WO2015190085A1

WO2015190085A1 - Transmission/reception device and transmission/reception method

Info

Publication number: WO2015190085A1
Application number: PCT/JP2015/002872
Authority: WO
Inventors: 友哉金子; 一実椎熊
Original assignee: 日本電気株式会社
Priority date: 2014-06-11
Filing date: 2015-06-09
Publication date: 2015-12-17

Abstract

According to one embodiment of the present invention, a transmission/reception device (1) is provided with: a filter (11) that is shared by transmission signals to be wirelessly transmitted to the outside, and reception signals to be wirelessly received from the outside; a limiter (14) that suppresses signal components having a predetermined amplitude or higher, said signal components being among signals supplied to a reception path via the filter (11); a low-noise amplifying unit (12) that amplifies signals that have passed through the limiter (14); and orthogonal demodulation unit (13) that outputs baseband signals (Irx, Qrx) by demodulating output signals of the low-noise amplifying unit (12).

Description

Transmission / reception apparatus and transmission / reception method

The present invention relates to a transmission / reception device and a transmission / reception method, and more particularly to a transmission / reception device and a transmission / reception method suitable for downsizing a device by reducing a circuit scale.

A wireless communication device such as a mobile phone base station is equipped with a transmission / reception duplexer (filter) shared by a transmission signal and a reception signal. This transmission / reception duplexer is required to have a low loss in the pass band and a steep attenuation characteristic outside the band. In order to satisfy this requirement, the transmission / reception duplexer generally has a resonance with a high Q value (Q value of approximately 1000 or more) such as a semi-coaxial resonator or a TE01δ mode dielectric resonator (DR (Dielectric Resonator)). A cavity-type transmission / reception duplexer configured using a plurality of filters is used.

However, since the physical dimensions of the cavity-type transmission / reception duplexer are determined by the wavelength of the signal frequency, the transmission / reception duplexer is particularly large when the resonance frequency is lowered. As a result, the circuit scale of the wireless communication device has increased.

Temporarily, if the number of resonators constituting the cavity type transmission / reception duplexer is reduced to reduce the size of the radio communication device, the attenuation characteristics of the transmission / reception duplexer will deteriorate. As a result, the transmission signal component leaking (wrapping around) from the transmission path to the reception path via the transmission / reception demultiplexer and the interference wave mixed into the reception path from the outside via the transmission / reception demultiplexer are not sufficiently attenuated. Therefore, there is a possibility that the low-noise amplification unit at the subsequent stage reaches saturation power or the gain of the low-noise amplification unit 12 decreases. In addition, intermodulation distortion and cross modulation distortion may occur due to the transmission signal component and the interference wave. As a result, the quality of the received signal may be degraded.

Further, in order to reduce the size of the wireless communication device, a small block type or monoblock type transmission / reception duplexer is used instead of the cavity type transmission / reception duplexer as the transmission / reception duplexer mounted on the wireless communication device. It is also possible. These small block-type or mono-block type transmission / reception demultiplexers are, for example, small-sized SAW (Surface-Acoustic-Wave), FBAR (Film-Bulk-Acoustic-Resonator), or TEM-DR (Transverse-Electro-Magnetic--Dielectric-Resonator). It is configured using a resonator. Since these small resonators are small-diameter resonators filled with a minute gap or a dielectric, a block type or monoblock type transmission / reception duplexer on which these are mounted is a cavity type transmission / reception duplexer. Compared with the withstand voltage and power, the withstand voltage is low.

Here, a wireless communication apparatus such as a mobile phone base station called a macro base station wirelessly transmits a high-power transmission signal of about 10 watts or more. Therefore, even if the received signal is very small power in the reception system filter as well as the transmission system filter, for example, due to the deterioration of the reflection coefficient of the transmission / reception antenna or poor connection, the transmission / reception duplexer mounted in the wireless communication device There is a possibility that a high-power transmission signal is applied outside the reception band. For this reason, if a small block type or monoblock type transmission / reception duplexer with a low power resistance of about several watts is used as the transmission / reception duplexer mounted in the wireless communication device, the performance of the transmission / reception duplexer deteriorates. Or the transmission / reception duplexer may be destroyed.

Furthermore, the passage loss of the block type or monoblock type transmission / reception duplexer is larger than that of the cavity type transmission / reception duplexer. Therefore, if a block-type or monoblock-type transmission / reception duplexer is used as the transmission / reception duplexer mounted in the wireless communication apparatus, the quality of the received signal may be deteriorated.

For these reasons, it is difficult to use a block type or monoblock type transmission / reception demultiplexer instead of the cavity type transmission / reception demultiplexer as the transmission / reception demultiplexer mounted on the wireless communication apparatus.

Related technology is disclosed in Patent Document 1. Patent Document 1 discloses a microwave band configured to provide a transmission / reception duplexer in a common input / output unit of a transmission high-power converter and a reception low-noise converter to prevent a transmission signal from wrapping around to a reception side. A transmission / reception shared wireless device is disclosed. This transmission / reception shared radio device includes a low-noise amplifier provided in a low-noise converter for reception, a first-stage amplifier element and a subsequent-stage amplifier element connected in cascade, and a stage for suppressing a transmission frequency band between the amplifier elements. And an inter-filter. As a result, the attenuation amount in the transmission frequency band required to prevent the leakage of the transmission signal to the reception side can be distributed to the transmitter / receiver demultiplexer and the interstage filter. . As a result, the size of the transmitter / receiver duplexer can be reduced.

In Patent Document 2, the amplifier is divided into a preamplifier and a main amplifier, an intermediate filter is inserted between them, and a part of required performance for the input side filter and output side filter is shared by this intermediate filter. An apparatus is disclosed.

Patent Document 3 discloses a canceller device that cancels a spectral component from a transmitter that enters the bandwidth of a receiver. Patent Document 4 discloses a transceiver that cancels out third-order distortion generated by a transmission signal leaking to the receiver side with the second-order distortion and the transmission signal.

Japanese Patent No. 2666424 Japanese Patent No. 2875703 Special table 2003-520549 gazette JP 2012-60433 A

As described above, Patent Document 1 discloses an example of a transmission / reception shared wireless device that can be miniaturized. However, the wireless communication device (transmission / reception device) still has a circuit without reducing the quality of the received signal. There is a demand for downsizing the apparatus by reducing the scale.

The present invention has been made to solve such a problem, and by providing a limiter before the low-noise amplifier provided on the reception path, the circuit can be obtained without degrading the quality of the reception signal. It is an object of the present invention to provide a transmission / reception apparatus and a transmission / reception method capable of reducing the scale and downsizing the apparatus.

According to one embodiment, the transmission / reception apparatus is supplied to a reception path through a filter shared by a transmission signal transmitted wirelessly to the outside and a reception signal wirelessly received from the outside, and the filter. A limiter that suppresses a signal component having a predetermined amplitude or more of the signal, a low noise amplifying unit that amplifies the signal that has passed through the limiter, and a demodulator that demodulates the output signal of the low noise amplifying unit and outputs a received baseband signal A section.

According to one embodiment, a transmission / reception method is a predetermined amplitude or more of signals supplied to a reception path via a filter shared by a transmission signal wirelessly transmitted to the outside and a reception signal wirelessly received from the outside. The signal component is suppressed by a limiter, the signal that has passed through the limiter is amplified using a low noise amplification unit, the output signal of the low noise amplification unit is demodulated, and a received baseband signal is output.

According to the embodiment, by providing a limiter in front of the low noise amplification unit provided on the reception path, the circuit size can be reduced and the apparatus can be downsized without degrading the quality of the received signal. Can be provided.

1 is a block diagram illustrating an outline of a transmission / reception device according to Embodiment 1. FIG. It is a figure which shows the specific structure of the limiter provided in the transmission / reception apparatus shown in FIG. It is a figure which shows the specific structure of the limiter provided in the transmission / reception apparatus shown in FIG. It is a figure which shows the level diagram of the transmission / reception apparatus shown in FIG. It is a figure which shows the spectrum of each signal before and behind the limiter provided in the transmission / reception apparatus shown in FIG. 3 is a block diagram showing a specific configuration of a transmission / reception device according to Embodiment 1. FIG. 6 is a block diagram illustrating a first modification of the transmission / reception apparatus according to Embodiment 1. FIG. FIG. 10 is a block diagram showing a second modification of the transmission / reception device according to Embodiment 1. 6 is a block diagram showing a transmission / reception device according to Embodiment 2. FIG. It is a figure which shows the specific structure of the low noise amplification part provided in the transmission / reception apparatus shown in FIG. FIG. 10 is a block diagram illustrating a first modification of the transmission / reception device according to the second embodiment. FIG. 10 is a block diagram illustrating a second modification of the transmission / reception device according to the second embodiment. FIG. 10 is a block diagram illustrating a third modification of the transmission / reception device according to the second embodiment. FIG. 10 is a block diagram illustrating a fourth modification of the transmission / reception device according to the second embodiment. FIG. 10 is a diagram illustrating a specific configuration of a limiter provided in a transmission / reception device according to Embodiment 3. It is a figure which shows the voltage-current characteristic of the limiter shown in FIG. It is a figure which shows the voltage-current characteristic of the limiter shown in FIG.

Hereinafter, embodiments will be described with reference to the drawings. Since the drawings are simple, the technical scope of the embodiments should not be narrowly interpreted based on the description of the drawings. Moreover, the same code | symbol is attached | subjected to the same element and the overlapping description is abbreviate | omitted.

In the following embodiments, when it is necessary for the sake of convenience, the description will be divided into a plurality of sections or embodiments. However, unless otherwise specified, they are not irrelevant to each other. Are partly or entirely modified, application examples, detailed explanations, supplementary explanations, and the like. Further, in the following embodiments, when referring to the number of elements (including the number, numerical value, quantity, range, etc.), especially when clearly indicated and when clearly limited to a specific number in principle, etc. Except, it is not limited to the specific number, and may be more or less than the specific number.

Furthermore, in the following embodiments, the constituent elements (including operation steps and the like) are not necessarily essential unless otherwise specified or apparently essential in principle. Similarly, in the following embodiments, when referring to the shapes, positional relationships, etc. of the components, etc., the shapes are substantially the same unless otherwise specified, or otherwise apparent in principle. And the like are included. The same applies to the above numbers and the like (including the number, numerical value, quantity, range, etc.).

<Embodiment 1>
FIG. 1 is a block diagram of the transmitting / receiving apparatus 1 according to the first embodiment. The transmission / reception apparatus 1 according to the present embodiment is used in, for example, a mobile phone base station, and a filter that is shared by a transmission signal and a reception signal, and a predetermined amplitude among signals supplied to the reception path through the filter. A limiter that suppresses the above signal components, a low noise amplification unit that amplifies a signal that has passed through the limiter, and a demodulation unit that demodulates an output signal of the low noise amplification unit and outputs a reception baseband signal. As a result, the transmission signal component supplied to the low noise amplification unit and the amplitude of the interference wave are suppressed to less than a predetermined value, so that the low noise amplification unit transmits the transmission signal component leaking from the transmission path to the reception path through the filter. In addition, it is less likely to be affected by interference waves mixed in the reception path via a filter from the outside. As a result, the attenuation characteristic required for the filter is relaxed, so that the number of resonator stages (number) provided in the cavity type filter can be reduced and the filter can be downsized. As a result, the transmitter / receiver 1 can reduce the size of the device by reducing the circuit scale without degrading the quality of the received signal. This will be specifically described below.

As shown in FIG. 1, the transmission / reception device 1 employs a direct conversion transmission / reception system, and includes a filter 11, a low noise amplification unit 12, an orthogonal demodulation unit 13, and a limiter 14.

The filter 11 is shared by, for example, a high-frequency transmission signal that is wirelessly transmitted to the outside via an input / output terminal such as an antenna, and a high-frequency reception signal that is wirelessly received from the outside via the input / output terminal. As a result, the transmission / reception device 1 can simultaneously transmit and receive via the common input / output terminal.

For example, the filter 11 is a filter used in an FDD (Frequency Division Duplexing) system that realizes simultaneous transmission and reception by separating the frequency bands of the transmission signal and the reception signal. In this case, the filter 11 constitutes a duplexer that demultiplexes the transmission signal and the reception signal. In the present embodiment, a case where the filter 11 is a filter used in the FDD method will be described as an example.

Alternatively, the filter 11 is a filter used for a TDD (Time Division Duplexing) system that realizes simultaneous simultaneous transmission and reception by time-division multiplexing a transmission signal and a reception signal. In this case, the filter 11 constitutes a band pass filter through which the transmission signal and the reception signal pass. In general, a switch circuit (not shown) that switches the filtering path to the transmission signal side and the reception signal side in a time division manner is further provided.

The filter 11 is required to have low loss in the pass band and steep attenuation characteristics outside the band. In order to satisfy this requirement, for example, the filter 11 is a cavity type configured by using a plurality of resonators having a high Q value (approximately Q value of approximately 1000 or more) such as a semi-coaxial resonator or a TE01δ mode dielectric resonator. A filter is used. Since the physical dimension of the cavity type filter 11 is determined by the wavelength of the resonance frequency, the filter 11 becomes large especially when the resonance frequency is lowered. That is, the cavity-type filter 11 is a main factor for increasing the circuit scale of the transceiver 1.

The limiter 14 suppresses signal components having a predetermined amplitude or more among signals supplied to the reception path via the filter 11.

(First specific configuration of limiter 14)
FIG. 2 is a diagram showing a first specific configuration of the limiter 14 as a limiter 14a.

Referring to FIG. 2, the limiter 14a has a diode D1. The cathode of the diode D1 is connected to the reception path between the filter 11 and the low noise amplification unit 12, and the anode of the diode D1 is connected to a ground voltage terminal (reference voltage terminal) to which the ground voltage GND is supplied. .

(Second specific configuration of limiter 14)
FIG. 3 is a diagram showing a second specific configuration of the limiter 14 as a limiter 14b.

Referring to FIG. 3, the limiter 14b further includes a diode D2 in addition to the diode D1. The cathode of the diode D2 is connected to the ground voltage terminal, and the anode of the diode D2 is connected to the reception path between the filter 11 and the low noise amplifying unit 12.

The low noise amplification unit 12 amplifies the signal that has passed through the limiter 14 with low noise.

Here, the reception signal is supplied to the reception path from the outside through the filter 11, but actually, the transmission signal component leaks from the transmission path through the filter 11 or is actually filtered from the outside. 11 may cause interference waves to enter. In particular, in the case of a design in which the number of resonators constituting the filter 11 is reduced for the purpose of miniaturization, the attenuation characteristic of the filter 11 is inferior, and this becomes remarkable (described later).

If there is no limiter 14, the low noise amplifying unit 12 not only amplifies the reception signal supplied from the outside to the reception path via the filter 11, but also leaks transmission from the transmission path to the reception path via the filter 11. Signal components, interference waves mixed in the reception path from the outside via the filter 11 and the like are directly amplified. In this case, there is a possibility that the low noise amplifying unit 12 reaches saturation power or the gain of the low noise amplifying unit 12 is lowered. In addition, intermodulation distortion and cross modulation distortion may occur due to the transmission signal component and the interference wave.

Therefore, the limiter 14 sets, for example, a value larger than the amplitude of the reception signal and smaller than the amplitude of the transmission signal component and the interference wave as a threshold value, so that the reception supplied from the outside to the reception path via the filter 11 is performed. The amplitudes of the transmission signal component leaking from the transmission path to the reception path through the filter 11 and the interference wave mixed into the reception path from the outside via the filter 11 are less than a predetermined amplitude (threshold value). To repress. As a result, the limiter 14 outputs a signal mainly composed of a reception signal in which the transmission signal component and the interference wave are suppressed.

Thereby, the low noise amplifying unit 12 can reduce intermodulation distortion and intermodulation distortion generated due to the transmission signal component and the interference wave. Further, it is possible to prevent the low noise amplifying unit 12 from reaching saturation power and the gain of the low noise amplifying unit 12 from being lowered. Therefore, the low noise amplification unit 12 is not easily affected by these transmission signal components and interference waves. That is, by providing the limiter 14, the allowable amount of transmission signal components and interference waves transmitted to the reception path is increased.

Therefore, attenuation characteristics required for the filter 11 can be relaxed. That is, it is possible to reduce the number of stages (number) of resonators provided in the cavity type filter 11. As a result, the transmission / reception device 1 can reduce the size of the device by reducing the circuit scale without degrading the quality of the received signal. Even considering the increase in the number of parts due to the provision of the limiter and the increase in the circuit scale due to the limiter, the downsizing of the transmission / reception apparatus 1 by downsizing the filter 11 has a great merit.

The orthogonal demodulator 13 demodulates the high-frequency signal output from the low noise amplifier 12 and outputs baseband signals Irx and Qrx. More specifically, the quadrature demodulator 13 mixes the high-frequency signal output from the low-noise amplifier 12 and the local oscillation signal LO (not shown), thereby generating a baseband signal (received baseband signal). Irx and Qrx are output. Then, the transmission / reception device 1 executes predetermined calculation processing based on the received baseband signals Irx and Qrx.

Subsequently, a change in power of each signal on the reception path will be described with reference to FIGS. FIG. 4 is a diagram illustrating a level diagram of the transmission / reception device 1. FIG. 4 also shows a level diagram of a general transmission / reception apparatus that does not have the limiter 14 for comparison. FIG. 5 is a diagram illustrating the spectrum of each signal before and after the limiter 14 provided in the transmission / reception apparatus 1. FIG. 5 also shows the spectrum of the output signal of the filter 11 provided in a general transmission / reception apparatus that does not have the limiter 14 for comparison. The horizontal axis represents frequency and the vertical axis represents power.

First, a high-power interference wave and a low-power reception signal are supplied to the antenna 10 from the outside, and a high-power transmission signal component is transmitted from the transmission path via the filter 11 (period A in FIG. 4). ).

Thereafter, the filter 11 passes the reception signal in the pass band and attenuates the transmission signal component and the interference wave outside the band. Here, since the number of stages of the resonators constituting the filter 11 is reduced for the purpose of miniaturization, the transmission signal component and the disturbing wave pass through the filter 11 without being sufficiently attenuated (period B in FIG. 4).

After that, the limiter 14 suppresses a signal component having a predetermined amplitude (a threshold value of the limiter 14) or more from signals supplied to the reception path via the filter 11 to be less than the predetermined amplitude (period C in FIG. 4 and FIG. 5). reference). That is, the limiter 14 allows the reception signal supplied to the reception path through the filter 11 to pass, and reduces the amplitudes of the transmission signal component and the interference wave supplied to the reception path through the filter 11 to be less than a predetermined amplitude. Repress. As a result, the limiter 14 outputs a signal mainly composed of a reception signal in which the transmission signal component and the interference wave are suppressed.

Thereafter, the low noise amplification unit 12 amplifies the signal that has passed through the limiter 14 with low noise (period D in FIG. 4). Here, the signal input to the low noise amplifier 12 is limited by the limiter 14. Therefore, even if the number of resonator stages constituting the filter 11 is small, the low noise amplifying unit 12 does not reach the saturation power and the gain of the low noise amplifying unit 12 does not decrease. Further, neither intermodulation distortion nor intermodulation distortion occurs due to the transmission signal component and the interference wave.

Thus, the transmission / reception device 1 can reduce the size of the device by suppressing an increase in circuit scale without degrading the quality of the received signal.

On the other hand, since a general transmission / reception apparatus does not have the limiter 14, it is necessary to attenuate the transmission signal component and the interference wave to at least less than the threshold of the limiter 14 only by the filter (period B in FIG. 4 and FIG. 5). reference). For this reason, a general transmission / reception apparatus cannot reduce the number of stages of resonators constituting a filter. That is, it is difficult to reduce the size of the device by reducing the circuit scale.

(Specific configuration of transmission / reception device 1)
FIG. 6 is a block diagram showing a specific configuration of the transmission / reception device 1 as the transmission / reception device 1a.

As shown in FIG. 6, the transmission / reception apparatus 1a employs a direct conversion transmission / reception system, and includes a local oscillator 15, an AD converter 16, an orthogonal modulation unit 21, a DA converter 22, a local oscillator 24, A high-power amplifier 25 and the antenna 10 are further provided.

First, the circuit configuration on the transmission path side will be described.
The DA converter 22 converts digital baseband signals (transmission baseband signals) I and Q into analog signals and outputs them. The quadrature modulation unit 21 modulates the analog baseband signals I and Q output from the DA converter 22 and outputs a high frequency signal. More specifically, the quadrature modulation unit 21 mixes the analog baseband signals I and Q output from the DA converter 22 and the local oscillation signal LO output from the local oscillator 24 to thereby generate a high-frequency signal. Is output.

The high-power amplifier 25 amplifies the high-frequency signal output from the quadrature modulation unit 21 and outputs a high-frequency transmission signal. This transmission signal is wirelessly transmitted to the outside through the antenna 10 after unnecessary components are removed by passing through the filter 11.

Next, the circuit configuration on the reception path side will be described.
A high-frequency reception signal wirelessly received from the outside via the antenna 10 is supplied to the reception path after unnecessary components are removed by passing through the filter 11. In practice, the transmission signal component and the interference wave are also supplied to the reception path via the filter 11.

The limiter 14 suppresses signal components (transmission signal component and interference wave) having a predetermined amplitude or more among signals (including reception signal, transmission signal component and interference wave) supplied to the reception path via the filter 11. The details of the limiter 14 are as described above.

The orthogonal demodulator 13 demodulates the high-frequency signal output from the low noise amplifier 12 and outputs baseband signals Irx and Qrx. More specifically, the quadrature demodulator 13 mixes the high-frequency signal output from the low noise amplifier 12 and the local oscillation signal LO output from the local oscillator 15 to thereby generate baseband signals Irx, Qrx. Is output.

The AD converter 16 converts the analog digital baseband signals Irx and Qrx output from the quadrature demodulator 13 into digital signals and outputs them. Then, the transmission / reception device 1 executes predetermined arithmetic processing based on the received baseband signals Irx and Qrx.

(First Modification of Transmitting / Receiving Device 1a)
FIG. 7 is a block diagram illustrating a first modification of the transmission / reception device 1a as the transmission / reception device 1b.

As shown in FIG. 7, the transmission / reception device 1b further includes a distortion compensation unit 20 that compensates for distortion of the transmission signal, as compared with the transmission / reception device 1a.

The distortion compensation unit 20 has a so-called digital predistortion type distortion compensation function, and distorts the baseband signals I and Q using a distortion compensation coefficient corresponding to the distortion of the output signal of the high-power amplifier 25. Compensation processing is performed. Details will be described below.

The distortion compensator 20 generates a distortion compensation component such that an input signal having the opposite phase and the same amplitude as that of the output signal of the high output amplifier 25 before distortion compensation is input to the high output amplifier 25. It is added to Q and output as baseband signals Ia and Qa. For this reason, the distortion that appears in the output signal of the high-power amplifier 25 before the distortion compensation is canceled out by the input signal of opposite phase. As a result, the high-power amplifier 25 can output a high-quality transmission signal (high-frequency radio signal) with suppressed distortion.

More specifically, the distortion compensator 20 includes an orthogonal demodulator 201, a local oscillator 202, an AD converter 203, a distortion calculator 204, a power calculator 205, a memory 206, a signal processor 207, Is provided.

The orthogonal demodulator 201 demodulates the transmission signal (high-frequency radio signal) output from the high-power amplifier 25 and outputs baseband signals (feedback signals) Ib and Qb. More specifically, the quadrature demodulator 201 mixes the transmission signal output from the high-power amplifier 25 and the local oscillation signal LO output from the local oscillator 202, thereby obtaining the baseband signals Ib and Qb. Output.

The AD converter 203 converts the analog baseband signals Ib and Qb output from the quadrature demodulator 201 into digital signals and outputs the digital signals.

The distortion calculation unit 204 compares the baseband signals I and Q with the baseband signals Ib and Qb, and calculates the distortion of the output signal of the high-power amplifier 25 from the difference. The power calculator 205 calculates the power value or amplitude value of the baseband signals I and Q. The memory 206 stores a plurality of distortion compensation coefficients, and outputs any distortion compensation coefficient selected based on the calculation results of the distortion calculation unit 204 and the power calculation unit 205 to the signal processing unit 207. .

The signal processing unit 207 performs distortion compensation processing on the baseband signals I and Q using the distortion compensation coefficient read from the memory 206 and outputs the baseband signals Ia and Qa. In other words, the signal processing unit 207 adds distortion compensation components for compensating for distortion of the output signal of the high-power amplifier 25 to the baseband signals I and Q, and outputs the baseband signals Ia and Qa. The baseband signals Ia and Qa that have been subjected to the distortion compensation processing are input to the DA converter 22. Thereby, the high-power amplifier 25 can output a high-quality transmission signal (high-frequency radio signal) in which distortion is suppressed.

Since the other configuration of the transmission / reception device 1b is the same as that of the transmission / reception device 1a, the description thereof is omitted.

As described above, the transmission / reception device 1b wirelessly transmits a high-quality transmission signal (high-frequency radio signal) by compensating for distortion of the high-frequency transmission signal output from the high-power amplifier 25 using the distortion compensation unit 20. can do.

(Second Modification of Transmitting / Receiving Device 1a)
FIG. 8 is a block diagram illustrating a second modification of the transmission / reception device 1a as the transmission / reception device 1c.

As shown in FIG. 8, the transmission / reception device 1a employs a direct conversion transmission / reception system, while the transmission / reception device 1c employs a superheterodyne transmission / reception system.

Specifically, the transmission / reception device 1c further includes

frequency conversion units

17 and 23 as compared with the transmission / reception device 1a.

First, the circuit configuration on the transmission path side will be described.
The quadrature modulation unit 21 modulates the baseband signals I and Q and outputs an intermediate signal. The DA converter 22 converts the digital intermediate signal output from the quadrature modulation unit 21 into an analog signal and outputs the analog signal. The frequency converter 23 mixes the analog intermediate signal output from the DA converter 22 and the local oscillation signal LO output from the local oscillator 24, and outputs a high-frequency signal. The high-power amplifier 25 amplifies the high-frequency signal output from the frequency conversion unit 23 and outputs a high-frequency transmission signal.

Next, the circuit configuration on the reception path side will be described.
The frequency conversion unit 17 mixes the high-frequency signal output from the low noise amplification unit 12 and the local oscillation signal LO output from the local oscillator 15 and outputs an intermediate signal. The AD converter 16 converts the analog intermediate signal output from the frequency conversion unit 17 into a digital signal and outputs the digital signal. The orthogonal demodulator 13 demodulates the digital intermediate signal output from the AD converter 16 and outputs baseband signals Irx and Qrx.

Since the other configuration of the transmission / reception device 1c is the same as that of the transmission / reception device 1a, the description thereof is omitted.

The transmission / reception device 1c employing the superheterodyne reception system can achieve the same effects as the transmission / reception device 1a employing the direct conversion reception system.

<Embodiment 2>
FIG. 9 is a block diagram illustrating the transmission / reception device 2 according to the second embodiment.

As illustrated in FIG. 9, the transmission / reception device 2 includes a distortion compensation unit 30 that compensates for the distortion of the demodulated baseband signals Irx and Qrx caused by the distortion of the received signal component, as compared with the transmission / reception device 1a. Further prepare.

The distortion compensation unit 30 has a so-called digital post (post) distortion distortion compensation function, and uses a distortion compensation coefficient corresponding to the distortion of the transmission signal component included in the output signal of the low noise amplification unit 12. Distortion compensation processing is performed on the baseband signals Irx and Qrx. Details will be described below. In this example, the distortion of the transmission signal output from the high-power amplifier 25 is assumed to be negligible.

The distortion compensator 30 converts the received signal component included in the output signal of the low noise amplifier 12 into distortion (more specifically, distortion of the received signal component generated between the antenna 10 and the output of the low noise amplifier 12). The baseband signals Irx and Qrxa are added to the baseband signals Irx and Qrx and output as baseband signals Irxa and Qrxa, with the signals having the opposite phase and the same amplitude as the distortion of the baseband signals Irx and Qrx caused by the above. Therefore, the distortions of the baseband signals Irx and Qrx are canceled out by the reverse phase signals. As a result, the received signal is demodulated into baseband signals Irxa and Qrxa while maintaining the quality.

More specifically, the distortion compensation unit 30 includes an orthogonal demodulation unit 301, a local oscillator 302, an AD converter 303, a distortion calculation unit 304, a power calculation unit 305, a memory 306, a signal processing unit 307, Is provided.

The orthogonal demodulation unit 301 demodulates the transmission signal component included in the output signal (high frequency signal) of the low noise amplification unit 12 and outputs baseband signals (feedback signals) Ib and Qb. More specifically, the quadrature demodulation unit 301 mixes the transmission signal component included in the output signal of the low noise amplification unit 12 and the local oscillation signal LO output from the local oscillator 302 to thereby generate a baseband signal. Ib and Qb are output.

The AD converter 303 converts the analog baseband signals Ib and Qb output from the quadrature demodulator 301 into digital signals and outputs them.

The distortion calculation unit 304 compares the baseband signals I and Q with the baseband signals Ib and Qb, and calculates the difference as the distortion of the transmission signal component included in the output signal of the low noise amplification unit 12. The power calculator 305 calculates the power value or the amplitude value of the baseband signals Irx and Qrx. The memory 306 stores a plurality of distortion compensation coefficients, and outputs any distortion compensation coefficient selected based on the calculation results of the distortion calculation unit 304 and the power calculation unit 305 to the signal processing unit 307. .

The signal processing unit 307 performs distortion compensation processing on the baseband signals Irx and Qrx using the distortion compensation coefficient read from the memory 306, and outputs the baseband signals Irxa and Qrxa. In other words, the signal processing unit 307 adds a distortion compensation component (distortion in reverse phase) for compensating for distortion of the baseband signals Irx and Qrx to the baseband signals Irx and Qrx, and thereby adds the baseband signal Irxa. , Qrxa.

Here, it is preferable that the low noise amplifying unit 12 has a configuration capable of amplifying operation in a wide band, such as a balanced amplifier. As a result, the low noise amplifying unit 12 can amplify not only the received signal but also the transmission signal components having different bands in a wide band. Thereby, the low noise amplifying unit 12 can amplify the transmission signal component with line formation and nonlinearity substantially the same as the case of the reception signal. As a result, the relationship between the transmission signal component and the distortion is approximated to the relationship between the reception signal and the distortion.

Therefore, the distortion compensator 30 calculates the distortion of the received signal component included in the output signal of the low noise amplifier 12 from the distortion of the transmission signal component included in the output signal of the low noise amplifier 12 calculated by the distortion calculator 304. Is estimated. Then, the distortion compensator 30 performs distortion compensation processing on the baseband signals Irx and Qrx so as to compensate for the distortion of the baseband signals Irx and Qrx caused by the estimated distortion of the received signal component. Apply.

Since the other configuration of the transmission / reception device 2 is the same as that of the transmission / reception device 1a, the description thereof is omitted.

As described above, the transmission / reception device 2 compensates the distortion of the demodulated baseband signals Irx and Qrx caused by the distortion of the reception signal component by using the distortion compensation unit 30, thereby obtaining a high-quality reception signal. Can be received wirelessly. More specifically, cross modulation distortion that occurs when the transmission signal component and the reception signal component are input to the low noise amplification unit 12, and the transmission signal component and the interference wave that are generated when the transmission signal component and the interference wave are input to the low noise amplification unit 12. It is possible to reduce the influence of cross modulation distortion and the like.

In addition, since distortion is compensated by the distortion compensator 30, the allowable amount of transmission signal components and interference waves transmitted to the reception path is further increased. Therefore, further attenuation of the attenuation characteristic of the filter 11 and relaxation of the intercept point of the low noise amplification unit 12 are possible. That is, according to the distortion compensation capability of the distortion compensation unit 30, the number of stages (number) of the plurality of resonators constituting the filter 11 is further reduced, or the number of amplifiers provided in the low noise amplification unit 12 is, for example, four It is possible to reduce from 2 to 2. Of course, if a wide-band amplification operation is possible by means of a negative feedback type or the like different from the balanced type, the low-noise amplification unit 12 can be configured only by a single amplifier capable of amplification operation with low noise. It is. As a result, further downsizing and cost reduction of the transmission / reception device 2 can be realized.

In this embodiment, the case where the distortion compensation unit 30 dynamically switches and outputs the distortion compensation coefficient according to the distortion of the transmission signal component included in the output signal of the low noise amplification unit 12 has been described as an example. Not limited to this. For example, the distortion compensation unit 30 may output the distortion compensation coefficient based only on the calculation result of the power calculation unit 205 (that is, the logical values of the baseband signals Irx and Qrx), or statically a predetermined distortion compensation Coefficients may be output.

Note that, when a superimposed signal of a high-power transmission signal component and an interference wave and a low-power reception signal is input to the limiter 14, the transconductance of the limiter 14 with respect to the low-power reception signal tends to decrease. In this case, third-order distortion appears in the signal that has passed through the limiter 14, but this third-order distortion can be compensated by the distortion compensation unit 30.

(Specific configuration of the low noise amplification unit 12)
FIG. 10 is a diagram illustrating a specific configuration of the low noise amplifying unit 12 as a low noise amplifying unit 12a.

As shown in FIG. 10, the low noise amplification unit 12 a includes an amplifier (first amplifier) 121, an amplifier (second amplifier) 122, a distributor 123, and a combiner 124.

The distributor 123 distributes and outputs the signal that has passed through the limiter 14. In the present embodiment, distributor 123 distributes and outputs the received signal to two according to the number of amplifiers. Further, in the present embodiment, distributor 123 distributes the received signal into two distributed signals having the same phase and outputs them.

The

amplifiers

121 and 122 are provided in parallel, and amplify and output the two distribution signals output from the distributor 123, respectively.

The synthesizer 124 synthesizes the output signals of the

amplifiers

121 and 122 and outputs them as an output signal of the low noise amplifying unit 12.

With this configuration, the low noise amplifying unit 12a can amplify not only the received signal but also the transmission signal components having different bands over a wide band.

It should be noted that the noise figure and gain characteristics of the low noise amplifying unit 12a are comparable to those of the amplifier alone. Actually, the noise figure and gain characteristics of the low noise amplifying unit 12a are slightly deteriorated due to the insertion loss of the distributor 123, but the number (number) of resonators provided in the cavity type filter 11 is reduced. Offset or mitigated by a reduction in insertion loss.

In this example, the distributor 123 provided in the low noise amplifying unit 12a distributes the received signal into two distributed signals having the same phase, but is not limited thereto. The distributor 123 may distribute and output the received signal into two distribution signals having different phases.

For example, the distributor 123 may distribute and output the received signal into two distribution signals having a phase difference of 180 degrees. Thereby, the low noise amplifying unit 12a operates as a so-called push-pull type amplifier. The push-pull type low noise amplifying unit 12a can not only improve the third-order intercept point but also suppress even-order harmonic components including DC by balancing. In particular, in the transmission / reception apparatus 1 that employs a direct conversion reception system, the secondary distortion in the quadrature demodulation unit 13 causes a direct current offset, so that the allowable amount of secondary distortion in the quadrature demodulation unit 13 is small. Therefore, the use of the push-pull type low noise amplifying unit 12a is also effective for keeping the quality of the received signal by suppressing the secondary distortion in the orthogonal demodulating unit 13 to an allowable amount or less.

Alternatively, the distributor 123 may distribute and output the received signal into two distribution signals having a phase difference of 90 degrees. Thereby, the low noise amplification unit 12a operates as a so-called balanced amplifier. The balanced low noise amplification unit 12a not only improves the third-order intercept point, but also eliminates the need for an isolator (not shown) provided between the low noise amplification unit 12a and the filter 11. Hereinafter, the reason why the isolator is not required in the balanced low noise amplification unit 12a will be briefly described.

Since general low noise amplifiers often perform noise matching using an input matching circuit, the reflection coefficient becomes large and the impedance matching state deteriorates. In order to improve impedance matching on the input side of the low noise amplifier, an isolator is provided between the low noise amplifier and the transmission / reception duplexer.

On the other hand, the balanced low noise amplification unit 12a amplifies the distribution signals having a phase difference of 90 degrees using a plurality of

amplifiers

121 and 122 provided in parallel. While performing matching, it is possible to improve the impedance matching state when the

amplifiers

121 and 122 are viewed from the output of the distributor 123. Therefore, an isolator for performing impedance matching is not necessary. That is, the balanced low noise amplifying unit 12a can perform both noise matching and impedance matching without an isolator.

In the present embodiment, the case where the low noise amplifying unit 12a includes two

amplifiers

121 and 122 provided in parallel has been described as an example, but the present invention is not limited thereto. The low noise amplifying unit 12a can be appropriately changed to a configuration including three or more amplifiers provided in parallel. By increasing the number of amplifiers, the intercept point can be further improved. On the other hand, an increase in the circuit scale is suppressed by reducing the number of amplifiers.

(First Modification of Transceiver 2)
FIG. 11 is a block diagram illustrating a first modification of the transmission / reception device 2 as the transmission / reception device 2a.

11, the transmission / reception device 2a includes a distortion compensation unit 30a in which

distortion compensation units

20 and 30 are combined in place of the distortion compensation unit 30 as compared with the transmission / reception device 2.

Specifically, the distortion compensation unit 30a includes an orthogonal demodulation unit 301, a local oscillator 302, an AD converter 303, a distortion calculation unit 304, a power calculation unit 305, a memory 306, and a signal processing unit 307. In addition, a selection unit SW1, a power calculation unit 308, a memory 309, and a signal processing unit 310 are further provided. The power calculation unit 308, the memory 309, and the signal processing unit 310 correspond to the power calculation unit 205, the memory 206, and the signal processing unit 207, respectively.

The selection unit SW1 selectively outputs either the output signal of the high output amplifier 25 or the transmission signal component included in the output signal of the low noise amplification unit 12. The selection unit SW1 selects and outputs the output signal of the high-power amplifier 25 at an arbitrary timing at the time of transmission, and the transmission signal component included in the output signal of the low noise amplification unit 12 at an arbitrary timing at the time of reception. Select and output.

The quadrature demodulator 301 demodulates one of the signals selected by the selector SW1 out of the output signal component included in the output signal of the high-power amplifier 25 and the output signal of the low-noise amplifier unit 12. Band signals Ib and Qb are output. The AD converter 303 converts the analog baseband signals Ib and Qb output from the quadrature demodulator 301 into digital signals and outputs them.

The distortion calculation unit 304 compares the baseband signals I and Q with the baseband signals Ib and Qb, and uses the difference as the distortion of the output signal of the high output amplifier 25 and the output signal of the low noise amplification unit 12. It is calculated as one of the distortions of the included transmission signal component. Since the description of the power calculation unit 305, the memory 306, and the signal processing unit 307 has been described above, a description thereof will be omitted. The descriptions of the power calculation unit 308, the memory 309, and the signal processing unit 310 are the same as those of the power calculation unit 205, the memory 206, and the signal processing unit 207, respectively.

Since the other configuration of the transmission / reception device 2a is the same as that of the transmission / reception device 2, the description thereof is omitted.

As described above, the transmission / reception device 2a uses the distortion compensation unit 30a to compensate not only the distortion of the demodulated baseband signals Irx and Qrx caused by the distortion of the received signal component, but also the distortion of the transmission signal. Has also compensated. Here, in order to compensate accurately the distortion of the demodulated baseband signal caused by the distortion of the received signal component, it is necessary to minimize the distortion of the transmission signal. Therefore, the transmitter / receiver 2a compensates for distortion of the transmission signal using the distortion compensator 30a, thereby accurately compensating for distortion of the demodulated baseband signals Irx and Qrx caused by distortion of the received signal component. is doing.

Also, the distortion compensation unit 30a provided in the transmission / reception device 2a is composed of

distortion compensation units

20 and 30 in which most of the components are shared. Therefore, the transmission / reception device 2a can suppress the increase in circuit scale and downsize the device.

(Second Modification of Transmitting / Receiving Device 2)
FIG. 12 is a block diagram illustrating a second modification of the transmission / reception device 2 as the transmission / reception device 2b.

As shown in FIG. 12, the transmission / reception device 2b further includes an interstage filter 18 provided between the low noise amplification unit 12 and the orthogonal demodulation unit 13 as compared with the transmission / reception device 2a.

The interstage filter 18 removes out-of-band spurious, unnecessary noise, and distortion included in the output signal of the low noise amplification unit 12.

Since the other configuration of the transmission / reception device 2b is the same as that of the transmission / reception device 2a, description thereof is omitted.

Since the interstage filter 18 is arranged after the low noise amplifying unit 12, even if the insertion loss is large, the noise figure of the entire apparatus is hardly deteriorated, and a high power transmission signal is transmitted to the antenna. There is no direct supply to the interstage filter 18 after total reflection at the end.

Therefore, the interstage filter 18 is configured using a small resonator such as SAW (Surface / Acoustic / Wave), FBAR (Film / Bulk / Acoustic / Resonator), or TEM-DR (Transverse / Electro / Magnetic / Dielectric / Resonator). A block or monoblock filter can be used. Thereby, an increase in circuit scale is suppressed.

(Third Modification of Transceiver 2)
FIG. 13 is a block diagram illustrating a third modification of the transmission / reception device 2 as the transmission / reception device 2c.

As shown in FIG. 13, the transmission / reception device 2a employs a direct conversion transmission / reception system, while the transmission / reception device 2c employs a so-called superheterodyne transmission / reception system.

Specifically, the transmission / reception device 2c includes a distortion compensation unit 30b further including a frequency conversion unit 311 and further includes

frequency conversion units

17 and 23 in place of the distortion compensation unit 30a, as compared with the transmission / reception device 2a. . Details of the superheterodyne transmission / reception system are as described above.

(Fourth Modification of Transmitting / Receiving Device 2)
FIG. 14 is a block diagram illustrating a fourth modification of the transmission / reception device 2 as the transmission / reception device 2d.

As illustrated in FIG. 14, the transmission / reception device 2 d further includes an interstage filter 18 provided between the low noise amplification unit 12 and the orthogonal demodulation unit 13, as compared with the transmission / reception device 2 c. Since the other configuration of the transmission / reception device 2d is the same as that of the transmission / reception device 2c, description thereof is omitted.

<Embodiment 3>
The transmission / reception apparatus 3 according to the present embodiment not only compensates for the third-order distortion using the distortion compensator, but also compensates for the second-order distortion by including the limiter 14 c as the limiter 14. This will be specifically described below.

(Third specific configuration of limiter 14)
FIG. 15 is a diagram showing a third specific configuration of the limiter 14 as a limiter 14c.

Referring to FIG. 15, the limiter 14c further includes a coil (RF choke) L1, a resistance element R1, and a variable voltage source VB1 in addition to the diodes D1 and D2. The coil L1 and the resistance element R1 are provided in series between the variable voltage source VB1 and the reception path.

Since the other configuration of the transmission / reception device 3 is the same as that of the transmission / reception devices 2 and 2a to 2d, description thereof is omitted.

Subsequently, the voltage-current characteristics of the limiter 14c will be described with reference to FIGS.

As shown in FIG. 16, ideally, the output current (current flowing through the diodes D1 and D2) with respect to the input voltage of the limiter 14c is symmetrical between the positive side and the negative side, and the input voltage is less than a certain threshold voltage. In this case, almost no current flows, and when the input voltage is equal to or higher than the threshold voltage, it is desirable that the current flows and the diode becomes conductive. In practice, the output current with respect to the input voltage of the limiter 14c (current flowing through the diodes D1 and D2) generally increases exponentially with the increase of the input voltage as shown in FIG. However, since this distortion is a third-order distortion (odd-order distortion) that mainly exhibits nonlinearity within the threshold value but is substantially symmetrical between the positive side and the negative side, it can be compensated by the distortion compensation unit 30 or the like in the subsequent stage. it can.

By the way, in the transmission / reception device 3, not only the third-order distortion is generated in the limiter 14c and the low noise amplifying unit 12, but also in the vicinity of the direct current in the low noise amplifying unit 12, the AD converter 16, the quadrature demodulating unit 13, and the like. Including even-order distortion also occurs. Here, the distortion compensator 30 and the like can compensate the third-order distortion, but cannot compensate the second-order distortion.

Therefore, the transmitter / receiver 3 intentionally destroys the symmetry of the output current (current flowing through the diodes D1 and D2) with respect to the input voltage by the limiter 14c by adjusting the voltage value of the variable voltage source VB1. (See FIG. 17). This makes it possible to compensate for even-order distortion that occurs in the subsequent stage of the limiter 14. In particular, in the direct conversion system reception system, the secondary distortion in the quadrature demodulator 13 causes a DC offset, so the allowable amount of secondary distortion in the quadrature demodulator 13 is small. Therefore, actively compensating and removing the second order distortion in the quadrature demodulator 13 using the limiter 14c also suppresses the second order distortion in the quadrature demodulator 13 below an allowable amount and maintains the quality of the received signal. It is valid.

In this embodiment, the case where the limiter 14c has a configuration in which the coil L1, the resistance element R1, and the variable voltage source VB1 are added to the limiter 14b has been described as an example, but the present invention is not limited to this. The limiter 14c can be appropriately changed to a configuration in which the coil L1, the resistance element R1, and the variable voltage source VB1 are added to the limiter 14a.

As a matter of course, the use of the push-pull type low noise amplifying unit 12 instead of using the limiter 14c can also suppress the occurrence of secondary distortion.

As described above, the transmission / reception apparatuses according to Embodiments 1 to 3 include the limiter before the low-noise amplification unit provided on the reception path. As a result, the transmission signal component supplied to the low noise amplification unit and the amplitude of the interference wave are suppressed to less than a predetermined value, so that the low noise amplification unit transmits the transmission signal component that leaks from the transmission path to the reception path through the filter. In addition, it is less likely to be affected by interference waves mixed in the reception path via a filter from the outside. As a result, the attenuation characteristic required for the filter is relaxed, so that the number of resonator stages (number) provided in the cavity type filter can be reduced and the filter can be downsized. As a result, the transmission / reception apparatus according to the first to third embodiments can reduce the circuit size and the size of the apparatus without degrading the quality of the received signal.

Further, the transmitting / receiving apparatus according to the second embodiment compensates for the distortion of the demodulated baseband signal caused by the distortion of the received signal component by using the distortion compensation unit, so that a high-quality received signal can be obtained. Can be received wirelessly.

Furthermore, the transmission / reception apparatus according to Embodiment 3 described above includes a limiter that can intentionally generate a second-order distortion, thereby compensating for the second-order distortion generated in the low-noise amplification unit or the like.

Note that the present invention is not limited to the above-described embodiment, and can be appropriately changed without departing from the spirit of the present invention.

Some or all of the above embodiments may be described as in the following supplementary notes, but are not limited to the following.

(Appendix 1)
A filter shared by a transmission signal wirelessly transmitted to the outside and a reception signal wirelessly received from the outside;
A limiter that suppresses a signal component having a predetermined amplitude or more among signals supplied to the reception path via the filter;
A low-noise amplifier for amplifying the signal that has passed through the limiter;
And a demodulator that demodulates an output signal of the low noise amplifier and outputs a received baseband signal.

(Appendix 2)
The limiter is
The transmission / reception device according to attachment 1, comprising a first diode.

(Appendix 3)
The limiter is
The transmission / reception apparatus according to appendix 2, further comprising a second diode provided in parallel with and opposite to the first diode.

(Appendix 4)
The limiter is
A variable voltage source;
A coil provided between the variable voltage source and the reception path;
The transmission / reception device according to appendix 2 or 3, further comprising a resistance element provided in series with the coil.

(Appendix 5)
Supplementary notes 1 to 3, further comprising a distortion compensation unit that performs distortion compensation processing on the received baseband signal using a distortion compensation coefficient corresponding to distortion of a transmission signal component included in the output signal of the low noise amplification unit. 5. The transmission / reception device according to any one of 4.

(Appendix 6)
The distortion compensation unit
A demodulator that demodulates the transmission signal component contained in the output signal of the low noise amplifier and outputs a feedback signal;
A distortion calculation unit that calculates distortion of the transmission signal component included in the output signal of the low noise amplification unit based on a comparison result between the feedback signal and a transmission baseband signal before modulation into the transmission signal When,
A signal processing unit that performs distortion compensation processing on the received baseband signal using a distortion compensation coefficient according to the calculation result of the distortion calculation unit;
The transmission / reception apparatus according to appendix 5, comprising:

(Appendix 7)
A modulation unit that modulates the transmission baseband signal and outputs a high-frequency signal;
A high-power amplifier that amplifies the high-frequency signal and outputs the transmission signal, and
The transmission / reception apparatus according to appendix 5, wherein the distortion compensation unit further performs distortion compensation processing on the transmission baseband signal using a distortion compensation coefficient corresponding to distortion of an output signal of the high-power amplifier.

(Appendix 8)
The distortion compensation unit
A selector that selectively outputs one of the output signal of the high-power amplifier and the transmission signal component included in the output signal of the low-noise amplifier;
A demodulator that demodulates the output signal of the selector and outputs a feedback signal;
Based on the result of comparing the feedback signal and the transmission baseband signal, distortion of the output signal of the high-power amplifier, and distortion of the transmission signal component included in the output signal of the low-noise amplifier, A distortion calculation unit for calculating any one of
A signal processing unit that performs distortion compensation processing on either the transmission baseband signal or the reception baseband signal using a distortion compensation coefficient according to the calculation result of the distortion calculation unit;
The transmission / reception device according to appendix 7, comprising:

(Appendix 9)
The distortion compensator calculates a distortion of the received signal component included in the output signal of the low noise amplification unit from the distortion of the transmission signal component included in the output signal of the low noise amplification unit calculated by the distortion calculation unit. Additional distortion 6 or 8 is performed, wherein a distortion compensation process is performed on the received baseband signal so as to compensate for the distortion of the received baseband signal caused by the estimated distortion of the received signal component. The transmitter / receiver described.

(Appendix 10)
The low noise amplification unit is
10. The transmitting / receiving apparatus according to any one of appendices 1 to 9, comprising a plurality of amplifiers provided in parallel.

(Appendix 11)
11. The transmission / reception device according to any one of appendices 1 to 10, wherein the demodulation unit outputs the reception baseband signal by mixing an output signal of the low noise amplification unit and a local oscillation signal.

(Appendix 12)
The transmission / reception apparatus according to any one of appendices 1 to 11, further comprising an interstage filter provided between the low-noise amplification unit and the demodulation unit.

(Appendix 13)
13. The transmission / reception device according to appendix 12, wherein the interstage filter is a block-type or monoblock-type filter configured using any of SAW, FBAR, and TEM-DR resonators.

(Appendix 14)
14. The transmission / reception device according to any one of appendices 1 to 13, wherein the filter is a cavity-type filter configured using a plurality of resonators.

(Appendix 15)
A signal component having a predetermined amplitude or more is suppressed by a limiter among signals supplied to the reception path via a filter shared by a transmission signal wirelessly transmitted to the outside and a reception signal wirelessly received from the outside,
The signal that has passed through the limiter is amplified using a low-noise amplifier,
A transmission / reception method for demodulating an output signal of the low noise amplification unit and outputting a reception baseband signal.

(Appendix 16)
The transmission / reception method according to claim 15, wherein distortion compensation processing is performed on the received baseband signal using a distortion compensation coefficient corresponding to distortion of a transmission signal component included in an output signal of the low noise amplification unit.

(Appendix 17)
In the distortion compensation process,
Demodulate the transmission signal component contained in the output signal of the low noise amplification unit to output a feedback signal,
Based on the comparison result between the feedback signal and the transmission baseband signal before modulation into the transmission signal, the distortion of the transmission signal component included in the output signal of the low noise amplification unit is calculated,
The transmission / reception method according to appendix 16, wherein a distortion compensation process is performed on the received baseband signal using a distortion compensation coefficient corresponding to the calculation result.

(Appendix 18)
Modulate the transmission baseband signal and output a high-frequency signal,
Amplifying the high-frequency signal by a high-power amplifier to output the transmission signal;
In the distortion compensation process,
The transmission / reception method according to appendix 16, wherein distortion compensation processing is performed on the transmission baseband signal using a distortion compensation coefficient corresponding to distortion of an output signal of the high-power amplifier.

(Appendix 19)
In the distortion compensation process,
Selectively output one of the output signal of the high-power amplifier and the transmission signal component included in the output signal of the low-noise amplifier,
Demodulate the selectively output signal and output a feedback signal,
Based on the result of comparing the feedback signal and the transmission baseband signal, distortion of the output signal of the high-power amplifier, and distortion of the transmission signal component included in the output signal of the low-noise amplifier, Either
The transmission / reception method according to appendix 18, wherein distortion compensation processing is performed on either the transmission baseband signal or the reception baseband signal using a distortion compensation coefficient corresponding to the calculation result.

(Appendix 20)
In the distortion compensation process,
From the calculated distortion of the transmission signal component included in the output signal of the low noise amplification unit, estimate the distortion of the reception signal component included in the output signal of the low noise amplification unit,
The transmission / reception according to appendix 17 or 19, wherein a distortion compensation process is performed on the received baseband signal so as to compensate for the distortion of the received baseband signal caused by the estimated distortion of the received signal component. Method.

(Appendix 21)
The transmission / reception method according to any one of appendices 15 to 20, wherein a plurality of amplifiers are provided in parallel as the low-noise amplification unit.

(Appendix 22)
The transmission / reception method according to any one of appendices 15 to 21, wherein the reception baseband signal is output by mixing an output signal of the low noise amplification unit and a local oscillation signal.

The present invention has been described above with reference to the embodiment, but the present invention is not limited to the above. Various changes that can be understood by those skilled in the art can be made to the configuration and details of the present invention within the scope of the invention.

This application claims priority based on Japanese Patent Application No. 2014-120276 filed on June 11, 2014, the entire disclosure of which is incorporated herein.

1, 1a, 1b, 1c Transmission /

reception device

2, 2a, 2b, 2c, 2d Transmission / reception device 30 Distortion compensation unit 301 Orthogonal demodulation unit 302 Local oscillator 303 AD converter 304 Distortion calculation unit 305 Power calculation unit 306 Memory 307 Signal processing unit 308 Power Calculation unit 309 Memory 310 Signal processing unit 311 Frequency conversion unit 12a Low noise amplification unit 121 Amplifier 122 Amplifier 123 Divider 124 Synthesizer 11 Filter 12 Low noise amplification unit 13

Orthogonal demodulation unit

14, 14a, 14b, 14c Limiter 15 Local oscillator 16 AD converter 17 Frequency conversion unit 18 Interstage filter 20 Distortion compensation unit 201 Quadrature demodulation unit 202 Local oscillator 203 AD converter 204 Distortion calculation unit 205 Power calculation unit 206 Memory 207 Signal processing unit 21 Orthogonal modulation unit 22 DA converter 23 Wavenumber conversion unit 24 local oscillator 25 high power amplifier D1 diode D2 diode L1 coil R1 resistance element SW1 switches VB1 variable voltage

Claims

A filter shared by a transmission signal wirelessly transmitted to the outside and a reception signal wirelessly received from the outside;
A limiter that suppresses a signal component having a predetermined amplitude or more among signals supplied to the reception path via the filter;
Low noise amplification means for amplifying the signal that has passed through the limiter;
Demodulating means for demodulating the output signal of the low noise amplifying means and outputting a received baseband signal.
The limiter is
The transmission / reception apparatus according to claim 1, comprising a first diode.
The limiter is
The transmission / reception apparatus according to claim 2, further comprising a second diode provided in parallel with and opposite to the first diode.
The limiter is
A variable voltage source;
A coil provided between the variable voltage source and the reception path;
The transmission / reception device according to claim 2, further comprising: a resistance element provided in series with the coil.
The distortion compensation means which performs a distortion compensation process with respect to the said received baseband signal using the distortion compensation coefficient according to distortion of the transmission signal component contained in the output signal of the said low noise amplification means is further provided. 5. The transmission / reception device according to any one of 4 to 4.
Modulation means for modulating a transmission baseband signal and outputting a high-frequency signal;
A high-power amplifier that amplifies the high-frequency signal and outputs the transmission signal, and
The transmission / reception apparatus according to claim 5, wherein the distortion compensation unit further performs distortion compensation processing on the transmission baseband signal using a distortion compensation coefficient corresponding to distortion of an output signal of the high-power amplifier.
The distortion compensation means includes
A selection means for selectively outputting one of the output signal of the high-power amplifier and the transmission signal component included in the output signal of the low-noise amplification means;
Demodulation means for demodulating the output signal of the selection means and outputting a feedback signal;
Based on the comparison result between the feedback signal and the transmission baseband signal, distortion of the output signal of the high-power amplifier, and distortion of the transmission signal component included in the output signal of the low-noise amplifier, Distortion calculation means for calculating any one of
Signal processing means for performing distortion compensation processing on either the transmission baseband signal or the reception baseband signal using a distortion compensation coefficient corresponding to the calculation result of the distortion calculation means;
The transmission / reception apparatus according to claim 6, comprising:
The low noise amplification means includes
The transmitting / receiving apparatus according to any one of claims 1 to 7, comprising a plurality of amplifiers provided in parallel.
The transmission / reception apparatus according to any one of claims 1 to 8, wherein the demodulation unit outputs the reception baseband signal by mixing an output signal of the low noise amplification unit and a local oscillation signal.
The transmission / reception apparatus according to any one of claims 1 to 9, further comprising an interstage filter provided between the low noise amplification means and the demodulation means.
A signal component having a predetermined amplitude or more is suppressed by a limiter among signals supplied to the reception path via a filter shared by a transmission signal wirelessly transmitted to the outside and a reception signal wirelessly received from the outside,
The signal that has passed through the limiter is amplified using low-noise amplification means,
A transmission / reception method for demodulating an output signal of the low noise amplification means and outputting a reception baseband signal.
The transmission / reception method according to claim 11, wherein a distortion compensation process is performed on the received baseband signal using a distortion compensation coefficient corresponding to a distortion of a transmission signal component included in an output signal of the low noise amplification means.
Modulate the transmission baseband signal and output a high-frequency signal,
Amplifying the high-frequency signal by a high-power amplifier to output the transmission signal;
In the distortion compensation process,
The transmission / reception method according to claim 12, wherein distortion compensation processing is performed on the transmission baseband signal using a distortion compensation coefficient corresponding to distortion of an output signal of the high-power amplifier.
In the distortion compensation process,
Selectively output one of the output signal of the high-power amplifier and the transmission signal component included in the output signal of the low-noise amplifier,
Demodulate the selectively output signal and output a feedback signal,
Based on the comparison result between the feedback signal and the transmission baseband signal, distortion of the output signal of the high-power amplifier, and distortion of the transmission signal component included in the output signal of the low-noise amplifier, Either
The transmission / reception method according to claim 13, wherein distortion compensation processing is performed on either the transmission baseband signal or the reception baseband signal using a distortion compensation coefficient corresponding to the calculation result.
The transmission / reception method according to any one of claims 11 to 14, wherein a plurality of amplifiers are provided in parallel as the low-noise amplification means.
The transmission / reception method according to any one of claims 11 to 15, wherein the reception baseband signal is output by mixing an output signal of the low noise amplification means and a local oscillation signal.