Transmitters, receivers and transceiving systems

Abstract

The purpose of this invention is to suppress the generation of noise components in audio signals. A transmitter is provided for transmitting a synthesized modulated signal obtained by analog modulation of a synthesized signal composed of a carrier modulated signal and an audio signal. The carrier modulated signal is generated based on a serial data signal storing predetermined information and a carrier signal. The audio signal is generated based on a sound wave from a sound source. The transmitter includes: a storage unit storing the predetermined information; and a control unit generating a serial data signal, the serial data signal including a preamble consisting of alternating specific bits and non-specific bits, wherein the width of the non-specific bits is a reference bit width, and the width of the specific bits is MN times the reference bit width (M and N are any integers from 1 to 9).

Description

Technical Field

[0001] This invention relates to a transmitter, a receiver, and a transceiver system. Background Technology

[0002] In existing transceiver systems, there are known transceiver systems that transmit and receive audio signals and data signals simultaneously (hereinafter referred to as "existing transceiver systems") (for example, see Patent Document 1). The transmitter of the existing transceiver system (hereinafter referred to as "existing transmitter") first generates data signals and audio signals.

[0003] Here, the data signal is generated based on predetermined information and serial data signals (so-called data frames). A data frame contains a preamble and a payload. In the data frame, the preamble contains a repeating pattern of a specific bit sequence, such as "101010...". The bit widths of each bit constituting the specific bit sequence are equal. The receiver of an existing transceiver system (hereinafter referred to as "existing receiver") identifies the start position of the payload within the data frame based on the repeating pattern of the specific bit sequence. That is, the repeating pattern of the specific bit sequence functions as an identification marker for the payload.

[0004] Next, the existing transmitter generates a synthesized signal. The synthesized signal is generated based on the data signal and the audio signal. The generated synthesized signal is then analog-modulated and transmitted to the existing receiver.

[0005] The existing receiver demodulates the received synthesized signal, extracting the data signal and audio signal. Then, based on a specific bit sequence repetition pattern, the existing receiver extracts predetermined information stored in the payload from the received data signal.

[0006] In recent years, the demand for higher capacity data signals transmitted and received along with audio signals has become increasingly urgent. Existing transceiver systems require devices conforming to communication standards such as BLE (Bluetooth Low Energy) to transmit and receive high-capacity data signals. Therefore, additional costs are incurred to introduce such devices. On the other hand, when existing transceiver systems transmit and receive high-capacity data signals without using such devices, the data signals may contain noise components based on the high-frequency components of the data signal. These noise components in the data signal can affect the audio signal. As a result, noise components may be introduced into the audio signal. Existing technical documents Patent documents:

[0007] Patent Document 1: Japanese Patent Application Publication No. 2004-128566. Summary of the Invention The problem the invention aims to solve

[0008] The purpose of this invention is to suppress the generation of noise components in audio signals. Solution for solving the problem

[0009] This invention relates to a transmitter for transmitting a composite modulated signal obtained by analog modulation of a composite signal composed of a carrier modulation signal and an audio signal. The transmitter is characterized in that the carrier modulation signal is generated based on a serial data signal storing predetermined information and a carrier signal, and the audio signal is generated based on sound waves from a sound source. The transmitter includes: a storage unit storing predetermined information; and a control unit generating a serial data signal, the serial data signal comprising a preamble consisting of alternating specific bits and non-specific bits, wherein when the width of the non-specific bits is a reference bit width, the width of the specific bits is MN times the reference bit width (M and N are any integers from 1 to 9). Invention Effects

[0010] This invention can suppress the generation of noise components in audio signals. Attached Figure Description

[0011] Figure 1 A schematic diagram illustrating an embodiment of the transceiver system of the present invention. Figure 2 This is a schematic diagram illustrating the relationship between the serial data signal, carrier signal, and audio signal generated by the transmitter of the present invention. Figure 3 This is a schematic diagram illustrating the structure of the aforementioned serial data signal (data frame). Figure 4 A functional block diagram illustrating an embodiment of the transmitter described above. Figure 5 This is a functional block diagram illustrating an embodiment of the receiver of the present invention. Figure 6 A flowchart illustrating an example of the operation of the aforementioned transmitter. Figure 7 This is a schematic diagram illustrating the waveform changes of the serial data signal and carrier signal generated by the aforementioned transmitter. Figure 8 A flowchart illustrating an example of the operation of the aforementioned receiver. Figure 9 This is a schematic diagram illustrating the waveform changes of the carrier modulation signal extracted by the aforementioned receiver. Detailed Implementation

[0012] The embodiments of the transmitter (hereinafter referred to as "the transmitter"), receiver (hereinafter referred to as "the receiver"), and transceiver system (hereinafter referred to as "the system") of the present invention will be described below with reference to the accompanying drawings.

[0013] ●Structure of this system● Figure 1This is a schematic diagram illustrating an implementation of the system.

[0014] This system 1 transmits and receives a composite modulated signal S6 obtained by FM modulation (analog modulation) of a composite signal S5 consisting of a carrier modulation signal S3 and an audio signal S4. This system 1 includes a transmitter 2 and a receiver 3. Details of the carrier modulation signal S3, the audio signal S4, the composite signal S5, and the composite modulated signal S6 are described later.

[0015] This transmitter 2 generates a serial data signal S1, a carrier signal S2, a carrier modulation signal S3, an audio signal S4, a synthesized signal S5, and a synthesized modulation signal S6. This transmitter 2 transmits the generated synthesized modulation signal S6 to this receiver 3. This transmitter 2 includes a storage unit 21, a control unit 22, a filter unit 23, a carrier signal generation unit 24, a carrier signal modulation unit 25, an audio signal generation unit 26, a synthesis unit 27, a synthesized signal modulation unit 28, and a transmission unit 29. Details of the serial data signal S1 and the carrier signal S2 are described later.

[0016] This receiver 3 receives the synthesized and modulated signal S6 from this transmitter 2. This receiver 3 includes a receiving unit 31, a signal extraction unit 32, an A / D conversion unit 33, a data signal output unit 34, an audio signal processing unit 35, and an audio signal output unit 36.

[0017] ●Relationships between signals● Figure 2 This is a schematic diagram illustrating the relationship between the serial data signal, carrier signal, and audio signal generated by this transmitter.

[0018] The serial data signal S1 is a data frame storing predetermined information. For example, the serial data signal S1 is a digital signal in the 30kHz-40kHz frequency band. The serial data signal S1 (data frame) includes a preamble, payload, and checksum.

[0019] The predetermined information may include, for example, information showing the results detected by a sensor (not shown) provided by this transmitter 2, or information input by a switch (not shown) provided by this transmitter 2.

[0020] The carrier signal S2 is the carrier used to transmit the serial data signal S1. The carrier signal S2 is modulated by the serial data signal S1 after linear processing. The carrier signal S2 is an analog signal.

[0021] The carrier modulation signal S3 is generated based on the serial data signal S1 and the carrier signal S2. Specifically, the carrier modulation signal S3 is generated by modulating the carrier signal S2 with the linearly processed serial data signal S1. The serial data signal S1 stores predetermined information. Therefore, the carrier modulation signal S3 contains predetermined information. The carrier modulation signal S3 is an analog signal.

[0022] Audio signal S4 is a signal generated based on sound waves from a sound source. Audio signal S4 is, for example, an analog signal in the 20Hz-20kHz frequency band.

[0023] The synthesized signal S5 is generated by combining the carrier modulation signal S3 and the audio signal S4. The synthesized signal S5 is an analog signal.

[0024] The synthesized modulation signal S6 is obtained by FM modulation (analog modulation) of the synthesized signal S5. The synthesized modulation signal S6 is an analog signal.

[0025] ●Generation of noise components● The serial data signal S1 generated by this transmitter 2 has a large data volume. That is, the serial data signal S1 contains high-frequency components. Therefore, the serial data signal S1 may contain noise components based on its high-frequency components.

[0026] This system 1 transmits and receives a synthesized modulated signal S6 generated from a serial data signal S1 and an audio signal S4. When the serial data signal S1 contains noise components, the transmission and reception of the synthesized modulated signal S6 by this system 1 may fail. Furthermore, the noise components contained in the serial data signal S1 will affect the audio signal S4. As a result, noise components may be introduced into the audio signal S4.

[0027] ●Structure of Data Frames● Figure 3 This is a schematic diagram illustrating the structure of a serial data signal (data frame). The diagram shows that a data frame contains a preamble, payload, and checksum. In the diagram, the scale from "0" to "X" (where X is an integer greater than or equal to 13) represents the size of the bit width. One scale (e.g., the length from "0" to "1") represents the size of one non-specific bit width. Details about non-specific bit widths will be explained later. In the diagram, the double arrows above the paper indicate the range of the data frame. In the diagram, the three double arrows at the bottom of the paper represent the range of the preamble, the range of the payload, and the range of the checksum. In the diagram, the dashed rectangle enclosing the scale and the double arrows indicating the range of the preamble represents a specific pattern P. In specific pattern P, the thin line represents the non-specific bit B2, and the thick line represents the specific bit B1. In the diagram, the graphic shown between the scale and the double arrows indicating the range of the payload represents the bit sequence of the payload. In the diagram, the double wavy lines represent a portion of the bit sequence with the payload omitted. In the diagram, the graphic shown between the scale and the double arrows indicating the range of the checksum represents the bit sequence of the checksum.

[0028] In the following description, "beginning" refers to the very first position of the data frame read by this receiver 3. "End" refers to the very last position of the data frame read by this receiver 3.

[0029] ●Preamble The preamble is a predetermined bit sequence read by the receiver 3 to enable the receiver 3 to determine the start position of the payload within the data frame. Each bit constituting the predetermined bit sequence contains either "0 (Low)" or "1 (High)". The preamble is positioned at the beginning of the data frame. The predetermined bit sequence (specific pattern P) of the preamble is composed of specific bits B1 and non-specific bits B2. In specific pattern P, specific bits B1 and non-specific bits B2 are alternately arranged. In other words, the preamble is a bit sequence composed of alternating specific bits B1 and non-specific bits B2.

[0030] Here, the receiver 3 determines the starting position of the payload within the data frame based on two or more specific bits B1. In the specific mode P, the specific bits B1 and the non-specific bits B2 are arranged alternately. Therefore, the number of both specific bits B1 and non-specific bits B2 constituting the specific mode P is two or more. That is, for example, the specific mode P is composed of two specific bits B1 and three non-specific bits B2.

[0031] Specific bit B1 is a bit with a specific bit width. The specific bit width is the time from the start of the rising edge to the start of the falling edge when this receiver 3 reads one specific bit B1.

[0032] The nonspecific bit B2 is a bit with a nonspecific bit width. The nonspecific bit width is the time from the start of the falling edge to the start of the rising edge when this receiver 3 reads one nonspecific bit B2. When the nonspecific bit width is the reference bit width (reference bit width), the specific bit width is MN times the reference bit width (M and N are any integers from 1 to 9).

[0033] In this embodiment, M is 1 and N is 5. That is, the specific bit width is 1.5 times the non-specific bit width (reference bit width).

[0034] Receiver 3 reads the preamble. Based on the read preamble, receiver 3 identifies a specific pattern P. When receiver 3 identifies the specific pattern P, it determines the starting position of the payload within the data frame. That is, the preamble within the data frame serves as an identification marker for the starting position of the payload.

[0035] ● Payload The payload is a sequence of bits storing predetermined information. The payload is positioned between the preamble and the checksum.

[0036] ●Checksum The checksum is a value calculated by this transmitter 2 based on the payload contained in the transmitted data frame. The checksum is configured at the end of the data frame.

[0037] Here, the receiver 3 calculates the checksum value based on the payload contained in the received data frame. The receiver 3 determines whether the calculated value is consistent with the checksum value contained in the received data frame. When the calculated value is consistent with the checksum value, the receiver 3 determines that the information stored in the received payload is the same as the predetermined information stored in the payload transmitted by the transmitter 2.

[0038] ●Structure of this transmitter● Figure 4 This is a functional block diagram illustrating an embodiment of the transmitter.

[0039] Storage unit 21 stores scheduled information. Storage unit 21 may be a non-volatile recording medium such as HDD (Hard Disk Drive), SSD (Solid State Drive), or flash memory, or a volatile recording medium such as RAM (Random Access Memory).

[0040] The control unit 22 generates a serial data signal S1 containing the predetermined information based on the predetermined information stored in the storage unit 21. The control unit 22 then sends the generated serial data signal S1 to the filter unit 23.

[0041] The filter unit 23 is a linear processing filter. The filter unit 23 receives the serial data signal S1 from the control unit 22. The filter unit 23 performs linear processing on the rising and falling edges of the serial data signal S1. The filter unit 23 then transmits the linearly processed serial data signal S1 to the carrier signal modulation unit 25.

[0042] Here, the waveforms of the rising and falling edges of the serial data signal S1 become smoother after linear processing. As a result, the slopes of the rising and falling edges of the serial data signal S1 become gentler.

[0043] ● Rising edge and falling edge The rising edge represents the portion of the serial data signal S1 where the voltage level transitions from "Low" to "High". The falling edge represents the portion of the serial data signal S1 where the voltage level transitions from "High" to "Low". When the voltage exceeds a predetermined threshold, the voltage level is "High". When the voltage does not exceed the predetermined threshold, the voltage level is "Low". When the voltage level is "High", the control unit 22 outputs a signal with a voltage level of "1". When the voltage level is "Low", the control unit 22 outputs a signal with a voltage level of "0".

[0044] The carrier signal generation unit 24 generates a carrier signal S2. The carrier signal generation unit 24 then sends the generated carrier signal S2 to the carrier signal modulation unit 25.

[0045] The carrier signal modulation unit 25 receives the linearly processed serial data signal S1 from the filter unit 23. The carrier signal modulation unit 25 receives the carrier signal S2 from the carrier signal generation unit 24. The carrier signal modulation unit 25 modulates the carrier signal S2 using the linearly processed serial data signal S1 to generate a carrier modulated signal S3. The carrier signal modulation unit 25 transmits the generated carrier modulated signal S3 to the synthesis unit 27.

[0046] The audio signal generation unit 26 generates an audio signal S4 based on the sound waves from the sound source. The audio signal generation unit 26 then sends the generated audio signal S4 to the synthesis unit 27.

[0047] The sound source is the object (person or thing) that makes a certain sound.

[0048] The synthesis unit 27 receives the carrier modulation signal S3 from the carrier signal modulation unit 25. The synthesis unit 27 receives the audio signal S4 from the audio signal generation unit 26. The synthesis unit 27 synthesizes the carrier modulation signal S3 and the audio signal S4 to generate a synthesized signal S5. The synthesis unit 27 sends the generated synthesized signal S5 to the synthesized signal modulation unit 28.

[0049] The synthesized signal modulation unit 28 receives the synthesized signal S5 from the synthesis unit 27. The synthesized signal modulation unit 28 performs FM modulation (analog modulation) on the synthesized signal S5 to generate a synthesized modulated signal S6. The synthesized signal modulation unit 28 transmits the generated synthesized modulated signal S6 to the transmitting unit 29.

[0050] It should be noted that the analog modulation in this invention is not limited to FM (Frequency Modulation) modulation. That is, for example, the analog modulation in this invention can also be AM (Amplitude Modulation) modulation or PM (Phase Modulation) modulation, etc.

[0051] The transmitting unit 29 receives the synthesized modulated signal S6 from the synthesized signal modulation unit 28. The transmitting unit 29 transmits the received synthesized modulated signal S6 to the receiver 3.

[0052] ●Structure of this receiver● Figure 5 This is a functional block diagram illustrating an embodiment of the receiver.

[0053] The receiving unit 31 receives the synthesized modulated signal S6 from the transmitter 2. The receiving unit 31 then transmits the received synthesized modulated signal S6 to the signal extraction unit 32.

[0054] The signal extraction unit 32 receives the synthesized modulated signal S6 from the receiving unit 31. The signal extraction unit 32 extracts the carrier modulated signal S3 and the synthesized signal S5 from the synthesized modulated signal S6. The signal extraction unit 32 sends the extracted carrier modulated signal S3 to the A / D conversion unit 33. The signal extraction unit 32 sends the extracted synthesized signal S5 to the audio signal processing unit 35. The signal extraction unit 32 includes a demodulation unit 321, a first extraction filter unit 322, and a second extraction filter unit 323.

[0055] The demodulation unit 321 receives the synthesized modulated signal S6 from the receiving unit 31. The demodulation unit 321 demodulates the synthesized signal S5 from the synthesized modulated signal S6. The demodulation unit 321 sends the demodulated synthesized signal S5 to the first extraction filter unit 322. The demodulation unit 321 sends the demodulated synthesized signal S5 to the audio signal processing unit 35.

[0056] The first extraction filter unit 322 is a bandpass filter. The first extraction filter unit 322 receives the demodulated synthesized signal S5 from the demodulation unit 321.

[0057] Here, the frequency band of the demodulated synthesized signal S5 includes the frequency band of the carrier modulation signal S3 and the frequency band of the audio signal S4. The first extraction filter unit 322 allows the frequency band of the carrier modulation signal S3 in the frequency band of the demodulated synthesized signal S5 to pass through (i.e., extracts it). That is, the first extraction filter unit 322 extracts the frequency band of the carrier modulation signal S3 from the frequency band of the demodulated synthesized signal S5. In other words, the first extraction filter unit 322 extracts the carrier modulation signal S3 from the demodulated synthesized signal S5. The first extraction filter unit 322 sends the extracted carrier modulation signal S3 to the second extraction filter unit 323.

[0058] The second extraction filter unit 323 is a low-pass filter. The second extraction filter unit 323 receives the extracted carrier modulation signal S3 from the first extraction filter unit 322.

[0059] Here, the frequency band of the extracted carrier modulation signal S3 includes a noise component. That is, the extracted carrier modulation signal S3 contains noise components. The second extraction filter unit 323 prevents the noise component frequency band of the extracted carrier modulation signal S3 from passing through (i.e., attenuates it). In other words, the second extraction filter unit 323 removes the noise component frequency band from the extracted carrier modulation signal S3. That is, the second extraction filter unit 323 removes the noise component from the extracted carrier modulation signal S3. The second extraction filter unit 323 then sends the noise-removed carrier modulation signal S3 to the A / D conversion unit 33.

[0060] Furthermore, the settings of the first extraction filter section 322, which serves as a bandpass filter, and the second extraction filter section 323, which serves as a low-pass filter, can be adjusted appropriately. Therefore, the first extraction filter section 322 and the second extraction filter section 323 are set separately to remove noise components.

[0061] The A / D conversion unit 33 is an analog-to-digital converter that converts analog signals into digital signals. The A / D conversion unit 33 receives the carrier modulation signal S3 extracted by the signal extraction unit 32, i.e., the carrier modulation signal S3 after noise has been removed by the second extraction filter unit 323. The A / D conversion unit 33 converts the carrier modulation signal S3 extracted by the signal extraction unit 32, i.e., the carrier modulation signal S3 after noise has been removed by the second extraction filter unit 323, into a digital signal. The converted carrier modulation signal S3 (hereinafter referred to as the "converted signal") is a serial data signal S1 after linear processing. That is, the serial data signal S1 after linear processing is restored by the A / D conversion unit 33. The converted signal includes the preamble, payload, and checksum of the serial data signal S1. The A / D conversion unit 33 sends the converted signal to the data signal output unit 34.

[0062] The data signal output unit 34 receives the conversion signal from the A / D conversion unit 33. The data signal output unit 34 reads the conversion signal. Based on the preamble contained in the read conversion signal, the data signal output unit 34 identifies a specific pattern P. Based on the specific bit width contained in the identified specific pattern P, the data signal output unit 34 determines the starting position of the payload. The data signal output unit 34 extracts predetermined information stored in the payload with the determined starting position. That is, the data signal output unit 34 extracts predetermined information from the conversion signal based on the specific bit width. The data signal output unit 34 sends the extracted predetermined information to the data output unit 5.

[0063] Data output device 5 is, for example, a display that shows predetermined information.

[0064] It should be noted that the data signal output unit 34 is an example of the information extraction unit in this invention.

[0065] The audio signal processing unit 35 receives the demodulated synthesized signal S5 from the demodulation unit 321.

[0066] Here, the audio signal processing unit 35 includes an audio signal extraction filter unit (not shown). The audio signal extraction filter unit is a bandpass filter. The frequency band of the demodulated synthesized signal S5 includes the frequency band of the carrier modulation signal S3 and the frequency band of the audio signal S4. The audio signal extraction filter unit allows the frequency band of the audio signal S4 in the frequency band of the demodulated synthesized signal S5 to pass through (i.e., extracts it). That is, the audio signal extraction filter unit extracts the frequency band of the audio signal S4 from the frequency band of the demodulated synthesized signal S5. In other words, the audio signal processing unit 35 extracts the audio signal S4 from the demodulated synthesized signal S5. That is, the audio signal S4 is restored by the audio signal processing unit 35. The audio signal processing unit 35 sends the extracted audio signal S4 to the audio signal output unit 36.

[0067] The audio signal output unit 36 ​​receives the extracted audio signal S4 from the audio signal processing unit 35. The audio signal output unit 36 ​​then sends the received audio signal S4 to the audio output unit 4.

[0068] Audio output device 4 is, for example, a speaker that outputs audio signal S4.

[0069] ●System Operations● The following describes the operation of System 1.

[0070] ● Operation of this transmitter In the following description, the pre-defined information is stored in the storage unit 21.

[0071] Figure 6 A flowchart illustrating an example of the transmitter's operation.

[0072] Figure 7 This is a schematic diagram illustrating the waveform changes of the serial data signal and carrier signal generated by this transmitter. The figure shows the serial data signal S1 being sent to the filter section 23. The figure shows that the serial data signal S1 and the carrier signal S2, after linear processing, are sent to the carrier signal modulation unit 25, respectively. The figure shows the carrier modulation signal S3 being transmitted from the carrier signal modulation unit 25. In the figure, the waveform on the right side of the paper represents the waveform of the serial data signal S1. In the figure, the waveform of the linearly processed serial data signal S1 on the right side of the paper represents the waveform of the linearly processed serial data signal S1. In the figure, the waveform above the paper of the carrier signal S2 represents the waveform of the carrier signal S2. In the figure, the waveform on the right side of the paper represents the waveform of the carrier modulation signal S3.

[0073] In the following Figure 6 The explanation will refer to the following: Figure 7 .

[0074] The signal generation process (ST1) involves the transmitter 2 generating a composite signal S5 based on the generated serial data signal S1, carrier signal S2, and audio signal S4. The transmitter 2 then transmits the composite signal S5 to the receiver 3 via analog modulation to obtain the composite modulated signal S6.

[0075] First, the control unit 22 generates a serial data signal S1 (ST11). Specifically, the control unit 22 reads predetermined information stored in the storage unit 21. After reading the predetermined information, the control unit 22 generates a serial data signal S1 (data frame) as a digital signal based on the predetermined information. That is, the control unit 22 generates the preamble, payload, and checksum constituting the data frame. At this time, the predetermined information is stored in the payload of the data frame.

[0076] Next, the control unit 22 sends the generated serial data signal S1 to the filter unit 23 (ST12).

[0077] Next, the filter unit 23 performs linear processing (ST13) on the serial data signal S1. Specifically, the filter unit 23 receives the serial data signal S1 from the control unit 22. The filter unit 23 performs linear processing on the rising and falling edges of the received serial data signal S1. At this time, the waveforms of the rising and falling edges of the serial data signal S1 become smoother after linear processing. As a result, the slopes of the rising and falling edges of the serial data signal S1 become gentler (see reference). Figure 7 The filter unit 23 sends the linearly processed serial data signal S1 to the carrier signal modulation unit 25.

[0078] Here, the steeper the slope of the rising and falling edges of the serial data signal S1, the more easily its high-frequency noise components are included in the serial data signal S1. That is, compared to the un-linearized serial data signal S1, the linearized serial data signal S1 is less likely to contain noise components.

[0079] On the other hand, the carrier signal generation unit 24 generates a carrier signal S2 (ST14). Specifically, the carrier signal generation unit 24 generates a carrier signal S2 (carrier) as an analog signal. The carrier signal generation unit 24 sends the generated carrier signal S2 to the carrier signal modulation unit 25.

[0080] Next, the carrier signal modulation unit 25 modulates the carrier signal S2 (ST15). Specifically, the carrier signal modulation unit 25 receives the linearly processed serial data signal S1 from the filter unit 23. The carrier signal modulation unit 25 receives the carrier signal S2 from the carrier signal generation unit 24. The carrier signal modulation unit 25 modulates the received carrier signal S2 using the received serial data signal S1 to generate a carrier modulation signal S3 as an analog signal (see reference). Figure 7 The carrier signal modulation unit 25 sends the generated carrier modulation signal S3 to the synthesis unit 27.

[0081] On the other hand, the audio signal generation unit 26 generates an audio signal S4 (ST16). Specifically, the audio signal generation unit 26 generates an audio signal S4 as an analog signal based on the sound waves from the sound source. The audio signal generation unit 26 then sends the generated audio signal S4 to the synthesis unit 27.

[0082] Next, the synthesis unit 27 generates a synthesized signal S5 (ST17). Specifically, the synthesis unit 27 receives a carrier modulation signal S3 from the carrier signal modulation unit 25. The synthesis unit 27 receives an audio signal S4 from the audio signal generation unit 26. The synthesis unit 27 synthesizes the received carrier modulation signal S3 and the received audio signal S4 to generate a synthesized signal S5 as an analog signal. The synthesis unit 27 sends the generated synthesized signal S5 to the synthesized signal modulation unit 28.

[0083] Next, the synthesized signal modulation unit 28 modulates the synthesized signal S5 (ST18). Specifically, the synthesized signal modulation unit 28 receives the synthesized signal S5 from the synthesis unit 27. The synthesized signal modulation unit 28 performs FM modulation (analog modulation) on the received synthesized signal S5 to generate a synthesized modulated signal S6 as an analog signal. The synthesized signal modulation unit 28 transmits the generated synthesized modulated signal S6 to the transmitting unit 29.

[0084] Next, the transmitting unit 29 transmits the synthesized modulated signal S6 to the receiver 3 (ST19). Specifically, the transmitting unit 29 of the transmitter 2 receives the synthesized modulated signal S6 from the synthesized signal modulation unit 28. The transmitting unit 29 then transmits the received synthesized modulated signal S6 to the receiver 3.

[0085] ● Operation of this receiver Figure 8 A flowchart illustrating an example of the operation of this receiver.

[0086] Figure 9 This is a schematic diagram illustrating the waveform changes of the carrier modulation signal extracted by this receiver. The figure shows the demodulated synthesized signal S5 being sent to the first extraction filter section 322. The figure shows the extracted carrier modulation signal S3 being sent to the second extraction filter section 323. The figure shows the carrier modulation signal S3, with noise components removed, being transmitted from the second extraction filter section 323. In the figure, the waveform above the paper of the extracted carrier modulation signal S3 represents the waveform of the extracted carrier modulation signal S3. In the figure, the waveform on the left side of the paper represents the waveform of the carrier modulation signal S3 after noise components have been removed. In the figure, the dashed circles represent waveforms containing noise components.

[0087] In the following Figure 8 The explanation will refer to the following: Figure 9 .

[0088] The restoration process (ST2) refers to the process by which the receiver 3 restores the linearly processed serial data signal S1 and audio signal S4 from the received synthesized modulated signal S6. The receiver 3 extracts predetermined information from the restored linearly processed serial data signal S1 (hereinafter referred to as the "restored data signal"). The receiver 3 transmits the extracted predetermined information to the data output device 5. The receiver 3 transmits the restored audio signal S4 to the audio output device 4.

[0089] First, the receiving unit 31 receives the synthesized modulated signal S6 (ST21). Specifically, the receiving unit 31 receives the synthesized modulated signal S6 from the transmitter 2. The receiving unit 31 then transmits the received synthesized modulated signal S6 to the demodulation unit 321 included in the signal extraction unit 32.

[0090] Next, the demodulation unit 321 demodulates the synthesized modulation signal S6 (ST22). Specifically, the demodulation unit 321 receives the synthesized modulation signal S6 from the receiving unit 31. The demodulation unit 321 demodulates the synthesized signal S5 from the received synthesized modulation signal S6. The demodulation unit 321 sends the demodulated synthesized signal S5 to the first extraction filter unit 322 included in the signal extraction unit 32. The demodulation unit 321 sends the demodulated synthesized signal S5 to the audio signal processing unit 35.

[0091] Next, the first extraction filter unit 322 extracts the carrier modulation signal S3 (ST23) from the demodulated synthesized signal S5. Specifically, the first extraction filter unit 322 receives the demodulated synthesized signal S5 from the demodulation unit 321. The first extraction filter unit 322 allows the frequency band of the carrier modulation signal S3 in the frequency band of the received synthesized signal S5 to pass through. That is, the first extraction filter unit 322 extracts the carrier modulation signal S3 from the received synthesized signal S5. The first extraction filter unit 322 then extracts the carrier modulation signal S3 (ST23) from the received synthesized signal S5. Figure 9 The signal is sent to the second extraction filter unit 323 of the signal extraction unit 32.

[0092] Here, as mentioned above, the extracted carrier modulation signal S3 contains noise components (refer to...). Figure 9 ).

[0093] Next, the second extraction filter unit 323 removes noise components (ST24) from the extracted carrier modulation signal S3. Specifically, the second extraction filter unit 323 receives the extracted carrier modulation signal S3 from the first extraction filter unit 322. The second extraction filter unit 323 prevents the frequency band of the noise component in the extracted carrier modulation signal S3 from passing through. That is, the second extraction filter unit 323 removes noise components from the extracted carrier modulation signal S3. The second extraction filter unit 323 outputs the noise-removed carrier modulation signal S3 (see reference 24) to the second extraction filter unit 323. Figure 9 )Send to A / D conversion unit 33.

[0094] Next, the A / D conversion unit 33 restores the linearly processed serial data signal S1 (ST25). Specifically, the A / D conversion unit 33 receives the noise-removed carrier modulation signal S3 from the second extraction filter unit 323. The A / D conversion unit 33 converts the noise-removed carrier modulation signal S3 into a digital signal. That is, the linearly processed serial data signal S1 (converted signal) is restored. The A / D conversion unit 33 sends the converted signal to the data signal output unit 34.

[0095] Here, as described above, the conversion signal includes the preamble, payload, and checksum from the serial data signal S1.

[0096] Next, the data signal output unit 34 extracts predetermined information from the converted signal (ST26). Specifically, the data signal output unit 34 receives the converted signal from the A / D conversion unit 33. The data signal output unit 34 reads the received converted signal. As a result, the data signal output unit 34 extracts the predetermined information stored in the payload from the converted signal according to the specific bit width of a specific bit B1 in a specific pattern P constituting the preamble.

[0097] Next, the data signal output unit 34 sends the extracted predetermined information to the data output unit 5 (ST27).

[0098] On the other hand, the audio signal processing unit 35 restores the audio signal S4 (ST28). Specifically, the audio signal processing unit 35 receives the demodulated synthesized signal S5 from the demodulation unit 321. The audio signal extraction filter unit included in the audio signal processing unit 35 allows the frequency band of the audio signal S4 in the frequency band of the demodulated synthesized signal S5 to pass through. That is, the audio signal extraction filter unit extracts the audio signal S4 from the demodulated synthesized signal S5. In other words, the audio signal S4 is restored. The audio signal processing unit 35 sends the extracted (restored) audio signal S4 to the audio signal output unit 36.

[0099] Next, the audio signal output unit 36 ​​sends the extracted (restored) audio signal S4 to the audio output unit 4 (ST29). Specifically, the audio signal output unit 36 ​​receives the extracted (restored) audio signal S4 from the audio signal processing unit 35. The audio signal output unit 36 ​​then sends the received audio signal S4 to the audio output unit 4.

[0100] ●Summary● As described above, transmitter 2 is a transmitter for transmitting a synthesized modulated signal S6, wherein the synthesized modulated signal S6 is obtained by analog modulation of a synthesized signal S5 composed of a carrier modulated signal S3 and an audio signal S4. Receiver 3 is a receiver that receives the synthesized modulated signal S6 from transmitter 2. The carrier modulated signal S3 is generated based on a serial data signal S1 storing predetermined information and a carrier signal S2. The audio signal S4 is generated based on sound waves from a sound source. Transmitter 2 includes: a storage unit 21 storing predetermined information; and a control unit 22 generating the serial data signal S1. The serial data signal S1 includes a preamble consisting of alternating specific bits B1 and non-specific bits B2. When the width of the non-specific bits is the reference bit width, the width of the specific bits is MN times the reference bit width (M and N are any integers from 1 to 9). That is, the width of the specific bits and the width of the non-specific bits are different. Therefore, receiver 3, which receives the synthesized modulated signal S6 from transmitter 2, can identify the starting position of the payload within the data frame based on the width of the specific bits. In other words, a specific bit width can serve as an identification marker for the payload.

[0101] Furthermore, the preamble in transmitter 2 contains a larger specific bit width than the non-specific bit width. A larger bit width results in a lower preamble frequency. A lower preamble frequency makes it less likely that noise components based on high-frequency elements will be included in the preamble. Therefore, compared to the preamble in a transceiver system composed only of non-specific bits B2, the preamble generated by transmitter 2 is less likely to contain noise components. That is, noise components are less likely to be generated in the serial data signal S1 generated by transmitter 2. In other words, noise components are less likely to be generated in the audio signal S4 after demodulation of the synthesized modulation signal S6 transmitted by transmitter 2.

[0102] Furthermore, as described above, the transmitter 2 includes: a carrier signal generation unit 24 that generates a carrier signal S2; a filter unit 23 that performs linear processing on the rising and falling edges of the serial data signal S1; and a carrier signal modulation unit 25 that uses the linearly processed serial data signal S1 to modulate the carrier signal S2 to generate a carrier modulation signal S3. That is, the serial data signal S1 in the transmitter 2 is subjected to linear processing. The waveforms of the rising and falling edges of the linearly processed serial data signal S1 become smoother. As a result, the slopes of the rising and falling edges become gentler. Generally speaking, the steeper the slopes of the rising and falling edges, the more likely it is to contain noise components based on high-frequency components. Therefore, compared to the un-linearly processed serial data signal S1, the serial data signal S1 linearly processed by the transmitter 2 is less likely to contain noise components. That is, noise components are less likely to be generated in the audio signal S4 after demodulation of the synthesized modulation signal S6 transmitted by the transmitter 2.

[0103] Furthermore, as described above, this receiver 3 is a receiver for receiving a synthesized modulated signal S6, wherein the synthesized modulated signal S6 is obtained by analog modulation of a synthesized signal S5 composed of a carrier modulated signal S3 and an audio signal S4. The carrier modulated signal S3 is generated based on a serial data signal S1 storing predetermined information and a carrier signal S2. The audio signal S4 is generated based on sound waves from a sound source. This receiver 3 includes: a demodulation unit 321 that demodulates the synthesized signal S5 from the synthesized modulated signal S6; a first extraction filter unit 322 that extracts the carrier modulated signal S3 from the demodulated synthesized signal S5; and a second extraction filter unit 323 that removes noise components from the extracted carrier modulated signal S3. The demodulated synthesized signal S5 in this receiver 3 may contain noise components based on high-frequency components. By passing the synthesized signal S5 through the first extraction filter unit 322 and the second extraction filter unit 323, the carrier modulated signal S3 with noise components removed is extracted. Based on the extracted carrier modulated signal S3, the serial data signal S1 is demodulated. Therefore, compared to the serial data signal S1 demodulated from the carrier modulation signal S3 that has not passed through the first extraction filter section 322 and the second extraction filter section 323, the serial data signal S1 demodulated by this receiver 3 is less likely to contain noise components. That is, the transmission and reception of the synthesized modulation signal S6 of this system 1 is less likely to fail.

[0104] ●Features of this transmitter, receiver, and system● The features of this transmitter, receiver, and system described above are summarized below.

[0105] ●Features of this transmitter This transmitter (e.g., transmitter 2) is a transmitter for transmitting a synthesized modulated signal (e.g., synthesized modulated signal S6), wherein the synthesized modulated signal is obtained by analog modulation (e.g., FM modulation) of a synthesized signal (e.g., synthesized signal S5) composed of a carrier modulated signal (e.g., carrier modulated signal S3) and an audio signal (e.g., audio signal S4), characterized in that the carrier modulated signal is generated based on a serial data signal (e.g., serial data signal S1) storing predetermined information and a carrier signal (e.g., carrier signal S2), and the audio signal is generated based on... Generated by sound waves from a sound source, this transmitter has: a storage unit (e.g., storage unit 21) that stores predetermined information; and a control unit (e.g., control unit 22) that generates a serial data signal, the serial data signal containing a preamble in which specific bits (e.g., specific bit B1) and non-specific bits (e.g., non-specific bit B2) are arranged alternately, the bit width of the non-specific bits (e.g., non-specific bit width) is a reference bit width, and the bit width of the specific bits (e.g., specific bit width) is MN times the reference bit width (M and N are any integers from 1 to 9).

[0106] In this transmitter, M can be any value from 1 to 3, and N can be 5.

[0107] The transmitter may also include: a carrier signal generation unit (e.g., carrier signal generation unit 24) that generates a carrier signal; a filter unit (e.g., filter unit 23) that performs linear processing on the rising and falling edges of the serial data signal; and a carrier signal modulation unit (e.g., carrier signal modulation unit 25) that modulates the carrier signal using the linearly processed serial data signal to generate a carrier modulated signal.

[0108] ●Features of this receiver This receiver (e.g., receiver 3) is a receiver for receiving a synthesized modulated signal (e.g., synthesized modulated signal S6), wherein the synthesized modulated signal is obtained by analog modulation (e.g., FM modulation) of a synthesized signal (e.g., synthesized signal S5) composed of a carrier modulated signal (e.g., carrier modulated signal S3) and an audio signal (e.g., audio signal S4). The receiver is characterized in that the carrier modulated signal is generated based on a serial data signal (e.g., serial data signal S1) storing predetermined information and a carrier signal (e.g., carrier signal S2), and the audio signal is generated based on a sound wave from a sound source. The receiver includes a signal extraction unit (e.g., signal extraction unit 32) that extracts the carrier wave from the synthesized modulated signal. The system includes a modulated signal; an A / D conversion unit (e.g., A / D conversion unit 33) that converts the extracted carrier modulation signal into a digital signal; and an information extraction unit (e.g., data signal output unit 34) that extracts predetermined information from the converted digital signal. The serial data signal contains a preamble consisting of alternating specific bits (e.g., specific bit B1) and non-specific bits (e.g., non-specific bit B2). When the bit width of the non-specific bits (e.g., non-specific bit width) is the reference bit width, the bit width of the specific bits (e.g., specific bit width) is MN times the reference bit width (M and N are any integers from 1 to 9). The information extraction unit extracts predetermined information from the digital signal based on the bit width of the specific bits.

[0109] In this receiver, M can be any value from 1 to 3, and N can be 5.

[0110] In this receiver, the signal extraction unit may further include: a demodulation unit (e.g., demodulation unit 321) that demodulates the synthesized signal from the synthesized modulated signal; a first extraction filter unit (e.g., first extraction filter unit 322) that extracts the carrier modulated signal from the demodulated synthesized signal; and a second extraction filter unit (e.g., second extraction filter unit 323) that removes noise components from the extracted carrier modulated signal.

[0111] In this receiver, the first extraction filter section can also be a bandpass filter, and the second extraction filter section can also be a low-pass filter.

[0112] ●Features of this system This system (e.g., system 1) is characterized by having: a transmitter for transmitting a synthesized modulated signal (e.g., synthesized modulated signal S6), which is obtained by analog modulation (e.g., FM modulation) of a synthesized signal (e.g., synthesized signal S5) composed of a carrier modulated signal (e.g., carrier modulated signal S3) and an audio signal (e.g., audio signal S4); and a receiver for receiving the synthesized modulated signal, wherein the carrier modulated signal is generated based on a serial data signal (e.g., serial data signal S1) storing predetermined information and a carrier signal (e.g., carrier signal S2), and the audio signal is generated based on a sound wave from a sound source; the transmitter is this transmitter (e.g., this transmitter 2), and the receiver is this receiver (e.g., this receiver 3). Explanation of reference numerals in the attached figures

[0113] 1: Transceiver System 2: Transmitter 21: Storage Department 22: Control Department 23: Filter Section 24: Carrier signal generation unit 25: Carrier signal modulation section 26: Audio signal generation unit 27:Synthetic Department 28: Synthetic Signal Modulation Unit 29: Launching section 3: Receiver 31: Receiving Department 32: Signal Extraction Unit 321: De-escalation Department 322: First Extraction Filter Section 323: Second Extraction Filter Section 33: A / D Conversion Section 34: Data signal output section 35: Audio Signal Processing Department 36: Audio signal output section 4: Audio output device 5: Data output device S1: Serial data signal S2: Carrier signal S3: Carrier modulation signal S4: Audio signal S5: Synthesized signal S6: Synthesized Modulation Signal P: Specific Pattern B1: Specific bit B2: Non-specific bit

Claims

1. A transmitter for transmitting a composite modulated signal obtained by analog modulation of a composite signal consisting of a carrier modulated signal and an audio signal, characterized in that, The carrier modulation signal is generated based on a serial data signal storing predetermined information and a carrier signal. The audio signal is generated based on sound waves from the sound source. The transmitter has: Storage unit, which stores the information; and The control unit generates the serial data signal. The serial data signal contains a preamble consisting of alternating specific and non-specific bits. When the width of the non-specific bit is the base bit width, The bit width of the specific bit is MN times the base bit width (M and N are any integers from 1 to 9).

2. The transmitter according to claim 1, wherein, M can be any one of 1 to 3. The value of N is 5.

3. The transmitter according to claim 1, wherein, The transmitter has: A carrier signal generation unit that generates the carrier signal; The filter section performs linear processing on the rising and falling edges of the serial data signal; as well as The carrier signal modulation unit uses the serial data signal that has undergone the linear processing to modulate the carrier signal and generate the carrier modulation signal.

4. A receiver for receiving a composite modulated signal obtained by analog modulation of a composite signal composed of a carrier modulated signal and an audio signal, characterized in that, The carrier modulation signal is generated based on a serial data signal storing predetermined information and a carrier signal. The audio signal is generated based on sound waves from the sound source. The receiver has: A signal extraction unit extracts the carrier modulation signal from the synthesized modulation signal; An A / D converter converts the extracted carrier modulation signal into a digital signal; and The information extraction unit extracts the information from the converted digital signal. The serial data signal contains a preamble consisting of alternating specific and non-specific bits. When the width of the non-specific bit is the base bit width, The bit width of the specific bit is MN times the base bit width (M and N are any integers from 1 to 9). The information extraction unit extracts the information from the digital signal based on the bit width of the specific bit.

5. The receiver according to claim 4, wherein, M can be any one of 1 to 3. The value of N is 5.

6. The receiver according to claim 4, wherein, The signal extraction unit includes: The demodulation unit demodulates the synthesized signal from the synthesized modulated signal; The first extraction filter unit extracts the carrier modulation signal from the demodulated synthesized signal; as well as The second extraction filter removes noise components from the extracted carrier modulation signal.

7. The receiver according to claim 6, wherein, The first extraction filter section is a bandpass filter. The second extraction filter section is a low-pass filter.

8. A transceiver system, characterized in that, The transceiver system has the following features: A transmitter used to transmit a synthesized modulated signal obtained by analog modulation of a composite signal consisting of a carrier modulated signal and an audio signal; and A receiver that receives the synthesized modulated signal. The carrier modulation signal is generated based on a serial data signal storing predetermined information and a carrier signal. The audio signal is generated based on sound waves from the sound source. The transmitter is the transmitter described in claim 1. The receiver is the receiver described in claim 4.

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