Radio transmitting device

Abstract

To provide a wireless transmission device capable of suppressing an output signal from a wireless transmission device that transmits a single carrier signal from having frequency characteristics within a transmission band specific to the wireless transmission device.SOLUTION: A wireless transmission device 1 that transmits a single carrier signal includes a compensator 100 that corrects a mapped digital signal sequence. The compensator 100 prevents the output signal from wireless transmission device 1 from having frequency characteristics within a transmission band by giving the output signal from a mapper the inverse characteristics of the transmission band frequency characteristics specific to the wireless transmission device 1.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present disclosure relates to a wireless transmission device that transmits a wideband single-carrier signal and that can prevent an output signal from the wireless transmission device from having frequency characteristics (amplitude deviation and phase deviation) within the transmission band that are specific to the wireless transmission device. [Background technology]

[0002] The sixth-generation mobile communication system (6G) requires bit rates exceeding 100 Gbps for high-capacity, high-speed wireless communication. One of the technologies to meet this requirement is broadband signal transmission. According to the Shannon-Hartley theorem, when the signal bandwidth is increased by a factor of L, the channel capacity also increases by a factor of L. To transmit wideband signals, it is necessary to use high-frequency bands that can secure a corresponding frequency band. However, increasing the output power of amplifiers operating in high-frequency bands, such as the sub-terahertz band (frequency bands above 100 GHz), is not easy. Amplifiers are typically operated with a backoff setting relative to the saturated output power to achieve linear amplification. Since the peak-to-average power ratio (PAPR) of single-carrier transmission is lower than that of multi-carrier transmission, the backoff of amplifiers used in single-carrier transmission can be smaller than that of amplifiers used in multi-carrier transmission. Therefore, in the same frequency band, the output power of a radio transmission apparatus using a single-carrier transmission method is greater than the output power of a radio transmission apparatus using a multi-carrier transmission method. Summary of the Invention [Problem to be solved by the invention]

[0003] However, with single-carrier transmission, transmission quality deteriorates due to the in-band frequency characteristics (amplitude deviation and phase deviation) inherent to wireless transmitters. As the transmission band widens, the amplitude deviation and phase deviation within the transmission band increase. Therefore, in wideband signal transmission, the amplitude deviation and phase deviation occurring in the individual circuits and wiring constituting the wireless transmitter accumulate, often resulting in large amplitude deviation and phase deviation for the entire wireless transmitter, resulting in significant degradation of transmission quality. Figure 1 shows an example of the frequency characteristics of a D-band amplifier. When transmitting a signal with a center frequency of 155 GHz and a bandwidth of 2 GHz, the in-band amplitude deviation of the amplifier is 1 dB, as shown in Figure 1. When transmitting a signal with a center frequency of 155 GHz and a bandwidth of 8 GHz, the in-band amplitude deviation is 2 dB, as shown in Figure 1. Thus, in many cases, the wider the bandwidth, the greater the amplitude deviation within the signal band, resulting in greater degradation of transmission quality. The same is true for phase deviation. Therefore, to achieve high-quality signal transmission, it is necessary to correct the amplitude deviation and phase deviation occurring within the wireless transmitter.

[0004] In view of the above-mentioned technical problems, the present disclosure provides a wireless transmission device that can suppress an output signal from a wireless transmission device that transmits a single carrier signal from having frequency characteristics (amplitude deviation and phase deviation) within the transmission band that are specific to the wireless transmission device. [Means for solving the problem]

[0005] The technical matters described herein are not intended to explicitly or implicitly limit the invention described in the claims, nor to enable anyone other than those who benefit from the invention (e.g., the applicant and the right holder) to limit the invention described in the claims, but are provided simply to facilitate understanding of the gist of the invention. The outline of the invention from other perspectives can be understood, for example, from the claims at the time of filing of this patent application. The wireless transmission device disclosed in this specification is a wireless transmission device that transmits a single-carrier signal and has a configuration in which a compensator is applied to a prior art wireless transmission device (described later). The compensator applies the inverse characteristic of the frequency characteristic within the transmission band that is unique to the wireless transmission device to the input signal of the wireless transmission device. [Effects of the Invention]

[0006] According to the wireless transmission device disclosed in this specification, the compensator applies the inverse characteristic of the frequency characteristic within the transmission band specific to the wireless transmission device to the input signal to the wireless transmission device, thereby preventing the output signal from the wireless transmission device from having the frequency characteristic within the transmission band (amplitude deviation and phase deviation) specific to the wireless transmission device.This makes it possible to improve the quality of signal transmission using a wideband single-carrier transmission system, which is susceptible to the influence of amplitude deviation and phase deviation occurring within the wireless transmission device. [Brief explanation of the drawings]

[0007] [Figure 1] An example of the frequency characteristics of a D-band amplifier. [Figure 2] 1 shows an example of the configuration of a wireless transmission device according to the prior art. [Figure 3] 1 shows an example of the configuration of a wireless transmission device according to a first embodiment. [Figure 4] 10 shows an example of the configuration of a wireless transmission device according to a modified example of the first embodiment. [Figure 5] 10 shows an example of the configuration of a wireless transmission device according to a second embodiment. [Figure 6] 10 shows an example of the configuration of a wireless transmission device according to a modified example of the second embodiment. [Figure 7] 10 shows an example of the configuration of a wireless transmission device according to a third embodiment. [Figure 8] 13 shows an example of the configuration of a wireless transmission device according to a modified example of the third embodiment. [Figure 9] 10 shows an example of the configuration of a wireless transmission device according to a fourth embodiment. [Figure 10] 13 shows an example of the configuration of a wireless transmission device according to a modified example of the fourth embodiment. [Figure 11] 13 shows an example of the configuration of a wireless transmission device according to a fifth embodiment. [Figure 12] 13 shows a configuration example of a wireless transmission device according to a modified example of the fifth embodiment. [Figure 13] Examples of correction values ​​obtained by the correction value calculator. (a) Example of amplitude correction value. (b) Example of phase correction value. [Figure 14] 10 shows an example of frequency characteristics of the output amplitude of an amplifier included in a wireless transmission device of the prior art and an example of frequency characteristics of the output amplitude of an amplifier included in the wireless transmission device of the fifth embodiment. [Figure 15] Examples of signal characteristics in a prior art wireless transmitter: (a) Eye pattern; (b) Signal constellation. [Figure 16] 10A and 10B are examples of signal characteristics in the wireless transmission device of the fifth embodiment, (a) an eye pattern, and (b) a signal point arrangement. [Figure 17] 10 shows examples of EVMs of a wireless transmission device of the prior art and a wireless transmission device of the fifth embodiment. [Figure 18] 13 shows an example of the configuration of a wireless transmission device according to a sixth embodiment. [Figure 19] 13 shows an example of the configuration of a wireless transmission device according to a modified example of the sixth embodiment. [Figure 20] An example of the configuration of a digital filter that includes a compensator. DETAILED DESCRIPTION OF THE INVENTION

[0008] The embodiments will be described with reference to the drawings. In order to clarify the gist of the embodiments, illustrations and descriptions of components that are actually necessary or may become necessary but are considered non-essential to the embodiments (such as intermediate amplifiers) will be omitted. In each drawing, to avoid complexity, only some of the same components are designated by reference numerals.

[0009] <Prior art> Before describing the embodiments, an outline of a wireless transmission device 900 of the prior art will be described (see FIG. 2). The wireless transmission device 900 for transmitting a single carrier signal comprises: (1) a mapper 10 that maps a digital signal sequence input to the wireless transmission device 900; (2) a D / A converter 11 that converts an output signal from the mapper 10 into an analog signal; (3) an IF oscillator 12 that generates a signal having an intermediate frequency; (4) an IF frequency converter 13 that converts the frequency of the output signal from the D / A converter 11 to the intermediate frequency using the output signal from the IF oscillator 12; and (5) an IF circuit 14 that operates at the intermediate frequency and provides frequency characteristics to the output signal from the IF frequency converter 13 (the IF circuit 14 may, for example, be a digital signal generator that generates a digital signal sequence by using the digital signal sequence generated by the IF frequency converter 13). (5) an RF circuit 17 that operates at a radio frequency and provides frequency characteristics to the output signal from the RF frequency converter 16 (the RF circuit 17 includes, for example, a filter for removing an image signal generated by the RF frequency converter 16, an amplifier for amplifying the output signal from the RF frequency converter 16, etc.); (6) an RF oscillator 15 that generates a signal having a radio frequency; (7) an RF frequency converter 16 that converts the frequency of the output signal from the IF circuit 14 to a radio frequency using the output signal from the RF oscillator 15; and (8) an RF circuit 17 that operates at a radio frequency and provides frequency characteristics to the output signal from the RF frequency converter 16 (the RF circuit 17 includes, for example, a filter for removing an image signal generated by the RF frequency converter 16, an amplifier for amplifying the output signal from the RF frequency converter 16, etc.). The output signal from the RF circuit 17 is radiated into space by a transmitting antenna 18. In the wireless transmitting device 900, the analog signal generated by the D / A converter 11 is affected by the frequency characteristics (amplitude deviation and phase deviation) inherent in the cascade connection of the IF frequency converter 13, the IF circuit 14, the RF frequency converter 16, and the RF circuit 17.

[0010] First Embodiment 3 has the same configuration as the radio transmission device 900, except for the compensator 100. The compensator 100 provides an input signal to the radio transmission device 1 with the inverse characteristic of the frequency characteristic within the transmission band that is unique to the radio transmission device 1.

[0011] Specifically, the wireless transmission device 1 for transmitting a single carrier signal includes: (1) a mapper 10 that maps a digital signal sequence input to the wireless transmission device 1; (2) a compensator 100 that performs signal processing on the output signal from the mapper 10; (3) a D / A converter 11 that converts the output signal from the compensator 100 into an analog signal; (4) an IF oscillator 12 that generates a signal having an intermediate frequency; (5) a first IF frequency converter 13a that converts the frequency of the output signal from the D / A converter 11 to the intermediate frequency using the output signal from the IF oscillator 12; and (6) an IF circuit 14 that operates at the intermediate frequency and provides frequency characteristics to the output signal from the first IF frequency converter 13a (the IF circuit 14 may be, for example, The IF circuit 14 includes (7) an RF oscillator 15 that generates a signal having a radio frequency; (8) a first RF frequency converter 16a that converts the frequency of the output signal from the IF circuit 14 to a radio frequency using the output signal from the RF oscillator 15; and (9) an RF circuit 17 that operates at a radio frequency and provides frequency characteristics to the output signal from the first RF frequency converter 16a (the RF circuit 17 includes, for example, a filter that removes the image signal generated by the first RF frequency converter 16a and an amplifier that amplifies the output signal from the first RF frequency converter 16a). The output signal from the RF circuit 17 is radiated into space by a transmitting antenna 18. The radio frequency is preferably 30 GHz or higher, specifically, a frequency included in the millimeter wave band (frequency band of 30 GHz to 300 GHz) or the sub-terahertz band (frequency band of 100 GHz or higher).

[0012] The compensator 100 applies the inverse characteristics of the in-band frequency characteristics specific to the wireless transmitting device 1 (i.e., the intrinsic frequency characteristics (amplitude deviation and phase deviation) of the cascade connection of the first IF frequency converter 13a, the IF circuit 14, the first RF frequency converter 16a, and the RF circuit 17) to the output signal from the mapper 10, thereby preventing the output signal from the RF circuit 17 from having the in-band frequency characteristics.

[0013] The compensator 100 of the first embodiment includes a correction value calculator 110 and a corrector 190. The correction value calculator 110 calculates a correction value in the time domain to be applied to the output signal from the mapper 10 so that the frequency characteristics of the amplitude and phase of the output signal from the RF circuit 17 are flat. For example, the correction value calculator 110 uses the frequency characteristics of each circuit constituting the wireless transmission device 1, which have been measured in advance, to calculate the inverse characteristics of the frequency characteristics resulting from a cascade connection of those circuits. The corrector 190 is a convolution calculator constituted by, for example, an adder, and applies the correction value calculated by the correction value calculator 110 to the output signal from the mapper 10. In other words, the corrector 190 applies the inverse characteristics calculated by the correction value calculator 110 to the output signal from the mapper 10.

[0014] Unlike the example shown in Fig. 3 in which frequency characteristics are corrected in the time domain, frequency characteristics may be corrected in the frequency domain as shown in Fig. 4. In the modified example of the first embodiment shown in Fig. 4, the compensator 100 includes a correction value calculator 110, a corrector 190, an FFT 111a, and an IFFT 111b. The FFT 111a performs a Fourier transform on the output signal from the mapper 10, the corrector 190 applies the inverse characteristic determined by the correction value calculator 110 to the output signal from the mapper 10 that has been Fourier transformed by the FFT 111a, and then the IFFT 111b performs an inverse Fourier transform on the output signal from the corrector 190. The corrector 190 is, for example, a multiplier. FIG. 4 illustrates part of the configuration of a modified example of the wireless transmitting device 1 of the first embodiment, and does not illustrate the IF oscillator 12, first IF frequency converter 13a, IF circuit 14, RF oscillator 15, first RF frequency converter 16a, RF circuit 17, and transmitting antenna 18, which are arranged downstream of the D / A converter 11 (these have the same functions and arrangement as those in the first embodiment (see FIG. 3)).

[0015] In this way, the compensator 100 provides the output signal from the mapper 10 with the inverse characteristic of the frequency characteristic within the transmission band that is specific to the wireless transmitting device 1, thereby flattening the frequency characteristic of the output signal from the RF circuit 17 (i.e., reducing the amplitude deviation and phase deviation of the output signal), thereby generating a high-quality transmission signal.

[0016] Second Embodiment In the wireless transmission device 1 of the second embodiment shown in FIG. 5, the compensator 100 is configured to provide the output signal from the mapper 10 with the inverse characteristic of the frequency characteristic within the transmission band specific to the wireless transmission device 1, based on the output signal from the IF circuit 14. This embodiment is useful when the frequency characteristic within the transmission band specific to the wireless transmission device 1 is highly dependent on the frequency characteristic inherent to the cascade connection of the first IF frequency converter 13a and the IF circuit 14. Only the differences between the first and second embodiments will be described below. For other technical matters, please refer to the description of the first embodiment. By this reference, the description of the first embodiment, excluding the differences, is expressly incorporated herein. FIG. 5 illustrates part of the configuration of the wireless transmission device 1 of the second embodiment, and does not illustrate the RF circuit 17 and the transmitting antenna 18, which are arranged downstream of the first RF frequency converter 16a (their functions and arrangements are the same as those in the first embodiment (see FIG. 3)).

[0017] In the wireless transmission device 1 of the second embodiment, the compensator 100 includes an IF signal divider 112a that divides the output signal from the IF circuit 14, a second IF frequency converter 13b that converts the frequency of the output signal from the IF signal divider 112a to a baseband frequency using the output signal from the IF oscillator 12, an A / D converter 112b that converts the output signal from the second IF frequency converter 13b to a digital signal, a correction value calculator 110, and a corrector 190. The IF signal divider 112a is disposed between the IF circuit 14 and a first RF frequency converter 16a. The first RF frequency converter 16a converts the frequency of the output signal from the IF signal divider 112a to a radio frequency. The compensator 100 determines the inverse characteristic of the in-band frequency characteristic specific to the wireless transmission device 1 based on the output signal from the A / D converter 112b and applies the inverse characteristic to the output signal from the mapper 10. The correction value calculator 110 uses the output signal from the A / D converter 112b to calculate a correction value in the time domain to be applied to the output signal from the mapper 10 so that the frequency characteristic of the output signal from the IF circuit 14 becomes flat. At this time, the correction value is calculated using a preamble signal. The corrector 190 is a convolution calculator configured, for example, by an adder, and applies the correction value calculated by the correction value calculator 110 to the output signal from the mapper 10. In other words, the corrector 190 applies the inverse characteristic calculated by the correction value calculator 110 to the output signal from the mapper 10.

[0018] Unlike the example shown in Fig. 5 in which the frequency characteristics are corrected in the time domain, the frequency characteristics may be corrected in the frequency domain as shown in Fig. 6. In the modification of the second embodiment shown in Fig. 6, the compensator 100 includes an IF signal distributor 112a, a second IF frequency converter 13b, an A / D converter 112b, a correction value calculator 110, a corrector 190, an FFT 111a, an FFT 111c, and an IFFT 111b. The FFT 111a performs a Fourier transform on the output signal from the mapper 10, the FFT 111c performs a Fourier transform on the output signal from the A / D converter 112b, the correction value calculator 110 uses the output signal from the FFT 111c to determine the inverse characteristic to be applied to the output signal from the mapper 10, the corrector 190 applies the inverse characteristic determined by the correction value calculator 110 to the output signal from the mapper 10 that has been Fourier transformed by the FFT 111a, and then the FFT 111b performs an inverse Fourier transform on the output signal from the corrector 190. The corrector 190 is, for example, a multiplier. FIG. 6 illustrates part of the configuration of a modified example of the wireless transmitting device 1 of the second embodiment, and does not illustrate the IF oscillator 12, first IF frequency converter 13a, IF circuit 14, RF oscillator 15, first RF frequency converter 16a, RF circuit 17, and transmitting antenna 18, which are arranged downstream of the D / A converter 11 (these have the same functions and arrangement as those in the second embodiment (see FIG. 5)).

[0019] By calculating the correction value using the output signal from the IF circuit 14 in this way, it is possible to correct the frequency characteristic within the transmission band even if the frequency characteristic within the transmission band specific to the wireless transmitting device 1 fluctuates due to heat, etc. Furthermore, it is possible to correct the frequency characteristic within the transmission band even if signal parameters such as bandwidth change.

[0020] Third Embodiment In the wireless transmission device 1 of the third embodiment shown in FIG. 7, the compensator 100 is configured to provide the output signal from the mapper 10 with an inverse characteristic of the frequency characteristic within the transmission band that is specific to the wireless transmission device 1, based on the output signal from the RF circuit 17. Only the differences between the first and third embodiments will be described below. For other technical matters, please refer to the description of the first embodiment. By this reference, the description of the first embodiment, excluding the differences, is expressly incorporated herein.

[0021] In the wireless transmission device 1 of the third embodiment, the compensator 100 includes an RF signal divider 112c that divides an output signal from the RF circuit 17, a second RF frequency converter 16b that converts the frequency of the output signal from the RF signal divider 112c to an intermediate frequency using the output signal from the RF oscillator 15, a second IF frequency converter 13b that converts the frequency of the output signal from the second RF frequency converter 16b to a baseband frequency using the output signal from the IF oscillator 12, an A / D converter 112b that converts the output signal from the second IF frequency converter 13b to a digital signal, a correction value calculator 110, and a corrector 190. The RF signal divider 112c is disposed between the RF circuit 14 and the transmitting antenna 18. The transmitting antenna 18 radiates a portion of the power of the output signal from the RF signal divider 112c into space. The compensator 100 determines an inverse characteristic of the in-band frequency characteristic specific to the wireless transmission device 1 based on the output signal from the A / D converter 112b and applies the inverse characteristic to the output signal from the mapper 10. The correction value calculator 110 uses the output signal from the A / D converter 112b to calculate a correction value in the time domain to be applied to the output signal from the mapper 10 so that the frequency characteristic of the output signal from the RF circuit 17 is flat. At this time, the correction value is calculated using a preamble signal. The corrector 190 is a convolution calculator configured, for example, by an adder, and applies the correction value calculated by the correction value calculator 110 to the output signal from the mapper 10. In other words, the corrector 190 applies the inverse characteristic calculated by the correction value calculator 110 to the output signal from the mapper 10.

[0022] Unlike the example shown in Fig. 7 in which the frequency characteristics are corrected in the time domain, the frequency characteristics may be corrected in the frequency domain as shown in Fig. 8. In the modification of the third embodiment shown in Fig. 8, the compensator 100 includes a correction value calculator 110, a corrector 190, an FFT 111a, an FFT 111c, an IFFT 111b, an RF signal distributor 112c, a second RF frequency converter 16b, a second IF frequency converter 13b, and an A / D converter 112b. The FFT 111a performs a Fourier transform on the output signal from the mapper 10, the FFT 111c performs a Fourier transform on the output signal from the A / D converter 112b, the correction value calculator 110 uses the output signal from the FFT 111c to determine the inverse characteristic to be applied to the output signal from the mapper 10, the corrector 190 applies the inverse characteristic determined by the correction value calculator 110 to the output signal from the mapper 10 that has been Fourier transformed by the FFT 111a, and then the FFT 111b performs an inverse Fourier transform on the output signal from the corrector 190. The corrector 190 is, for example, a multiplier. FIG. 8 illustrates part of the configuration of a modified example of the wireless transmitting device 1 of the third embodiment, and does not illustrate the IF oscillator 12, first IF frequency converter 13a, IF circuit 14, RF oscillator 15, first RF frequency converter 16a, RF circuit 17, and transmitting antenna 18, which are arranged downstream of the D / A converter 11 (these have the same functions and arrangement as those in the third embodiment (see FIG. 7)).

[0023] By calculating the correction value using the output signal from the RF circuit 17 in this way, it is possible to correct the frequency characteristic within the transmission band even if the frequency characteristic within the transmission band specific to the wireless transmitting device 1 fluctuates due to heat, etc. Furthermore, it is possible to correct the frequency characteristic within the transmission band even if signal parameters such as bandwidth are changed.

[0024] <Fourth embodiment> In the wireless transmission device 1 of the fourth embodiment shown in FIG. 9, the compensator 100 performs spectrum comparison between the input signal to the wireless transmission device 1 and a signal that has frequency characteristics within the transmission band specific to the wireless transmission device 1, thereby providing an output signal from the mapper 10 with the inverse characteristics of the frequency characteristics within the transmission band specific to the wireless transmission device 1. Only the differences between the modified example of the third embodiment (see FIG. 8) and the fourth embodiment will be described below. For other technical matters, please refer to the description of the modified example of the third embodiment. By this reference, the description of the modified example of the third embodiment, excluding the differences, is expressly incorporated herein. FIG. 9 illustrates a portion of the configuration of the wireless transmission device 1 of the fourth embodiment, and does not illustrate the IF oscillator 12, first IF frequency converter 13a, IF circuit 14, RF oscillator 15, first RF frequency converter 16a, RF circuit 17, and transmitting antenna 18, which are arranged downstream of the D / A converter 11 (their functions and arrangements are the same as those in the third embodiment (see FIG. 7)).

[0025] The compensator 100 included in the wireless transmission device 1 of the fourth embodiment includes, in addition to the components of the compensator 100 included in the wireless transmission device 1 (see FIG. 8) of the modified example of the third embodiment, a BB signal distributor 113 that distributes an output signal from the mapper 10. The FFT 111a performs a Fourier transform on the output signal from the mapper 10, the BB signal distributor 113 distributes the output signal from the FFT 111a, the FFT 111c performs a Fourier transform on the output signal from the A / D converter 112b, the correction value calculator 110 compares the spectrum of the output signal from the BB signal distributor 113 with that of the output signal from the FFT 111c to identify inverse characteristics to be applied to the output signal from the mapper 10, the corrector 190 applies the inverse characteristics identified by the correction value calculator 110 to the output signal from the BB signal distributor 113, and then the IFFT 111b performs an inverse Fourier transform on the output signal from the corrector 190.

[0026] The configuration in which the compensator 100 performs the above-described spectrum comparison may be applied to the modification of the second embodiment (see FIG. 6). The compensator 100 included in the wireless transmission device 1 of the modification of the fourth embodiment (see FIG. 10) includes a BB signal distributor 113 that distributes the output signal from the mapper 10, in addition to the components of the compensator 100 included in the wireless transmission device 1 of the modification of the second embodiment (see FIG. 6). The processing content of the compensator 100 is as described in the second embodiment and its modifications and the fourth embodiment and its modifications. FIG. 10 illustrates part of the configuration of the wireless transmission device 1 of the modification of the fourth embodiment, and does not illustrate the IF oscillator 12, first IF frequency converter 13a, IF circuit 14, RF oscillator 15, first RF frequency converter 16a, RF circuit 17, and transmitting antenna 18, which are arranged downstream of the D / A converter 11 (their functions and arrangements are the same as those in the second embodiment (see FIG. 5)).

[0027] Fifth Embodiment In the wireless transmission device 1 of the fifth embodiment shown in FIG. 11, the compensator 100 has a configuration that uses an equalizer to calculate the inverse characteristics of the frequency characteristics within the transmission band that are specific to the wireless transmission device 1. Hereinafter, only the differences between the modified example of the third embodiment (see FIG. 8) and the fifth embodiment will be described. For other technical matters, please refer to the description of the modified example of the third embodiment. By this reference, the description of the modified example of the third embodiment, excluding the differences, is expressly incorporated herein. FIG. 11 illustrates a part of the configuration of the wireless transmission device 1 of the fifth embodiment, and does not illustrate the IF oscillator 12, first IF frequency converter 13a, IF circuit 14, RF oscillator 15, first RF frequency converter 16a, RF circuit 17, and transmitting antenna 18, which are arranged downstream of the D / A converter 11 (their functions and arrangements are the same as those in the third embodiment (see FIG. 7)).

[0028] The compensator 100 included in the wireless transmission device 1 of the fifth embodiment includes a correction value calculator 110, a corrector 190, an FFT 111a, an IFFT 111b, an RF signal distributor 112c, a second RF frequency converter 16b, a second IF frequency converter 13b, and an A / D converter 112b. The correction value calculator 110 includes a BB signal distributor 110a that distributes the output signal from the A / D converter 112b, an equalizer 110b that equalizes the output signal from the BB signal distributor 110a, an FFT 110c that Fourier transforms the output signal from the BB signal distributor 110a, an FFT 110d that Fourier transforms the output signal from the equalizer 110b, and a signal comparator 110e that compares the output signal from the FFT 110c with the output signal from the FFT 110d. The equalizer 110b has the same configuration as an equalizer used in a wireless transmission device of the prior art, and is configured, for example, by an FIR (Finite Impulse Response) filter. The signal comparator 110e calculates the inverse characteristic of the frequency characteristic within the transmission band specific to the wireless transmission device 1 by comparing the output signal from the FFT 110c with the output signal from the FFT 110d. The FFT 111a performs a Fourier transform on the output signal from the mapper 10, the FFT 111c performs a Fourier transform on the output signal from the A / D converter 112b, the corrector 190 applies the inverse characteristic determined by the correction value calculator 110 to the output signal from the mapper 10 that has been Fourier transformed by the FFT 111a, and then the IFFT 111b performs an inverse Fourier transform on the output signal from the corrector 190.

[0029] A configuration in which compensator 100 calculates inverse characteristics using an equalizer may be applied to the modification of the second embodiment (see FIG. 6). Compensator 100 included in wireless transmission device 1 of the modification of the fifth embodiment (see FIG. 12) includes correction value calculator 110, corrector 190, FFT 111a, IFFT 111b, IF signal distributor 112a, second IF frequency converter 13b, and A / D converter 112b. The configuration of compensator 100 is the same as the configuration of compensator 100 shown in FIG. 11. FIG. 11 illustrates part of the configuration of wireless transmission device 1 of the modification of the fifth embodiment, and does not illustrate IF oscillator 12, first IF frequency converter 13a, IF circuit 14, RF oscillator 15, first RF frequency converter 16a, RF circuit 17, and transmitting antenna 18, which are arranged downstream of D / A converter 11 (their functions and arrangements are the same as those in the second embodiment (see FIG. 5)).

[0030] FIG. 13(a) shows an example of an amplitude correction value obtained by the correction value calculator 110 of the fifth embodiment, and FIG. 13(b) shows an example of a phase correction value obtained by the correction value calculator 110 of the fifth embodiment. FIG. 14 shows an example of the frequency characteristic of the amplitude of the output of an amplifier included in a wireless transmission device (Conv.) of the prior art that does not have a frequency characteristic correction function, and an example of the frequency characteristic of the amplitude of the output of an amplifier included in the wireless transmission device 1 (Prop.) of the fifth embodiment shown in FIG. 11. Note that the modulation rate of the transmission signal is 8 Gbaud, the roll-off factor is 0.2, the modulation method is 64QAM (Quadrature Amplitude Modulation), the signal bandwidth is 9.6 GHz, and the center frequency is 155 GHz. According to the calculation result of the correction value calculator 110, the digital signal sequence was corrected in the frequency domain using the corrector 190 in the signal band from 150.2 GHz to 159.8 GHz. 14, it can be seen that a correction of about 2.5 dB was made around 152.4 GHz, where the deviation was large. Furthermore, when the standard deviation was calculated in the band from 151.8 GHz to 158.2 GHz, which was not shaped by the roll-off filter, the standard deviation was 1.8 for the wireless transmission device of the prior art, but 1.2 for the wireless transmission device 1 shown in FIG.

[0031] FIG. 15(a) shows an eye pattern for a prior art wireless transmission device without a frequency characteristic compensation function, and FIG. 15(b) shows a signal constellation for a 64QAM signal for the prior art wireless transmission device without a frequency characteristic compensation function. FIG. 16(a) shows an eye pattern for the wireless transmission device 1 of the fifth embodiment shown in FIG. 11, and FIG. 16(b) shows a signal constellation for a 64QAM signal for the wireless transmission device 1 of the fifth embodiment shown in FIG. 11. These figures confirm that correcting the frequency characteristic opens the eye and achieves a signal constellation close to the ideal 64QAM signal constellation. FIG. 17 shows the EVM (Error Vector Magnitude) for the prior art wireless transmission device without a frequency characteristic compensation function and the wireless transmission device 1 of the fifth embodiment shown in FIG. 11. Here, the modulation rates of the transmission signals are 2, 4, 6, and 8 Gbaud. It can be seen that the EVM improved by approximately 9 dB for the 2 Gbaud signal and approximately 12 dB for the 8 Gbaud signal.

[0032] Sixth Embodiment In the wireless transmission device 1 of the sixth embodiment shown in FIG. 18, the correction value calculator 110 and the corrector 190 are configured with digital filters. Hereinafter, only the differences between the third embodiment (see FIG. 7) and the sixth embodiment will be described. For other technical matters, please refer to the description of the third embodiment. By this reference, the description of the third embodiment, excluding the differences, is expressly incorporated herein. FIG. 18 illustrates a part of the configuration of the wireless transmission device 1 of the sixth embodiment, and does not illustrate the IF oscillator 12, first IF frequency converter 13a, IF circuit 14, RF oscillator 15, first RF frequency converter 16a, RF circuit 17, and transmitting antenna 18, which are arranged downstream of the D / A converter 11 (their functions and arrangements are the same as those in the third embodiment (see FIG. 7)).

[0033] The compensator 100 included in the wireless transmission device 1 of the sixth embodiment includes a BB signal divider 113, a digital filter 114, an RF signal divider 112c, a second RF frequency converter 16b, a second IF frequency converter 13b, and an A / D converter 112b. An example of the configuration of the digital filter 114 is shown in Fig. 20. The digital filter 114 includes N delay elements 114a, N multipliers 114b, an adder 114c, and a subtractor 114d (N is a predetermined integer equal to or greater than 2). The ith delay element 114a outputs a delay value x(ni) of the input value. The tap coefficient of the ith multiplier 114b is set to p i (n), y(n)=Σ i=0 N p i The subtractor 114d calculates the difference ε(n) between the delayed value x(n) of the input value and the output signal from the A / D converter 112b. The digital filter 114 calculates the mean square error E[{ε(n)} 2 ] is the tap coefficient p i By calculating (n), the amplitude deviation and the phase deviation are corrected. The tap control algorithm can be a method used in digital equalizers, such as the LMS (Least Mean Square) algorithm or the zero-forcing algorithm.

[0034] A configuration in which the correction value calculator 110 and the corrector 190 are realized by digital filters may be applied to the second embodiment (see FIG. 5). A compensator 100 included in a wireless transmission device 1 of a modification of the sixth embodiment (see FIG. 19) includes a BB signal divider 113, a digital filter 114, an IF signal divider 112a, a second IF frequency converter 13b, and an A / D converter 112b. The configuration of the digital filter 114 is the same as the configuration of the digital filter 114 shown in FIG. 18. FIG. 19 illustrates a part of the configuration of a wireless transmission device 1 of a modification of the sixth embodiment, and does not illustrate the IF oscillator 12, the first IF frequency converter 13a, the IF circuit 14, the RF oscillator 15, the first RF frequency converter 16a, the RF circuit 17, and the transmitting antenna 18, which are arranged downstream of the D / A converter 11 (their functions and arrangements are the same as those in the second embodiment (see FIG. 5)).

[0035] The digital filter 114 is implemented as, for example, a field programmable gate array (FPGA), a complex programmable logic device (CPLD), an application specific integrated circuit (ASIC), or the like.

[0036] <Addendum 1> The technical features disclosed in the various embodiments and their modifications described above are not necessarily mutually exclusive, and technical features of one embodiment or its modifications may be applied to technical features of another embodiment or its modifications, provided that there is no contradiction from a technical viewpoint.

[0037] The claims as of the filing of this application do not necessarily exhaustively claim all inventions disclosed in this specification. In this regard, this should not be understood or construed as meaning that the applicant has pre-filing waived any right to a patent for any invention not claimed at the time of filing this application. To the extent permitted by the laws, regulations, or treaties of any country or region where this application is filed, the applicant reserves the right to a patent for any invention not claimed in this application, the right to file a divisional application for such invention, the right to claim such invention by amendment, and any other rights, unless the applicant expressly and conclusively expresses a contrary intention.

[0038] An example of a summary of the present invention based on another aspect is as follows.

[0039] A first invention is a wireless transmission device for transmitting a single-carrier signal, including a mapper that maps a digital signal sequence, a compensator that performs signal processing on an output signal from the mapper, a D / A converter that converts the output signal from the compensator into an analog signal, a first IF frequency converter that converts the frequency of the analog signal from the D / A converter to an intermediate frequency, an IF circuit that operates at the intermediate frequency and imparts frequency characteristics to the output signal from the first IF frequency converter, a first RF frequency converter that converts the frequency of the output signal from the IF circuit to a radio frequency, and an RF circuit that operates at a radio frequency and imparts frequency characteristics to the output signal from the first RF frequency converter. The compensator applies an inverse characteristic of a frequency characteristic within a transmission band specific to the wireless transmission device to the output signal from the mapper, thereby preventing the output signal from the RF circuit from having the frequency characteristic within the transmission band.

[0040] A second invention is characterized in that, in the first invention, the compensator includes an IF signal divider that divides an output signal from the IF circuit, a second IF frequency converter that converts the frequency of the output signal from the IF signal divider to a baseband frequency, and an A / D converter that converts the output signal from the second IF frequency converter into a digital signal, and the compensator identifies an inverse characteristic based on the output signal from the A / D converter and applies the inverse characteristic to the output signal from the mapper.

[0041] A third invention is characterized in that, in the first invention, the compensator includes an RF signal divider that divides an output signal from the RF circuit, a second RF frequency converter that converts the frequency of the output signal from the RF signal divider to an intermediate frequency, a second IF frequency converter that converts the frequency of the output signal from the second RF frequency converter to a baseband frequency, and an A / D converter that converts the output signal from the second IF frequency converter to a digital signal, and the compensator identifies an inverse characteristic based on the output signal from the A / D converter and applies the inverse characteristic to the output signal from the mapper.

[0042] A fourth invention is characterized in that, in the second or third invention, the compensator includes a BB signal distributor that distributes the output signal from the mapper, and the compensator identifies an inverse characteristic by comparing the spectrum of the output signal from the BB signal distributor with the spectrum of the output signal from the A / D converter, and applies the inverse characteristic to the output signal from the mapper.

[0043] In a fifth aspect of the present invention, in the first aspect, the compensator includes an IF signal divider that divides an output signal from the IF circuit, a second IF frequency converter that converts the frequency of the output signal from the IF signal divider to a baseband frequency, an A / D converter that converts the output signal from the second IF frequency converter into a digital signal, a BB signal divider that divides the output signal from the A / D converter, and an equalizer that equalizes the output signal from the BB signal divider. The compensator is characterized in that it identifies an inverse characteristic by comparing the output signal from the BB signal divider with the output signal from the equalizer, and applies the inverse characteristic to the output signal from the mapper.

[0044] In a sixth aspect of the present invention, in the first aspect, the compensator includes an RF signal divider that divides an output signal from the RF circuit, a second RF frequency converter that converts the frequency of the output signal from the RF signal divider to an intermediate frequency, a second IF frequency converter that converts the frequency of the output signal from the second RF frequency converter to a baseband frequency, an A / D converter that converts the output signal from the second IF frequency converter to a digital signal, a BB signal divider that divides the output signal from the A / D converter, and an equalizer that equalizes the output signal from the BB signal divider. The compensator is characterized in that it identifies an inverse characteristic by comparing the output signal from the BB signal divider with the output signal from the equalizer and applies the inverse characteristic to the output signal from the mapper.

[0045] A seventh invention is characterized in that, in the first invention, the compensator includes an IF signal divider that divides an output signal from the IF circuit, a second IF frequency converter that converts the frequency of the output signal from the IF signal divider to a baseband frequency, an A / D converter that converts the output signal from the second IF frequency converter into a digital signal, a BB signal divider that divides an output signal from the mapper, and a digital filter that identifies an inverse characteristic based on the output signal from the A / D converter and the output signal from the BB signal divider, and applies the inverse characteristic to the output signal from the mapper.

[0046] An eighth invention is characterized in that, in the first invention, the compensator includes an RF signal divider that divides an output signal from the RF circuit, a second RF frequency converter that converts the frequency of the output signal from the RF signal divider to an intermediate frequency, a second IF frequency converter that converts the frequency of the output signal from the second RF frequency converter to a baseband frequency, an A / D converter that converts the output signal from the second IF frequency converter to a digital signal, a BB signal divider that divides an output signal from the mapper, and a digital filter that identifies an inverse characteristic based on the output signal from the A / D converter and the output signal from the BB signal divider, and applies the inverse characteristic to the output signal from the mapper.

[0047] A ninth invention is characterized in that, in any one of the first to eighth inventions, the radio frequency is 30 GHz or higher.

[0048] <Addendum 2> 1. (Hardware configuration, etc.) The block diagrams used to explain the above embodiments show functional blocks. These functional blocks (components) are realized by hardware or by a combination of hardware and software. The method for realizing each functional block is not particularly limited. That is, each functional block may be realized by a single physical entity that is physically or logically coupled, or by two physical entities that are physically or logically separated.

[0049] Functions may include, but are not limited to, judging, determining, calculating, computing, processing, deriving, investigating, searching, verifying, receiving, transmitting, outputting, accessing, resolving, selecting, choosing, establishing, comparing, assuming, expecting, regarding, broadcasting, notifying, communicating, forwarding, configuring, reconfiguring, allocating, mapping, and assigning.

[0050] 2. (Applicable system) Each aspect / embodiment described in the present disclosure may be any of the following: LTE (Long Term Evolution), LTE-Advanced (LTE-A), SUPER 3G, IMT-Advanced, 4G (4th generation mobile communication system), 5G (5th generation mobile communication system), 6th generation mobile communication system (6G), xth generation mobile communication system (xG) (xG (x is, for example, an integer or decimal number)), FRA (Future Radio Access), NR (new Radio), New radio access (NX), Future generation radio access (FX), W-CDMA (registered trademark), GSM (registered trademark), CDMA2000, UMB (Ultra Mobile Broadband), IEEE 802.11 (Wi-Fi (registered trademark)), IEEE 802.16 (WiMAX (registered trademark)), IEEE The present invention may be applied to at least one of systems using 802.20, UWB (Ultra-Wideband), Bluetooth (registered trademark), or other appropriate systems, and next-generation systems that are extended, modified, created, or defined based on these systems. The present invention may also be applied to a combination of multiple systems (e.g., a combination of at least one of LTE and LTE-A with 5G).

[0051] 3. (Handling of input and output information, etc.) Input and output information may be stored in a specific location (for example, memory) or may be managed using a management table. Input and output information may be overwritten, updated, or added to. Output information may be deleted. Input information may be sent to another device.

[0052] 4.(Judgment method) The determination may be made based on a value represented by one bit (0 or 1), a Boolean value (true or false), or a numerical comparison (e.g., comparison with a predetermined value).

[0053] 5. (Software) Software shall be construed broadly to mean instructions, instruction sets, code, code segments, program code, programs, subprograms, software modules, applications, software applications, software packages, routines, subroutines, objects, executable files, threads of execution, procedures, functions, etc., whether referred to as software, firmware, middleware, microcode, hardware description language, or otherwise.

[0054] 6. ("Connected") The term "connected," or any variation thereof, means any connection, direct or indirect, between two or more elements, and may include the presence of one or more intermediate elements between two elements that are "connected" to each other. The connection between elements may be physical, logical, or a combination thereof. As used in this disclosure, two elements may be considered to be "connected" to each other using one or more wires, cables, and / or printed electrical connections, as well as electromagnetic energy having wavelengths in the radio frequency range, microwave range, and optical (both visible and invisible) range, as some non-limiting and non-exhaustive examples.

[0055] 7. ("Based on") As used in this disclosure, the phrase "based on" does not mean "based only on," unless expressly stated otherwise. In other words, the phrase "based on" means both "based only on" and "based at least on."

[0056] 8. ("First", "Second") As used in this disclosure, any reference to an element using a designation such as "first," "second," etc. does not generally limit the quantity or order of those elements. These designations may be used in this disclosure as a convenient method of distinguishing between two or more elements. Thus, a reference to a first and a second element does not imply that only two elements may be employed or that the first element must in some way precede the second element.

[0057] 9. (Open format) When used in this disclosure, the terms "include," "including," and variations thereof are intended to be inclusive, similar to the term "comprising." Furthermore, when used in this disclosure, the term "or" is not intended to be an exclusive or.

[0058] <Addendum 3> While the present invention has been described with reference to exemplary embodiments, those skilled in the art will recognize that various changes can be made and equivalents can be substituted for elements thereof without departing from the scope of the invention. Furthermore, many modifications can be made to adapt a particular system, device, or component thereof to the teachings of the present invention without departing from the essential scope of the invention. Therefore, it is intended that the invention not be limited to the particular embodiment disclosed for carrying out this invention, but rather that the invention will include all embodiments falling within the scope of the appended claims.

[0059] Furthermore, the use of terms such as "first" and "second," if any, does not denote any order or importance, and terms such as "first" and "second" are used to distinguish between elements. The terms used herein are for the purpose of describing embodiments and are not intended to limit the present invention in any way. The term "comprises" and its conjugations, when used in this specification and / or the appended claims, reveal the presence of the stated features, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, steps, operations, elements, components, and / or groups thereof. The term "and / or" includes any and all combinations of one or more of the associated listed elements, if any. In the claims and the specification, unless otherwise specified, the use of words such as "connected," "coupled," "joined," "connected," or synonyms thereof, and all forms thereof, does not necessarily negate the presence of one or more intermediate elements between two elements that are, for example, "connected" or "coupled" to each other or "coupled" to each other. In the claims and the specification, the term "optional," if any, should be understood as a term that represents the same meaning as the universal symbol ∀, unless otherwise specified. For example, the phrase "for any X" has the same meaning as "for all X" or "for each X."

[0060] Unless otherwise specified, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Furthermore, terms such as those defined in commonly used dictionaries should be interpreted to have a meaning consistent with their meaning in the context of the relevant art and this disclosure, and should not be interpreted ideally or excessively formally unless explicitly defined.

[0061] It will be understood that in describing the present invention, many techniques and steps are disclosed. Each of these has distinct advantages, and each can be used in combination with one or more, or in some cases all, of the other disclosed techniques. Therefore, to avoid cluttering, this specification will refrain from describing every possible combination of individual techniques or steps. Nevertheless, the specification and claims should be read with the understanding that such combinations are fully within the scope of the present invention and claims.

[0062] The corresponding structure, material, acts, and equivalents of all functional elements combined with means or steps in the following claims are intended to include the structure, material, or acts, if any, that perform the function in combination with other elements.

[0063] Although the present invention has been described above with reference to exemplary embodiments, it is not limited to these embodiments. Various modifications and variations are possible without departing from the spirit of the present invention. The selected and described embodiments are intended to illustrate the principles of the present invention and its practical application. The present invention may be used in various embodiments with various modifications and variations, which are determined according to the expected use. All such modifications and variations are intended to be included within the scope of the present invention, as defined by the appended claims, and are intended to be accorded the same protection when interpreted in accordance with the breadth that is fairly, legally, and equitably to be given. [Explanation of symbols]

[0064] 1. Radio transmitting device 10 Mapper 11 D / A converter 12 IF oscillator 13 IF frequency converter 13a First IF frequency converter 13b Second IF frequency converter 14 IF circuit 15 RF oscillator 16 RF frequency converters 16a First RF frequency converter 16b Second RF frequency converter 17 RF circuit 18 transmitting antennas 100 Compensator 110 Correction value calculator 110a BB signal splitter 110b Equalizer 110c FFT 110d FFT 110e signal comparator 111a FFT 111b IFFT 111c FFT 112a IF signal splitter 112b A / D converter 112c RF signal splitter 113 BB signal splitter 114 Digital Filter 114a Delay 114b multiplier 114c Adder 114d Subtractor 190 Corrector 900 Radio transmitting device

Claims

1. A radio transmission device for transmitting a single carrier signal, comprising: a mapper that maps a digital signal sequence; a compensator for performing signal processing on the output signal from the mapper; a D / A converter for converting the output signal from the compensator into an analog signal; a first IF frequency converter that converts the frequency of the analog signal from the D / A converter into an intermediate frequency; an IF circuit that operates at the intermediate frequency and provides a frequency characteristic to an output signal from the first IF frequency converter; a first RF frequency converter that converts the frequency of the output signal from the IF circuit into a radio frequency; an RF circuit that operates at the radio frequency and provides a frequency characteristic to an output signal from the first RF frequency converter; Including, The compensator is an IF signal distributor that distributes an output signal from the IF circuit; a second IF frequency converter that converts the frequency of the output signal from the IF signal distributor to a baseband frequency; an A / D converter that converts the output signal from the second IF frequency converter into a digital signal; a BB signal distributor that distributes an output signal from the A / D converter; an equalizer for equalizing the output signal from the BB signal distributor; Including, The compensator identifies an inverse characteristic of the frequency characteristic within the transmission band specific to the wireless transmitting device by comparing the output signal from the BB signal distributor with the output signal from the equalizer, and applies the inverse characteristic to the output signal from the mapper, thereby preventing the output signal from the RF circuit from having the frequency characteristic within the transmission band. Radio transmitting device.

2. A radio transmission device for transmitting a single carrier signal, comprising: a mapper that maps a digital signal sequence; a compensator for performing signal processing on the output signal from the mapper; a D / A converter for converting the output signal from the compensator into an analog signal; a first IF frequency converter that converts the frequency of the analog signal from the D / A converter into an intermediate frequency; an IF circuit that operates at the intermediate frequency and provides a frequency characteristic to an output signal from the first IF frequency converter; a first RF frequency converter that converts the frequency of the output signal from the IF circuit into a radio frequency; an RF circuit that operates at the radio frequency and provides a frequency characteristic to an output signal from the first RF frequency converter; Including, The compensator is an RF signal distributor that distributes an output signal from the RF circuit; a second RF frequency converter that converts the frequency of the output signal from the RF signal distributor into an intermediate frequency; a second IF frequency converter that converts the frequency of the output signal from the second RF frequency converter to a baseband frequency; an A / D converter that converts the output signal from the second IF frequency converter into a digital signal; a BB signal distributor that distributes an output signal from the A / D converter; an equalizer for equalizing the output signal from the BB signal distributor; Including, The compensator identifies an inverse characteristic of the frequency characteristic within the transmission band specific to the wireless transmitting device by comparing the output signal from the BB signal distributor with the output signal from the equalizer, and applies the inverse characteristic to the output signal from the mapper, thereby preventing the output signal from the RF circuit from having the frequency characteristic within the transmission band. Radio transmitting device.

3. 3. The radio transmission device according to claim 1, The radio frequency is 30 GHz or higher. A radio transmitting device characterized by:

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