TWI440368B - Signal extending system, and transmitter and receiver thereof - Google Patents

Description

Signal extension system and its transmitting end and receiving end

The present invention relates to a signal extension system and a transmitting end and a receiving end thereof, and more particularly to a signal extending system for transmitting stereo and its transmitting end and receiving end.

Please refer to FIG. 1 , which is a schematic diagram showing a conventional signal extension system. The signal extension system 1 includes a transmitting end 2, a receiving end 3, and a net route 4. The transmitting end 2 is electrically connected to the receiving end 3 via the network route 4. The transmitting end 2 includes a differential driver 21 and an interface 22, and the receiving end 3 includes a differential receiver 31 and an interface 32. The mesh route 4 includes twisted pairs 41 to 48, and the twisted pairs 41 to 48 are electrically connected to the interface 22 and the interface 32. The twisted pairs 41 to 46 are used to transmit video signals, and the twisted pairs 47 and 48 are used, for example, to transmit differential signals A+ and A-. Further, the twisted wires 41 and 42 are used to transmit red video data, the twisted wires 43 and 44 are used to transmit green video data, and the twisted wires 45 and 46 are used to transmit blue video data. The twisted pairs 47 and 48 are used to transmit the differential signals A+ and A-.

The differential driver 21 converts the tone signal A into a differential signal A+ and an A-output to the interface 22, and the differential signals A+ and A- are transmitted to the interface 32 via the twisted pairs 47 and 48, respectively. The differential receiver 31 receives the differential signals A+ and A- from the interface 32 and converts the differential signals A+ and A- into a single tone signal output. However, the conventional signal extension system can only transmit a single tone signal, but cannot transmit stereo sound, and thus cannot provide a user with a better sound field effect.

The invention relates to a signal extension system and a transmitting end and a receiving end thereof, which can transmit stereo to improve the shortcoming that the traditional signal extending system can only transmit a single tone signal.

According to the invention, a signal extension system is proposed. The signal extension system includes a transmitting end and a receiving end. The transmitting end includes a modulation circuit and a first interface. The modulation circuit includes a first modulator and a second modulator. The first modulator modulates the left channel signal according to the carrier signal having the first frequency band to generate the left channel modulation signal, and the second modulator modulates the right channel signal according to the carrier signal having the second frequency band to generate Right channel modulation signal. The first interface is coupled to the modulation circuit. The receiving end includes a second interface and a demodulation circuit. The demodulation circuit is coupled to the second interface, and respectively demodulates the left channel modulation signal and the right channel modulation signal to output the left channel signal and the right channel signal. The first interface and the second interface are electrically connected.

According to the invention, a signal extension system is proposed. The signal extension system includes a transmitting end and a receiving end. The transmitting end includes a modulation circuit and a first interface. The modulation circuit includes a first modulator, a second modulator, and a differential signal generating circuit. The first modulator modulates the left channel signal according to the carrier signal having the first frequency band to generate the left channel modulation signal, and the second modulator modulates the right channel signal according to the carrier signal having a second frequency band. Generate a right channel modulation signal. The differential signal generating circuit generates a differential signal according to the left channel modulation signal and the right channel modulation signal. The first interface is used to output a differential signal. The receiving end includes a second interface and a demodulation circuit. The second interface is for receiving a differential signal. The demodulation circuit includes a signal separation circuit and a demodulation module. The signal separation circuit separates the differential signal into a left channel modulation signal and a right channel modulation signal according to the first frequency band and the second frequency band. The demodulation module demodulates the left channel modulation signal and the right channel modulation signal respectively to output the left channel signal and the right channel signal.

According to the invention, a transmitting end of a signal extension system is proposed. The transmitting end of the signal extension system includes a modulation circuit and an interface. The modulation circuit includes a first modulator and a second modulator. The first modulator modulates the left channel signal according to the carrier signal having the first frequency band to generate the left channel modulation signal, and the second modulator modulates the right channel signal according to the carrier signal having the second frequency band to generate Right channel modulation signal. The interface is coupled to the modulation circuit.

According to the invention, a receiving end of a signal extension system is proposed. The receiving end of the signal extension system includes an interface and a demodulation circuit. The interface receives the differential signal. The demodulation circuit includes a signal separation circuit and a demodulation module. The signal separation circuit separates the differential signal into a left channel modulation signal and a right channel modulation signal according to the first frequency band and the second frequency band. The demodulation module demodulates the left channel modulation signal and the right channel modulation signal respectively to output the left channel signal and the right channel signal.

In order to better understand the above and other aspects of the present invention, the preferred embodiments are described below, and in conjunction with the drawings, the detailed description is as follows:

Please refer to FIG. 2, which is a schematic diagram of a signal extension system in accordance with the present invention. The signal extension system 5 includes a transmitting end 6, a receiving end 7, and a net route 4. The transmitting end 6 is electrically connected to the receiving end 7 via the network route 4, and the transmitting end 6 transmits a video signal, an audio signal, a differential signal or a power signal to the receiving end 7, for example.

First embodiment

Please refer to FIG. 3, which is a schematic diagram of a signal extension system according to a first embodiment of the present invention. The signal extension system 5, the transmission end 6 and the receiving end 7 are respectively represented by the signal extension system 5a, the transmission end 6a and the receiving end 7a in the first embodiment. The signal extension system 5a includes a transmitting end 6a, a receiving end 7a, and a net route 4. The mesh route is, for example, a twisted pair cable (CAT-5 line). The transmitting end 6a includes a modulation circuit 61a and an interface 62, and the interface 62 is coupled to the modulation circuit 61a. The modulation circuit 61a generates a left channel modulation signal SL5 according to the left channel signal SL1, and generates a right channel modulation signal SR5 according to the right channel signal SR1.

The receiving end 7a includes a demodulation circuit 71a and an interface 72, and the interface 72 is electrically connected to the interface 62 via the network route 4. Interface 62 and interface 72 are, for example, network interfaces. The mesh route 4 includes twisted pairs 41 to 48, and the twisted pairs 41 to 48 are electrically connected to the interface 62 and the interface 72. The twisted pairs 41 to 46 are used, for example, to transmit video signals, and the twisted pairs 47 and 48 are used, for example, to transmit audio signals, differential signals, or audio signals plus power signals. For example, twisted pairs 41 and 42 are used to transmit red video data, twisted pairs 43 and 44 are used to transmit green video data, and twisted pairs 45 and 46 are used to transmit blue video data. The twisted pairs 47 and 48 are used to transmit audio signals, differential signals or audio signals plus power signals. In the first embodiment, the audio signal is the left channel modulation signal SL5 and the right channel modulation signal SR5, and the left channel modulation signal sL5 and the right channel modulation signal sR5 are respectively connected by the twisted pair 47. And 48 transmission. The demodulation circuit 71a is coupled to the interface 72. The demodulation circuit 71a is configured to respectively demodulate the left channel modulation signal SL5 and the right channel modulation signal SR5 to output the left channel signal SL1 and the right channel signal SR1, thereby generating a stereo effect.

The signal extension system 5a can improve the problem that the conventional signal extension system can only transmit a single tone. In addition, the signal extension system 5a can achieve the function of transmitting stereo without additional micro controller unit (MCU), thereby reducing production cost and increasing product competitiveness.

Please refer to FIG. 4, FIG. 5 and FIG. 6 at the same time. FIG. 4 is a schematic diagram showing the first modulation circuit, and FIG. 5 is a left channel signal SL4, a carrier signal SL1 and a left The waveform diagram of the channel modulation signal, and the sixth diagram shows the waveform diagram of the right channel signal SR4, the carrier signal SR1 and the right channel modulation signal SR5. The modulation mode of the modulation circuit 61a is, for example, amplitude modulation, frequency modulation, or phase modulation. For convenience of description, the following embodiments are described by taking amplitude modulation as an example. The modulation circuit 61a includes a modulator 611 and a modulator 612. The modulator 611 modulates the left channel signal SL1 according to the carrier signal SL4 having the first frequency band to generate the left channel modulation signal SL5, and the modulator 612 modulates the right channel signal according to the carrier signal SR4 having the second frequency band. SR1 to generate a right channel modulation signal SR5. The first frequency band and the second frequency band may be different frequency bands. For example, the first frequency band is, for example, 1 MHz, and the second frequency band is, for example, 2 MHz.

Further, the modulator 611 further includes an adder 6111 and a mixer 6112, and the modulator 612 further includes an adder 6121 and a mixer 6122. The adder 6111 generates a left channel signal SL3 having a DC component based on the left channel signal SL1 and the DC level SL2. The mixer 6112 modulates the left channel signal SL3 having the DC component according to the carrier signal SL4 having the first frequency band to generate the left channel modulation signal SL5. Similarly, the adder 6121 generates a right channel signal SR3 having a DC component based on the right channel signal SR1 and the DC level SR2. The mixer 6122 modulates the right channel signal SR3 having the DC component according to the carrier signal SR4 having the second frequency band to generate the right channel modulation signal SR5.

Please refer to FIG. 7 , FIG. 8 and FIG. 9 at the same time, FIG. 7 is a schematic diagram showing a first type of demodulation circuit, and FIG. 8 is a diagram showing a left-channel modulation signal SL5 passing through a half-wave rectification circuit. The waveform of the rectified signal SL6 outputted after 711 and the filtered signal SL3 outputted after passing through the low-pass filter circuit 712, and FIG. 9 is a rectified signal SR6 outputted by the right-channel modulation signal SR5 after passing through the half-wave rectification circuit 711. And the waveform diagram of the filtered signal SR3. The demodulation circuit 71a includes a half-wave rectification circuit 711, a low-pass filter circuit 712, and a DC removal circuit 713. The half-wave rectifying circuit 711 performs half-wave rectification on the left channel modulation signal SL5 and the right channel modulation signal SR5 to output the rectified signal SL6 and the rectified signal SR6, respectively. The low pass filter circuit 712 performs low pass filtering on the rectified signal SL6 and the rectified signal SR6 to output the filtered signal SL3 and the filtered signal SR3. The DC removing circuit 713 removes the DC components of the filtered signal SL3 and the filtered signal SR3 to output the left channel signal SL1 and the right channel signal SR1.

Second embodiment

Referring to FIG. 10, FIG. 10 is a schematic diagram showing a signal extension system according to a second embodiment of the present invention. The signal extension system 5b is mainly different from the signal extension system 5a in that the transmission end 6b further includes a boosting circuit 63, and the receiving end 7b further includes a step-down circuit 73. The boosting circuit 63 is for boosting the DC voltage V1 (for example, 5 V) to a DC voltage V2 (for example, 20 V), and outputting the DC voltage V2 to the interface 62. The DC voltage V2 can be transmitted to the interface 72 via the interface 62 with the right channel modulation signal SR5, and the DC voltage V2 is represented by the signal SR7 in the form of the right channel modulation signal SR5. The DC voltage V3 is, for example, a ground voltage. In another embodiment, if the DC voltage V3 is 20V, the DC voltage V2 is a ground voltage (not shown). The DC voltage V3 can be transmitted to the interface 72 via the interface 62 with the left channel modulation signal SL5, and the DC voltage V3 is represented by the signal SL7 in the form of the left channel modulation signal SL5. The step-down circuit 73 is configured to reduce the DC voltage V2 (for example, 20 V) to a DC voltage V1 (for example, 5 V), and the DC voltage V1 can be a power source of the receiving terminal 7b. It can be seen that the transmitting end 6b can further output the audio signal plus the power signal to the receiving end 7b to provide the power supply required by the receiving end 7b, thereby achieving a cost saving effect.

Third embodiment

Please refer to FIG. 11 , FIG. 12 and FIG. 13 simultaneously. FIG. 11 is a schematic diagram showing a signal extension system according to a third embodiment of the present invention, and FIG. 12 is a second modulation circuit. FIG. 13 is a schematic diagram showing a second demodulation circuit. The signal extension system 5c is mainly different from the signal extension system 5a in that the transmission end 6c is different from the transmission end 6a, and the reception end 7c is different from the reception end 7a. The transmission end 6c is mainly different from the transmission end 6a in the modulation circuit 61b. Unlike the modulation circuit 61a, the receiving end 7c is mainly different from the receiving end 7a in that the demodulating circuit 71b is different from the demodulating circuit 71a.

The modulation circuit 61b is mainly different from the modulation circuit 61a in that the modulation circuit 61b includes a differential signal generation circuit 615 in addition to the modulators 611 and 612. The differential signal generating circuit 615 generates the differential signals D1 and D2 according to the left channel modulation signal SL5 and the right channel modulation signal SR5. Further, the differential signal generating circuit 615 includes an adder 613 and a single-ended differential circuit 614. The adder 613 adds the left channel modulation signal SL5 and the right channel modulation signal SR5 to output a single-ended signal S9. The single-ended to differential circuit 614 converts the single-ended signal S9 into differential signals D1 and D2.

The demodulation circuit 71b is mainly different from the demodulation circuit 71a in that the demodulation circuit includes a signal separation circuit 717 in addition to the half-wave rectification circuit 711, the low-pass filter circuit 712, and the DC removal circuit 713. The signal separation circuit 717 separates the differential signals D1 and D2 into a left channel modulation signal SL5 and a right channel modulation signal SR5 according to the first frequency band and the second frequency band. Further, the signal separation circuit 717 includes a differential to single-ended circuit 714, a left channel filter 715, and a right channel filter 716. The differential to single-ended circuit 714 converts the differential signals D1 and D2 into a single-ended signal S9. The left channel filter 715 filters the single-ended signal S9 according to the first frequency band to output the left channel modulation signal SL5, and the right channel filter 716 filters the single-ended signal S9 according to the second frequency band to output the right channel modulation. Signal SR5. The operations of the subsequent half-wave rectification circuit 711, the low-pass filter circuit 712, and the DC removal circuit 713 have been described in detail in the first embodiment, and are not described herein.

Fourth embodiment

Referring to FIG. 14, FIG. 14 is a schematic diagram showing a signal extension system according to a fourth embodiment of the present invention. Signal extension system 5d and signal extension system The main difference is that the transmitting end 6d further includes a boosting circuit 63, and the receiving end 7d further includes a step-down circuit 73. The boosting circuit 63 is for boosting the DC voltage V1 (for example, 5 V) to a DC voltage V2 (for example, 20 V), and outputting the DC voltage V2 to the interface 62. The DC voltage V2 can be transmitted to the interface 72 via the interface 62 along with the differential signal D2, and the DC voltage V2 is represented by the signal D21 in the form of the differential signal D2 in FIG. The DC voltage V3 is, for example, a ground voltage. The DC voltage V3 can be transmitted to the interface 72 via the interface 62 along with the differential signal D1, and the DC voltage V3 is represented by the signal D11 in the form of the differential signal D1 in FIG. The aforementioned step-down circuit 73 In order to reduce the DC voltage V2 to the DC voltage V1, the DC voltage V1 can be the power source of the receiving terminal 7d. It can be seen that the transmitting end 6d can further output the differential signal plus the power signal to the receiving end 7d to provide the power supply required by the receiving end 7d, thereby achieving a cost saving effect.

The aforementioned signal extension system can improve the problem that the conventional signal extension system can only transmit a single tone, and can realize the function of transmitting stereo without additionally adding a Micro Controller Unit (MCU). In this way, not only can reduce production costs, but also increase product competitiveness. Furthermore, the transmitting end of the signal extension system can further provide the power supply required by the receiving end, thereby achieving a cost saving effect.

In conclusion, the present invention has been disclosed in the above preferred embodiments, and is not intended to limit the present invention. A person skilled in the art can make various changes and modifications without departing from the spirit and scope of the invention. Therefore, the scope of the invention is defined by the scope of the appended claims.

1. . . Traditional signal extension system

2, 6, 6a, 6b, 6c, 6d. . . Transmitter

3, 7, 7a, 7b, 7c, 7d. . . Receiving end

4. . . Web route

5, 5a, 5b, 5c, 5d. . . Signal extension system according to an embodiment of the invention

twenty one. . . Differential driver

22, 32, 62, 72. . . interface

31. . . Differential receiver

41~48. . . Twisted pair

61a, 61b. . . Modulation circuit

63. . . Boost circuit

71a, 71b. . . Demodulation circuit

73. . . Buck circuit

611, 612. . . Modulator

613. . . Adder

614. . . Single-ended differential circuit

615. . . Differential signal generation circuit

711‧‧‧Half-wave rectifier circuit

712‧‧‧Low-pass filter circuit

713‧‧‧DC removal circuit

714‧‧‧Differential to single-ended circuit

715‧‧‧left channel filter

716‧‧‧Right channel filter

717‧‧‧Signal separation circuit

6111, 6121‧‧ ‧ adder

6112, 6122‧‧‧ Mixer

A‧‧‧monophonic signal

A+, A-, D1, D2‧‧‧Differential signals

SL1‧‧‧left channel signal

SR1‧‧‧Right channel signal

SL2, SR2‧‧‧ DC level

SL3, SR3‧‧‧ filter signal

SL4‧‧‧ has the carrier signal of the first frequency band

SR4‧‧‧ with carrier signal in the second frequency band

SL5‧‧‧left channel modulation signal

SR5‧‧‧Right channel modulation signal

SL6, SR6‧‧‧ rectified signal

SL7, SR7, D11, D21‧‧‧ signals

S9‧‧‧ single-ended signal

V1, V2, V3‧‧‧ DC voltage

Figure 1 is a schematic diagram showing a conventional signal extension system.

Figure 2 is a schematic illustration of a signal extension system in accordance with the present invention.

Figure 3 is a schematic diagram showing a signal extension system in accordance with a first embodiment of the present invention.

Figure 4 is a schematic diagram showing the first modulation circuit.

Figure 5 is a schematic diagram showing the waveforms of the left channel signal, the carrier signal, and the left channel modulation signal.

Figure 6 is a schematic diagram showing the waveforms of the right channel signal, the carrier signal, and the right channel modulation signal.

Figure 7 is a schematic diagram showing the first demodulation circuit.

FIG. 8 is a schematic diagram showing waveforms of the rectified signal SL6 and the filtered signal SL3.

FIG. 9 is a schematic diagram showing waveforms of the rectified signal SR6 and the filtered signal SR3.

Figure 10 is a schematic diagram showing a signal extension system in accordance with a second embodiment of the present invention.

Figure 11 is a schematic diagram showing a signal extension system in accordance with a third embodiment of the present invention.

Figure 12 is a schematic diagram showing a second modulation circuit.

Figure 13 is a schematic diagram showing a second type of demodulation circuit.

Figure 14 is a schematic diagram showing a signal extension system in accordance with a fourth embodiment of the present invention.

6a. . . Transmitter

7a. . . Receiving end

4. . . Web route

5a. . . Signal extension system according to an embodiment of the invention

62, 72. . . interface

41~48. . . Twisted pair

61a. . . Modulation circuit

71a. . . Demodulation circuit

SL1. . . Left channel signal

SR1. . . Right channel signal

SL5. . . Left channel modulation signal

SR5. . . Right channel modulation signal

Claims (17)

A signal extension system includes: a transmitting end, comprising: a modulation circuit, comprising: a first modulator for modulating a left channel signal according to a carrier signal having a first frequency band to generate a a left channel modulation signal; and a second modulator for modulating a right channel signal according to a carrier signal having a second frequency band to generate a right channel modulation signal; a first interface The modulation circuit is coupled to the left channel modulation signal and the right channel modulation signal; a receiving end includes: a second interface for receiving the left channel modulation signal and the a right channel modulation signal; and a demodulation circuit coupled to the second interface, the demodulation circuit is configured to respectively demodulate the left channel modulation signal and the right channel modulation signal to output the left sound The channel signal and the right channel signal; and a network route, comprising: a pair of twisted wires for electrically connecting the first interface and the second interface, and transmitting the left channel modulation signal and the right sound Modulation signal. The signal extension system of claim 1, wherein the first frequency band is different from the second frequency band. The signal extension system of claim 1, wherein the demodulation circuit comprises: a half-wave rectification circuit for respectively performing half-wave rectification on the left channel modulation signal and the right channel modulation signal to output a first rectification signal and a second rectification signal a low-pass filter circuit for low-pass filtering the first rectified signal and the second rectified signal to output a first filtered signal and a second filtered signal; and a DC removal circuit for removing The first filtered signal and the DC component of the second filtered signal output the left channel signal and the right channel signal. The signal extension system of claim 1, wherein the demodulation circuit further comprises: a half-wave rectification circuit for performing half-wave rectification on the left channel modulation signal and the right channel modulation signal, respectively. And outputting a first rectified signal and a second rectifying signal; and a low pass filtering circuit for low pass filtering the first rectified signal and the second rectified signal to output a first filtered signal and a second filtered And a DC removal circuit for removing the DC component of the first filtered signal and the second filtered signal to output the left channel signal and the right channel signal. The signal extension system of claim 1, wherein the modulation circuit further comprises: a boosting circuit for boosting a first DC voltage to a second DC voltage, and the second DC The voltage is output to the first interface. The signal extension system of claim 5, wherein the demodulation circuit further comprises: a step-down circuit for reducing the second DC voltage to a third DC voltage. A signal extension system comprising: a transmitting end, comprising: a modulation circuit, comprising: a first modulator for modulating a left channel signal according to a carrier signal having a first frequency band to generate a left channel modulation signal; a second modulator for modulating a right channel signal according to a carrier signal having a second frequency band to generate a right channel modulation signal; and a differential signal generating circuit for using the left sound The channel modulation signal and the right channel modulation signal generate a differential signal; a first interface for outputting the differential signal; and a receiving end comprising: a second interface for receiving the differential signal; a demodulation circuit comprising: a signal separation circuit for separating the differential signal into the left channel modulation signal and the right channel modulation signal according to the first frequency band and the second frequency band; The module respectively demodulates the left channel modulation signal and the right channel modulation signal to output the left channel signal and the right channel signal; and a network route, including: a pair of twisted pairs, The first interface and the second interface are electrically connected, and the differential signal is transmitted. The signal extension system of claim 7, wherein the first frequency band is different from the second frequency band. The signal extension system of claim 7, wherein the demodulation module comprises: a half-wave rectification circuit for separately modulating the left channel and the right channel The modulated signal is subjected to half-wave rectification to output a first rectified signal and a second rectified signal; a low pass filter circuit for low pass filtering the first rectified signal and the second rectified signal to output a first a filter signal and a second filter signal; and a DC removal circuit for removing the DC components of the first filter signal and the second filter signal to output the left channel signal and the right channel signal. The signal extension system of claim 7, wherein the differential signal generation circuit comprises: an adder for adding the left channel modulation signal and the right channel modulation signal to output a single And a single-ended differential circuit for converting the single-ended signal into the differential signal. The signal extension system of claim 7, wherein the signal separation circuit further comprises: a differential to single-ended circuit for converting the differential signal into the single-ended signal; a left channel filter And filtering the single-ended signal according to the first frequency band to output the left channel modulation signal; and a right channel filter for filtering the single-ended signal according to the second frequency band to output the right sound Modulation signal. The signal extension system of claim 7, wherein the modulation circuit further comprises: a boosting circuit for boosting a first DC voltage to a second DC voltage, and the second DC The voltage is output to the first interface. For example, the signal extension system described in claim 12, wherein The demodulation circuit further includes: a step-down circuit for reducing the second DC voltage to a third DC voltage. A transmitting end of the signal extension system, comprising: a modulation circuit, comprising: a first modulator for modulating a left channel signal according to a carrier signal having a first frequency band to generate a left channel a second modulation device for modulating a right channel signal according to a carrier signal having a second frequency band to generate a right channel modulation signal; and a first interface coupled to the The modulation circuit is connected to a receiving end via a network route, and the first interface is configured to output the left channel modulation signal and the right channel modulation signal. The transmitting end according to claim 14, wherein the receiving end comprises: a second interface connecting the network route; and a demodulating circuit coupled to the second interface, the demodulating circuit is used The left channel modulation signal and the right channel modulation signal are separately demodulated to output the left channel signal and the right channel signal; wherein the first interface and the second interface are electrically connected. The receiving end of the signal extension system includes: a first interface for receiving a differential signal or/and a power signal, and connected to a transmitting end via a network route; and a demodulating circuit comprising: a signal a separating circuit for separating the differential signal into a left channel modulation signal and a right channel modulation signal according to a first frequency band and a second frequency band; And a demodulation module, respectively demodulating the left channel modulation signal and the right channel modulation signal to output a left channel signal and a right channel signal. The receiving end of claim 16, wherein the transmitting end comprises: a modulation circuit, comprising: a first modulator for modulating the left signal according to a carrier signal having the first frequency band Channel signal for generating the left channel modulation signal; a second modulator for modulating the right channel signal according to a carrier signal having the second frequency band to generate the right channel modulation signal; a differential signal generating circuit for generating the differential signal according to the left channel modulation signal and the right channel modulation signal; and a second interface for outputting the differential signal or/and a power signal.