JP4595848B2 - Signal generation circuit - Google Patents

Description

  The present invention relates to a circuit that generates and outputs a high-precision analog signal in an output of a low-frequency signal such as sound, a control device, a sensor, or the like.

As a method for generating an arbitrary signal, for example, there is a technique for generating an arbitrary signal by synthesizing a phase modulation signal like an amplitude phase modulation circuit of Patent Document 1 below. Next, the technique of Patent Document 1 will be briefly described.
Japanese Patent No. 3427952

  FIG. 15 shows a block configuration of a circuit in the above-mentioned Patent Document 1, in which data to be transmitted is input and a modulation signal is output. 100 is an input data string, 101 is a serial-parallel converter, 102 is a memory, 103 is a conversion circuit that converts input data into phase information, 104 is a phase modulation circuit, 105 is a carrier generation circuit, 106 is phase information, and 107 is a synthesis The circuit 108 is a phase modulation signal, and 109 is an amplitude phase modulation signal. Further, a time change of the value of the phase information 106, a real time waveform of the phase modulation signal 108, and a real time waveform of the amplitude phase modulation signal 109 are shown.

The basic operation will be described below.
The conversion circuit 103 is a circuit that converts input data into phase information of two phase modulation signals, and includes a series-parallel converter 101 and a memory 102. The memory 102 stores in advance the relationship of the phase information of the phase modulation signal with respect to the preceding and following data including an arbitrary symbol. The input data 100 is sequentially input to the serial / parallel converter 101, the output of the serial / parallel converter 101 is input as an address of the memory 102, and the memory 102 outputs two pieces of phase information 106. The two phase modulation circuits 104 phase-modulate the carrier of the carrier generation circuit 105 with the respective phase information 106 to generate two phase modulation signals 108. The two generated phase modulation signals 108 are analog-added and synthesized by a synthesis circuit 107, and an amplitude phase modulation signal 109 is generated as a final output.

  FIG. 16 shows the principle that the two phase modulation signals 108 are converted into the amplitude phase modulation signal 109 in the synthesis circuit 107, and is represented by a signal space diagram. In the signal space diagram, the angle around the center represents the phase of the modulation signal, the distance from the center represents the amplitude of the modulation signal, and the vector represents the amplitude and phase of the modulation signal. Angle 201 and angle 202 are phase information θ1 and θ2 at time t of two phase modulation signals S1 = E · sin (ωt + θ1) and S2 = E · sin (ωt + θ2), respectively. Is an angle. The angle 200 is the angle θ0 at the time t of the amplitude phase modulation signal R = A · sin (ωt + θ0), which is the final output signal corresponding to the input data, and is the angle of the vector 109.

Here, in the memory 102, for example, when θ1 and θ2 are output for inputs corresponding to A and θ0, θ1 and θ2 are determined so that the following expression (1) is established.
θ0 = (θ1 + θ2) / 2, A = cos (θ1−θ0) + cos (θ0−θ2) Equation (1)
In the signal space diagram of FIG. 16, equation (1) represents the following. That is, θ0 is the average value of θ1 and θ2, and the amplitude A is the sum of two lengths cos (θ1−θ0) and cos (θ0−θ2) obtained by projecting the two vectors 108 onto the vector 601, respectively. is there. Thus, the vector 109 is equal to the combined vector of the two vectors 108. Since this relationship is established at each time, the combination of the phase modulation signals S1 and S2 generated so as to satisfy the expression (1) becomes the amplitude phase modulation signal R.

  In the above-described conventional example, processing is performed by converting into a phase modulation signal without using a quadrature modulation circuit, which is advantageous in terms of device variations and power consumption. However, the above-described conventional example can generate a modulated signal having a carrier frequency of ω, but has a drawback that it cannot generate an arbitrary baseband signal having no carrier frequency, such as an audio signal. It was.

Further, there are cases where it is desired to reproduce the input baseband signal at another time, for example, at another place, such as an audio signal, but this cannot be solved by the above-described conventional example.
Further, for example, there are cases where a plurality of input baseband signals such as audio multiplexed signals of audio signals, stereo signals, surround audio signals, etc. are input together and signals are generated simultaneously, but this cannot be solved by the conventional example.

Therefore, an object of the present invention is to provide a signal generation circuit that processes a phase modulation signal and generates a baseband signal having no carrier frequency.
It is another object of the present invention to provide a signal generation circuit that can use a logic circuit and can be implemented as an LSI.

It is another object of the present invention to provide a signal generation circuit that generates an arbitrary baseband signal with high accuracy even if a device that easily adds noise to the AM component is included.
It is another object of the present invention to provide a signal generation circuit capable of reproducing a baseband signal at another time, for example, at another place with respect to an input baseband signal.

  It is another object of the present invention to provide a signal generation circuit that processes a plurality of baseband signals collectively and generates a plurality of baseband signals simultaneously.

The present invention has the following means in order to solve the above problems.
An arbitrary frequency is BHz, and an integer of 2 or more is n.
Amplitude modulation means for amplitude-modulating a carrier signal having a frequency higher than BHz with a level value obtained by sampling an arbitrary baseband signal having a frequency component equal to or lower than BHz, and generating the amplitude-modulated signal; and Phase modulation conversion means for converting a carrier signal having the same frequency as the signal into n phase modulation signals obtained by phase modulation, and a carrier for multiplying the n phase modulation signals by a carrier signal having the same frequency as the carrier signal, respectively. Multiplying means, combining means for adding n outputs of the carrier multiplying means, and low-pass filter means for passing a frequency component of BHz or less of the output of the combining means.

  Alternatively, phase modulation conversion means for generating a digital signal having the same phase as the phase modulation signal, and a digital carrier signal having the same phase as the carrier signal of the carrier multiplication means and the digital signal are multiplied by exclusive OR. Carrier multiplication means is included.

  Alternatively, frequency modulation means for generating a frequency modulation signal by frequency-modulating a carrier signal having a frequency higher than BHz with a level value obtained by sampling an arbitrary baseband signal having a frequency component equal to or lower than BHz, and the frequency modulation signal, Phase modulation conversion means for converting a carrier signal having the same frequency as that of the carrier signal into n phase modulation signals obtained by phase modulation, synthesis means for adding the n phase modulation signals, and output of the synthesis means as a frequency It has a frequency detection means for detecting.

  Further, the phase modulation conversion means generates n phase information, generates n phase modulation signals, and stores the n phase information in a storage circuit, or the n phase information Each of the quantizing means samples each modulation signal into digital data, and the memory means stores n outputs of the quantizing means in a memory circuit.

  Further, when the n pieces of phase information are stored, the n phase information is read out from the storage unit and the n phase modulation signals are reproduced, or the n phase modulation signals are reproduced. When digital data obtained by sampling is stored, the digital data is sequentially read from the storage circuit to reproduce n phase modulation signals.

  Furthermore, the baseband signal of m channels (m is an integer of 1 or more) is multiplied by local signals that oscillate at 0 Hz, B / m Hz, 2 B / m Hz, ... (m−1) / m Hz, respectively. And frequency converting means, and combining means for combining the frequency-converted m signals into one baseband signal having a band of BHz or lower. In addition, the synthesized one baseband signal is multiplied by 0 times, B / m Hz, 2B / m Hz,.. And m low-pass filter means for passing a frequency component of B / m Hz or less of each output of the multiplication means.

  Alternatively, a first sampling unit that samples m-channel baseband signals having a bandwidth of B / m Hz or less at a timing of 2 B / m Hz and a signal sampled by the sampling unit are sequentially switched and output to 1 There is a combining means for outputting two baseband signals. Also, there is provided second sampling means for sampling the synthesized one baseband signal at 2 B Hz, and separation means for sequentially separating the signals sampled by the second sampling means.

  Since the present invention converts the input baseband signal into a plurality of phase modulation signals, synthesizes them, and outputs them through a low-pass filter or frequency detection circuit, it becomes possible to reproduce an arbitrary baseband signal without a carrier, For example, an audio signal can be generated. Further, when the number of phase modulation signals to be converted and combined is increased, the accuracy of the arbitrary baseband signal to be combined can be increased.

Further, according to the present invention, the number of phase modulation signals to be combined can be configured as two, so that the circuit scale and power consumption can be reduced.
In addition, the present invention processes a digital signal and a digital carrier signal, which are binary rectangular wave-shaped phase modulation signals having a constant amplitude, so that a logic circuit can be used, and an LSI can be realized. A configuration with low power consumption is possible.

  In addition, since the present invention processes a frequency modulation signal, an arbitrary baseband signal can be generated with high accuracy even if a device that easily adds noise to the AM component is included.

  Further, according to the present invention, a plurality of baseband signals can be simultaneously output by processing the plurality of baseband signals as one arbitrary baseband signal. For example, simultaneous output of audio multiplexed signals, stereo audio signals, surround audio signals, and the like can be performed.

  Further, the present invention converts a plurality of phase information and further a plurality of phase modulation signals, stores the plurality of phase information or the plurality of phase modulation signals, sequentially reads and processes the stored signals, Since the band signal is reproduced, a plurality of baseband signals can be simultaneously output by sequentially reading out and reproducing the stored signal at another time, for example, at another place with respect to the input of the baseband signal. . If the storage device at the time of storage and the storage device at the time of playback are connected by a communication line, a network, an input / output interface, etc., data can be transferred to a remote location for playback and can be applied to content services. . For example, it can be realized using a removable storage medium as a storage device. For example, it is also possible to provide a device until the above-mentioned storage is performed as a recorder and a device from the above-described storage until playback as a player.

Thus, the present invention can reproduce a high-quality audio signal and generate a high-precision control signal with a simple circuit, and can be used in many fields such as consumer equipment and industrial equipment.
Furthermore, the present invention can be applied to communications in which voice and digital signals are integrated, and can be used in many multimedia fields such as ubiquitous devices expected to be developed in the future.

An embodiment of the present invention will be described.
FIG. 1 shows a block diagram of an embodiment of the present invention. 300 is an arbitrary baseband signal having a frequency equal to or lower than the arbitrary frequency BHz, 301 is an oscillation circuit that oscillates at a carrier frequency (oscillation frequency ω / 2πHz (ω / 2π> B)), and 302 is an amplitude obtained by multiplying the carrier signal by an arbitrary signal. An amplitude modulation circuit (multiplication circuit) that generates a modulation signal corresponds to the baseband signal modulation means, 306 is an amplitude modulation signal modulated by an arbitrary signal, and 303 is a phase modulation signal for generating the amplitude modulation signal 306 by synthesis Is a conversion memory for storing phase information, 106 is phase information, 104 is a phase modulation circuit, 310 is a frequency ω / 2πHz (ω / 2π> B) for generating a carrier signal necessary for generating a phase modulation signal Is an oscillation circuit that oscillates at, 108 is a phase modulation signal, 303 and 104 are combined to correspond to the phase modulation conversion means, 304 is a carrier multiplication circuit for performing frequency conversion, and 311 is a carrier signal necessary for performing frequency conversion The An oscillation circuit that oscillates at a generated frequency ω / 2πHz (ω / 2π> B), 307 is a frequency-modulated phase modulation signal, 107 is a synthesis circuit that adds and synthesizes two phase modulation signals, and 308 is after synthesis 305 is a low-pass filter that passes the frequency BHz or less, and 309 is a regenerated arbitrary signal having a frequency of BHz or less. In FIG. 1, the real-time waveform and frequency spectrum of the signals 300, 306, 108, 307, 308, and 309 of each part are shown at the same time.

  The operation of this circuit is performed as follows. Arbitrary baseband signal 300 is input to amplitude modulation circuit 302 and multiplied by a signal that oscillates at a carrier frequency (oscillation frequency ω / 2πHz (ω / 2π> B)), and amplitude modulation signal 306 is generated.

  Next, although not shown, the amplitude modulation signal 306 is sampled at a sampling frequency of 2 B Hz or more, and the sampling level value of the amplitude modulation signal 306 is stored in advance as a relationship between the amplitude modulation signal pattern and the phase information of the phase modulation signal. And phase information 106 of two phase modulation signals is obtained as an output, and the phase modulation circuit 104 generates a phase modulation signal 108 based on the phase information 106. The frequency of the phase modulation signal 108 is a carrier frequency ω / 2π Hz (ω / 2π> B) generated by the carrier oscillation circuit 310.

  The phase modulation signal 108 is multiplied by the carrier signal (oscillation frequency ω / 2π Hz) generated by the oscillation circuit 311 by the carrier multiplication circuit 304 to generate a frequency-modulated phase modulation signal 307. The two frequency-converted phase modulation signals 307 are synthesized by addition by the synthesis circuit 107 to generate a synthesized signal 308. This synthesized signal is reproduced as an original arbitrary baseband signal through a low-pass filter 305 that passes a frequency lower than ω / (2π) Hz and lower than a frequency BHz.

The reason why the original arbitrary baseband signal is reproduced in this embodiment will be described.
Assuming that the arbitrary baseband signal 300 is f (t), the frequency of the carrier signal 301 is ω / (2π) Hz, and the amplitude modulation signal 306 is a (t) a (t) becomes Formula (2).

a (t) = f (t) ・ sin (ωt + θ0) (2)
Here, θ0 is an initial phase. Next, it is assumed that the two-phase phase modulation signal 108 is S1 and S2, and is expressed by the following equation (3).

S1 = E ・ sin (ωt + θ1), S2 = E ・ sin (ωt + θ2) (3)
In order to represent the amplitude modulation signal 306 as the combined output S1 + S2 of S1 and S2, it is necessary to set the phase information 106 of each phase modulation signal 108 to θ1 and θ2, and to have the relationship of the following equation (4). is there.

θ0 = (θ1 + θ2) / 2
f (t) / 2 = Ecos (θ1−θ0) + Ecos (θ2−θ0) (4)
Here, E is the amplitude of the phase modulation signals S1 and S2. Here, the combined signal g (t) of the phase modulation signals S1 and S2 is generated using Equation (4), and becomes equal to the original amplitude modulation signal a (t) as follows.

g (t) ＝ S1 + S2 = E ・ sin (ωt + θ1) + E ・ sin (ωt + θ2)
= 2 ・ E ・ sin (ωt + ((θ1 + θ2) / 2) ・ cos ((θ1−θ2) / 2)
= 2 ・ E ・ cos ((θ1−θ2) / 2) ・ sin (ωt + θ0)
= 2 ・ E ・ cos (θ1−θ0) ・ sin (ωt + θ0)
= 2 ・ f (t) ・ sin （ωt + θ0）
= 2 ・ a (t) ・ ・ ・ Formula (5)
Finally, the composite signal g (t) is multiplied by the carrier signal sin (ωt + θ0) having the carrier frequency ω / (2π) Hz and the phase θ0, and the following equation (6) is obtained. This corresponds to the synthesized signal 308. Furthermore, since the output signal 309 after passing through the low-pass filter that passes BHz or less is k (t) and the frequency 2ω / (2π) Hz is not passed, Expression (7) is obtained.

g (t) ・ sin (ωt + θ0)
= 2 ・ f (t) ・ sin (ωt + θ0) ・ sin (ωt + θ0)
= 2 ・ f (t) ・ 1/2 (−cos (ωt + 2θ0 + ωt) + cos (ωt + θ0− (ωt + θ0))
＝ f (t) ・ (−cos (2ωt + 2θ0) +1) (6)
∴ k (t) = f (t) (7)
From equation (7), it can be seen that the signal k (t) after passing through the low-pass filter is equal to the original arbitrary baseband signal f (t).

  Here, the phase-modulated signal was synthesized, then carrier multiplied and passed through a low-pass filter. Since it is a linear circuit, it goes without saying that the same result as that obtained when each of the phase-modulated signals is subjected to carrier multiplication and then combined and passed through a low-pass filter can be obtained. A circuit configuration in the former case is shown in FIG. The circuit configuration in the latter case is the configuration shown in FIG. In FIG. 2, the order of the carrier multiplier 304 and the synthesis circuit 107 in FIG. 1 is switched, the output of the phase modulation circuit 104 is added by the synthesis circuit 107, the carrier multiplication circuit 304 performs carrier multiplication, and the low-pass filter Through 305. The carrier multiplication and the low-pass filter correspond to detection means for reproducing the original baseband signal from the amplitude modulation signal.

  The description of the signal space diagram of FIG. 16 is the same as described above, and the synthesis of S1 and S2 is obtained by the phase relationship according to the equation (4) and the relationship of the sum of the projected lengths. It is done.

  As described above, the arbitrary baseband signal is once converted into a modulation signal having a carrier, decomposed into a phase modulation signal, frequency-converted again by the carrier signal, returned to the original frequency, synthesized, and synthesized by the low-pass filter. An arbitrary baseband signal having no carrier can be reproduced.

  Another embodiment of the present invention will be described. In the above-described embodiment, the signal is converted into two phase modulation signals. Here, an integer equal to or larger than 2 is set to n, and converted into n phase modulation signals and synthesized. FIG. 3 shows a block configuration. 3 are the same as those shown in FIG. 1, but the memory 303 converts the input into n pieces of phase information 106. The phase information 106, the phase modulation signal 108, and the frequency-converted phase N modulation signals 307 are respectively generated, n phase modulation circuits 104 and carrier multiplication circuits 304 are used, and a synthesis circuit 107 synthesizes n signals.

  FIG. 12 is a signal space diagram showing the synthesis of a plurality of phase modulation signals as in this embodiment. For example, FIG. 12 shows the case of the synthesis of six waves. When the amplitude of one phase modulation signal is E, it is possible to synthesize signals at a level below 6E. The synthesis of such n phase modulation signals needs to satisfy the condition of the following formula (8).

A = E ・ cos (θ1−θ0) + E ・ cos (θ2−θ0) + ・ ・ + E ・ cos (θn−θ0),
0 = sin (θ1−θ0) + sin (θ2−θ0) + ・ ・ + sin (θn−θ0) (8)
However, the phase modulation signal
S1 = E · sin (ωt + θ1), S2 = E · sin (ωt + θ2), ..., Sn = E · sin (ωt + θn)
And The signal to be synthesized is A · sin (ωt + θ0).

  Equation (8) represents the following in the signal space diagram of FIG. That is, for i in the range of 1 to n, sin (θi−θ0) is the length obtained by projecting the vector Si in the direction orthogonal to the combined signal vector, and the n sums of the projected components are zero. The n sums of the vectors Si are directed in the direction of the composite signal. The amplitude A of the combined signal is the sum of n lengths E · cos (θi−θ0) obtained by projecting n vectors Si in the direction of the combined signal vector. Therefore, the synthesized signal vector is equal to the vector of the sum of n vectors Si. Since this relationship is established at each time, the combination of the phase modulation signals S1, S2,... Sn generated to satisfy the equation (8) becomes the amplitude phase modulation signal A.sin (ωt + θ0).

  Since n phase modulation signals are combined in this way, a baseband signal having a higher peak level can be combined as n increases, and the dynamic range increases. In addition, the above-described embodiment is a case where n is 2, which is advantageous in that the circuit scale and power consumption are small.

  Here, FIG. 13 and FIG. 14 show the relationship between the accuracy of the phase modulation and the accuracy of the synthesized signal. FIG. 13 shows how the accuracy increases as the number of phases of the phase modulation signal increases. The angle quantization interval is finely converted. FIG. 14 is a composite of a plurality of the phase modulation signals of FIG. 13 and shows the accuracy of the composite signal. It can be seen that when the number of phases increases and the number n of phase modulation signals to be combined increases, the angle and amplitude quantization intervals are finely output, and the accuracy of the combined signal is improved.

Next, another embodiment of the present invention will be described.
When the above-mentioned phase modulation signal S1 has a positive level, the digital signal having a level of + E and a negative level of -E and having a frequency phase of ωt + θ1 as DS1, and the other phase modulation. When signal S2 has a positive level, it has a level of + E, and when it has a negative level, it has a level of -E, and a digital signal having frequency phase ωt + θ2 is DS2, carrier signal is C, and C is positive The digital carrier signal having a level of +1 when having a level of +1 and the digital carrier signal having a level of -1 when having a negative level as DC are multiplied by exclusive OR, and then the digital signal DS2 And the digital carrier signal DC are multiplied by exclusive OR, the multiplied signals are added in an analog manner, and the resulting combined signal is a low frequency band having a passband of a frequency BHz lower than ω / (2π) Hz. Passing fee Through data to generate any of the baseband signal having the frequency original B Hz. The configuration of this embodiment can be realized by a configuration similar to the block configuration of FIG. 1, except that the phase modulator 104 outputs the output signal 108 as digital signals DS1 and DS2, and the carrier generator 311 is a digital carrier signal DC. Is different in that the multiplier 304 performs multiplication by exclusive OR. In this way, since a binary rectangular wave having a constant amplitude is processed, a logic circuit can be used and an LSI can be realized.

  In this embodiment, the digital signals DS1 and DS2 and the digital carrier signal DC have the same phase as the phase modulation signals S1 and S2 and the carrier C, respectively, but have high-order frequency components due to being rectangular waves. Different from the previous case. Therefore, the result of multiplying the digital signals DS1 and DS2 and the digital carrier signal DC by exclusive OR is the same as the result of multiplying the phase modulation signals S1 and S2 by the carrier signal C, and the higher-order frequency components. Is different. Therefore, these two types of signals are added and passed through the low-pass filter, so that the high-order frequency components are removed, and therefore coincide. As a result, it was shown that the original baseband signal can be reproduced as in the above-described embodiment.

  As described above, one embodiment for converting and synthesizing into two digital signals has been described. However, as another embodiment of the present invention, a configuration for converting into n digital signals DS1, DS2,. There is.

  The configuration of this embodiment can be realized by the same configuration as the block configuration of FIG. 3, but the phase modulator 104 outputs the output signal 108 as digital signals DS1, DS2,... DSn, and the carrier generator 311 A digital carrier signal DC is output, and a multiplier 304 performs multiplication by exclusive OR.

  Since the n digital signals DS1, DS2,... DSn have the same phase as the phase modulation signals S1, S2,... Sn, the memory 303 outputs the phase information θ0, θ1,. Therefore, the conversion is performed by the same relational expression as the above-described expression (8).

  As described above, as n increases, the dynamic range increases and the accuracy of the synthesized signal improves. Furthermore, a logic circuit can be used, and LSI can be realized. In addition, the above-described embodiment is a case where n is 2, which is advantageous in that the circuit scale and power consumption are small.

  Next, FIG. 4 shows another embodiment of the present invention, in which 300 is an arbitrary signal, 400 is a frequency modulation circuit corresponding to the baseband signal modulation means, 401 is a frequency modulation signal, and 402 is reproduced. The frequency modulation signal 403 is a frequency modulation signal detection circuit.

  In this embodiment, instead of amplitude-modulating an arbitrary signal, a frequency modulation signal 401 is generated by the frequency modulation circuit 400 and sampled (not shown). The sampled digital data is input to the memory 303, two phase information 106 is generated, further converted into two phase modulation signals 108 by the phase modulation circuit 104, added and synthesized by the synthesis circuit 107, and the frequency modulation signal 402 is played back. Next, detection is performed using a frequency detection circuit (FM detection) 403, and the original arbitrary baseband signal 309 is extracted. 303 and 104 together correspond to the phase modulation conversion means.

  Here, although not shown, the frequency modulation signal 401 is sampled at a sampling frequency of 2 B Hz or higher, and the level information L of each sample point is used to set the frequency of the carrier signal to ω + L, and the frequency modulation signal A · sin ( (ω + L) t + θ0) is generated once. Next, since the frequency modulation signal 401 can be interpreted as a carrier signal having the frequency ω and a phase transition of L · t added thereto, it has the following relationship.

That is,
Lt + θ0 = (θ1 + θ2) / 2,
A = E · cos (θ1− (θ0 + Lt)) + E · cos (θ2− (θ0 + Lt)) (9)
The memory 303 generates two pieces of phase information 106 having the relationship Further, the phase modulation circuit 104 generates two phase modulation signals S1 = E · sin (ωt + θ1) and S2 = E · sin (ωt + θ2). Next, when the two phase modulation signals S1 and S2 are added and synthesized, the frequency modulation signal 402 is reproduced for the same reason as described above with reference to FIG. The frequency modulation signal 402 is frequency-detected, and as a result, the input baseband signal is reproduced.

Because of such a configuration, it is possible to generate an arbitrary signal with high accuracy even if a device that easily adds noise to the AM component is included.
Next, another embodiment of the present invention will be described. In the above description, the configuration is described in which the frequency modulation signal is converted into two phase modulation signals and synthesized. However, here, n is an integer of 2 or more, and the frequency modulation signal is n phase modulation signals S1, S2,. Convert to Sn and synthesize. The block configuration (not shown) of this embodiment is similar to that shown in FIG. 4 in each part and signal. However, n pieces of phase information 106 and phase modulation signals 108 are generated and combined using n phase modulation circuits 104. The circuit 107 is different in that it synthesizes n phase modulation signals.

  Here, similarly, the frequency modulation signal is sampled at a sampling frequency of 2 BHz or more, and the level information L of each sampling point is used to set the frequency of the carrier signal to ω + L and the frequency modulation signal A · sin ((ω + Assuming that L) t + θ0) is generated, the synthesis of such n phase modulation signals needs to satisfy the condition of the following equation (10).

A = E ・ cos (θ1− (Lt + θ0)) + E ・ cos (θ2− (Lt + θ0)) + ・ ・ + E ・ cos (θn− (Lt + θ0)),
0 = sin (θ1− (Lt + θ0)) + sin (θ2− (Lt + θ0)) + ・ ・ + sin (θn− (Lt + θ0))
... Formula (10)
However, the phase modulation signal
S1 = E · sin (ωt + θ1), S2 = E · sin (ωt + θ2), ..., Sn = E · sin (ωt + θn)
And

  As described above, even if a device in which noise is easily added to the AM component is included, the accuracy is high. As n increases, the dynamic range increases and the accuracy of the synthesized signal improves. In addition, the above-described embodiment is a case where n is 2, which is advantageous in that the circuit scale and power consumption are small.

Furthermore, another embodiment of the present invention will be described.
In the embodiment described so far, the signal generation circuit of the present invention generates n pieces of phase information and n pieces of phase modulation signals in a process until a baseband signal is inputted and outputted. Therefore, as another embodiment of the present invention, the n pieces of phase information generated in the middle or the n pieces of phase modulation signals are temporarily stored as a data string in a storage device such as a memory. When the stored data sequence is sequentially read and n pieces of phase information are recorded, n phase modulation signals are reproduced by n phase modulation circuits, and when n phase modulation signals are stored, they are read sequentially. Thus, a configuration may be implemented in which the original n baseband signal is generated by processing the n phase modulation signals thus reproduced and processing them as described above. Since it is stored in a memory or the like, it is possible to reproduce the baseband signal at a different time from when the baseband signal is input, for example, at a different location.

FIG. 5 and FIG. 6 further show a block configuration of another embodiment of the present invention based on the above embodiment.
FIG. 5 shows a block diagram of a configuration in which the relationship between the level of the arbitrary signal of the generated phase modulation signal and the phase information is stored in the large-scale memory by the generation algorithm of the phase modulation signal.

  The configuration of FIG. 5 will be described. 500 is a plurality of baseband signals, 501 is a combining circuit that combines a plurality of baseband signals and multiplexes them into one combined signal, 502 is a combined baseband signal, and 503 is a combined baseband signal 502. Memory that pre-stores the relationship with the phase information of the phase-modulated signal to be combined, 104 is stored as the phase modulation circuit, and 504 stores the phase-modulated signal converted from the multiplexed combined signal A large-scale memory 307 is a phase modulation signal.

  The operation of FIG. 5 will be described. The plurality of baseband signals 500 are combined by the combining circuit 501 as described later, and a combined signal 502 is output. Next, the synthesized signal 502 is regarded as one arbitrary baseband signal and is sampled (not shown), and n phase information is generated by the memory 503 in which the relationship between the arbitrary baseband signal and the phase information is stored in advance. In the same manner as described above, n phase modulation signals are generated by 104, and the n phase modulation signals are sampled and quantized and stored in the large-scale memory 504, although not shown. Here, n pieces of phase information may be accumulated.

  FIG. 6 shows a block configuration for reproducing the signal stored in FIG. In FIG. 6, 504 is a large-scale memory, 304 is a carrier multiplication circuit, 107 is a synthesis circuit for analog addition, 305 is a low-pass filter, and 602 is a separation circuit.

The operation of FIG. 6 will be described. The data stored in advance in the large-scale memory 504 is sequentially read to reproduce n phase modulation signals.
When the baseband signal is amplitude-modulated, the reproduced n phase modulation signals and the carrier (oscillation frequency ω / 2πHz) are multiplied by the carrier multiplier circuit 304, and the n outputs of the carrier multiplier circuit 304 are combined. The synthesized signal is input to the low-pass filter 305 and a frequency component equal to or lower than the frequency BHz lower than ω / (2π) Hz is passed, and a baseband signal corresponding to 502 is reproduced.

  When the baseband signal is frequency-modulated, although not shown, the reproduced n phase modulation signals are synthesized by the synthesis circuit 107, the synthesized signal is frequency-detected, and the baseband signal corresponding to 502 is reproduced. .

The reproduced baseband signal is separated by the separation circuit 602 as will be described later, and a plurality of original baseband signals are reproduced. Reference numeral 601 denotes a plurality of reproduced baseband signals.
Using the configuration of FIG. 5 to store in the large scale memory 504 and to read out the baseband signal by reading from the large scale memory 504 using the configuration of FIG. Can do. The large-scale memory 504 may be a detachable portable storage device. Further, the large-scale memory 504 in FIG. 5 and the large-scale memory 504 in FIG. 6 may be connected by a communication means or input / output means (not shown) to transfer data corresponding to the stored signal. It can be applied to content services. 5 can be used as a recorder, and the circuit shown in FIG. 6 can be used as a player.

  One embodiment of the synthesis circuit 501 and the separation circuit 602 is shown in FIGS. 7 and 8, respectively. FIG. 7 shows a configuration in which a plurality of baseband signals 500 are combined into one baseband signal 502, and FIG. 8 shows a configuration in which one baseband signal 502 is separated into a plurality of baseband signals 500.

  The combining circuit 501 in FIG. 7 includes an oscillator 702 that generates m local signals, where m is an integer equal to or greater than 1, and a combining circuit 701 that performs addition. The operation of the synthesis circuit 501 will be described. Assuming that the number of channels of the plurality of baseband signals 500 is m, and the band of one baseband signal 502 is 0 to BHz, the local signal 702 (oscillating at a frequency of B / m intervals to the plurality of baseband signals 500) Oscillation frequencies: f0 = 0, f1 = B / m, f2 = 2B / m,..., Fm−1 = (m−1) B / m) are multiplied and synthesized by the synthesis circuit 701. As a result, one baseband signal 502 is generated.

  The separation circuit 602 in FIG. 8 includes an oscillator 702 that generates m local signals and a low-pass filter 305. The operation of the separation circuit 602 will be described. One baseband signal 502 is multiplied by a plurality of baseband signals 500 by m local signals 702 that oscillate at a frequency of B / m Hz intervals, and each of the m multiplied outputs is B / m by a low-pass filter 305. By passing frequency components of less than or equal to Hz, the original plurality of baseband signals can be reproduced at the output 601.

Next, another embodiment of the configuration of the synthesis circuit 501 and the separation circuit 602 is shown in FIGS. 9 and 10, respectively.
9 shows a configuration for combining a plurality of baseband signals 500 into one baseband signal 502, and FIG. 10 shows a configuration for separating one baseband signal 502 into a plurality of baseband signals 500.

  The combining circuit 501 in FIG. 9 sequentially switches and outputs a plurality of inputs. The operation of the synthesis circuit 501 will be described. If the number of channels of a plurality of baseband signals 500 is m and the band of one baseband signal 502 is 0 to BHz, each of the plurality of baseband signals 500 is sampled at a sampling interval of m / (2B) seconds. Then, one baseband signal 502 can be generated by sequentially selecting sample data of each baseband signal from 1 to m. For example, if the baseband signal 500 of the k-th channel is output to the output 502 for a specific 1 / (2B) second, the k + 1-th channel is output for the next 1 / (2B) second. Next to the mth channel, the output returns to the first channel, and this is repeated in m / (2B) seconds.

  The separation circuit 602 in FIG. 10 sequentially switches the input to a plurality of outputs. The operation of the separation circuit 602 will be described. One baseband signal 502 is sampled at a sampling frequency of 2 BHz, each sample value is sequentially cut, and the original plurality of baseband signals are reproduced. For example, if the baseband signal 502 is output to the kth channel as the baseband signal 601 at a certain time, the baseband signal 502 is output to the k + 1th channel after the next 1 / (2B) seconds. . Next to the mth channel, the output returns to the first channel, and this is repeated in m / (2B) seconds.

  FIG. 11 shows a real-time waveform of one baseband signal 502 synthesized and generated using the configurations of FIGS. 9 and 10, and it can be seen that a plurality of baseband signals 500 are sequentially output. . A broken line or a chain line is a plurality of baseband signals, respectively, and is a single baseband signal 502 obtained by combining signals sampled at black dots.

  In this way, a plurality of baseband signals can be input and reproduced simultaneously and output simultaneously.

It is a figure which shows the block configuration of the signal generation circuit by one Embodiment of this invention. It is a figure which shows the block configuration of the signal generation circuit by one Embodiment of this invention. It is a figure which shows the block configuration of the signal generation circuit by one Embodiment of this invention. It is a figure which shows the block configuration of the signal generation circuit by one Embodiment of this invention. It is a figure which shows the block configuration of the signal storage circuit by one Embodiment of this invention. It is a figure which shows the block configuration of the signal generation circuit by one Embodiment of this invention. It is a figure which shows the block configuration of the synthetic | combination circuit by one Embodiment of this invention. It is a figure which shows the block configuration of the isolation | separation circuit by one Embodiment of this invention. It is a figure which shows the block configuration of the synthetic | combination circuit by one Embodiment of this invention. It is a figure which shows the block configuration of the isolation | separation circuit by one Embodiment of this invention. It is a figure which shows the time waveform which synthesize | combines several baseband signal by one Embodiment of this invention. It is a signal space diagram which shows the principle of conversion and the synthesis | combination of a phase modulation signal by one Embodiment of this invention. It is a figure showing the precision of the phase modulation signal corresponding to the number of phases. It is a figure showing the synthetic | combination precision of the baseband signal corresponding to the number of phases and the number of synthetic signals in the signal generation circuit of this invention. It is a figure which shows the block configuration of the signal generation circuit by a prior art. It is a signal space diagram which shows the principle of conversion and a synthesis | combination of a phase modulation signal by a prior art.

Explanation of symbols

100 input signal 101 serial-parallel conversion circuit 102 memory 103 conversion circuit 104 phase modulation circuit 105 carrier generation circuit 106 phase information 107 synthesis circuit 108 phase modulation signal 109 amplitude phase modulation signal 200 angle 201 angle 202 angle 300 input signal 301 carrier generation circuit 302 Multiplier 303 Memory 304 Multiplier 305 Low pass filter 306 Amplitude modulation signal 307 Frequency conversion signal 308 Phase modulation synthesis signal 309 Baseband signal 310 Carrier generation circuit 311 Carrier generation circuit 400 Frequency modulation circuit 401 Frequency modulation signal 402 Phase modulation synthesis signal 403 Frequency detection circuit 500 Baseband signal 501 synthesis circuit 502 Synthesis baseband signal 503 Memory 504 Large scale memory 601 Baseband signal 602 Separation circuit 701 Synthesis circuit 702 Local oscillator

Claims (10)

Baseband signal modulation means for generating an amplitude modulation signal by amplitude-modulating a carrier signal having a frequency higher than BHz at a level value obtained by sampling an arbitrary baseband signal having a frequency component equal to or lower than an arbitrary frequency BHz;
Let n be an integer greater than or equal to 2,
Phase modulation conversion means for converting the amplitude modulation signal into n phase modulation signals obtained by phase modulation of a carrier signal having the same frequency as the carrier signal;
Carrier multiplying means for multiplying each of the n phase modulation signals by a carrier signal having the same frequency as the carrier signal;
Combining means for adding n outputs of the carrier multiplying means;
Low pass filter means for passing the frequency component of BHz or less of the output of the synthesizing means,
A signal generation circuit for generating the baseband signal. A baseband signal modulation means for generating a frequency modulation signal by frequency-modulating a carrier signal having a frequency higher than BHz at a level value obtained by sampling an arbitrary baseband signal having a frequency component equal to or lower than an arbitrary frequency BHz;
Let n be an integer greater than or equal to 2,
Phase modulation conversion means for converting the frequency modulation signal into n phase modulation signals obtained by phase modulating a carrier signal having the same frequency as the carrier signal;
Combining means for adding n outputs of the phase modulation converting means;
Frequency detection means for frequency detection of the output of the synthesis means;
A signal generation circuit for generating the baseband signal. A sample point level A obtained by sampling an arbitrary baseband signal having a frequency component of an arbitrary frequency BHz or less at a sampling frequency of 2 × BHz or higher is set to a carrier signal sin (ωt + θ0) at a frequency ω / (2π) Hz higher than BHz. ) To output an amplitude modulation signal A · sin (ωt + θ0),
The amplitude modulation signal is an integer greater than or equal to 2 and n phase modulation signals S1 = E · sin (ωt + θ1), S2 = E · sin (ωt + θ2), Sn = E · sin (ωt + phase modulation conversion means for converting to θn),
Carrier multiplying means for multiplying each of the n phase modulation signals S1, S2,..., Sn by a carrier signal sin (ωt + θ0);
Synthesis means for analog addition of n output signals of the multiplication means;
Low pass filter means for inputting the summed composite signal and passing a frequency component below BHz;
In the phase modulation conversion means, the n phase modulation signals S1, S2,.
A = E ・ cos (θ1−θ0) + E ・ cos (θ2−θ0) + ・ ・ + E ・ cos (θn−θ0),
0 = sin (θ1−θ0) + sin (θ2−θ0) + ・ ・ + sin (θn−θ0)
The baseband signal is generated by performing conversion so as to satisfy the above relationship. A sample point level A obtained by sampling an arbitrary baseband signal having a frequency component of an arbitrary frequency BHz or less at a sampling frequency of 2 × BHz or higher is set to a carrier signal sin (ωt + θ0) at a frequency ω / (2π) Hz higher than BHz. ) To output an amplitude modulation signal A · sin (ωt + θ0),
Phase modulation conversion means for converting the amplitude modulation signal into n digital signals DS1, DS2,.
Carrier multiplication means for multiplying each of the n digital signals DS1, DS2,..., DSn by a digital carrier signal DC by exclusive OR,
Synthesis means for analog addition of n output signals of the multiplication means;
Low pass filter means for inputting the summed composite signal and passing a frequency component below BHz;
For all integers i in the range of 1 to n, the digital signal DSi has a positive phase modulation signal Si = E · sin (ωt + θi) obtained by phase-modulating a carrier of ω / (2π) Hz with phase information θi. When it has a level, it has a level of + E, and when the phase modulation signal Si has a negative level, it has a level of -E, and the frequency phase is a signal having ωt + θi,
The digital carrier signal DC is a signal having a level of +1 when the carrier signal sin (ωt + θ0) of ω / (2π) Hz has a positive level, and a level of −1 when having a negative level, In the phase modulation conversion means, the n digital signals DS1, DS2,.
A = E ・ cos (θ1−θ0) + E ・ cos (θ2−θ0) + ・ ・ + E ・ cos (θn−θ0),
0 = sin (θ1−θ0) + sin (θ2−θ0) + ・ ・ + sin (θn−θ0)
The baseband signal is generated by performing conversion so as to satisfy the above relationship. A carrier signal sin (ωt + θ0) at a frequency ω / (2π) Hz higher than BHz based on level information L of a sample point obtained by sampling an arbitrary baseband signal having a frequency component equal to or lower than the arbitrary frequency BHz at a sampling frequency of 2 × BHz or higher. ) Is frequency-modulated to generate a frequency-modulated signal A · sin ((ω + L) t + θ0),
N phase modulation signals S1 = E · sin (ωt + θ1), S2 = E · sin (ωt + θ2)..., Sn = E · sin (ωt +) phase modulation conversion means for converting to θn),
Combining means for analogly adding the n phase modulation signals S1, S2,..., Sn;
Frequency detection means for detecting the frequency by inputting the added composite signal, and
In the phase modulation conversion means, the n phase modulation signals S1, S2,.
A = E ・ cos (θ1− (Lt + θ0)) + E ・ cos (θ2− (Lt + θ0)) + ・ ・ + E ・ cos (θn− (Lt + θ0)),
0 = sin (θ1− (Lt + θ0)) + sin (θ2− (Lt + θ0)) + ・ ・ + sin (θn− (Lt + θ0))
The baseband signal is generated by performing conversion so as to satisfy the above relationship. The phase modulation conversion unit generates n phase information and n phase modulation signals, and stores the n phase information in a storage circuit, or n outputs of the phase modulation conversion unit Each of the phase modulation signal of each of the above-mentioned quantization means to be digital data, and any one of the storage means for storing the n outputs of the quantization means in a storage circuit;
In the case of storing the n pieces of phase information, phase modulation means for sequentially reading the n pieces of phase information from the storage circuit and reproducing n pieces of phase modulation signals based on the n pieces of phase information;
In the case of storing the n outputs of the quantizing means, further comprising any means for sequentially reading the n outputs from the storage circuit and reproducing the phase modulation signal,
Outputting the phase-modulated signal signal to either the carrier multiplying means or the combining means;
6. The signal generation circuit according to claim 1, wherein the baseband signal is generated. An amplitude modulation signal is generated by amplitude-modulating a carrier signal with a level value obtained by sampling an arbitrary baseband signal having a frequency component equal to or lower than an arbitrary frequency BHz, or the carrier signal is frequency-modulated and frequency-modulated with the level value. Baseband signal modulating means for generating any one of the modulated signals to generate a signal;
Phase modulation conversion means for converting the modulated signal into n pieces of phase information, where n is an integer of 2 or more, and further converting into n pieces of phase modulated signals;
Storage means for storing the n pieces of phase information in a storage circuit, or quantization means for sampling each of n output phase modulation signals of the phase modulation conversion means into digital data, and the quantization means A signal storage circuit having storage means for storing the n outputs of the baseband signal in the storage circuit, and storing data obtained by converting the baseband signal. An amplitude modulation signal is generated by amplitude-modulating a carrier signal having a frequency higher than BHz with a level value obtained by sampling an arbitrary baseband signal having a frequency component equal to or lower than an arbitrary frequency BHz, or the carrier signal is generated with the level value. Frequency modulation is performed to generate one of the frequency modulation signals. The modulation signal is converted into n pieces of phase information, where n is an integer of 2 or more, and the n pieces of phase information are stored. Storage means stored in the circuit,
Or any one of storage means for converting the n pieces of phase information into n pieces of phase modulation signals, sampling each of the n pieces of phase modulation signals as digital data, and storing the digital data in a storage circuit Storage means,
When the n pieces of phase information are stored, the n pieces of phase information are sequentially read from the storage circuit, and n phase modulation signals are reproduced by the n pieces of phase information; Means for reproducing the n phase modulation signals by sequentially reading the digital data from the storage circuit when storing digital data obtained by sampling the number of phase modulation signals;
Carrier multiplying means for multiplying the n phase modulation signals of the reproducing means by a carrier signal having the same frequency as the carrier signal when the baseband signal is amplitude-modulated;
When the baseband signal is amplitude-modulated, a combining unit that adds n outputs of the carrier multiplying unit;
When the baseband signal is frequency-modulated, a synthesis unit that adds n phase modulation signals output from the reproduction unit;
When the baseband signal is amplitude-modulated, it has a low-pass filter means that inputs the added combined signal and passes a frequency component of BHz or less,
When the baseband signal is frequency-modulated, it has frequency detection means for detecting the frequency by inputting the added combined signal,
A signal generation circuit for generating the baseband signal. Frequency conversion by multiplying m channel baseband signal by 0 Hz, B / m Hz, 2B / m Hz, ... (m−1) / m Hz, local signals oscillating at an integer of 1 or more, m Means to
Synthesizing means for synthesizing m frequency-converted signals into one baseband signal having a bandwidth of BHz or less;
Multiplying the synthesized one baseband signal by 0 Hz, B / m Hz, 2B / m Hz, local signals oscillating at (m−1) B / m Hz, respectively. Multiplication means;
M low-pass filter means for passing a frequency component of B / m Hz or less of each output of the multiplication means;
9. The signal generation circuit according to claim 1, wherein the m-channel baseband signal is generated. First sampling means for sampling an m-channel baseband signal having a band of B / m Hz or less where m is an integer greater than or equal to 1 at a timing of 2B / m Hz;
Combining means for sequentially switching and outputting the signal sampled by the sampling means to output one baseband signal;
A second sampling means for sampling the synthesized one baseband signal at 2 BHz;
Separating means for sequentially separating the signals sampled by the second sampling means;
9. The signal generation circuit according to claim 1, wherein the m-channel baseband signal is generated.