JP3886982B2 - Signal generator for moving body test - Google Patents

Description

  The present invention relates to a mobile test signal generator for testing a mobile terminal such as a mobile phone, and frequency switching between a control signal and a communication signal and frequency hopping between communication signals. The present invention relates to a technique for realizing an operation with a simple configuration.

  Among mobile communication networks such as mobile phones, GSM base stations, for example, perform control information and communication information communication with mobile terminals alternately and in a time-division manner, and signals modulated with communication information The frequency is changed sequentially to make it less susceptible to interference and multipath. In this way, sequentially changing the frequency of a signal modulated with communication information is called frequency hopping. (Note that some control information may be included in communication information for frequency hopping depending on the communication procedure. However, it is treated as communication information in the following description).

  Therefore, a signal generator used in a pseudo base station apparatus for testing a GSM mobile terminal needs to have a frequency switching function including this frequency hopping.

FIG. 13 shows a conventional configuration of the signal generator 10 having the frequency switching function.
The signal generator 10 includes two sets of transmitters 11A and 11B and a synchronization control unit 17.

  The transmitters 11A and 11B receive digital control information or communication information, generate a baseband signal composed of an in-phase component I and a quadrature component Q, and perform quadrature modulation on the baseband signals I and Q. An orthogonal modulation unit 13 and a frequency conversion unit 14 that converts a signal obtained by the orthogonal modulation into a communication frequency band are included.

  The two transmitters 11 </ b> A and 11 </ b> B are synchronously controlled via the synchronization control unit 17. The synchronization control unit 17 outputs a signal orthogonally modulated with control information from one transmitter 11A at a predetermined frequency every predetermined time, and a signal modulated with communication information from the other transmitter 11B during that time. Are output while sequentially changing.

  A technique for performing frequency switching including frequency hopping by controlling the two transmitters 11A and 11B in this manner is disclosed in Patent Document 1, for example.

Japanese National Patent Publication No. 8-510627

  However, in the method of realizing frequency switching using two transmitters as described above, the overall configuration of the apparatus becomes large and the cost increases.

  In order to solve this problem, for example, as shown in FIG. 14, the signal generation device 10 ′ includes a baseband signal generation unit 12, an orthogonal modulation unit 13, and a frequency conversion unit 14, and the control unit 15 performs orthogonal modulation. It is also conceivable to switch the frequency of the local oscillator circuit 13a of the unit 13 and the local oscillator circuit 14a of the frequency converter 14.

  However, the local oscillation circuit 13a of the quadrature modulation unit 13 and the local oscillation circuit 14a of the frequency conversion unit 14 are generally systems in which the oscillation frequency is locked by PLL control, depending on the band of the loop filter inserted in the PLL loop. If the lock time is determined and frequency switching that requires a high speed of 1 millisecond or less is performed, it is necessary to widen the band of the loop filter to shorten the lock time. If it is widened, there will be a problem that the phase noise becomes large and the signal purity is lowered.

  An object of the present invention is to solve this problem and to provide a mobile test signal generator capable of high-speed frequency switching without causing a decrease in signal purity with a simple configuration.

In order to achieve the object, a mobile test signal generator according to claim 1 of the present invention comprises:
Baseband signal generating means (21) for generating baseband signals (I, Q) respectively corresponding to control information and communication information for notifying a mobile terminal to be tested;
A first local oscillator circuit (24a) that outputs a first local oscillator signal (La) for quadrature modulation, and a second local oscillator circuit (24b) that outputs a second local oscillator signal (Lb) for quadrature modulation ) And a modulation local oscillation signal generating means (24) having a changeover switch (24c) for selectively outputting either the first local oscillation signal or the second local oscillation signal as a modulation local oscillation signal (Li). )When,
A quadrature that performs quadrature modulation processing with the in-phase component (I), quadrature component (Q) of the baseband signal, and a modulation local oscillation signal, and outputs a quadrature modulation signal in an intermediate frequency band lower than the communication frequency band of the mobile terminal Modulation means (23);
A frequency conversion local signal generating means (27) for outputting a frequency conversion local signal (Lr) for converting the intermediate frequency band orthogonal modulation signal into the communication frequency band;
A frequency conversion means (26) for mixing the orthogonal modulation signal in the intermediate frequency band output from the orthogonal modulation means and the local signal for frequency conversion, and converting the mixed signal into an orthogonal modulation signal in the communication frequency band;
The baseband signal generation means and the modulation local oscillation signal generation means are controlled so that the orthogonal modulation signal modulated by the control information and the orthogonal modulation signal modulated by the communication information are output in a time division manner at different frequencies. And a mobile unit test signal generator comprising control means (30) for sequentially changing the frequency of the orthogonal modulation signal modulated by the communication information,
The frequency conversion local oscillation signal generating means,
A third local oscillation circuit (27a) that outputs a third local oscillation signal (Lc) for frequency conversion, and a fourth local oscillation signal for frequency conversion (frequency conversion range wider than that of the second local oscillation circuit). Ld) fourth local oscillator circuit (27b) and a selector switch for selectively outputting either the third local oscillator signal or the fourth local oscillator signal as a frequency conversion local oscillator signal (Lr) (27c)
The control means includes
A state in which a baseband signal corresponding to control information is output from the baseband signal generation means is a first state, and in the first state, the first local oscillation signal is output as a modulation local oscillation signal , and the third to output as a frequency conversion local oscillation signal of the local oscillation signal of Rutotomoni, modulating at least one of the frequency of the second local oscillation signal and the fourth local oscillator signal, then the communication information to be output changed set according to the expected frequency of the orthogonal modulation signal, the state where the output of the baseband signal corresponding to the communication information from the baseband signal generating means is in the second state, when the second state, Outputting the local signal changed and set according to at least the predetermined frequency of the second local signal for modulation and the fourth local signal for frequency conversion; Frequency It is characterized in that to output the modulated signal.

According to a second aspect of the present invention, there is provided the mobile test signal generator according to the first aspect of the present invention.
The quadrature modulation means includes
A first phase shifter (101) for shifting the modulation local oscillation signal by 90 degrees; a first mixer (102) for mixing one of the in-phase component and the quadrature component of the baseband signal and the modulation local oscillation signal; A second mixer (103) for mixing one of the in-phase component and the quadrature component and the phase-shifted local oscillation signal phase-shifted by 90 degrees by the first phase shifter; the other of the in-phase component and the quadrature component of the baseband signal; A third mixer (104) for mixing the modulation local oscillation signal, a fourth mixer (105) for mixing the other in-phase component and quadrature component of the baseband signal and the phase-shift local oscillation signal, and the first mixer A first synthesizer (105) for adding the output and the output of the fourth mixer, and a second synthesizer (106) for subtracting the output of the third mixer from the output of the second mixer,
The frequency conversion means includes
A second phase shifter (201) that shifts the frequency conversion local oscillation signal by 90 degrees, and one of the outputs of the first and second combiners of the quadrature modulation means is mixed with the frequency conversion local oscillation signal. A fifth mixer (202), a sixth mixer (203) for mixing the other of the outputs of the first synthesizer and the second synthesizer with the phase-shifted local oscillation signal phase-shifted by the second phase shifter; A third synthesizer (204) for adding the outputs of the fifth mixer and the sixth mixer;
Furthermore, baseband signal replacement means (22) capable of switching in-phase and quadrature components of the baseband signal input to the quadrature modulation means;
Modulation signal switching means (25) for inputting the output of the first synthesizer and the output of the second synthesizer of the quadrature modulation means in a replaceable manner to the fifth mixer and the sixth mixer of the frequency conversion means; Is provided,
The control means includes
At least the replacement of the in-phase component and the quadrature component in the baseband signal replacement means and the replacement of the modulation signal in the modulation signal replacement means are synchronously controlled to suppress the image component of the quadrature modulation signal output from the frequency conversion means. It is characterized by that.

Moreover, the mobile generator test signal generator according to claim 3 of the present invention comprises :
Baseband signal generating means (21) for generating baseband signals (I, Q) respectively corresponding to control information and communication information for notifying a mobile terminal to be tested;
A first local oscillator circuit (24a) that outputs a first local oscillator signal (La) for quadrature modulation, and a second local oscillator circuit (24b) that outputs a second local oscillator signal (Lb) for quadrature modulation ) And a modulation local oscillation signal generating means (24) having a changeover switch (24c) for selectively outputting either the first local oscillation signal or the second local oscillation signal as a modulation local oscillation signal (Li). )When,
A quadrature that performs quadrature modulation processing with the in-phase component (I), quadrature component (Q) of the baseband signal, and a modulation local oscillation signal, and outputs a quadrature modulation signal in an intermediate frequency band lower than the communication frequency band of the mobile terminal Modulation means (23);
A frequency conversion local signal generating means (27) for outputting a frequency conversion local signal (Lr) for converting the intermediate frequency band orthogonal modulation signal into the communication frequency band;
A frequency conversion means (26) for mixing the orthogonal modulation signal in the intermediate frequency band output from the orthogonal modulation means and the local signal for frequency conversion, and converting the mixed signal into an orthogonal modulation signal in the communication frequency band;
The baseband signal generation means and the modulation local oscillation signal generation means are controlled so that the orthogonal modulation signal modulated by the control information and the orthogonal modulation signal modulated by the communication information are output in a time division manner at different frequencies. And a mobile unit test signal generator comprising control means (30) for sequentially changing the frequency of the orthogonal modulation signal modulated by the communication information,
The quadrature modulation means includes
A first phase shifter (101) for shifting the modulation local oscillation signal by 90 degrees; a first mixer (102) for mixing one of the in-phase component and the quadrature component of the baseband signal and the modulation local oscillation signal; A second mixer (103) for mixing one of the in-phase component and the quadrature component and the phase-shifted local oscillation signal phase-shifted by 90 degrees by the first phase shifter; the other of the in-phase component and the quadrature component of the baseband signal; A third mixer (104) for mixing the modulation local oscillation signal, a fourth mixer (105) for mixing the other in-phase component and quadrature component of the baseband signal and the phase-shift local oscillation signal, and the first mixer A first synthesizer (105) for adding the output and the output of the fourth mixer, and a second synthesizer (106) for subtracting the output of the third mixer from the output of the second mixer,
The frequency conversion means includes
A second phase shifter (201) that shifts the frequency conversion local oscillation signal by 90 degrees, and one of the outputs of the first and second combiners of the quadrature modulation means is mixed with the frequency conversion local oscillation signal. A fifth mixer (202), a sixth mixer (203) for mixing the other of the outputs of the first synthesizer and the second synthesizer with the phase-shifted local oscillation signal phase-shifted by the second phase shifter; A third synthesizer (204) for adding the outputs of the fifth mixer and the sixth mixer;
Furthermore, baseband signal replacement means (22) capable of switching in-phase and quadrature components of the baseband signal input to the quadrature modulation means;
Modulation signal switching means (25) for inputting the output of the first synthesizer and the output of the second synthesizer of the quadrature modulation means in a replaceable manner to the fifth mixer and the sixth mixer of the frequency conversion means; Is provided,
The control means includes
At least the replacement of the in-phase component and the quadrature component in the baseband signal replacement means and the replacement of the modulation signal in the modulation signal replacement means are synchronously controlled to suppress the image component of the quadrature modulation signal output from the frequency conversion means. It is characterized by that.

A signal generator for a moving body test according to claim 4 of the present invention provides :
Baseband signal generating means (21) for generating baseband signals (I, Q) respectively corresponding to control information and communication information for notifying a mobile terminal to be tested;
Modulation local oscillation signal generating means (24) for outputting a modulation local oscillation signal (Li) for orthogonal modulation;
Quadrature modulation means (23) for performing quadrature modulation processing with the in-phase component (I), quadrature component (Q) and modulation local oscillation signal of the baseband signal, and outputting a quadrature modulation signal in a predetermined intermediate frequency band;
Baseband signal replacement means (22) capable of switching in-phase and quadrature components of a baseband signal input to the quadrature modulation means;
A frequency conversion local signal for receiving the quadrature modulation signal in the intermediate frequency band output from the quadrature modulation means and converting the signal to the communication frequency band of the mobile terminal and outputting the signal (Lr) for frequency conversion Generating means (27);
A frequency conversion means (26) for mixing the orthogonal modulation signal in the intermediate frequency band output from the orthogonal modulation means and the local signal for frequency conversion, and converting the mixed signal into an orthogonal modulation signal in the communication frequency band;
The baseband signal generation means, the modulation local oscillation signal generation means, the baseband signal replacement means, and the frequency conversion local oscillation signal generation means are controlled, and the orthogonal modulation signal modulated by the control information and the communication A mobile test signal comprising: control means (30) for sequentially changing the frequency of the orthogonal modulation signal modulated by the communication information and outputting the orthogonal modulation signal modulated by the information in a time division manner at a different frequency. A generator,
The control means includes
The baseband signal output from the baseband signal generating means in accordance with the control information is input to the quadrature modulation means as the first state which is a predetermined replacement state of the baseband signal replacement means, and the frequency conversion means The frequency conversion local oscillation signal input to the modulation local oscillation signal generating means is output at a first frequency shifted by the frequency of the modulation local oscillation signal,
The baseband signal output from the baseband signal generation means in accordance with communication information is input to the quadrature modulation means as the second state opposite to the first state, and the baseband signal replacement means is input to the quadrature modulation means. With respect to the frequency conversion local oscillation signal input to the conversion means, a second frequency shifted from the modulation local oscillation signal generation means by the frequency of the modulation local oscillation signal is opposite to the first frequency. By outputting, the frequency of the control information and the communication information is switched and output .

According to a fifth aspect of the present invention, there is provided the mobile body test signal generator according to the fourth aspect of the present invention .
The modulation local oscillation signal generating means includes:
A first local oscillation circuit (24a) that outputs a first local oscillation signal (La) for quadrature modulation, and a second local oscillation circuit (Lb) that outputs a second local oscillation signal (Lb) for quadrature modulation ( 24b), and a changeover switch (24c) that selectively outputs one of the first local oscillation signal and the second local oscillation signal as a modulation local oscillation signal (Li),
The control means includes
In synchronization with the switching of the control information and the communication information, either one of the first local signal and the second local signal from the modulation local signal generation means is used as the modulation local signal. It is characterized in that it is output to an orthogonal modulation means .

According to a sixth aspect of the present invention, there is provided the mobile body test signal generator according to the fourth aspect of the present invention.
The frequency conversion local oscillation signal generating means,
A third local oscillation circuit (27a) for outputting a third local oscillation signal (Lc) for frequency conversion, and a fourth local oscillation signal for frequency conversion in a frequency variable range wider than that of the second local oscillation circuit. A fourth local oscillator circuit (27b) that outputs (Ld) and either the third local oscillator signal or the fourth local oscillator signal are selectively output as a frequency conversion local oscillator signal (Lr). A changeover switch (27c),
The control means includes
Synchronously with the switching of the control information and the communication information, either the third local oscillation signal or the fourth local oscillation signal is sent from the frequency conversion local oscillation signal generation means to the frequency conversion local oscillation signal. And output to the frequency conversion means .

According to a seventh aspect of the present invention, there is provided the mobile body test signal generator according to the fourth aspect of the present invention.
The quadrature modulation means includes
A first phase shifter (101) for shifting the modulation local oscillation signal by 90 degrees; a first mixer (102) for mixing one of the in-phase component and the quadrature component of the baseband signal and the modulation local oscillation signal; A second mixer (103) for mixing one of the in-phase component and the quadrature component and the phase-shifted local oscillation signal phase-shifted by 90 degrees by the first phase shifter; the other of the in-phase component and the quadrature component of the baseband signal; A third mixer (104) for mixing the modulation local oscillation signal, a fourth mixer (105) for mixing the other in-phase component and quadrature component of the baseband signal and the phase-shift local oscillation signal, and the first mixer A first synthesizer (105) for adding the output and the output of the fourth mixer, and a second synthesizer (106) for subtracting the output of the third mixer from the output of the second mixer,
The frequency conversion means includes
A second phase shifter (201) that shifts the frequency conversion local oscillation signal by 90 degrees, and one of the outputs of the first and second combiners of the quadrature modulation means is mixed with the frequency conversion local oscillation signal. A fifth mixer (202), a sixth mixer (203) for mixing the other of the outputs of the first synthesizer and the second synthesizer with the phase-shifted local oscillation signal phase-shifted by the second phase shifter; A third synthesizer (204) for adding the outputs of the fifth mixer and the sixth mixer;
Further, a modulation signal switching means (25) for inputting the output of the first synthesizer and the output of the second synthesizer of the quadrature modulation means in a replaceable manner to the fifth mixer and the sixth mixer of the frequency conversion means. )
The control means includes
Synchronizing at least the replacement of the in-phase component and the quadrature component in the baseband signal replacement means and the replacement of the modulation signal in the modulation signal replacement means, and suppressing the image component of the quadrature modulation signal output from the frequency conversion means. It is characterized by that.

Thus, the mobile test signal generator according to claim 1 of the present invention performs frequency switching including frequency hopping by switching the modulation local oscillation signal to the quadrature modulation means, and also modulates the signal modulated by the control information. Since the frequency of the local signal for communication information is changed and set during transmission, the frequency can be switched at high speed with a simple configuration without causing a decrease in signal purity.

Further, the frequency conversion local oscillator signal used by the frequency converting means, two independent local oscillator circuit is to select from the local oscillation signal for outputting each one of one of the local oscillation signal and the frequency conversion for the modulation While the local oscillator signal is selected, at least one frequency of the other local oscillator signal for modulation and the other local oscillator signal for frequency conversion is changed and set, so the signal purity can be achieved with a simple configuration. It is possible to perform high-speed frequency switching including frequency hopping over a wide frequency range without causing a decrease in the frequency.

Further, the mobile test signal generator according to claims 2 and 3 of the present invention synchronizes the replacement of the baseband signal with respect to the orthogonal modulation means and the replacement of the orthogonal modulation signal in the intermediate frequency band with respect to the frequency conversion means. High-speed frequency switching including frequency hopping can be performed in a state where image components are suppressed.

The mobile test signal generator according to claim 4 of the present invention changes the output frequency by exchanging the baseband signal in synchronization with the switching of the control information and the communication information. Fast frequency switching is possible without changing the frequency.

According to a fifth aspect of the present invention, there is provided a mobile test signal generating apparatus, wherein the first local signal and the second local signal are transmitted from the modulation local signal generating means in synchronization with the switching of the control information and the communication information. Since either one of the signals is output to the quadrature modulation means, signal purity can be reduced over a wide frequency range with a simple configuration by combining baseband switching and modulation local oscillation signal switching. In addition, high-speed frequency switching including frequency hopping is possible.

According to a sixth aspect of the present invention, there is provided a mobile unit test signal generating apparatus including a third local oscillation signal and a fourth local station from the frequency conversion local oscillation signal generating means in synchronism with switching between control information and communication information. Since either one of the emitted signals is output to the frequency conversion means, a wide frequency range can be achieved with a simple configuration by combining baseband switching, switching of the modulation local oscillation signal, and switching of the frequency conversion local oscillation signal. High-speed frequency switching including frequency hopping is possible without causing a decrease in signal purity over a range.

In the mobile test signal generator according to claim 7 of the present invention , the quadrature modulation means and the frequency conversion means are configured as an image removal type, and the two modulation signals can be switched to the frequency conversion means. Fast frequency switching including frequency hopping is possible with the image component suppressed.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 shows a configuration of a moving body test signal generator 20 to which the present invention is applied.

  This mobile test signal generator 20 includes a baseband signal generator 21, a baseband signal switch 22, a quadrature modulator 23, a modulation local signal generator 24, a frequency converter 26, and a frequency conversion local signal. The generating means 27 and the control means 30 are configured.

  Baseband signal generating means 21 generates baseband signals I and Q corresponding to control information and communication information, respectively, and inputs them to quadrature modulating means 23 via baseband signal replacing means 22.

  The baseband signal exchanging means 22 includes, for example, a switch that can input the in-phase component I and the quadrature component Q of the baseband signal to the quadrature modulation means 23 and is controlled by the control means 30.

  The quadrature modulation means 23 modulates the in-phase component I, the quadrature component Q, and the intermediate frequency band (for example, 4.8 MHz band) output from the modulation local oscillation signal generation means 24 input via the baseband signal replacement means 22. A quadrature modulation process is performed with the local oscillation signal Li to output a modulation signal X in the intermediate frequency band.

  As shown in FIG. 2, the quadrature modulation means 23 includes a phase shifter 101, a double balanced first mixer 102, a second mixer 103, and a combiner 106. Note that the quadrature modulation means 23 may realize the functions of the above units by numerical calculation processing.

  The first mixer 102 receives a modulation local oscillation signal Li, and the second mixer 103 receives a phase shift local oscillation signal Li ′ obtained by shifting the modulation local oscillation signal Li by 90 degrees by the phase shifter 101. Is done.

  One of the in-phase component I and the quadrature component Q of the baseband signal is input to the first mixer 102 via the input terminal 23a, and the other is input to the second mixer 103 via the input terminal 23b.

  The baseband signal input to the first mixer 102 is mixed with the modulation local oscillation signal Li (multiplication: the same applies hereinafter), and the baseband signal input to the second mixer 103 is mixed with the phase shift local oscillation signal Li ′. The mixed outputs of both mixers 102 and 103 are added and combined by a combiner 106, and the combined signal is output as a modulation signal X in the intermediate frequency band.

Here, the frequency of the modulation local oscillation signal Li is Fi, (2πFi) t is p, and each local oscillation signal Li, Li ′ is
Li = cos p
Li ′ = sin p
When the in-phase component I is input to the mixer 102 and the quadrature component Q is input to the mixer 103 (straight state), the output X of the synthesizer 106 is as follows.

  X = I · cos p + Q · sin p (1)

  Conversely, when the quadrature component Q is input to the mixer 102 and the in-phase component I is input to the mixer 103 (cross state), the output X of the synthesizer 106 is as follows.

  X = Q · cos p + I · sin p (2)

  This intermediate frequency band modulation signal X is input to the frequency conversion means 26.

  On the other hand, the modulation local oscillation signal generating means 24 selects two independent local oscillation circuits 24a and 24b and local oscillation signals La and Lb output from the local oscillation circuits 24a and 24b, thereby modulating the local station. And a selector switch 24c that outputs the signal Li to the quadrature modulation means 23. The frequencies Fa and Fb of the two local signals La and Lb and the state of the changeover switch 24c are controlled by the control means 30. One of the local oscillator circuits 24a may be fixed in frequency.

  The frequency conversion means 26 is constituted by a single double balanced mixer, and mixes the input modulation signal X and the frequency conversion local signal Lr.

That is, the frequency of the frequency conversion local signal Lr (hereinafter also referred to as carrier frequency) is Fr, (2πFr) t = h, and the frequency conversion local signal Lr is
Lr = cos h
Then, the signal Z output from the frequency converting means 26 is
Z = X ・ cos h
It becomes.

  When the modulation signal X is expressed by the above equation (1), the signal Z can be expressed as follows.

Z = (I · cos p + Q · sin p) cos h
= {I · cos (p + h) + Q · sin (p + h)} / 2
+ {I.cos (ph) -Q.sin (ph)} / 2
...... (3)

  Here, since p + h = 2π (Fi + Fr) t and ph = 2π (Fr−Fi) t, the signal component A of the first item in the signal Z can be expressed as follows.

A =
{I · cos 2π (Fi + Fr) t + Q · sin 2π (Fi + Fr) t} / 2
...... (4)

  The signal component B of the second item of the signal Z can be expressed as follows.

B =
{I · cos 2π (Fr−Fi) t−Q · sin 2π (Fr−Fi) t} / 2
...... (5)

  The signal component A is a desired quadrature modulation signal having a frequency (Fi + Fr) quadrature-modulated with a baseband signal, and is a sideband component on the high frequency side (upper side) with respect to the carrier frequency Fr. The signal component B is an image component having a frequency (Fr-Fi), and not only the frequency but also the phase differs from the desired quadrature modulation signal A.

  When the modulation signal X is expressed by the above equation (2), the signal Z is expressed as follows.

Z = X ・ cos h
= (Q ・ cos p + I ・ sin p) sin h
= {I.cos (ph) + Q.sin (ph)} / 2
-{I.cos (p + h) -Q.sin (p + h)} / 2
...... (6)

  Similarly to the above, using the frequency, the signal component C of the first item of the signal Z in the above equation (6) can be expressed as follows.

C =
{I · cos 2π (Fr−Fi) t + Q · sin 2π (Fr−Fi) t} / 2
...... (7)

  This signal component C is a desired quadrature modulation signal having a frequency (Fr-Fi) quadrature modulated with a baseband signal, and becomes a sideband component on the low frequency side (lower side) with respect to the local frequency Fr. With respect to the signal component A shown in Expression (4), the amplitude phase information is the same only by shifting the frequency to the low frequency side (lower side) by 2 Fi.

  Further, the signal component D of the second item of the signal Z in the above equation (6) can be expressed as follows.

D =
− {I · cos 2π (Fr + Fi) t−Q · sin 2π (Fr + Fi) t} / 2
...... (8)

  This signal component D is an image component of frequency (Fr + Fi), and differs from the desired quadrature modulation signal C not only in frequency but also in phase.

  In other words, the frequency of the desired quadrature modulation signal can be varied by 2Fi simply by exchanging the baseband signal by the baseband signal exchanging means 22, and this signal switching can be performed at high speed. Compared with the configuration in which the frequency is switched by changing the frequency of the local oscillator circuit having the PLL configuration, the frequency can be switched much faster.

  Therefore, the switching of the frequency between the control information and the communication information by this baseband signal replacement operation can be realized by, for example, only one local oscillator circuit 24a, and the frequency of the local oscillator circuit may be fixed. .

  However, hopping of the frequency of the orthogonal modulation signal modulated by the communication information cannot be realized only by exchanging the baseband signal.

  Therefore, in the mobile test signal generator 20 of this embodiment, the switching of the baseband signal switching means 22 and the switching of the modulation local signal Li output from the modulation local signal generation means 24 are combined. Furthermore, high-speed frequency switching processing including frequency hopping is realized by using frequency variation processing of one local oscillation signal Lb together.

  The switching of the local oscillation signal Li for modulation can be performed at high speed because simple signal selection processing may be performed in the same manner as the replacement of the baseband signal, and while the local oscillation signal La is selected. Since the frequency of the other local oscillation signal Lb can be variably set, high-speed switching can be performed without reducing the signal purity.

  For example, as shown in FIG. 3, the control means 30 outputs the control information signal having the fixed frequency F0 and the communication information signal alternately in a time-division manner, while changing the output frequency of the communication information signal. Control of baseband signal generation means 21, baseband signal switching means 22, modulation local oscillation signal generation means 24, and frequency conversion local oscillation signal generation means 27 in accordance with a schedule for sequentially hopping F1, F2, F3,. I do.

FIG. 4 is a flowchart showing an example of the processing procedure of the control means 30.
The operation of the embodiment will be described below based on this flowchart chart.

  Here, the case where the control means 30 performs frequency switching control based on the above-described schedule of FIG. 3 will be described. In the following description, it is assumed that the frequency F0 for control information is higher than each frequency for communication information.

  First, the control means 30 sets each local oscillation frequency Fa, Fb, Fr as follows, for example (S1).

Fi = Fa = Fb = (F0−F1) / 2
Fr = (F0 + F1) / 2
Note that the above initial setting is an example in which the local oscillation frequencies Fa and Fb are equalized.
Fa = F0−Fr (fixed value)
Fb = F1-Fr
Should be set so as to satisfy.

  Next, the baseband signal switching means 22 is set in the straight state (the first state in this case), and the local oscillation signal La is selectively output from the modulation local oscillation signal generation means 24 to generate the baseband signal. The baseband signals I and Q corresponding to the control information are output from the means 21 for a predetermined time (S2). It is assumed that the control information includes scheduled frequency information for hopping communication information.

  The in-phase component I of the baseband signal is input to the input terminal 23 a of the quadrature modulation unit 23 through the baseband signal replacement unit 22, and the quadrature component Q is input to the quadrature modulation unit 23 through the baseband signal replacement unit 22. Since the signal is input to the input terminal 23b, the state shown in the above equations (1) and (3) is obtained, and the frequency conversion means 26 receives a desired frequency F0 (= Fr + Fa) as shown in FIG. A signal Z composed of the orthogonal modulation signal A and the image component B having the frequency Fr-Fa is output.

  Here, as described above, the image component B is different from the desired quadrature modulation wave in frequency and phase information, and is not correctly demodulated on the mobile terminal side, so that it is not recognized as effective information.

  On the other hand, the orthogonal modulation signal A correctly modulated with the baseband signal corresponding to the control information is demodulated by the mobile terminal to be tested, and the control information is notified. The mobile terminal performs a process of switching the reception frequency of the communication information at the next timing from the scheduled frequency information of hopping included in the control information.

  Next, the control means 30 switches the baseband signal switching means 22 to the cross state (set to the second state in this case), and selectively outputs the local oscillation signal Lb from the modulation local oscillation signal generation means 24, Baseband signals I and Q corresponding to communication information are output from the band signal generating means 21 for a predetermined time (S3).

  Since the in-phase component I of this baseband signal is input to the input terminal 23b of the quadrature modulation means 23 and the quadrature component Q is input to the input terminal 23a, the states shown in the above equations (2) and (6) are obtained, and the frequency conversion is performed. As shown in FIG. 5B, the means 26 outputs a signal Z comprising a desired quadrature modulation signal C having a frequency F1 (= Fr−Fb) and an image component D having a frequency Fr + Fb. The signal C is received by the mobile terminal to be tested, and the communication information is demodulated.

  Note that, in the case of the initial setting value of the frequency described above, the frequency of the image component D matches the control frequency F0, but the reception frequency of the mobile terminal is set to the frequency F1 by the control information received before that. Therefore, the image component D is not received or demodulated.

  After outputting the signal modulated with the communication information in this way, the control means 30 returns the baseband signal replacement means 22 to the straight state, and the local oscillation signal La is selectively output from the modulation local oscillation signal generation means 24. In this way, baseband signals I and Q corresponding to the control information are output from the baseband signal generating means 21 for a predetermined time, and modulated with the control information as shown in FIG. A signal of frequency F0 is transmitted, and the frequency of the local oscillation signal Lb is changed and set to Fb = Fr−F2 according to the frequency F2 of the signal modulated by the communication information scheduled to be transmitted next.

  Therefore, the local oscillation circuit 24b only has to lock the local oscillation signal Lb while transmitting the signal modulated with the control information, and even if a narrow band loop filter is used, the local oscillation circuit 24b can sufficiently drive the locked state. The local signal Lb with high signal purity can be output.

  When the transmission of the signal modulated with this control information is completed, the control means 30 switches the baseband signal switching means 22 to the cross state again, and the local oscillation signal Lb is selected from the local oscillation signal generation means 24 for modulation. The baseband signals I and Q corresponding to the communication information are output from the baseband signal generator 21 for a predetermined time so as to be output (S5).

  For this reason, as shown in FIG. 5C, the frequency conversion means 26 generates a signal Z consisting of a desired quadrature modulation signal C of frequency F2 (= Fr−Fb) and an image component D of frequency Fr + Fb. The quadrature modulation signal C is output and received by the mobile terminal to be tested, and the communication information is demodulated.

  At this time, since the local oscillation signal Lb is sufficiently stable and the signal purity is high, the stability and signal purity of the output quadrature modulation signal C are also high.

When the transmission of the signal modulated with this communication information is completed, the baseband signal switching means 22 is again returned to the straight state so that the local signal La is selectively output from the local signal generating means 24 for modulation. Then, baseband signals I and Q corresponding to the control information are output from the baseband signal generating means 21 for a predetermined time, and the signal is returned to the state of FIG. 5A, and the signal of the frequency F0 modulated by the control information is output. In accordance with the frequency F3 of the signal modulated with the communication information scheduled to be transmitted next, the frequency of the local oscillation signal Lb is
Fb = Fr−F3
(S6).

  As a result, as shown in FIG. 5D, the frequency conversion means 26 generates a signal Z composed of a desired quadrature modulation signal C having the frequency F3 (= Fr−Fb) and the image component D having the frequency Fr + Fb. The quadrature modulation signal C is output and received by the mobile terminal to be tested, and the communication information is demodulated.

  Thereafter, the local signal Lb is sequentially changed as Fr-F4, Fr-F5,... According to the hopping frequency, and the same processing is repeated to modulate the signal modulated with the control information and the communication information. The frequency switching between the received signals and the frequency hopping of the signal modulated with the communication information are performed, and various tests are performed on the mobile terminal.

  In the description so far, the local oscillation signals La and Lb are alternately switched to realize frequency switching including frequency hopping. However, the frequency F0 of the signal modulated by the control information is the carrier frequency Fr for frequency conversion. And the frequency of the signal modulated by the communication information of the frequency switching destination (for example, F1), the baseband signal switching means 22 without switching the local oscillation signal La to the local oscillation signal Lb. By switching the state, it is possible to switch the frequency of the signal modulated with the control information and the signal modulated with the communication information, and the switching operation between the local oscillation signal La and the local oscillation signal Lb can be reduced. .

  When the frequency F0 for control information is lower than each frequency for communication information, the baseband signal switching means 22 is set to the cross state (the first state in this case) when a signal modulated with the control information is output. When the signal modulated with the communication information is output, the baseband signal replacement unit 22 may be set in a straight state (the second state in this case).

  Thus, in the signal generator 20 of the embodiment, when the baseband signal corresponding to the control information is output from the baseband signal generator 21, the input state of the baseband signal to the quadrature modulator 23 is set to the first state. The local oscillation signal La is output as the modulation local oscillation signal Li, and the frequency of the other local oscillation signal Lb is changed according to the planned frequency of the orthogonal modulation signal modulated by the communication information to be output next. When the baseband signal corresponding to the communication information is output from the baseband signal generation means 21, the input state of the baseband signal to the quadrature modulation means 23 is set to the second state opposite to the first state, and the station transmission is performed. The signal Lb is output as a modulation local oscillation signal Li, and an orthogonal modulation signal having a predetermined frequency is output.

  Therefore, the frequency of the output signal including frequency hopping can be switched at high speed without reducing the signal purity with a simple configuration.

  In the above embodiment, the quadrature modulation signal in the intermediate frequency band is generated and then converted into the communication frequency band. However, the frequency of the local signal output from the local signal generation means 24 for modulation is changed to the communication frequency band. Thus, the frequency conversion means 26 and the frequency conversion local oscillation signal generation means 27 can be omitted.

  In the description of the operation, the baseband signal replacement and the modulation local oscillation signal are continuously synchronized so that the upper sideband and lower sideband of the frequency of the local oscillation signal Lr for frequency conversion are synchronized. However, if only the modulation local oscillation signal is switched without performing the baseband signal replacement processing, the frequency of the output signal is changed to one of the local oscillation signals Lr. It can be changed on the sideband side.

  Furthermore, the baseband signal switching means 22 can be omitted, and the frequency switching including the frequency hopping can be performed only by switching the modulation local oscillation signal, and the configuration can be further simplified.

  In the above description of the operation, one local oscillation signal La is used for modulation of control information, and the other local oscillation signal Lb is continuously used for modulation of communication information. On the other hand, the opposite state, that is, the state where one local oscillation signal La is used for modulation of communication information and the other local oscillation signal Lb is used for modulation of control information. However, in this case, it is necessary to make the frequencies of the signals La and Lb from both stations once the same, this is done when changing the frequency of the output signal only by replacing the baseband signal as described above. Is possible.

  In other words, as described above, when the baseband signal can be switched and either the first local oscillation signal La or the second local oscillation signal Lb can be selected as the modulation local oscillation signal Li. Is a method of sequentially outputting a signal having a predetermined frequency in synchronism with the switching of the baseband signal of the control information and the communication information, by switching the baseband signal, switching the modulation local oscillation signal, or a combination thereof. Frequency switching including frequency hopping can be performed at high speed with a simple configuration.

  Further, in the above-described embodiment, frequency hopping is included by the combination of the replacement of the baseband signal and the switching of the modulation local oscillation signal and the frequency change setting of the local oscillation signal not selected from the modulation local oscillation signals. Although frequency switching has been performed, like the mobile test signal generator 20 shown in FIG. 6, two independent local oscillator circuits 27a and 27b and the local oscillator signal Lc output by the local oscillator circuits 27a and 27b , Ld, and the frequency conversion local oscillation signal generation means 27 is configured by the changeover switch 27c that outputs the frequency conversion local oscillation signal Lr to the frequency conversion means 26 as the frequency conversion local oscillation signal Lr. Switching is possible.

  In this case, the frequency variable range of at least one of the two local oscillator circuits 27a and 27b (here, the local oscillator circuit 27b) is wider than the local oscillator circuit 24b of the modulation local oscillator signal generating means 24, and the communication frequency. It shall be a wide band corresponding to the band. The frequency variable step is also wider than the frequency variable step of the local oscillator circuit 24b.

  In the case of the mobile test signal generator 20 having this configuration, the control unit 30 performs the frequency switching process according to the procedure shown in FIG. 7, for example.

That is, in the same manner as described above, the frequencies Fa to Fd of the local signals La to Ld are
Fa = F0−Fc
Fb = Fd−F1
After that, the baseband signal switching means 22 is set in a straight state, the local signals La and Lc are selected, and control information is output for a predetermined time (S1 ', S2').

  Thereby, as shown to (a) of FIG. 5, the orthogonal modulation signal of the frequency F0 modulated by the control information can be output.

  Next, the baseband signal switching means 22 is set to the cross state, the local signals Lb and Ld are selected, and the communication information is output for a predetermined time (S3 ').

  As a result, as shown in FIG. 5B, it is possible to output an orthogonal modulation signal having the frequency F1 modulated by the control information.

  After the transmission of the communication information of the frequency F1 is completed, the baseband signal switching means 22 is again returned to the straight state, the local signals La and Lc are selected, the control information is output for a predetermined time, and the next communication At least one of the frequencies Fb and Fd of the local signals Lb and Ld is changed and set according to the information transmission frequency F2 (S4 ').

That is, when the output frequency of the next communication information is F2,
Fb = Fd−F2
The frequencies Fb and Fd that satisfy the above are set.

  Here, when the frequency hopping interval is much narrower than the variable step of the frequency conversion local oscillation signal, it can be dealt with only by changing the frequency of the modulation local oscillation signal Fb, and the frequency hopping interval is frequency conversion. In the case of an integral multiple of the variable step of the local oscillation signal for the signal, it can be dealt with only by changing the frequency of the local oscillation signal Fd for frequency conversion. In this case, the frequencies Fb and Fd of both local oscillation signals are both change.

  Thereafter, as shown in steps S5 ′ and S6 ′, the frequencies of the local signals Lb and Ld are sequentially changed and set in accordance with the scheduled output frequencies F3, F4,. Frequency switching including hopping can be performed at high speed over a wide frequency range.

  In this case as well, it is not necessary to use one local signal Lc for frequency conversion of control information and the other local signal Ld for frequency modulation of communication information. If the frequency of both local signals Lc and Ld is made the same when changing the frequency of the output signal only by replacing the baseband signal, the reverse state, that is, one local signal Lc is used for frequency conversion of communication information. And the other local oscillation signal Lb can be used for frequency conversion of control information.

  That is, as described above, the baseband signal can be switched and the modulation local oscillation signal can be switched, and either the third local oscillation signal or the fourth local oscillation signal can be selected as the frequency conversion local oscillation signal. In this case, the baseband signal is switched, the modulation local oscillation signal is switched, the frequency conversion local oscillation signal is switched, or any combination thereof is used to switch the control information and communication information baseband signal. By sequentially outputting signals of the scheduled frequencies in synchronization, frequency switching including frequency hopping can be performed at high speed in a wide frequency range with a simple configuration.

  In the above-described two embodiments, the output signal Z is allowed to include an image component. However, when the image component adversely affects the test of the mobile terminal, the mobile object shown in FIG. Like the terminal test signal generator 20, the modulation signal replacement unit 25 is provided between the orthogonal modulation unit 23 and the frequency conversion unit 26, and the frequency conversion unit 26 is configured to be an image removal type, thereby eliminating an unnecessary image. Component output can be prevented.

  Here, the quadrature modulation means 23 transmits the baseband signals I and Q input via the baseband signal replacement means 22 and the intermediate frequency band local oscillation signal output from the modulation local oscillation signal generation means 24 in the same manner as described above. A quadrature modulation process is performed with the signal Li, and two modulation signals X and Y are output.

  As shown in FIG. 9, the quadrature modulation unit 23 includes a phase shifter 101, a double balanced first mixer 102 to a fourth mixer 105, a first combiner 106, and a second combiner 107.

  Modulation local signal Li is input to first mixer 102 and third mixer 104, and phase shifter 101 shifts the phase of modulation local signal Li to 90 to second mixer 103 and fourth mixer 105. The phase-shifted local signal Li ′ that has been phase-shifted is input.

  One of the baseband signals I and Q is input to the first mixer 102 and the second mixer 103 via the input terminal 23a, and the other is input to the third mixer 104 and the fourth mixer via the input terminal 23b. 105 is input.

  The baseband signal input to the first mixer 102 is mixed with the modulation local oscillation signal Li, and the baseband signal input to the fourth mixer 105 is mixed with the phase shift local oscillation signal Li ′. Are added and combined by the first combiner 106, and the combined signal is output from the output terminal 23c as one modulation signal X.

  Further, the baseband signal input to the second mixer 103 is mixed with the phase-shifted local signal Li ′, and the baseband signal input to the third mixer 104 is mixed with the local signal Li, so that both mixers 103 and 104 are mixed. Are mixed by the second combiner 107 and the combined signal is output as the other modulation signal Y from the output terminal 23d.

Here, similarly to the above, the frequency of the modulation local oscillation signal Li is Fi, (2πFi) t is p, and the local oscillation signals Li and Li ′ are respectively
Li = cos p
Li ′ = sin p
When the in-phase component I is input to the mixer 102 and the mixer 103, and the quadrature component Q is input to the mixer 104 and the mixer 105, the output X of the first combiner 106 and the output Y of the second combiner 107 are as follows: Become.

X = I · cos p + Q · sin p
Y = Q ・ cos p-I ・ sin p ...... (9)

  The output X of the above formula (9) is the orthogonal modulation signal itself in the intermediate frequency band. In this orthogonal modulation means 23, the orthogonal modulation signal in the communication frequency band of the mobile terminal in the image removal type frequency conversion means 26 described later. A modulation signal Y different from the output X is generated so that an image component generated when the signal is obtained can be suppressed.

  Conversely, when the quadrature component Q is input to the mixer 102 and the mixer 103 and the in-phase component I is input to the mixer 104 and the mixer 105, the output X of the first combiner 106 and the output Y of the second combiner 107 are as follows: become that way.

X = Q · cos p + I · sin p
Y = I ・ cos p-Q ・ sin p ...... (10)

  These two sets of modulation signals X and Y in the intermediate frequency band are input to the frequency conversion means 26 via the modulation signal replacement means 25, respectively.

  The modulation signal replacement means 25 is composed of a switch that can input the modulation signals X and Y to the frequency conversion means 26 and is controlled by the control means 30 in the same manner as the baseband signal replacement means 22.

  The frequency conversion means 26 is called an image suppression type mixer, and includes a phase shifter 201, a double balanced first mixer 202, a second mixer 203, and a combiner 204 as shown in FIG. 10.

  The phase shifter 201 and the first mixer 202 are supplied with the frequency conversion local oscillation signal Lr from the frequency conversion local oscillation signal generating means 27, and the second mixer 203 is input with the frequency conversion local station. A phase-shifting station originating signal Lr ′ obtained by shifting the originating signal Lr by 90 degrees is input. As shown in FIG. 1, the frequency conversion local oscillation signal generating means 27 is composed of a single local oscillation circuit and two independent local oscillation circuits 27a as shown in FIG. 27b and a changeover switch 27c.

  In the frequency conversion means 26 configured as described above, the modulation signal input to the first mixer 202 via the input terminal 26a is mixed with the local signal Lr for frequency conversion and input to the second mixer 203 via the input terminal 26b. And the mixed output of both mixers 202 and 203 are added and combined by the combiner 204, and one sideband component is suppressed by the combination, and the other sideband is mixed. Only the signal Z consisting of components is output.

That is, similarly to the above, the frequency of the frequency conversion local oscillation signal Lr is Fr, (2πFr) t = h, and the local oscillation signals Lr and Lr ′ are
Lr = cos h
Lr ′ = sin h
When the modulation signal X is input to the first mixer 202 and the modulation signal Y is input to the second mixer 203, the signal Z output from the frequency conversion means 26 is
Z = X · cos h + Y · sin h
It becomes.

When the two modulation signals X and Y are expressed by the above equation (9), the signal Z is
Z = (I · cos p + Q · sin p) cos h
+ (Q ・ cos p-I ・ sin p) ・ sin h
= I · cos (p + h) + Q · sin (p + h)
It can be expressed as

  Here, since p + h = 2π (Fi + Fr) t, the signal Z can be expressed as follows.

Z = I · cos 2π (Fi + Fr) t + Q · sin 2π (Fi + Fr) t
...... (11)

  This signal Z is a desired quadrature modulation signal having a frequency (Fi + Fr) quadrature-modulated with a baseband signal.

  Further, when the two modulation signals X and Y are expressed by the above equation (10), the modulation signal Y is input to the first mixer 202, and the modulation signal X is input to the second mixer 203, the signal Z is It is expressed as

Z = Y · cos h + X · sin h
= (I ・ cos p-Q ・ sin p) cos h
+ (Q ・ cos p + I ・ sin p) sin h
= I · cos (hp) + Q · sin (hp)

  Here, since h−p = 2π (Fr−Fi) t, the signal Z can be expressed as follows.

Z = I · cos 2π (Fr−Fi) t + Q · sin 2π (Fr−Fi) t
(12)

  This signal Z is a quadrature modulated signal having a frequency (Fr-Fi) that is quadrature modulated with a baseband signal, and becomes a sideband component on the low frequency side (lower side) with respect to the local frequency Fr. The amplitude and phase information are the same only by shifting the frequency to the low frequency side (lower side) by 2 Fi with respect to the signal indicated by.

  That is, when the baseband signal corresponding to the control information is output from the baseband signal generation means 21, the states of the baseband signal replacement means 22 and the modulation signal replacement means 25 are as shown in FIG. The in-phase component I is input to the input terminal 23a of the quadrature modulation means 23, the quadrature component Q is input to the input terminal 23b, the modulation signal X is input to the input terminal 26a of the frequency conversion means 26, and the other input terminal 26b. In the straight state (the first state in this case) in which the modulation signal Y is input, the frequency conversion means 26 outputs, for example, an orthogonal frequency F0 = Fr + Fi modulated with control information as shown in FIG. Only modulated signal Z can be output (carrier leakage and residual sideband components are ignored).

  Further, when the baseband signal corresponding to the communication information is output from the baseband signal generating means 21, the quadrature component Q is input to the input terminal 23a of the orthogonal modulation means 23 as shown in FIG. A cross state in which the in-phase component I is input to the input terminal 23b, the modulation signal Y is input to the input terminal 26a of the frequency conversion means 26, and the modulation signal X is input to the other input terminal 26b (this state is the second state) In this case, only the quadrature modulation signal Z having the frequency F1 = Fr−Fi modulated by the communication information can be output from the frequency conversion means 26 as shown in FIG.

  Similarly to the above, in synchronization with the replacement of the baseband signal and the modulation signal, the local oscillation signal La of the modulation local oscillation signal generation means 24 is switched in the same manner as described above, and the local oscillation signal Lb is transmitted during the transmission of the control information. By performing the change setting, frequency switching including frequency hopping can be performed at high speed in a state where the image component is suppressed as shown in FIGS.

  Further, as described above, in the case where the frequency conversion local oscillation signal generation means 27 selectively outputs the two local oscillation signals Lc and Ld, the frequency conversion local oscillation signal generation means 27 is synchronized with the replacement of the baseband signal and the modulation signal. Similarly, the local oscillation signals La and Lb and the local oscillation signals Lc and Ld are switched, and at least one of the local oscillation signals Lb and Ld is changed during transmission of the control information, so that (c) and (d) in FIG. The frequency switching including frequency hopping can be performed at a high speed and over a wide frequency range with the image component suppressed.

  In the above description, the output frequency of the signal modulated with the control information is fixed. However, even when the control frequency is changed, each of the mobile test signal generators 20 described above is used for modulation. Can be accommodated by changing and setting the frequency of the local oscillation signal La during the transmission period of communication information, and has two local oscillation circuits for frequency conversion. However, it is possible to respond by changing and setting at least one of the frequencies of the local oscillation signals La and Lc during the transmission period of the communication information.

The figure which shows the structure of the Example of this invention. Configuration diagram of the main part of the embodiment Diagram showing an example of frequency switching The flowchart which shows the process sequence of the principal part of an Example. Output signal spectrum diagram of the embodiment The block diagram which shows the structure of other embodiment. The flowchart which shows the process sequence of the principal part of the Example of FIG. The block diagram which shows the structure of other embodiment. The figure which shows the principal part structure of embodiment of FIG. The figure which shows the principal part structure of embodiment of FIG. The figure for demonstrating operation | movement of other embodiment. Output signal spectrum diagram of the embodiment of FIG. Diagram showing the configuration of a conventional device The figure which shows the other structure of the conventional apparatus.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 20 ... Signal generator for moving body test, 21 ... Baseband signal generation means, 22 ... Baseband signal replacement means, 23 ... Orthogonal modulation means, 24 ... Modulation local oscillation signal generation means, 25 ... Modulation signal replacement means 26... Frequency conversion means 27... Frequency conversion local signal generation means 30.

Claims (7)

Baseband signal generating means (21) for generating baseband signals (I, Q) respectively corresponding to control information and communication information for notifying a mobile terminal to be tested;
A first local oscillator circuit (24a) that outputs a first local oscillator signal (La) for quadrature modulation, and a second local oscillator circuit (24b) that outputs a second local oscillator signal (Lb) for quadrature modulation ) And a modulation local oscillation signal generating means (24) having a changeover switch (24c) for selectively outputting either the first local oscillation signal or the second local oscillation signal as a modulation local oscillation signal (Li). )When,
A quadrature that performs quadrature modulation processing with the in-phase component (I), quadrature component (Q) of the baseband signal, and a modulation local oscillation signal, and outputs a quadrature modulation signal in an intermediate frequency band lower than the communication frequency band of the mobile terminal Modulation means (23);
A frequency conversion local signal generating means (27) for outputting a frequency conversion local signal (Lr) for converting the intermediate frequency band orthogonal modulation signal into the communication frequency band;
A frequency conversion means (26) for mixing the orthogonal modulation signal in the intermediate frequency band output from the orthogonal modulation means and the local signal for frequency conversion, and converting the mixed signal into an orthogonal modulation signal in the communication frequency band;
The baseband signal generation means and the modulation local oscillation signal generation means are controlled so that the orthogonal modulation signal modulated by the control information and the orthogonal modulation signal modulated by the communication information are output in a time division manner at different frequencies. And a mobile unit test signal generator comprising control means (30) for sequentially changing the frequency of the orthogonal modulation signal modulated by the communication information,
The frequency conversion local oscillation signal generating means,
A third local oscillation circuit (27a) that outputs a third local oscillation signal (Lc) for frequency conversion, and a fourth local oscillation signal for frequency conversion (frequency conversion range wider than that of the second local oscillation circuit). Ld) fourth local oscillator circuit (27b) and a selector switch for selectively outputting either the third local oscillator signal or the fourth local oscillator signal as a frequency conversion local oscillator signal (Lr) (27c)
The control means includes
A state in which a baseband signal corresponding to control information is output from the baseband signal generation means is a first state, and in the first state, the first local oscillation signal is output as a modulation local oscillation signal , and the third to output as a frequency conversion local oscillation signal of the local oscillation signal of Rutotomoni, modulating at least one of the frequency of the second local oscillation signal and the fourth local oscillator signal, then the communication information to be output changed set according to the expected frequency of the orthogonal modulation signal, the state where the output of the baseband signal corresponding to the communication information from the baseband signal generating means is in the second state, when the second state, Outputting the local signal changed and set according to at least the predetermined frequency of the second local signal for modulation and the fourth local signal for frequency conversion; Frequency Mobile test signal generating apparatus characterized by outputting the modulated signal. The quadrature modulation means includes
A first phase shifter (101) for shifting the modulation local oscillation signal by 90 degrees; a first mixer (102) for mixing one of the in-phase component and the quadrature component of the baseband signal and the modulation local oscillation signal; A second mixer (103) for mixing one of the in-phase component and the quadrature component and the phase-shifted local oscillation signal phase-shifted by 90 degrees by the first phase shifter; the other of the in-phase component and the quadrature component of the baseband signal; A third mixer (104) for mixing the modulation local oscillation signal, a fourth mixer (105) for mixing the other in-phase component and quadrature component of the baseband signal and the phase-shift local oscillation signal, and the first mixer A first synthesizer (105) for adding the output and the output of the fourth mixer, and a second synthesizer (106) for subtracting the output of the third mixer from the output of the second mixer,
The frequency conversion means includes
A second phase shifter (201) that shifts the frequency conversion local oscillation signal by 90 degrees, and one of the outputs of the first and second combiners of the quadrature modulation means is mixed with the frequency conversion local oscillation signal. A fifth mixer (202), a sixth mixer (203) for mixing the other of the outputs of the first synthesizer and the second synthesizer with the phase-shifted local oscillation signal phase-shifted by the second phase shifter; A third synthesizer (204) for adding the outputs of the fifth mixer and the sixth mixer;
Furthermore, baseband signal replacement means (22) capable of switching in-phase and quadrature components of the baseband signal input to the quadrature modulation means;
Modulation signal switching means (25) for inputting the output of the first synthesizer and the output of the second synthesizer of the quadrature modulation means in a replaceable manner to the fifth mixer and the sixth mixer of the frequency conversion means; Is provided,
The control means includes
At least the replacement of the in-phase component and the quadrature component in the baseband signal replacement means and the replacement of the modulation signal in the modulation signal replacement means are synchronously controlled to suppress the image component of the quadrature modulation signal output from the frequency conversion means. The moving body test signal generator according to claim 1. Baseband signal generating means (21) for generating baseband signals (I, Q) respectively corresponding to control information and communication information for notifying a mobile terminal to be tested;
A first local oscillator circuit (24a) that outputs a first local oscillator signal (La) for quadrature modulation, and a second local oscillator circuit (24b) that outputs a second local oscillator signal (Lb) for quadrature modulation ) And a modulation local oscillation signal generating means (24) having a changeover switch (24c) for selectively outputting either the first local oscillation signal or the second local oscillation signal as a modulation local oscillation signal (Li). )When,
A quadrature that performs quadrature modulation processing with the in-phase component (I), quadrature component (Q) of the baseband signal, and a modulation local oscillation signal, and outputs a quadrature modulation signal in an intermediate frequency band lower than the communication frequency band of the mobile terminal Modulation means (23);
A frequency conversion local signal generating means (27) for outputting a frequency conversion local signal (Lr) for converting the intermediate frequency band orthogonal modulation signal into the communication frequency band;
A frequency conversion means (26) for mixing the orthogonal modulation signal in the intermediate frequency band output from the orthogonal modulation means and the local signal for frequency conversion, and converting the mixed signal into an orthogonal modulation signal in the communication frequency band;
The baseband signal generation means and the modulation local oscillation signal generation means are controlled so that the orthogonal modulation signal modulated by the control information and the orthogonal modulation signal modulated by the communication information are output in a time division manner at different frequencies. And a mobile unit test signal generator comprising control means (30) for sequentially changing the frequency of the orthogonal modulation signal modulated by the communication information,
The quadrature modulation means includes
A first phase shifter (101) for shifting the modulation local oscillation signal by 90 degrees; a first mixer (102) for mixing one of the in-phase component and the quadrature component of the baseband signal and the modulation local oscillation signal; A second mixer (103) for mixing one of the in-phase component and the quadrature component and the phase-shifted local oscillation signal phase-shifted by 90 degrees by the first phase shifter; the other of the in-phase component and the quadrature component of the baseband signal; A third mixer (104) for mixing the modulation local oscillation signal, a fourth mixer (105) for mixing the other in-phase component and quadrature component of the baseband signal and the phase-shift local oscillation signal, and the first mixer A first synthesizer (105) for adding the output and the output of the fourth mixer, and a second synthesizer (106) for subtracting the output of the third mixer from the output of the second mixer,
The frequency conversion means includes
A second phase shifter (201) that shifts the frequency conversion local oscillation signal by 90 degrees, and one of the outputs of the first and second combiners of the quadrature modulation means is mixed with the frequency conversion local oscillation signal. A fifth mixer (202), a sixth mixer (203) for mixing the other of the outputs of the first synthesizer and the second synthesizer with the phase-shifted local oscillation signal phase-shifted by the second phase shifter; A third synthesizer (204) for adding the outputs of the fifth mixer and the sixth mixer;
Furthermore, baseband signal replacement means (22) capable of switching in-phase and quadrature components of the baseband signal input to the quadrature modulation means;
Modulation signal switching means (25) for inputting the output of the first synthesizer and the output of the second synthesizer of the quadrature modulation means in a replaceable manner to the fifth mixer and the sixth mixer of the frequency conversion means; Is provided,
The control means includes
At least the replacement of the in-phase component and the quadrature component in the baseband signal replacement means and the replacement of the modulation signal in the modulation signal replacement means are synchronously controlled to suppress the image component of the quadrature modulation signal output from the frequency conversion means. A signal generator for testing a moving body. Baseband signal generating means (21) for generating baseband signals (I, Q) respectively corresponding to control information and communication information for notifying a mobile terminal to be tested;
Modulation local oscillation signal generating means (24) for outputting a modulation local oscillation signal (Li) for orthogonal modulation;
Quadrature modulation means (23) for performing quadrature modulation processing with the in-phase component (I), quadrature component (Q) and modulation local oscillation signal of the baseband signal, and outputting a quadrature modulation signal in a predetermined intermediate frequency band;
Baseband signal replacement means (22) capable of switching in-phase and quadrature components of a baseband signal input to the quadrature modulation means;
A frequency conversion local signal for receiving the quadrature modulation signal in the intermediate frequency band output from the quadrature modulation means and converting the signal to the communication frequency band of the mobile terminal and outputting the signal (Lr) for frequency conversion Generating means (27);
A frequency conversion means (26) for mixing the orthogonal modulation signal in the intermediate frequency band output from the orthogonal modulation means and the local signal for frequency conversion, and converting the mixed signal into an orthogonal modulation signal in the communication frequency band;
The baseband signal generation means, the modulation local oscillation signal generation means, the baseband signal replacement means, and the frequency conversion local oscillation signal generation means are controlled, and the orthogonal modulation signal modulated by the control information and the communication A mobile test signal comprising: control means (30) for sequentially changing the frequency of the orthogonal modulation signal modulated by the communication information and outputting the orthogonal modulation signal modulated by the information in a time division manner at a different frequency. A generator,
The control means includes
The baseband signal output from the baseband signal generating means in accordance with the control information is input to the quadrature modulation means as the first state which is a predetermined replacement state of the baseband signal replacement means, and the frequency conversion means The frequency conversion local oscillation signal input to the modulation local oscillation signal generating means is output at a first frequency shifted by the frequency of the modulation local oscillation signal,
The baseband signal output from the baseband signal generation means in accordance with communication information is input to the quadrature modulation means as the second state opposite to the first state, and the baseband signal replacement means is input to the quadrature modulation means. With respect to the frequency conversion local oscillation signal input to the conversion means, a second frequency shifted from the modulation local oscillation signal generation means by the frequency of the modulation local oscillation signal is opposite to the first frequency. A moving body test signal generating apparatus characterized in that, by outputting, the frequency of the control information and the communication information is switched and output . The modulation local oscillation signal generating means includes:
A first local oscillation circuit (24a) that outputs a first local oscillation signal (La) for quadrature modulation, and a second local oscillation circuit (Lb) that outputs a second local oscillation signal (Lb) for quadrature modulation ( 24b), and a changeover switch (24c) that selectively outputs one of the first local oscillation signal and the second local oscillation signal as a modulation local oscillation signal (Li),
The control means includes
In synchronization with the switching of the control information and the communication information, either one of the first local signal and the second local signal from the modulation local signal generation means is used as the modulation local signal. 5. The signal generator for moving body test according to claim 4 , wherein the signal is output to an orthogonal modulation means . The frequency conversion local oscillation signal generating means,
A third local oscillation circuit (27a) for outputting a third local oscillation signal (Lc) for frequency conversion, and a fourth local oscillation signal for frequency conversion in a frequency variable range wider than that of the second local oscillation circuit. A fourth local oscillator circuit (27b) that outputs (Ld) and either the third local oscillator signal or the fourth local oscillator signal are selectively output as a frequency conversion local oscillator signal (Lr). A changeover switch (27c),
The control means includes
Synchronously with the switching of the control information and the communication information, either the third local oscillation signal or the fourth local oscillation signal is sent from the frequency conversion local oscillation signal generation means to the frequency conversion local oscillation signal. 6. The moving body test signal generating apparatus according to claim 4, wherein the frequency converting means outputs the output as a moving object test signal generating apparatus. The quadrature modulation means includes
A first phase shifter (101) for shifting the modulation local oscillation signal by 90 degrees; a first mixer (102) for mixing one of the in-phase component and the quadrature component of the baseband signal and the modulation local oscillation signal; A second mixer (103) for mixing one of the in-phase component and the quadrature component and the phase-shifted local oscillation signal phase-shifted by 90 degrees by the first phase shifter; the other of the in-phase component and the quadrature component of the baseband signal; A third mixer (104) for mixing the modulation local oscillation signal, a fourth mixer (105) for mixing the other in-phase component and quadrature component of the baseband signal and the phase-shift local oscillation signal, and the first mixer A first synthesizer (105) for adding the output and the output of the fourth mixer, and a second synthesizer (106) for subtracting the output of the third mixer from the output of the second mixer,
The frequency conversion means includes
A second phase shifter (201) that shifts the frequency conversion local oscillation signal by 90 degrees, and one of the outputs of the first and second combiners of the quadrature modulation means is mixed with the frequency conversion local oscillation signal. A fifth mixer (202), a sixth mixer (203) for mixing the other of the outputs of the first synthesizer and the second synthesizer with the phase-shifted local oscillation signal phase-shifted by the second phase shifter; A third synthesizer (204) for adding the outputs of the fifth mixer and the sixth mixer;
Further, a modulation signal switching means (25) for inputting the output of the first synthesizer and the output of the second synthesizer of the quadrature modulation means in a replaceable manner to the fifth mixer and the sixth mixer of the frequency conversion means. )
The control means includes
Synchronizing at least the replacement of the in-phase component and the quadrature component in the baseband signal replacement means and the replacement of the modulation signal in the modulation signal replacement means, and suppressing the image component of the quadrature modulation signal output from the frequency conversion means. The signal generator for mobile body test according to claim 4 or claim 5 or claim 6,

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