CN113132557A - Signal compensation method and signal intermediate equipment thereof - Google Patents
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Abstract
The invention provides a signal compensation method, which comprises connecting a multimedia information source device and a signal intermediate device by a first transmission line. Then, the second transmission line is used to connect the signal intermediate device and the multimedia information display device. Then, according to the signal transmission protocol, the signal intermediate device receives the link training signals from the multimedia information source device and the multimedia information display device through the first transmission line and the second transmission line, respectively. Finally, the signal intermediate device adjusts the multimedia signal transmitted to the multimedia information display device through the second transmission line according to the electrical characteristic of the link training signal.
Description
[ technical field ] A method for producing a semiconductor device
The present invention relates to a signal compensation technique, and more particularly, to a signal compensation method for compensating signal attenuation caused by transmission via a transmission line and a signal intermediate apparatus thereof.
[ background of the invention ]
In recent years, multimedia audio and video technology has developed quite rapidly. For example: the High-Definition Multimedia Interface (HDMI) or Digital Visual Interface (DVI) or Display Port (DP) transmission Interface with High-speed data transmission capability can achieve the goal of distortion-free output because it transmits uncompressed audio signals and High-resolution video signals through the same cable without the need of converting analog signals into Digital signals (a/D) or converting Digital signals into analog signals (D/a).
Among them, USB, HDMI, DisplayPort, etc. are advanced to the stage of high-speed transmission, for example: according to the DisplayPort 1.4 standard, the cable supports four channels in each display output, the data transmission rate of each channel can reach 8.1Gbps, therefore, the four channels can simultaneously transmit high-resolution audio and video signals, and the total bandwidth can reach 32.4 Gbps. However, in the field of high-speed transmission, the higher the frequency of data, the more susceptible it is to attenuation during transmission due to the impedance of the data transmission line.
Please refer to fig. 1, which is a schematic diagram of a signal transmission system in the prior art. The system 1 has a signal switching device 10 having a plurality of signal input interfaces 100, each signal input interface 100 can be connected to a corresponding signal source 11, for example: a computer for receiving the multimedia signal outputted from the signal source 11. The signal input interface 100 is electrically connected to a signal conversion device (dongle)13 and a signal source 11 through a transmission line 12. The transmission line 12 is typically twisted pair, such as: cat.5, etc. The signal conversion device 13 has an interface 130 at one end for connecting with the transmission line 12, and an image interface 131 at the other end, for example: RGB, HDMI, DVI, DisplayPort, etc., and a control signal interface 132 for connecting to the signal source 11. The signal switching system 1 further has a plurality of output interfaces 101 for electrically connecting with a remote signal control device (console)14 through a transmission line 12, the signal control device 14 is connected with a display 15 and an input device 16, such as: keyboard, mouse, etc. connected electrically.
Since the transmission line 12 has a long length when transmitting signals, which affects the quality of the transmitted signals, especially for high frequency signals, the signals are more prone to be attenuated due to long distance transmission. Therefore, in the prior art, a test signal is usually loaded on the signal conversion device 13 side and transmitted to the signal control device 14. Under the structure, the signal conversion device 13 can be used as a transmitter of the test signal, and the signal control device 14 can be used as a receiver of the test signal, after the signal control device 14 receives the test signal, the multimedia signal is compensated according to the attenuation state of the test signal.
[ summary of the invention ]
The invention provides a signal compensation method and signal intermediate equipment thereof, which is characterized in that in the signal transmission process conforming to a transmission protocol, a link training signal (link training signal) from a multimedia information source device (source) and/or a multimedia information display equipment (sink) is captured, for example: the training check signal (training check) or the training result signal (training result) has a specific stability characteristic by the link training signal, such as: the invention uses frequency or voltage, current signal as reference, and detects the change of continuous AC signal to judge the signal attenuation degree, and then automatically adjusts the compensation parameter for compensating multimedia signal.
The invention provides a signal compensation method and signal intermediate equipment thereof, which utilize a bidirectional transmission Link Training (Link Training) mechanism of an auxiliary transmission Channel (AUX Channel) to capture a differential signal output by a sending end or a receiving end and detect the electrical characteristics of the differential signal after transmission, thereby achieving the effects of judging the attenuation of a wire length and compensating the signal.
In one embodiment, the present invention provides a signal compensation method, which includes the following steps. First, a multimedia information source device and a signal intermediate device are connected by a first transmission line. Then, the second transmission line is used to connect the signal intermediate device and the multimedia information display device. Then, according to the signal transmission protocol, the signal intermediate device receives the link training signals from the multimedia information source device and the multimedia information display device through the first transmission line and the second transmission line, respectively. Finally, the signal intermediate device adjusts the multimedia signal transmitted to the multimedia information display device through the second transmission line according to the electrical characteristic of the link training signal.
In one embodiment, the method for adjusting the multimedia signal according to the electrical characteristic of the link training signal further comprises the following steps: first, the differential signal in the link training signal is captured. Then, a single-ended signal is generated according to the differential signal, and a DC voltage level is generated according to the single-ended signal. Finally, the multimedia signal transmitted to the multimedia information display equipment through the second transmission line is adjusted according to the DC voltage level.
In one embodiment, the present invention provides a signal intermediate device, which is electrically connected to a multimedia information source device through a first transmission line and electrically connected to a multimedia information display device through a second transmission line, and further includes a plurality of first transmission interfaces, at least one second transmission interface, a switching module, and a signal processor. Wherein, each first transmission interface is electrically connected with the multimedia information source device through a first transmission line. Each second transmission interface is electrically connected with the multimedia information display equipment through a second transmission line. The switching module is electrically connected with the plurality of first transmission interfaces and at least one second transmission interface, and is used for switching and selecting one of the first transmission interfaces to be electrically connected with one of the second transmission interfaces. The signal processor captures a link training signal from the multimedia information source device and the multimedia information display device according to a signal transmission protocol, and adjusts the multimedia signal transmitted to the multimedia information display device through the second transmission line according to the electrical characteristic of the link training signal.
In one embodiment, the signal processor includes a signal capturing unit, a signal converting unit and a signal processing unit, wherein the signal capturing unit captures a differential signal in the link training signal by impedance isolation and converts the differential signal into a single-ended signal, the signal converting unit generates a dc level signal according to the single-ended signal, and the signal processing unit adjusts the multimedia signal transmitted to the multimedia information display device through the second transmission line according to the dc voltage level.
In one embodiment, the present invention further provides a signal intermediate apparatus, which is suitable for a multimedia information source device and a multimedia information display apparatus, the signal intermediate apparatus is electrically connected to the multimedia information source device directly through a first transmission line, the signal intermediate apparatus is electrically connected to the multimedia information display apparatus directly through a second transmission line, and the signal intermediate apparatus includes a signal processor, which receives a training check signal and a multimedia signal from the multimedia information source device through the first transmission line, and transmits the received training check signal and the received multimedia signal to the multimedia information display apparatus through the second transmission line. Furthermore, the signal processor adjusts the multimedia signal according to the electrical characteristic of the training check signal and transmits the multimedia signal to the multimedia information display device through the second transmission line, so that the multimedia information display device can normally display the multimedia signal.
In another embodiment, the signal processor further receives a training result signal from the multimedia information display device via the second transmission line in response to the training check signal, adjusts the received multimedia signal according to the electrical characteristic of the training result signal, and further transmits the adjusted multimedia signal to the multimedia information display device via the second transmission line, so that the multimedia information display device can normally display the multimedia signal.
The specific techniques employed in the present invention will be further illustrated by the following examples and accompanying drawings.
[ description of the drawings ]
FIG. 1 is a diagram of a closed signal transmission system in the prior art.
FIG. 2 is a schematic diagram of a signal intermediate apparatus according to an embodiment of the present invention.
Fig. 3A and 3B are schematic flow charts illustrating a signal compensation method according to an embodiment of the present invention.
FIG. 4 is a diagram showing the relationship between the voltage and the time of the signal outputted from the signal processor according to the present invention.
Fig. 5 is a schematic diagram of a first embodiment of the intermediate device of the present invention.
Description of the main element symbols:
2. 2 b-a transmission system; 20-signal intermediate equipment; 20 a-an intermediate device; 200-a first transmission interface; 201-a second transmission interface; 202-a switching module; 202 a-first switch; 202 b-a second switch; 21. 21 a-a multimedia information display device; 22-a signal processor; 22-a signal processor; 220-a signal acquisition unit; 221-a signal conversion unit; 222-a signal processing unit; 223-multimedia signal processing unit; 2230-an adjustment unit; 3-multimedia information source devices 9 a-9 e-transmission lines; 90-multimedia information transmission channel; 91-auxiliary transmission channel; 900-single-ended signal; 910-DC voltage level; 912-single ended signal; 913-DC voltage level; 4-signal compensation method; 40-43, 430-433-flow. [ detailed description ] embodiments
Various exemplary embodiments may be described more fully hereinafter with reference to the accompanying drawings, in which some exemplary embodiments are shown. The inventive concept may, however, be embodied in many different forms and should not be construed as limited to the exemplary embodiments set forth herein. Rather, these exemplary embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the inventive concept to those skilled in the art. Like numbers refer to like elements throughout. The present invention will be described in detail with reference to the drawings by using various embodiments of an firm-providing method and its firm-providing apparatus, which are not intended to limit the present invention.
Please refer to fig. 2, which is a diagram illustrating a signal intermediate apparatus according to an embodiment of the present invention. The signal transmission system 2 shown in fig. 2 has a signal intermediate device 20, which is a KVM switch or a matrix array switch in this embodiment, the signal intermediate device 20 has a plurality of first transmission interfaces 200 and at least one second transmission interface 201, wherein the first transmission interfaces 200 are electrically connected to the multimedia information source apparatus 3 through transmission lines 9a, and the second transmission interfaces 201 are electrically connected to the multimedia information display device 21 through transmission lines 9 b. The multimedia information source apparatus 3 may be a player, for example: but the invention is not limited to DVD players, blu-ray DVD players, computers, etc. The multimedia information display device 21, for example: but the invention is not limited to televisions, video walls, computer monitors, etc.
The first transmission interface 200 and the second transmission interface 201 may be DVI, HDMI, or DisplayPort interfaces, and in this embodiment, are DisplayPort interfaces. The transmission lines 9a and 9b may be wires for transmitting multimedia audio/video signals, for example: DisplayPort signal lines, HDMI signal lines, DVI signal lines, etc., or may be twisted pair lines, such as: category five twisted pair (category 5, cat.5), category six or category seven twisted pair, etc., but the invention is not limited thereto. In the present embodiment, the transmission lines 9a and 9b are DisplayPort transmission lines for transmitting DisplayPort signals of DisplayPort transmission protocol. The output signal from the multimedia source device 3 is transmitted to the signal intermediate device 20 through the transmission line 9a, and the signal intermediate device 20 transmits the output signal to the multimedia display device 21 through the transmission line 9 b. In one embodiment, the output signal includes a multimedia signal related to multimedia information, an auxiliary signal related to control information, and a hot-plug detection signal related to hot-plug detection. Wherein the multimedia signal and the auxiliary signal are differential signals. Since the present embodiment is described with respect to the video interface of DisplayPort, the following DisplayPort output signals are all in compliance with the specification of the video transmission protocol of DisplayPort, but the invention is not limited thereto.
Referring back to fig. 2, the channel established by the transmission line 9a or 9b between the intermediate signal device 20 and the multimedia information source apparatus 3 or the multimedia information display device 21 has a multimedia information transmission channel 90 and an auxiliary transmission channel 91, wherein the transmission channel 90 is used for transmitting a plurality of pairs of audio/video differential signals ML _ Lane _0 to ML _ Lane _3 in the DisplayPort signal, and the auxiliary transmission channel 91 is a bidirectional half-duplex channel and is used for transmitting auxiliary signals (AUX _ CH _ p, AUX _ CH _ n) of differential nature in the DisplayPort signal, and the auxiliary signal of DisplayPort is used for managing and controlling signals, such as VESA EDID, MCCS and DisplayPort standards. It should be noted that the signals of the DisplayPort interface include hot plug signal (HPD), ground and power pins, which are well known in the art and will not be described herein. Further, it is to be noted that the transmission lines constituting the multimedia information transmission channel and the auxiliary transmission channel are, for example: twisted pairs of multiple pairs have conductor characteristics such as: the material, transmission attenuation characteristics, or impedance characteristics are the same.
In this embodiment, the signal intermediate apparatus 20 further includes a switching module 202 and a signal processor 22. The switching module 202 is electrically connected to the plurality of first transmission interfaces 200 and the at least one second transmission interface 201, and the switching module 202 can be used to switch and select one of the first transmission interfaces 200 to be electrically connected to one of the second transmission interfaces 201 according to the control selection signal, so that the multimedia information source device 3 connected to the selected first transmission interface 200 can output the output signal to the multimedia information display apparatus 21 electrically connected to the selected second transmission interface 201 to display and output the video information. In the present embodiment, the switch module 202 further has a plurality of first switches 202a and second switches 202b electrically connected to the signal processor 22 respectively for receiving the control signal from the signal processor 22 to select switching. Each of the first switches 202a is electrically connected to a plurality of the multimedia sink devices 3, and the plurality of first switches 202a are electrically connected to the second switch 202 b. The signal processor 22 is coupled to the second transmission interface 201 for compensating the multimedia signal output to the second transmission interface 201. It is noted that the switching module 202 is not limited in the above manner, for example: in another embodiment, the switching module 202 may also be a cross point switch (crossbar).
In the DisplayPort transmission protocol, the multimedia signal and the auxiliary signal are high-speed differential signals, and when the signal is transmitted through a transmission line, the quality of the signal depends on the length of the transmission line, and the longer the transmission line, the more the attenuation of the video quality increases, and once the attenuation reaches a certain degree, the multimedia information display device 21 cannot smoothly output the video information. In order to solve the signal attenuation problem without adding additional components for generating test signals to the multimedia source device, in the present embodiment, the DisplayPort transmission protocol is utilized to have fixed characteristics, such as: link training signals (link training signals) with bidirectional communication characteristics of frequency and voltage, for example: the training check signal (training check) sent by the multimedia information source device and/or the training result signal (training result) sent by the multimedia information display apparatus 21 are used to detect the signal attenuation, so as to perform signal compensation on the multimedia signal and maintain the effect that the output signal output by the multimedia information source device 3 can be displayed on the multimedia information display apparatus 21.
In one embodiment, please refer to fig. 3A and 3B, which are schematic flow charts illustrating a signal compensation method according to an embodiment of the present invention. The flow of the present embodiment is illustrated by the architecture shown in fig. 2. First, in step 40, channels are respectively established on the transmission line 9a between the signal intermediate apparatus 20 and the multimedia information display apparatus 21 and the transmission line 9b between the signal intermediate apparatus 20 and the multimedia information source device 3, wherein the channels include a multimedia information transmission channel 90 and an auxiliary transmission channel 91. Then, step 41 is performed, according to the signal transmission protocol, the signal intermediate device 20 starts to transmit a link training signal to handshake the multimedia information source device 3 and the multimedia information display device 21, where the link training signal includes a training check signal sent by the multimedia information source device 3 and a training result signal sent by the multimedia information display device 21 in response to the training check signal, and the detailed handshake process is based on the transmission protocol and is not described herein again. The signal intermediate apparatus 20 transmits the training check signal received from the multimedia information source device 3 to the multimedia information display apparatus 21 via the auxiliary transmission channel. In one embodiment of step 41, after the Source multimedia device 3 is powered on, the Source multimedia device 3 transmits the output signal conforming to the DisplayPort protocol to the signal intermediary apparatus 20 via the transmission line 9 a. After receiving the output signal, the signal intermediate apparatus 20 transmits the output signal output by the selected multimedia information source device 3 to the multimedia information display apparatus 21 coupled to the selected transmission interface 201 according to the transmission interface 201 selected by the switching module 202.
Once the multimedia information source device 3 is connected to the multimedia information display apparatus 21, the multimedia information source device 3 outputs an output signal conforming to the DisplayPort transmission protocol to the signal intermediate apparatus 20 through the output interface 200 of the connected audio/video signal. The multimedia signal in the output signal is transmitted to the signal intermediate apparatus 20 through the channel 90, and the auxiliary signal in the output signal is transmitted to the signal intermediate apparatus 20 through the channel 91. The signal intermediate apparatus 20 outputs the multimedia signal to the multimedia information display apparatus 21 via the multimedia information transmission channel 90 of the transmission line 9 b. The auxiliary signal is outputted to the multimedia information display device 21 through the auxiliary transmission channel 91 of the transmission line 9b, and since the auxiliary signal is a signal belonging to bidirectional communication, the multimedia information source apparatus 3 will read the EDID information of the multimedia information display device 21 through the signal intermediate device 20, then read the DPCD information, and then send out the training check signal to the multimedia information display device 21 for link training (link training) conforming to the transmission protocol.
Then, in step 42, after the multimedia information display apparatus 21 receives the training check signal, it generates a training result signal responding to the training check signal, also according to the signal transmission protocol, and returns the training result signal to the signal intermediate apparatus 20 via the auxiliary transmission channel 91. When the signal intermediate apparatus 20 receives the training result signal returned from the multimedia information display apparatus 21, step 43 is performed to determine compensation information according to the electrical characteristic of the training result signal, and then compensate the multimedia signal output to the multimedia information display apparatus 21 through the multimedia information transmission channel 90 according to the determined compensation information. In the embodiment, the electrical characteristic is implemented by a voltage, but the invention is not limited thereto.
In step 43, the determining the compensation information by the signal intermediate apparatus 20 according to the electrical characteristic further includes step 430 of retrieving a differential signal transmitted back from the multimedia information display apparatus. Since the auxiliary signal is a differential signal and the type of the signal in the auxiliary channel is not just a single link training (link training), the signal processor 22 in this embodiment uses a listening mode to capture the signal for determination. There are many ways of determining, for example: in one embodiment, the signal processor 22 determines whether the training result signal is a training result signal according to the monitored format of the returned differential signal, such as header data (header), according to the protocol specification of DisplayPort. In one embodiment, the signal processor 22 may retrieve the returned training result signal after receiving the training check signal and waiting for a specific time difference. In another embodiment, the signal processor 22 can determine whether the training result signal is obtained according to the voltage of the returned differential signal. For example: in one embodiment, the signal processor 22 determines whether the returned differential signal is the training result signal according to a voltage difference between a first voltage information of the training result signal and a second voltage information of the returned differential signal. In another embodiment, the signal processor 22 can determine whether the training result signal is a training result signal according to the frequency of the returned differential signal (e.g., 1MHz, but the invention is not limited thereto). In the embodiment of step 430, the determination is made by voltage.
After step 430, step 431 is performed to convert the extracted differential signal into a single-ended signal 912. In this step, as shown in fig. 2 and 4, the signal extraction unit 220 generates a single-ended signal 912 according to the extracted differential signal. Then, in step 432, the signal conversion unit 221 generates a dc voltage level 913 according to the single-ended signal 912. Then, in step 433, when the returned differential signal is judged to be the training result signal according to the level of the dc voltage level signal 913, the compensation information is determined according to the dc voltage level 913. The signal processing unit 222 converts the dc voltage level 913 into a digital signal for performing an operation within the signal processing unit 222. In an embodiment of step 433, the signal processing unit 222 determines the compensation information by using a lookup table (lookup table). The lookup table has information of voltage attenuation and corresponding compensation value. The establishment method of the lookup table firstly measures the electrical characteristic attenuation of the transmission line relative to the sections with different lengths, and then establishes the relation between the electrical characteristic attenuation and the sections with different lengths. And finally, establishing a relation between the attenuation amount and the pre-compensation according to different attenuation amounts to form a lookup table. In step 433, since the voltage value of the training result signal returned from the multimedia information display device 21 has a certain standard according to the communication protocol of the DisplayPort image signal, the dc voltage level 913 is compared with the standard voltage value to determine whether the training result signal is the training result signal, and if the training result signal is the training result signal, the multimedia signal output to the multimedia information transmission channel 90 is compensated according to the compensation information after the compensation information is determined according to the corresponding dc voltage level.
Please refer to fig. 5, which is a diagram illustrating another embodiment of a signal intermediate apparatus according to the present invention. The signal intermediate apparatus 20a in the transmission system 2b of the present embodiment is suitable for the multimedia information source device 3 and the multimedia information display apparatus 21 a. In this embodiment, the multimedia information source device may be a DVD player, a blu-ray DVD player, or a computer, but the invention is not limited thereto. The multimedia information display device 21a is a television, a projector, or the like, but the invention is not limited thereto.
The input interface 200 of the signal intermediate device 20a is electrically connected to the multimedia information source apparatus 3 directly via the first transmission line 9f, the output interface 201 of the signal intermediate device 20a is electrically connected to the multimedia information display device 21a directly via the second transmission line 9g, and the signal intermediate device 20a has a signal processor 22 therein for receiving the training check signal and the multimedia information from the multimedia information source apparatus 3 via the first transmission line 9f from the input interface 200 and transmitting the received training check signal and multimedia information to the multimedia information display device 21a via the output interface 201 via the second transmission line 9 g.
The signal processor 22 includes a signal acquisition unit 220, a signal conversion unit 221, a signal processing unit 222 and a multimedia signal processing unit 223. The multimedia signal processing unit 223 is used for receiving the multimedia information transmitted from the multimedia information transmission channel 90 in the transmission line 9f and outputting the multimedia information to the multimedia information display device 21a, the signal capturing unit 220 captures the training result signal from the multimedia information display device 21a in response to the training verification signal from the auxiliary channel 91, and generates the compensation information through the signal processing of the signal converting unit 221 and the signal processing unit 222. The adjusting unit 2230 of the multimedia signal processing unit 223 adjusts the received multimedia message according to the compensation information, and further transmits the adjusted multimedia message to the multimedia message display device 21a via the second transmission line 9g, so that the multimedia message display device 21a can normally display the multimedia message. The compensation and adjustment method is the process shown in fig. 3A and 3B, and is not described herein again.
It should be noted that, in the foregoing embodiment, the signal attenuation from the signal intermediate apparatus 20 or 20a to the multimedia information display apparatus 21 or 21a is detected for compensation, and in another embodiment, the signal attenuation from the signal intermediate apparatus 20 or 20a to the multimedia information display apparatus 21 or 21a is not limited. For example, the method according to the above embodiment can also be applied to detect the signal attenuation from the multimedia source device 3 to the signal intermediate apparatus 20 or 20a, or compensate the multimedia message by combining the detection of the signal attenuation from the signal intermediate apparatus 20 or 20a to the multimedia message display apparatus 21 or 21a and the detection of the signal attenuation from the multimedia source device 3 to the signal intermediate apparatus 20 or 20 a. The spirit of the present invention lies in utilizing the fixed signal characteristics in the AV transmission protocol, such as: the frequency and voltage signals, and therefore the attenuation between the signal intermediate device 20 or 20a and the multimedia information source device 3, can be determined by using the training check signal belonging to the link signal.
As shown in fig. 4 and fig. 5, in an embodiment, the signal capturing unit 220, which is a buffer component in this embodiment, is used to monitor and capture the differential signal on the auxiliary transmission channel 91 and convert the differential signal into a single-ended signal, and preferably, the signal can be further amplified during the conversion process to facilitate the interpretation. In addition to the buffer elements capable of capturing the differential signals on the auxiliary transmission channel 91, it is necessary or not necessary to further select the buffer elements having the impedance isolation effect, such as: the impedance characteristic is 100 ohms or a differential amplifier that can match the transmission line impedance without affecting the signal quality, and is used to extract the training check signal without affecting the signal quality of the auxiliary transmission channel 91. The signal extraction unit 220 in the embodiment has the effects of impedance isolation and attenuation effective amplification, but the invention is not limited thereto.
Then, a dc voltage level 910 is generated by the signal conversion unit 221 according to the single-ended signal 900. Finally, the signal processing unit 222 determines whether the training check signal belongs to the training check signal according to the DC voltage level 910. In one embodiment, the differential signal may have a specific frequency, such as: 1MHz, but the present invention is not limited thereto, to determine whether the training check signal belongs to. In one embodiment, the determination may be made based on header data (header) unique to the auxiliary signal. In addition, in another embodiment, it can be determined whether the training check signal belongs to the training check signal according to the voltage of the captured differential signal. When the training check signal is determined, the compensation information can be determined according to the dc voltage level 910, which is described above and will not be described herein.
Through the foregoing description of the embodiments, according to the spirit of the present invention, the signal attenuation caused by the long distance from the multimedia information source device to the signal intermediate device and from the multimedia information display device to the signal intermediate device can be found out, and the compensation amount for compensating the multimedia signal can be determined according to the attenuation amount, so that the compensated multimedia signal can be normally displayed by the multimedia information display device. Although the foregoing embodiments are described with respect to the multimedia transport protocol of DisplayPort, the spirit can be extended to other transport protocols. For example, in the high speed multimedia transmission protocol such as DVI or HDMI, the electrical signal with a fixed period can be found out and the attenuation can be determined according to the above-mentioned spirit.
Although the present invention has been described with reference to particular embodiments, it will be understood by those skilled in the art that various changes in form, construction, features, methods and quantities may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.
Claims (16)
1. A signal compensation method, comprising the steps of:
connecting a multimedia information source device and signal intermediate equipment by a first transmission line;
connecting the signal intermediate equipment and the multimedia information display equipment by a second transmission line;
according to a signal transmission protocol, the signal intermediate device receives link training signals from the multimedia information source device and the multimedia information display device through the first transmission line and the second transmission line respectively; and
the signal intermediate equipment adjusts the multimedia signal transmitted to the multimedia information display equipment through the second transmission line according to the electrical characteristic of the link training signal.
2. The method of claim 1, wherein the step of adjusting the multimedia signal according to the electrical characteristic of the link training signal further comprises the steps of:
capturing a differential signal in the link training signal;
generating a single-ended signal according to the differential signal;
generating a DC voltage level according to the single-ended signal; and
and adjusting the multimedia signal transmitted to the multimedia information display equipment through the second transmission line according to the DC voltage level.
3. The signal compensation method of claim 2, wherein the link training signal comprises a training check signal and a training result signal.
4. The method of claim 3, wherein the signal processing device determines whether the differential signal is an AC signal with a specific frequency to determine whether the differential signal is the training result signal.
5. The signal compensation method of claim 3, wherein the determining the returned differential signal as the training result signal by the signal intermediate apparatus further comprises:
the signal intermediate device determines whether the returned differential signal is the training result signal according to a voltage difference between first voltage information about the training result signal and second voltage information about the received differential signal, wherein the first voltage information and the second voltage information are defined by the signal transmission protocol.
6. The signal compensation method of claim 5, further comprising the step of building a look-up table, wherein the step of building the look-up table further comprises the steps of:
measuring the electrical characteristic attenuation of the transmission line relative to different length sections;
establishing a relation between the electrical characteristic attenuation quantity and the sections with different lengths; and
and establishing a relation between the attenuation amount and the pre-compensation according to different attenuation amounts to form the lookup table.
7. The signal compensation method of claim 6, wherein the signal intermediate device determines compensation information via the lookup table according to the attenuation information of the training result signal, so as to compensate the multimedia signal outputted to the second transmission line.
8. A signal intermediate device, electrically connected to a multimedia information source device through a first transmission line and electrically connected to a multimedia information display device through a second transmission line, the signal intermediate device comprising:
a plurality of first transmission interfaces, each of the first transmission interfaces being electrically connected to the multimedia information source device via the first transmission line;
the multimedia information display equipment comprises at least one first transmission interface, at least one second transmission interface and a first transmission line, wherein the first transmission interface is electrically connected with the multimedia information display equipment through the first transmission line;
the switching module is electrically connected with the plurality of first transmission interfaces and the at least one second transmission interface and used for switching and selecting one of the first transmission interfaces to be electrically connected with one of the second transmission interfaces; and
the signal processor captures a link training signal from the multimedia information source device and the multimedia information display equipment according to a signal transmission protocol, and adjusts the multimedia signal transmitted to the multimedia information display equipment through the second transmission line according to the electrical characteristic of the link training signal.
9. The signal intermediate apparatus of claim 8, wherein the signal processor comprises a signal capturing unit, a signal converting unit and a signal processing unit, wherein the signal capturing unit captures a differential signal in the link training signal and converts the differential signal into a single-ended signal, the signal converting unit generates a DC level signal according to the single-ended signal, and the signal processing unit adjusts the multimedia signal transmitted to the multimedia information display apparatus through the second transmission line according to the DC voltage level.
10. The signal intermediate apparatus of claim 9, wherein the link training signal comprises a training check signal and a training result signal.
11. The signal processing apparatus of claim 10, wherein the signal processor determines whether the differential signal is an ac signal with a specific frequency to determine whether the differential signal is the training result signal.
12. The signal processing apparatus of claim 10, wherein the signal processor determines whether the returned differential signal is the training result signal according to a voltage difference between a first voltage information related to the training result signal and a second voltage information related to the received differential signal, which is defined by the signal transmission protocol.
13. The signal intermediate apparatus of claim 9, wherein the signal processor stores a look-up table having information on signal attenuation and compensation relationship, and the signal processor determines compensation information via the look-up table according to the electrical characteristic for compensating the multimedia signal output to the multimedia information display apparatus.
14. A signal intermediary device adapted to be used in a multimedia information source device and a multimedia information display device, the signal intermediary device being electrically connected to the multimedia information source device via a first transmission line, the signal intermediary device being electrically connected to the multimedia information display device via a second transmission line, the signal intermediary device comprising: the signal processor receives the training check signal and the multimedia signal from the multimedia information source device through the first transmission line, and transmits the received training check signal and the adjusted multimedia signal to the multimedia information display equipment through the second transmission line, so that the multimedia information display equipment can normally display the multimedia signal.
15. The signal intermediate apparatus of claim 14, wherein the signal processor further receives a training result signal from the multimedia information display apparatus in response to the training check signal via the second transmission line, adjusts the received multimedia signal according to an electrical characteristic of the training result signal, and further transmits the adjusted multimedia signal to the multimedia information display apparatus via the second transmission line, so that the multimedia information display apparatus normally displays the multimedia signal.
16. The signal intermediate apparatus of claim 14, wherein the signal processor adjusts the multimedia signal according to the electrical characteristic of the training verification signal and transmits the adjusted multimedia signal to the multimedia information display apparatus via the second transmission line, so that the multimedia information display apparatus normally displays the multimedia signal.
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| TW108148765 | 2019-12-31 | ||
| TW108148765A TWI749439B (en) | 2019-12-31 | 2019-12-31 | Method for compensating signal and signal relaying device using the same |
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| TW202127818A (en) | 2021-07-16 |
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