Transmitting / receiving device, control method for transmitting / receiving device, and program

Abstract

To provide a transmitter-receiver that realizes a desired S / N ratio of feedback systems using a reception system ADC, without providing feedback system-only ADC of DPD.SOLUTION: The transmitter-receiver includes a transmission system that includes a plurality of transmission units and a DPD unit, a reception system that includes the same number of reception units and a selection unit, the same number of antennas, and a synthesis unit. The transmission unit includes a power amplifier that supplies a transmission signal to the antennas. The reception unit includes an ADC for reception. The DPD unit includes a computation unit that computes a coefficient having a strain whose characteristic is inverse to the power amplifier, and a multiplication unit that multiplies the coefficient to digital transmission signals. In a TDD transmission period, the selection unit selects one feedback signal of the power amplifier and outputs it as a selection unit output signal, each of at least two ADCs for reception converts the selection unit output signal from analog to digital and generates two digital feedback signals, and the synthesis unit combines at least two digital feedback signals to generate a composite signal and supplies the composite signal to the computation unit.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a transmitting / receiving device, a control method for a transmitting / receiving device, and a program. [Background technology]

[0002] Regarding feedback signals for digital predistortion (DPD), there are the following patent documents:

[0003] Patent Document 1 relates to a wireless communication device capable of measuring a transmitted wireless signal with high accuracy by preventing interference caused by a clock.

[0004] US Pat. No. 5,399,633 relates to an adaptive transmitter predistortion technique that can select the shared receiver that provides the best feedback signal.

[0005] Patent Document 3 relates to a digital predistortion processing method and apparatus including a feedback signal conversion section having a radio frequency signal converter including an analog-to-digital converter (ADC). [Prior art documents] [Patent documents]

[0006] [Patent Document 1] JP 2012-028990 A [Patent Document 2] Special Publication No. 2014-534704 [Patent Document 3] Special Publication No. 2019-536381 Summary of the Invention [Problem to be solved by the invention]

[0007] The following analysis is given by the inventors.

[0008] Digital predistortion (DPD) is a method to compensate for the nonlinearity of a power amplifier (PA) by adding a distortion with an inverse characteristic to the signal before inputting it to the power amplifier in order to suppress distortion components generated by the nonlinearity of the power amplifier. DPD is sometimes used, for example, in the signal processing part of wireless base stations.

[0009] DPD feeds back the output signal of the power amplifier to the signal processing unit, creating distortion with the inverse characteristics. For example, the signal processing unit of a wireless base station includes a transceiver device that includes a transmission system and a reception system. The feedback system of the DPD in the transmission system and the reception system each require an analog-to-digital converter (ADC). However, the ADC used in the feedback system of the DPD in the transmission system is required to have a higher gain (higher signal-to-noise ratio) than the ADC used in the reception system, and conventionally, when constructing a transmission system, a dedicated ADC is used for the DPD feedback system.

[0010] An object of the present invention is to provide a transmission / reception device, a control method for the transmission / reception device, and a program that contribute to enabling a desired S / N ratio of a DPD feedback system to be achieved by using an ADC in the receiving system, without providing a high-gain (high S / N ratio) ADC dedicated to the DPD feedback system. [Means for solving the problem]

[0011] According to a first aspect of the present invention, a digital predistortion unit (DPDU) is provided, comprising: a transmission system including a plurality of transmission units and a digital predistortion unit; a reception system including a number of reception units equal to the number of the transmission units and a selection unit connected to each of the reception units; antennas equal to the number of the transmission units; and a synthesis unit; Each of the antennas is connected to one of the transmitters and to the selector; Each of the transmitters includes a power amplifier that generates a power-amplified transmission signal from an input signal of the transmitter and supplies the power-amplified transmission signal to the antenna; Each of the receiving units includes a receiving analog / digital converter that converts a received signal received by the antenna into a digital received signal; the digital predistortion unit includes a calculation unit that calculates a coefficient having a distortion characteristic of the inverse of each of the power amplifiers based on a feedback signal of a signal output from each of the power amplifiers, and a multiplication unit that multiplies each digital transmission signal by a coefficient having a distortion characteristic of the inverse of each of the power amplifiers of the transmission units, and outputs each digitally predistorted signal to each of the transmission units as the input signal; During the transmission period of the time division duplex method, the selection unit selects a feedback signal of a transmission signal output by one power amplifier of the transmission unit, and outputs the feedback signal as a selection unit output signal; Each of the at least two receiving analog / digital converters performs analog / digital conversion on the selection unit output signal to generate at least two digital feedback signals; A transmitting / receiving device can be provided in which the synthesis unit synthesizes the at least two digital feedback signals to generate a synthesis signal, and supplies the synthesis signal to the calculation unit.

[0012] According to a second aspect of the present invention, each of the transmitting units further includes a coupler connected between the power amplifier and the antenna, the coupler outputting a feedback signal of the transmission signal; the selection unit includes the same number of switches as the receiving units, each of the switches including a plurality of inputs to which the feedback signals of the couplers of the different transmitting units are respectively supplied, and an output connected to an input of the receiving analog-to-digital converter; and In the transmission period of the time division duplex method, each of the switches of the selection unit selects, from among the plurality of inputs, an input to which a feedback signal of a coupler of one of the transmission units is supplied, and outputs a switch output signal as the selection unit output signal; A transceiver device according to a first aspect can be provided, in which each of the at least two receiving analog / digital converters performs analog / digital conversion on the switch output signal of each of the switches in the selection section to generate the at least two digital feedback signals.

[0013] According to a third aspect of the present invention, there is provided a computer included in the transmitting / receiving device according to the second aspect, controlling each of the switches to select an input to which a distributed output signal supplied by the same coupler is supplied from among the plurality of inputs and to output the selected input; A control method for a transceiver device can be provided, the control method including the step of periodically switching the selection of the input. This method is associated with a specific machine, that is, a computer that executes the control method for the transceiver device.

[0014] According to a fourth aspect of the present invention, a computer included in the transmitting / receiving device according to the second aspect of the present invention includes: A process of controlling each of the switches to select an input from the plurality of inputs to which a distributed output signal provided by the same coupler is supplied, and to output the selected input; It is possible to provide a program that executes a process of controlling the input selection so as to periodically switch the input selection.

[0015] These programs can be recorded on a computer-readable storage medium. The storage medium can be a non-transient medium such as a semiconductor memory, a hard disk, a magnetic recording medium, an optical recording medium, etc. The present invention can also be embodied as a computer program product. Effect of the Invention

[0016] According to the present invention, it is possible to provide a transceiver device, a control method for a transceiver device, and a program that contribute to enabling a desired S / N ratio of a DPD feedback system to be achieved using an ADC in the receiving system, without providing a high-gain (high S / N ratio) ADC dedicated to the DPD feedback system. [Brief description of the drawings]

[0017] [Figure 1] FIG. 2 is a diagram illustrating an example of a configuration of a transmitting / receiving device according to an embodiment of the present invention. [Diagram 2] FIG. 1 is a diagram illustrating an overview of a method for compensating for nonlinearity of a power amplifier using DPD. [Diagram 3] 2 is a diagram illustrating an example of the configuration of a synthesis unit of a transmission / reception device according to an embodiment of the present invention. FIG. [Figure 4] 1 is a diagram illustrating an example of a configuration of a transmission / reception device according to a first embodiment of the present invention. [Diagram 5] FIG. 11 is a diagram illustrating an example of a configuration of a transmission / reception device according to a second exemplary embodiment of the present invention. [Figure 6] FIG. 11 is a diagram illustrating an example of the operation of a control unit of the transmitting / receiving device according to the second exemplary embodiment of the present invention. [Figure 7] FIG. 2 is a diagram showing the configuration of a computer that constitutes a control unit of the transmitting / receiving device of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0018] First, an overview of one embodiment of the present invention will be described with reference to the drawings. Note that the reference numerals in the drawings attached to this overview are attached to each element for convenience as an example to aid in understanding, and are not intended to limit the present invention to the illustrated form. Furthermore, the connection lines between blocks in the drawings and the like referred to in the following description include both bidirectional and unidirectional lines. The unidirectional arrows are intended to diagrammatically indicate the flow of the main signal (data), and do not exclude bidirectionality.

[0019] Fig. 1 is a diagram showing an example of the configuration of a transceiver according to an embodiment of the present invention. Referring to Fig. 1, a transceiver 10 according to an embodiment of the present invention includes a transmission system 100 including two transmission units 110, 120 and a digital predistortion (DPD) unit 150, a reception system 200 including reception units 211, 221 in the same number as the two transmission units 110, 120 and a selection unit 201 connected to each of the reception units 211, 221, antennas 310, 320 in the same number as the two transmission units, and a synthesis unit 300. Note that, in one embodiment of the present invention, a configuration including two transmission units and two reception units is described, but these are merely examples and are not intended to limit the number of transmission units and reception units to two.

[0020] The antenna 310 is connected to the transmitting unit 110 and the selecting unit 201 , and the antenna 320 is connected to the transmitting unit 120 and the selecting unit 201 .

[0021] Each of the transmitting units 110 and 120 includes a power amplifier 111 and 121 that generates a power-amplified transmission signal from an input signal of the transmitting unit 110 and 120 and supplies the power-amplified transmission signal to the antenna. Each of the receiving units 211 and 221 includes a receiving analog / digital converter 212 and 222 that converts a reception signal received by the antenna 310 and 320 into a digital reception signal.

[0022] The digital predistortion unit 150 includes a calculation unit 153 that calculates coefficients having distortion characteristics inverse to those of the power amplifiers 111, 121 based on feedback signals 21, 31 of the signals output from the power amplifiers 111, 121, respectively, and a multiplication unit 151 that multiplies each digital transmission signal 20, 30 by a coefficient having distortion characteristics inverse to those of the power amplifiers 111, 121 of each of the transmission units 110, 120, and outputs each digitally predistorted signal as the input signal to each of the transmission units 110, 120.

[0023] Next, an overview of a method for compensating for nonlinearity of a power amplifier by digital predistortion (DPD) will be described with reference to Fig. 2. Fig. 2 is a diagram showing an overview of a method for compensating for nonlinearity of a power amplifier by DPD.

[0024] As shown in "PA characteristic 80" in Fig. 2, even if the input signal level of a power amplifier (PA) increases, the output signal level of the PA does not increase proportionally, and the output signal of the PA becomes distorted. This is called the nonlinearity of the power amplifier (PA). In order to improve the nonlinearity of the power amplifier (PA), in DPD, the input signal to the PA is multiplied in advance by a coefficient having a distortion with the inverse characteristic of the nonlinearity of the PA, as shown in "DPD characteristic 81" in Fig. 2, and then input to the PA, thereby compensating so that the input signal level and output signal level of the PA become the ideal characteristics of the PA, as shown in "overall characteristic 82" in Fig. 2.

[0025] Next, the operation of one embodiment of the present invention will be described with reference to Fig. 1. In one embodiment of the present invention, as an example, the operation will be described when the transceiver device 10 is transmitting during a transmission period of a time division duplex (TDD) system. TDD is a communication system in which the frequency band used is divided finely in the time axis direction and transmission and reception are alternately repeated. During transmission by the transceiver device under TDD control (for example, during a downlink (DL) period when the transceiver device 10 is a wireless base station), the ADC of the receiving system is unused, and it becomes possible to utilize the ADC of the receiving system as an ADC of the feedback system of DPD.

[0026] During a transmission period using the time division duplex method, the selection unit 201, for example, selects a feedback signal 21 of the transmission signal output by the power amplifier 111 of one of the transmission units 110, and outputs it as selection unit output signals 22 and 32, and each of at least two receiving analog / digital converters 212 and 222 analog / digital converts the selection unit output signals 22 and 32 to generate at least two digital feedback signals 61 and 62.

[0027] The combiner 300 combines at least two digital feedback signals 61 and 62 to generate a combined signal 71 , and supplies the combined signal 71 to the calculator 153 .

[0028] In one embodiment of the present invention, the DPD unit 150 includes a calculation unit 153 that determines a coefficient having an inverse characteristic distortion of the DPD, and a multiplication unit 151 that multiplies the digital transmission signal by the coefficient, and the DPD unit 150 receives a transmission signal folded back at the antenna 310, 320 terminal as a feedback signal 21, 31, and the calculation unit 153 subtracts the PA characteristic obtained by the digital feedback signal 61, 62 obtained by analog-to-digital conversion of the feedback signal 21, 31 from the ideal characteristic of the PA to obtain a coefficient having the inverse characteristic distortion of the DPD, and the multiplication unit 151 multiplies the digital transmission signal by the coefficient having the inverse characteristic distortion determined by the calculation unit 153, and adds the distortion of the inverse characteristic of the PA to the digital transmission signal and outputs the signal. In this way, the distortion of the inverse characteristic of the PA is given to the digital transmission signal and inputted to the PA as an input signal of the PA, thereby compensating for the nonlinearity of the PA so that the output of the PA for the input of the DPD unit becomes the ideal characteristic of the PA.

[0029] The selection unit 201 may periodically switch the selection of the inputs of the feedback signals 21 and 31 of the transmission signal, and the calculation unit 153 of the digital predistortion unit 150 of the transmission system 100 may periodically generate coefficients having the inverse distortion characteristics of all the power amplifiers 111 and 121 for performing the digital predistortion process, using the composite signal 71. Furthermore, the selection of the inputs may be switched so that all of the inputs of the feedback signals 21 and 31 of the transmission signal are selected within a predetermined period, and the calculation unit 153 of the digital predistortion unit 150 of the transmission system 100 may generate coefficients having the inverse distortion characteristics of all the power amplifiers 111 and 121 for performing the digital predistortion process within a predetermined period.

[0030] As described above, until the coefficients having the distortion of the inverse characteristics of the power amplifier generated periodically or within a predetermined period are generated again, the coefficients are continuously multiplied by each digital transmission signal by the multiplier 151. That is, the coefficients having the distortion of the inverse characteristics of the power amplifier generated for the PA111 are continuously multiplied by the digital transmission signal of Lane0 by the multiplier 151 and sent to the transmitter 110, and the coefficients having the distortion of the inverse characteristics of the power amplifier generated for the PA121 are continuously multiplied by the digital transmission signal of Lane1 by the multiplier 151 and sent to the transmitter 120.

[0031] 3 is a diagram showing an example of the configuration of a combiner of a transmitting / receiving device according to an embodiment of the present invention. The combiner 300 includes phase adjustment units 301 and 302 and an adder 305. The phase adjustment units 301 and 302 combine the digital feedback signals 61 and 62 received from the receiving ADC 212 and the receiving ADC 222 in phase to obtain a combined signal 71 with a maximum S / N ratio, i.e., adjust the phases to be in phase before combining, enhance the signals to improve the gain, and add them in the adder 305 to output the combined signal 71.

[0032] Regarding the improvement of the gain, in one embodiment of the present invention, when digital feedback signals 61 and 62 generated using two receiving ADCs are added in phase, the amplitude of the digital feedback signals is doubled and the power is quadrupled because the digital feedback signals are correlated. On the other hand, the noise contained in the digital feedback signal is uncorrelated and the noises to be added are indefinitely positive or negative, so the amplitude is not added but the power is added. Therefore, when the power of the digital feedback signal and the noise are subtracted, the gain is 3 dB. Similarly, when the number of receiving ADCs used is increased to 4 or 8, the gain becomes 6 dB or 9 dB.

[0033] As described above, according to one embodiment of the present invention, during a transmission period of the time division duplex system, two ADCs of two unused receiving systems of the transceiver can be used as ADCs of the feedback system of the DPD. Furthermore, the outputs of the two ADCs of the receiving systems can be combined to input a feedback signal having an improved S / N ratio to the calculation unit of the DPD section. Therefore, according to one embodiment of the present invention, it is possible to provide a transceiver, a control method for the transceiver, and a program that contribute to making it possible to realize a desired S / N ratio of the feedback system of the DPD using the ADCs of the receiving systems without providing a high-gain (high S / N ratio) ADC dedicated to the feedback system of the DPD.

[0034] [First embodiment] Next, a transmitting / receiving device according to a first embodiment of the present invention will be described with reference to the drawings. It is a diagram showing an example of the configuration of the transmitting / receiving device according to the first embodiment of the present invention. In FIG. 4, components with the same reference symbols as those in FIG. 1 indicate the same components. In the transmitting / receiving device 10 according to the first embodiment of the present invention, a transmitting system 100 includes four transmitting units 110, 120, 130, and 140, a receiving system 200 includes four receiving units 211, 221, 231, and 241, and four antennas 310, 320, 330, and 340. The first embodiment of the present invention is an embodiment in which each of the transmitting units 110, 120, 130, 140 further includes couplers 113, 123, 133, 143 that output feedback signals of the transmission signals and are connected between the power amplifiers 111, 121, 131, 141 and the antennas 310, 320, 330, 340, and the selecting unit 201 includes the same number (four) of switches (SW) 215, 225, 235, 245 as the number of receiving units. Note that the configuration including four transmitting units and four receiving units is merely an example, and it is not intended to limit the number of transmitting units and receiving units to four.

[0035] 4, each of the transmitters 110, 120, 130, 140 includes a digital-to-analog converter (DAC) 112, 122, 132, 142, a power amplifier (PA) 111, 121, 131, 141, and a coupler 113, 123, 133, 143. The output of the transmit signal of each of the couplers 113, 123, 133, 143 is connected to an antenna 310, 320, 330, 340, respectively.

[0036] Each of the switches 215, 225, 235, 245 includes a number of inputs to which feedback signals 21, 31, 41, 51, which are the distributed output signals of the couplers of the different transmitting sections, and one of the transmit signal outputs of each coupler 113, 123, 133, 143, are respectively supplied, and one output connected to the input of the receiving analog / digital converter 212, 222, 232, 242.

[0037] When the transceiver 10 is in a receiving operation period, i.e., a time division duplex (TDD) reception period (for example, when the transceiver 10 is a wireless base station, an uplink (UL) period), each switch 215, 225, 235, 245 selects input 4, the output of the antenna 310 is supplied to the receiving ADC 212 via SW215, the output of the receiving ADC 212 is processed as a digital received signal of Lane 0, the output of the antenna 320 is supplied to the receiving ADC 222 via SW225, the output of the receiving ADC 222 is processed as a digital received signal of Lane 1, the output of the antenna 330 is supplied to the receiving ADC 232 via SW235, the output of the receiving ADC 232 is processed as a digital received signal of Lane 2, and the output of the antenna 340 is supplied to the receiving ADC 242 via SW245, and the output of the receiving ADC 242 is processed as a digital received signal of Lane 3.

[0038] During a period of transmission operation of the transceiver 10 (for example, a downlink (DL) period when the transceiver 10 is a wireless base station), i.e., during a transmission period using the time division duplex method, each of the switches 215, 225, 235, 245 of the selection unit 201 selects from among a plurality of inputs, i.e., from among inputs 0 to 3, input 0 of one of the transmission units 110, 120, 130, 140, for example, transmission unit 110, to which a feedback signal from coupler 113 is supplied, and outputs the switch output signal 22 as the selection unit output signal 22 of the selection unit 201.

[0039] Each of the receiving analog / digital converters 212, 222, 232, 242 of at least two, for example four, of the receiving units 211, 221, 231, 241 performs analog / digital conversion on the switch output signals 22, 32, 42, 52 of each of the switches 215, 225, 235, 245 of the selection unit 201 to generate at least two, for example four digital feedback signals 61, 62, 63, 64.

[0040] The combiner 300 combines at least two, for example, four digital feedback signals 61 , 62 , 63 , and 64 to generate a combined signal 71 , and supplies the combined signal 71 to the calculator 153 .

[0041] In the first embodiment of the present invention, the DPD unit 150 includes a calculation unit 153 that determines a coefficient having an inverse characteristic distortion of DPD, and a multiplication unit 151 that multiplies the digital transmission signal by the coefficient. The DPD unit 150 receives, as feedback signals 21, 31, 41, 51, distributed output signals of transmission signals that are distributed and folded back by couplers 113, 123, 133, 143 at the antenna ends of transmitting antennas 310, 320, 330, 340, respectively. The calculation unit 153 subtracts the characteristics of the PA obtained from a composite signal 71 of digital feedback signals 61, 62, 63, 64 obtained by analog-to-digital conversion of the feedback signals 21, 31, 41, 51 from the ideal characteristics of the PA to determine a coefficient having the inverse characteristic distortion of DPD. The multiplication unit 151 multiplies the digital transmission signal by the coefficient having the inverse characteristic distortion determined by the calculation unit 153, and adds the distortion of the inverse characteristic of the PA to the digital transmission signal and outputs it. In this way, the digital transmit signal is given distortion with the inverse characteristics of the PA, input to each transmitting unit, converted to an analog signal by DACs 112, 122, 132, 142, and input to PAs 111, 121, 131, 141 as input signals to PAs 111, 121, 131, 141. This compensates for the nonlinearity of the PA so that the outputs of PAs 111, 121, 131, 141 in response to the digital transmit signal of Lane 0, the digital transmit signal of Lane 1, the digital transmit signal of Lane 2, and the digital transmit signal of Lane 3 which are input to DPD unit 150, conform to the ideal characteristics of the PA.

[0042] The configuration of combining unit 300 in the first embodiment of the present invention can be configured in the same way as combining unit 300 described using FIG. 3, by adding phase adjustment units 303 and 304 that adjust the phase of digital feedback signals 63 and 64 to combining unit 300 of one embodiment of the present invention described using FIG. 3, making adder unit 305 a four-input adder unit, and adding the outputs of phase adjustment units 303 and 304 in four-input adder unit 305.

[0043] The switches 215, 225, 235, 245 of the selection unit 201 may periodically switch the input selection of the feedback signals 21, 31, 41, 51 of the transmission signal, and the calculation unit 153 of the digital predistortion unit 150 of the transmission system 100 may periodically generate coefficients having the inverse distortion characteristics of all the power amplifiers 111, 121, 131, 141 for performing the digital predistortion process, using the composite signal 71. Furthermore, the input selection may be switched so that all the inputs of the feedback signals 21, 31, 41, 51 of the transmission signal are selected within a predetermined period, and the calculation unit 153 of the digital predistortion unit 150 of the transmission system 100 may generate coefficients having the inverse distortion characteristics of all the power amplifiers 111, 121, 131, 141 for performing the digital predistortion process within a predetermined period.

[0044] As described above, the coefficients having the distortion of the inverse characteristic of the power amplifier generated periodically or within a predetermined period of time are continuously multiplied by each digital transmission signal by the multiplier 151 until regeneration is performed. That is, the coefficients having the distortion of the inverse characteristic of the power amplifier generated for the PA111 are continuously multiplied by the digital transmission signal of Lane0 by the multiplier 151 and sent to the transmitter 110, the coefficients having the distortion of the inverse characteristic of the power amplifier generated for the PA121 are continuously multiplied by the digital transmission signal of Lane1 by the multiplier 151 and sent to the transmitter 120, the coefficients having the distortion of the inverse characteristic of the power amplifier generated for the PA131 are continuously multiplied by the digital transmission signal of Lane2 by the multiplier 151 and sent to the transmitter 130, and the coefficients having the distortion of the inverse characteristic of the power amplifier generated for the PA141 are continuously multiplied by the digital transmission signal of Lane3 by the multiplier 151 and sent to the transmitter 140.

[0045] As described above, according to the first embodiment of the present invention, during a transmission period of the time division duplex system, each ADC of a plurality of unused receiver units of the receiving system of the transmitting / receiving device can be used as an ADC of the feedback system of the DPD. Furthermore, the outputs of the ADCs of the plurality of receiver units of the receiving system can be combined to provide a feedback signal having an improved S / N ratio to the calculation unit of the DPD unit. Therefore, according to the first embodiment of the present invention, it is possible to provide a transmitting / receiving device, a control method for the transmitting / receiving device, and a program that contribute to making it possible to realize a desired S / N ratio of the feedback system of the DPD using the ADC of the receiving system without providing a high-gain (high S / N ratio) ADC dedicated to the feedback system of the DPD.

[0046] [Second embodiment] Next, a second embodiment of the present invention will be described with reference to the drawings. Fig. 5 is a diagram showing an example of the configuration of a transmission / reception device according to the second embodiment of the present invention. In Fig. 5, components with the same reference symbols as those in Fig. 4 indicate the same components. The second embodiment shown in Fig. 5 is an embodiment in which a control unit 400 that controls the switches 215, 225, 235, and 245 of a selection unit 201 is provided in the transmission / reception device 10 of the first embodiment shown in Fig. 4.

[0047] Next, the operation of the transmitting / receiving device according to the second embodiment of the present invention will be described with reference to the drawings. Fig. 6 is a diagram showing an example of the operation of the control unit of the transmitting / receiving device according to the second embodiment of the present invention. Fig. 6 shows only the switch 215 out of the switches 215, 225, 235, and 245 in Fig. 5, but the other switches 225, 235, and 245 are also controlled by the control unit 400 in the same manner as the switch 215.

[0048] 6 shows an example of the TDD mode and selection of switch inputs 0 to 4 of switch 215. Feedback signal 21 is input to input 0 of switch 215, feedback signal 31 is input to input 1, feedback signal 41 is input to input 2, feedback signal 51 is input to input 3, and the received signal of antenna 310 is input to input 4. The same feedback signals 21 to 51 as those inputs 0 to 3 of switch 215 are input to inputs 0 to 3 of other switches 225, 235, and 245. The received signals of antennas 320, 330, and 340 are input to input 4 of other switches 225, 235, and 245, respectively.

[0049] The control unit 400 selects input 4 of each switch 215, 225, 235, 245 during the reception period in accordance with a TDD mode signal indicating the transmission period and reception period of the time division duplex (TDD) system, and the output of antenna 310 is supplied to receiving ADC 212 via SW215, the output of antenna 320 is supplied to receiving ADC 222 via SW225, the output of antenna 330 is supplied to receiving ADC 232 via SW235, and the output of antenna 340 is supplied to receiving ADC 242 via SW245.

[0050] On the other hand, the control unit 400 selects one of the inputs 0 to 3 of each of the switches 215, 225, 235, and 245 during the transmission period.

[0051] During each transmission period or throughout several transmission periods, the control unit 400 controls each of the switches 215, 225, 235, 245 to select and output an input from among multiple inputs 0 to 3 to which a distribution output signal (feedback signal) supplied by the same coupler is supplied, for example, input 0 to which the distribution output signal (feedback signal 21) supplied by coupler 113 is supplied, and controls the selection of inputs 0 to 3 to be switched periodically.

[0052] When the periodic selection switching is performed, the calculation unit 153 of the digital predistortion unit 150 in the transmission system 100 periodically generates coefficients having inverse distortion characteristics of all power amplifiers for performing digital predistortion processing, using the composite signal 71.

[0053] Furthermore, during each transmission period or throughout several transmission periods, the control unit 400 controls each of the switches 215, 225, 235, 245 to select and output an input from among multiple inputs 0 to 3 to which a distributed output signal supplied by the same coupler is supplied, for example, input 0 to which a distributed output signal supplied by coupler 113 is supplied, and controls the selection of inputs 0 to 3 to be switched so that all of inputs 0 to 3 are selected within a specified period.

[0054] When switching is performed so that all of the inputs 0 to 3 are selected within the above-mentioned specified period, the calculation unit 153 of the digital predistortion unit 150 in the transmission system generates coefficients having the inverse distortion characteristics of all the power amplifiers for executing the digital predistortion processing within the specified period.

[0055] As described above, the coefficients having the distortion of the inverse characteristic of the power amplifier generated periodically or within a predetermined period of time are continuously multiplied by each digital transmission signal by the multiplier 151 until regeneration is performed. That is, the coefficients having the distortion of the inverse characteristic of the power amplifier generated for the PA111 are continuously multiplied by the digital transmission signal of Lane0 by the multiplier 151 and sent to the transmitter 110, the coefficients having the distortion of the inverse characteristic of the power amplifier generated for the PA121 are continuously multiplied by the digital transmission signal of Lane1 by the multiplier 151 and sent to the transmitter 120, the coefficients having the distortion of the inverse characteristic of the power amplifier generated for the PA131 are continuously multiplied by the digital transmission signal of Lane2 by the multiplier 151 and sent to the transmitter 130, and the coefficients having the distortion of the inverse characteristic of the power amplifier generated for the PA141 are continuously multiplied by the digital transmission signal of Lane3 by the multiplier 151 and sent to the transmitter 140.

[0056] As described above, according to the second embodiment of the present invention, in a transmission period of the time division duplex system, each ADC of a plurality of unused receivers of a transmission system of a transmission / reception device can be used as an ADC of a feedback system of DPD. Furthermore, it is possible to provide a transmission / reception device, a control method for the transmission / reception device, and a program that can periodically generate coefficients having distortions with inverse characteristics of all power amplifiers for performing digital predistortion processing, and can generate coefficients having distortions with inverse characteristics of all power amplifiers for performing digital predistortion processing within a predetermined period.

[0057] Furthermore, the outputs of the ADCs of the multiple receivers in the receiving system can be combined to input a feedback signal having an improved S / N ratio to the calculation unit of the DPD unit. Therefore, according to one embodiment of the present invention, it is possible to provide a transmitting / receiving device, a control method for a transmitting / receiving device, and a program that contribute to making it possible to realize a desired S / N ratio of the DPD feedback system using the ADCs in the receiving system without providing a high-gain (high S / N ratio) ADC dedicated to the DPD feedback system.

[0058] Although each embodiment of the present invention has been described above, the present invention is not limited to the above-mentioned embodiments, and further modifications, substitutions, and adjustments can be made without departing from the basic technical idea of ​​the present invention. For example, the configuration of the transmitting / receiving device, the configuration of each element, and the operation of the control device shown in each drawing are examples to help understand the present invention, and are not limited to the configurations shown in these drawings. In addition, "A and / or B" is used to mean at least either A or B.

[0059] Moreover, the procedures shown in the first to second embodiments can be realized by a program that causes a computer (9000 in FIG. 7) functioning as the transceiver or the control unit of the transceiver of the present invention to realize the function as the transceiver or the control unit of the transceiver. Such a computer is exemplified by a configuration including a CPU (Central Processing Unit) 9010, a communication interface 9020, a memory 9030, and an auxiliary storage device 9040 in FIG. 7. That is, the CPU 9010 in FIG. 7 executes a control program for the transceiver or the control unit of the transceiver, and performs an update process for each calculation parameter held in the auxiliary storage device 9040 or the like.

[0060] The memory 9030 is a RAM (Random Access Memory), a ROM (Read Only Memory), or the like.

[0061] In other words, each part (processing means, function) of the transmission / reception device or the control unit of the transmission / reception device shown in the above-mentioned first to second embodiments can be realized by a computer program that causes the processor of the above-mentioned computer to execute each of the above-mentioned processes using its hardware.

[0062] Finally, preferred embodiments of the present invention will be summarized. [First form] (See the transmitting / receiving device according to the first aspect above) [Second Form] (See the transmitting / receiving device according to the second aspect above.) [Third Form] In the transmitting / receiving device described in the first or second aspect, it is preferable that the calculation unit of the digital predistortion unit of the transmission system periodically generates coefficients having inverse distortion characteristics of all of the power amplifiers for performing digital predistortion processing, using the composite signal. [Fourth Form] In the transmitting / receiving device described in the first or second aspect, it is preferable that the calculation unit of the digital predistortion unit of the transmission system generates coefficients having inverse distortion characteristics of all of the power amplifiers for performing digital predistortion processing within a predetermined period of time. [Fifth Form] In the transceiver device described in the first aspect, it is preferable that the combining unit includes a phase adjustment unit that adjusts the at least two digital feedback signals to be in phase, and combines the at least two digital feedback signals after adjusting them to be in phase. [Sixth Form] In the transceiver device described in the second aspect, it is preferable that the combining unit includes a phase adjustment unit that adjusts the at least two digital feedback signals to be in phase, and combines the at least two digital feedback signals after adjusting them to be in phase. [7th form] The transmitting / receiving device according to the second or sixth aspect further includes a control unit that controls the switch, It is preferable that the control unit controls each of the switches to select and output an input from among the multiple inputs to which a distribution output signal supplied by the same coupler is supplied, and controls the selection of the input to be switched periodically. [8th form] The transmitting / receiving device according to the second or sixth aspect further includes a control unit that controls the switch, It is preferable that the control unit controls each of the switches to select and output an input from among the multiple inputs to which a distribution output signal supplied by the same coupler is supplied, and controls the selection of the input to be switched so that all of the inputs are selected within a predetermined period of time. [9th form] (See the control method of the transmitting / receiving device according to the third aspect above.) [10th form] (See Programme for the Fourth Aspect above)

[0063] The disclosures of the above patent documents are incorporated herein by reference. Within the framework of the entire disclosure of the present invention (including the scope of claims), modifications and adjustments of the embodiments and examples are possible based on the basic technical ideas. Furthermore, within the framework of the disclosure of the present invention, various combinations and selections of the various disclosed elements (including each element of each claim, each element of each embodiment or example, each element of each drawing, etc.) are possible. In other words, the present invention naturally includes various modifications and corrections that a person skilled in the art would be able to make in accordance with the entire disclosure including the scope of claims and the technical ideas. In particular, with regard to the numerical ranges described in this specification, any numerical value or subrange included in the range should be interpreted as being specifically described even if not otherwise specified. [Explanation of symbols]

[0064] 10 Transmitting and receiving equipment 100 Transmission system 110, 120, 130, 140 Transmitter 111, 121, 131, 141 Power amplifiers 112, 122, 132, 142 Digital / Analog Converters 113, 123, 133, 143 Coupler 150 Digital Pre-Distortion (DPD) Section 151 Multiplication section 153 Arithmetic section 200 Receiving System 201 Selection Section 211, 221, 231, 241 Receiver 212, 222, 232, 242 Receiver analog / digital converter 215, 225, 235, 245 Switch (SW) 300 Synthesis section 301, 302, 303, 304 Phase adjustment section 305 Addition section 310, 320, 330, 340 Antennas 400 Control section 9000 Computers 9010 CPU 9020 Communication Interface 9030 Memory 9040 Auxiliary storage device

Claims

1. A transmission system including a plurality of transmission units and a digital predistortion unit, a reception system including the same number of reception units as the plurality of transmission units and a selection unit connected to each of the reception units, an antenna the same number as the plurality of transmission units, and a synthesis unit, Each of the antennas is connected to one of the transmitters and to the selector; Each of the transmitters includes a power amplifier that generates a power-amplified transmission signal from an input signal of the transmitter and supplies the power-amplified transmission signal to the antenna; Each of the receiving units includes a receiving analog / digital converter that converts a received signal received by the antenna into a digital received signal; the digital predistortion unit includes a calculation unit that calculates a coefficient having a distortion characteristic of the inverse of each of the power amplifiers based on a feedback signal of a signal output from each of the power amplifiers, and a multiplication unit that multiplies each digital transmission signal by a coefficient having a distortion characteristic of the inverse of each of the power amplifiers of the transmission units, and outputs each digitally predistorted signal to each of the transmission units as the input signal; During the transmission period of the time division duplex method, the selection unit selects a feedback signal of a transmission signal output by one power amplifier of the transmission unit, and outputs the feedback signal as a selection unit output signal; Each of the at least two receiving analog / digital converters performs analog / digital conversion on the selection unit output signal to generate at least two digital feedback signals; A transceiver device, wherein the synthesis unit synthesizes the at least two digital feedback signals to generate a synthesis signal, and supplies the synthesis signal to the calculation unit, a transmission / reception device, wherein the calculation unit of the digital predistortion unit of the transmission system periodically generates coefficients having inverse distortion characteristics of all of the power amplifiers for performing digital predistortion processing using the composite signal.

2. Each of the transmitting units further includes a coupler connected between the power amplifier and the antenna, the coupler outputting a feedback signal of the transmission signal; the selection unit includes the same number of switches as the receiving units, each of the switches including a plurality of inputs to which the feedback signals of the couplers of the different transmitting units are respectively supplied, and an output connected to an input of the receiving analog-to-digital converter; and In the transmission period of the time division duplex method, each of the switches of the selection unit selects, from among the plurality of inputs, an input to which a feedback signal of a coupler of one of the transmission units is supplied, and outputs a switch output signal as the selection unit output signal; 2. The transmitting / receiving device according to claim 1, wherein each of the at least two receiving analog / digital converters performs analog / digital conversion on the switch output signal of each of the switches in the selection section to generate the at least two digital feedback signals.

3. The transmitting / receiving device according to claim 1 , wherein the combining unit includes a phase adjusting unit that adjusts the at least two digital feedback signals to have the same phase, and combines the at least two digital feedback signals after adjusting them to have the same phase.

4. The transmitting / receiving device according to claim 2 , wherein the combining unit includes a phase adjusting unit that adjusts the at least two digital feedback signals to have the same phase, and combines the at least two digital feedback signals after adjusting them to have the same phase.

5. Further comprising a control unit that controls the switch, The transmitting / receiving device according to claim 2 or 4, wherein the control unit controls each of the switches to select and output an input from among the multiple inputs to which a distributed output signal supplied by the same coupler is supplied, and controls the selection of the input to be switched periodically.

6. Further comprising a control unit that controls the switch, 5. The transmitting / receiving device according to claim 2 or 4, wherein the control unit controls each of the switches to select and output an input from among the multiple inputs to which a distribution output signal supplied by the same coupler is supplied, and controls the selection of the input to be switched so that all of the inputs are selected within a predetermined period of time.

7. A computer included in the transmitting / receiving device according to claim 2, controlling each of the switches to select an input to which a distributed output signal supplied by the same coupler is supplied from among the plurality of inputs and to output the selected input; A control method for a transmitting / receiving device, comprising the step of controlling the input selection to be switched periodically.

8. A computer included in the transmitting / receiving device according to claim 2, A process of controlling each of the switches to select an input from the plurality of inputs to which a distributed output signal provided by the same coupler is supplied, and to output the selected input; A program that executes a process of controlling the input selection to be switched periodically.

Images