulation data signals c0X0 to c15X0 in the order of the signals are assigned to the subcarriers in the order in which the frequency of each subcarrier is large (second order), that is, in the reverse order of the first multicarrier modulation signal S1. The second multi-carrier modulation signal S2 is transmitted alternately.

  On the other hand, when the reception block 2A receives the multicarrier modulation signal S1 and the multicarrier modulation signal S2, the multicarrier modulation signal S1 is first input to the OFDM demodulator 25, and then the multicarrier modulation is performed. The signal S2 is input to the OFDM demodulator 25.

  As a result, in the reception block 2A, the spread modulation data signals c0X0 to c15X0 assigned to the subcarriers are acquired as the multicarrier modulation signal S1 in ascending order of the frequency of the subcarriers (see FIG. 7A). In addition, in the reception block 2A, the spread modulation data signals c0X0 to c15X0 assigned to the subcarriers in the descending order of the frequency of the subcarriers are acquired as the multicarrier modulation signal S2 (see FIG. 7A).

  In FIG. 7, the spread modulation data signals c0X0 to c15X0 are simplified and expressed as C0 to C15. Hereinafter, the spread modulation data signals c0X0 to c15X0 are referred to as spread modulation data signals C0 to C15. A number attached to the code C indicates a signal number indicating the signal order of each spread modulation data signal.

  In the reception block 2A, the spread modulation data signals C0 to C15 acquired from the multicarrier modulation signal S1 are sequentially stored in the averaging circuit 28 in the order (signal order) acquired in the OFDM demodulator 25. The spread modulation data signals C0 ′ to C15 ′ acquired from the carrier modulation signal S2 are rearranged in the reverse order from the order acquired in the OFDM demodulator 25 and sequentially stored in the averaging circuit 28 (FIG. 7 (c)).

  Then, by the averaging circuit 28, the same content as the spread modulation data signal included in the multicarrier modulation signal S1 and the spread modulation data signal included in the second multicarrier modulation signal S2 and included in the first multicarrier modulation signal S1. An average signal that represents the average between the signal and the spread modulation data signal that represents is obtained (see FIG. 7D).

  The spreading code generation unit 32 generates the same spreading code as the spreading code generation unit 19 in the transmission block 1 and outputs it to the despreader 31. The despreader 31 divides the average signal acquired by the averaging circuit 28 by the spreading code output from the spreading code generator 32, and acquires the modulated data signal X0 whose signal level is averaged.

  The transceiver A1 sequentially performs the above processing for the modulated data signal X1, the modulated data signal X2,..., And the modulated data signal X15. Thereby, transmission of data represented by the modulated data signals X0 to X15 for a specific user can be performed with high quality.

  FIG. 7 is a diagram for explaining basic processing of the transceiver A1 according to the second embodiment. FIGS. 7A and 7B are diagrams showing the relationship (SN ratio) between the frequency of subcarriers to which spread modulation data signals C0 to C15 are assigned and the characteristics of each subcarrier. FIGS. 7C and 7D are diagrams showing the relationship between the signal number of each spread modulation data signal and the SN ratio of each spread modulation data signal. FIG. 7 shows that the spread modulation data signal is the modulation data generated later as the signal number of the spread modulation data signal increases.

  When the multicarrier modulation signal S1 obtained by the OFDM modulator 13 is output to the transmission line L and reaches the reception side, for example, the frequency spectrum shown in FIG. 7A is obtained on the reception side.

  In this frequency spectrum, it can be seen that the SN ratio decreases as the frequency of the subcarrier increases. Therefore, it can be understood that the spread modulation data signal assigned to each subcarrier is more likely to be attenuated during transmission through the transmission line L as the frequency of the subcarrier increases.

  In the multicarrier modulation signal S1, as described above, each spread modulation data signal is assigned to each subcarrier in the order of increasing frequency of each subcarrier (in increasing order). That is, in the multicarrier modulation signal S1, spread modulation data signals C0 to C15 are allocated to subcarriers 0 to 15 of frequencies f0 to f15 as shown in FIG.

  As can be seen from FIG. 7 (a), the spread modulation data signal assigned to the subcarrier tends to attenuate as the frequency of the subcarrier increases. It is easy to attenuate.

  On the other hand, when the multicarrier modulation signal S2 obtained by the OFDM modulator 13 is output to the transmission line L and reaches the receiving side, for example, the frequency spectrum shown in FIG. 7B is obtained on the receiving side.

  In this frequency spectrum, since the characteristics of the transmission line L are the same, it can be seen that the SN ratio decreases as the frequency of the subcarrier increases as in FIG. Therefore, it can be understood that the spread modulation data signal assigned to each subcarrier is more likely to be attenuated during transmission through the transmission line L as the frequency of the subcarrier increases.

  In the multicarrier modulation signal S2, as described above, the spread modulation data signals in the signal order are assigned to the subcarriers in the descending order of the frequency of the subcarriers (in decreasing order). That is, in the multicarrier modulation signal S2, spread modulation data signals C0 to C15 are allocated to subcarriers 15 to 0 having frequencies f15 to f0, as shown in FIG. 7B.

  As can be seen from FIG. 7B, the spread modulation data signal assigned to the subcarrier is less likely to be attenuated as the subcarrier frequency is smaller. Difficult to attenuate.

  As described above, when the multicarrier modulation signal S1 arrives at the reception side, the frequency spectrum shown in FIG. 7A is obtained, while when the multicarrier modulation signal S2 arrives at the reception side, The frequency spectrum shown in FIG. 7 (b) is obtained.

  As described above, the spread modulation data signals allocated to the subcarriers in the reverse order of the multicarrier modulation signal S1 are rearranged in the signal order by the second acquisition unit 27 and averaged by the multicarrier modulation signal S2. It is output to the circuit 28.

  As a result, when each spread modulation data signal acquired from the multicarrier modulation signal S1 and each spread modulation data signal acquired from the multicarrier modulation signal S2 are stored in the averaging circuit 28, FIG. ) Is obtained.

  In addition, as each spreading | diffusion modulation | alteration data signal rearranged by the 2nd acquisition part 27, the spreading | diffusion modulation | alteration data signal C0'-C15 'is illustrated in FIG.7 (c), respectively. In FIG. 7C, the signal number of the spread modulation data signal becomes larger as the order of input to the averaging circuit 28 becomes later.

  The averaging circuit 28 is acquired from the spread modulation data signals C0 to C15 acquired and stored from the first multicarrier modulation signal S1 and the second multicarrier modulation signal S2, and is rearranged by the second acquisition unit 27. The stored spread modulation data signals C0 ′ to C15 ′ are averaged between spread modulation data signals in the same input order (spread modulation data signals having the same signal number) (FIG. 7 (d)). )reference).

  7C and 7D, the averaging circuit 28 determines the signal level of the spread modulation data signal C0 and the spread modulation data signal C0 ′ in the same input order as the spread modulation data signal C0. An average level between the signal levels is acquired as an average signal. The averaging circuit 28 performs the same processing for the spread modulation data signals C1 to C15 and the spread modulation data signals C1 'to C15'.

  Thus, a threshold value that can demodulate a modulated data signal obtained by despreading a spread modulation data signal with 16QAM by the SN ratio of a certain subcarrier due to the characteristics of the transmission path or the generation of impulse noise. Even if the signal level becomes smaller than (the SN ratio indicated by the broken line in FIG. 7), the signal level of the spread modulation data signal having a small SN ratio is assigned to a subcarrier whose signal-to-noise ratio is not so small. Thus, it is supplemented to the extent that it exceeds the threshold (see FIG. 7D).

  A transceiver according to an aspect of the present invention provides a plurality of modulated data signals modulated in a predetermined modulation scheme and given a predetermined order as a signal order with respect to a plurality of subcarriers having different frequencies. A first signal generation unit that generates a first multicarrier modulation signal by assigning a first order that is the order of magnitudes of carrier frequencies; and the plurality of modulated data signals in an order opposite to the first order. A second signal generation unit that generates a second multicarrier modulation signal by assigning the subcarriers to each subcarrier in a second order, and a transmission unit that transmits the first multicarrier modulation signal and the second multicarrier modulation signal. Receiving each of the first multi-carrier modulation signal and the second multi-carrier modulation signal, and each modulation data included in the first multi-carrier modulation signal Comprising a No., between each modulated data signal included in the second multi-carrier modulated signal, and a receiving unit for obtaining an average signal representing an average of the modulated data signal to each other sequentially are equal in the signal sequence.

  According to this configuration, the first multicarrier modulation signal in which each modulated data signal is assigned to each subcarrier in the first order that is the order of the frequency of each subcarrier from the transmitter on the transmission side, The second multicarrier modulation signal assigned to each subcarrier in the second order, in which each modulated data signal is in the reverse order of the first order, is transmitted to the receiver-side transceiver.

  On the other hand, when the transmitter / receiver on the receiving side receives the first multicarrier modulation signal from the transmitter / receiver, the transmitter / receiver receives the modulated data signal included in the first multicarrier modulation signal and the second multicarrier modulation. An average signal is generated by averaging modulated data signals having the same order in the signal order among the modulated data signals included in the signal. The modulated data signals having the same order in the signal order have the same content (information represented by the two modulated data signals before being modulated by the subcarrier is the same).

  As a result, the modulated data signal that has been allocated to a subcarrier of a certain frequency and arrives at a receiver on the receiving side, and the transmission / reception on the receiving side that has the same content as the modulated data signal but is allocated to a subcarrier of another frequency An average signal is obtained from the modulated data signal arriving at the machine.

  Therefore, even if the S / N ratio of the modulated data signal assigned to a subcarrier of a certain frequency is small due to the characteristics of the transmission path connecting the transceivers, the level of the modulated data signal is the same as that of the modulated data signal. However, it is supplemented by the level of the modulated data signal assigned to subcarriers of other frequencies.

  As a result, even when the S / N ratio is reduced in a carrier wave of a specific frequency, it is possible to realize high-quality data transmission without hindering the original function of transmitting modulated data.

  In addition, when the first multicarrier modulation signal and the second multicarrier modulation signal are transmitted from the transmission unit, the reception unit performs the modulation in the first order from the first multicarrier modulation signal. By acquiring a data signal, the first multicarrier modulation signal and the second multicarrier modulation signal are transmitted from the first signal acquisition unit that acquires the modulated data signals arranged in the order of the signals, and the transmission unit. A second signal acquisition unit that acquires the modulated data signals in the order of the signals by acquiring the modulated data signals in the second order from the second multi-carrier modulation signal; The modulated data signals acquired by the first signal acquisition unit and the modulated data signals acquired by the second signal acquisition unit in the signal order By averaging the turn is equal to the modulated data signal to each other, and the average signal acquisition unit that acquires an average signal for each modulated data signal is preferably provided with a.

  According to this configuration, when the first multicarrier modulation signal and the second multicarrier modulation signal are transmitted from the transmission unit, the first signal acquisition unit transmits each modulated data signal in the first order from the first multicarrier modulation signal. To get. At the same time, the second signal acquisition unit acquires the modulated data signals included in the second multicarrier modulation signal in a second order opposite to the first order.

  Then, the average signal acquisition unit obtains each modulation data signal acquired by the first signal acquisition unit and each modulation data signal acquired by the second signal acquisition unit in the order acquired by the first signal acquisition unit. An average signal for each modulated data signal is acquired by averaging the modulated data signals in the same order as acquired by the second signal acquisition unit.

  As a result, the modulated data signal that has been allocated to a subcarrier of a certain frequency and arrives at a receiver on the receiving side, and the transmission / reception on the receiving side that has the same content as the modulated data signal but is allocated to a subcarrier of another frequency The structure which acquires the average signal between the modulated data signals which arrived at the machine can be embodied.

  An OFDM modulator that sequentially receives the modulated data signals and assigns the received modulated data signals to the subcarriers in the first order; and the first multicarrier modulated signal or the second multicarrier modulated signal. And an OFDM demodulator that acquires each of the modulated data signals in the first order from the received multicarrier modulated signal, and the first signal generation unit receives the modulated data signals in the first order. The first multi-carrier modulation signal is generated by the OFDM modulator by outputting to the OFDM modulator in the signal order, and the second signal generation unit is configured to output the modulated data signals in the order reverse to the signal order. By outputting to the OFDM modulator, the OFDM modulator generates the second multicarrier modulation signal. The first signal acquisition unit, when the input of the first multicarrier modulation signal is received by the OFDM demodulator, the modulation data obtained by ordering the modulation data signals acquired by the OFDM demodulator. The second signal acquisition unit reverses the order of the modulated data signals acquired by the OFDM demodulator when the input of the second multicarrier modulation signal is received by the OFDM demodulator. It is preferable to obtain the modulated data signals in the order of the signals.

  According to this configuration, the first signal generation unit and the second signal generation unit can share and use one OFDM modulator. Further, the first signal acquisition unit and the second signal acquisition unit can share and use one OFDM demodulator. Therefore, it becomes easy to simplify the circuit of the transceiver.

  Moreover, it is preferable that the said transmission part transmits the signal which contains the said 1st multicarrier modulation signal and the said 2nd multicarrier modulation signal alternately.

  According to this configuration, since the transmission unit transmits a signal that alternately includes the first multicarrier modulation signal and the second multicarrier modulation signal, the reception unit that has received the signal receives the first multicarrier modulation signal from the first multicarrier modulation signal. The carrier modulation signal and the second multicarrier modulation signal can be easily obtained.

  Further, each modulation data signal is provided in the preceding stage of the first signal generation unit and the second signal generation unit, and each modulation data signal is subjected to spread modulation by performing a spreading process for multiplying each modulation data signal by a spreading code of a plurality of digits. By generating a plurality of spread modulation data signals that are signals, and using each spread modulation data signal instead of each modulation data signal by the first signal generation unit and the second signal generation unit, It is preferable to further include a spread processing unit that generates the first multicarrier modulation signal and the second multicarrier modulation signal.

  According to this configuration, the spread processing unit performs a spread process for multiplying each modulated data signal by a multiple-digit spread code to obtain a plurality of spread modulated data signals that are each modulated data signal subjected to the spread process. The first multicarrier modulation signal and the second multicarrier modulation signal can be generated by the first signal generation unit and the second signal generation unit based on each spread modulation data signal.

  As a result, multi-carrier communication using a plurality of spread modulation data signals acquired by performing spreading processing for multiplying each modulation data signal by a multi-digit spreading code, so-called multi-carrier CDMA (Code Division Multiple Access) communication, is performed. It can be carried out.

  Therefore, even if multi-carrier modulation signals with different counterparts are mixed in the transmission path, the receiver-side transceiver uses the spreading code corresponding to the target multi-carrier modulation signal to Since each modulated data signal can be acquired appropriately from the above, high-quality data transmission can be realized.

  In addition, a despreading processing unit that performs a despreading process to remove the spreading code on the average signal acquired by the receiving unit, and acquires each modulated data signal whose signal level is averaged from the average signal. It is preferable to further provide.

  According to this configuration, each spread data signal whose signal level is averaged is obtained from the average signal by performing despreading processing by dividing the spread code on the average signal obtained by the receiving unit.

  As a result, when performing multi-carrier CDMA communication, even if attenuation occurs in a specific subcarrier, the signal level of the modulated data signal assigned to the subcarrier in which attenuation has occurred and the subcarrier in which attenuation has not occurred. An average is obtained between the signal level of the modulated data signal having the same content as the modulated data signal allocated to the subcarriers that have been assigned attenuation.

  Therefore, when performing multi-carrier CDMA communication, high-quality data transmission can be realized even if the SN ratio of a subcarrier of a specific frequency is reduced.

  As described above, a transceiver that can realize high-quality data transmission at a low cost without impairing the original function of transmitting modulated data even when the signal-to-noise ratio in the carrier wave of a specific frequency becomes small is provided. can do.

  This application is based on Japanese Patent Application No. 2010-034968 filed on Feb. 19, 2010, the contents of which are included in the present application.

  Note that the specific embodiments or examples made in the section for carrying out the invention are to clarify the technical contents of the present invention, and are limited to such specific examples. The present invention should not be interpreted in a narrow sense, and various modifications can be made within the scope of the spirit of the present invention and the following claims.

Claims (4)

A plurality of modulated data signals modulated in a predetermined modulation scheme and given a predetermined order as a signal order are sub-frequency different from each other in a frequency order of the subcarriers. A first signal generator for generating a first multicarrier modulation signal by assigning in order of 1;
A second signal generation unit that generates a second multicarrier modulation signal by assigning the plurality of modulated data signals to the subcarriers in a second order that is the reverse order of the first order;
A transmitter for transmitting a signal alternately including the first multicarrier modulation signal and the second multicarrier modulation signal;
Receiving the first multicarrier modulation signal and the second multicarrier modulation signal, each modulation data signal included in the first multicarrier modulation signal and each modulation data signal included in the second multicarrier modulation signal A receiver for obtaining an average signal representing an average of modulated data signals having the same order in the signal order,
With
The receiver is
The modulated data signals included in the second multicarrier modulated signal are rearranged in the order of the signals, and the rearranged modulated data signals and the modulated data signals included in the first multicarrier modulated signal, An average signal acquisition unit for acquiring the average signal by averaging the modulated data signals having the same order ; and
By acquiring the modulated data signals in the first order from the first multicarrier modulation signal when the first multicarrier modulation signal and the second multicarrier modulation signal are transmitted from the transmission unit. A first signal acquisition unit for acquiring the modulated data signals arranged in the signal order;
By acquiring the modulated data signals in the second order from the second multicarrier modulation signal when the first multicarrier modulation signal and the second multicarrier modulation signal are transmitted from the transmission unit. A second signal acquisition unit for acquiring the modulated data signals arranged in the order of the signals,
The first and second signal acquisition units are
An OFDM demodulator that receives an input of the first multicarrier modulation signal or the second multicarrier modulation signal and obtains the modulated data signals in the first order from the received multicarrier modulation signal;
A selector connected between the OFDM demodulator and the average signal acquisition unit,
The second signal acquisition unit receives modulation data signals for the number of subcarriers output from the OFDM demodulator via the selector, and receives the modulation data signals for the received number of subcarriers. An acquisition unit that outputs to the average signal acquisition unit in the signal order,
When the modulated data signal of the first multicarrier signal is output from the OFDM demodulator, the selector outputs the output modulated data signal to the average signal acquisition unit, and the OFDM demodulator When the modulated data signal of the second multicarrier signal is output from the transmitter / receiver, the transmitter / receiver outputs the output modulated data signal to the acquisition unit . It said sequential accepts the modulated data signal, further comprising an OFDM modulator for assigning the respective modulated data signal received on each subcarrier in the first order,
The first signal generator is
By outputting each modulated data signal to the OFDM modulator in the order of the signals, the OFDM modulator generates the first multicarrier modulated signal,
The second signal generator is
Outputting each of the modulated data signals to the OFDM modulator in the reverse order of the signal order to generate the second multi-carrier modulated signal by the OFDM modulator;
The first signal acquisition unit includes:
When the input of the first multicarrier modulation signal is received by the OFDM demodulator, the modulation data signals acquired by the OFDM demodulator are acquired as the modulation data signals arranged in the signal order,
The second signal acquisition unit includes:
When the input of the second multicarrier modulation signal is received by the OFDM demodulator, the order of the modulated data signals acquired by the OFDM demodulator is reversed, and the modulated data signals are arranged in the order of the signals. The transceiver according to claim 1 to be acquired. Each modulation data signal is spread-modulated by performing a spreading process for multiplying each modulation data signal by a multi-digit spreading code, which is provided before the first signal generation unit and the second signal generation unit. A plurality of spread modulation data signals that are signals, and the first signal generation unit and the second signal generation unit use the spread modulation data signals instead of the modulation data signals. The transmitter / receiver according to claim 1 or 2 , further comprising a spread processing unit that generates one multicarrier modulation signal and the second multicarrier modulation signal. A despreading processing unit that performs despreading processing on the average signal acquired by the receiving unit to remove the spreading code, and acquires each modulated data signal whose signal level is averaged from the average signal; The transceiver according to claim 3 .

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