CN113132557B - Signal compensation method and signal intermediate device thereof - Google Patents
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- H—ELECTRICITY
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- H04N5/00—Details of television systems
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- H—ELECTRICITY
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- H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
- H04N5/00—Details of television systems
- H04N5/222—Studio circuitry; Studio devices; Studio equipment
- H04N5/262—Studio circuits, e.g. for mixing, switching-over, change of character of image, other special effects ; Cameras specially adapted for the electronic generation of special effects
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Abstract
本发明提供一种讯号补偿方法，首先以第一传输线连接多媒体信息来源装置与讯号中间设备。接着以第二传输线连接讯号中间设备与多媒体信息显示设备。然后，根据讯号传输协议，讯号中间设备分别经由第一传输线以及第二传输线接收来自多媒体信息来源装置以及多媒体信息显示设备的链路训练讯号。最后，讯号中间设备根据链路训练讯号的电性特征调整经由第二传输线传送至多媒体信息显示设备的多媒体讯号。
The present invention provides a signal compensation method, firstly, a multimedia information source device and a signal intermediate device are connected by a first transmission line. Then, the signal intermediate device and the multimedia information display device are connected by a second transmission line. Then, according to the signal transmission protocol, the signal intermediate device receives link training signals from the multimedia information source device and the multimedia information display device via 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 via the second transmission line according to the electrical characteristics of the link training signal.
Description
[ Field of technology ]
The present invention relates to signal compensation, and more particularly, to a signal compensation method and signal intermediate device for compensating signal attenuation caused by transmission via a transmission line.
[ Background Art ]
In recent years, multimedia video and audio technology has been developed quite rapidly. For example, a multimedia interface (High-Definition Multimedia Interface, HDMI) or a digital video interface (Digital Visual Interface, DVI) or a Display Port (DP) transmission interface with High-speed data transmission capability can achieve the goal of distortion-free output because the multimedia interface transmits uncompressed audio signals and video signals with High resolution through the same cable without performing a program of converting analog signals into digital signals (A/D) or converting digital signals into analog signals (D/A).
In which USB, HDMI, displayPort, etc. are advanced to a stage of high-speed transmission, for example, according to DisplayPort 1.4 standard, four channels are supported by the cable in each path of display output, and the data transmission rate of each channel can reach 8.1Gbps, so that the four channels simultaneously transmit high-resolution audio and video signals, and the total bandwidth can reach 32.4Gbps. However, in the technical field of high-speed transmission, the higher the frequency of data is, the more susceptible the impedance of the data transmission wire is to attenuation during transmission.
Fig. 1 is a schematic diagram of a prior art signal transmission system architecture. The system 1 has a signal switching device 10 with a plurality of signal input interfaces 100, each signal input interface 100 can be connected with a corresponding signal source 11, such as a computer, for receiving multimedia signals output by 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, e.g., cat.5, etc. The signal conversion device 13 has an interface 130 at one end connected to the transmission line 12, an image interface 131 at the other end, such as RGB, HDMI, DVI, displayPort, 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 electrically connected to a remote signal control device (console) 14 through a transmission line 12, wherein the console 14 is electrically connected to a display 15 and an input device 16, such as a keyboard, a mouse, etc.
Since the transmission line 12 is used for transmitting signals, the line length thereof affects the quality of the transmitted signals, especially for high frequency signals, the signals are more likely to be attenuated due to long-distance transmission. Therefore, in the prior art architecture, a test signal is usually loaded on the signal conversion device 13 side and transmitted to the signal control device 14. Under such a 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, and the signal control device 14 can compensate the multimedia signal according to the attenuation state of the test signal after receiving the test signal.
[ Invention ]
The invention provides a signal compensation method and a signal intermediate device thereof, which are characterized in that in the signal transmission process conforming to a transmission protocol, link training signals (LINK TRAINING SIGNAL) from a multimedia information source device (source) and/or a multimedia information display device (sink) are extracted, for example, a training check signal (TRAINING CHECK) or a training result signal (training result) are used, the link training signals have specific stable characteristics, for example, signals of frequency, voltage, current and the like are used as references, the change of continuous alternating signals is detected, so as to judge the degree of signal attenuation, and further, compensation parameters for compensating the multimedia signals are automatically adjusted.
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 (auxiliary Channel, AUX Channel) to capture differential signals output by a transmitting end or a receiving end and detect the electrical characteristics of the differential signals after transmission, thereby achieving the effects of line length attenuation judgment and signal compensation.
In one embodiment, the present invention provides a signal compensation method, which includes the following steps. First, connect the multimedia information source device and the signal intermediate device by the first transmission line. Then, the signal intermediate device and the multimedia information display device are connected by a second transmission line. 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 characteristics of the link training signal.
In one embodiment, the method adjusts the multimedia signal according to the electrical characteristics of the link training signal, and further comprises the steps of first capturing the differential signal in the link training signal. Then, a single-ended signal is generated according to the differential signal, and then a DC voltage level is generated according to the single-ended signal. Finally, the multimedia signal transmitted to the multimedia information display device through the second transmission line is adjusted according to the DC voltage level.
In an 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 is electrically connected to a multimedia information display device through a second transmission line, and the signal intermediate device further includes a plurality of first transmission interfaces, at least one second transmission interface, a switching module, and a signal processor. 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 device through a second transmission line. The switching module is electrically connected with the 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 the 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 an embodiment, the signal processor includes a signal capturing unit, a signal converting unit and a signal processing unit, wherein the signal capturing unit isolates a differential signal in a captured link training signal by impedance and converts the differential signal into a single-ended signal, the signal converting unit generates a direct current level signal according to the single-ended signal, and the signal processing unit adjusts a multimedia signal transmitted to the multimedia information display device through the second transmission line according to the direct current voltage level.
In an embodiment, the present invention further provides a signal intermediate device, which is suitable for a multimedia information source device and a multimedia information display device, wherein the signal intermediate device is directly and electrically connected with the multimedia information source device via a first transmission line, and the signal intermediate device is directly and electrically connected with the multimedia information display device via a second transmission line, and the signal intermediate device includes a signal processor, which receives a training check signal and a multimedia signal from the multimedia information source device via the first transmission line, and transmits the received training check signal and multimedia signal to the multimedia information display device via the second transmission line. Further, 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 returned by the multimedia information display device in response to the training check signal through the second transmission line, 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 through the second transmission line, so that the multimedia information display device normally displays the multimedia signal.
The specific technology adopted by the present invention will be further described by the following examples and attached drawings.
[ Description of the drawings ]
FIG. 1 is a schematic diagram of a prior art closed signal transmission system.
Fig. 2 is a schematic diagram of an embodiment of the signal intermediate device according to the present invention.
Fig. 3A and 3B are flowcharts illustrating an embodiment of a signal compensation method according to the present invention.
FIG. 4 is a graph showing the voltage versus time of signals output by 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 main reference numerals:
2.2 b-transmission system, 20-signal intermediate equipment, 20 a-intermediate equipment, 200-first transmission interface, 201-second transmission interface, 202-switching module, 202 a-first switch, 202 b-second switch, 21 a-multimedia information display equipment, 22-signal processor, 220-signal acquisition unit, 221-signal conversion unit, 222-signal processing unit, 223-multimedia signal processing unit, 2230-adjusting unit, 3-multimedia information source device 9 a-9 e-transmission line, 90-multimedia information transmission channel, 91-auxiliary transmission channel, 900-single-ended signal, 910-direct voltage standard, 912-single-ended signal, 913-direct voltage standard, 4-signal compensation method, 40-43, 430-433-flow. [ detailed description ] of the invention
Various exemplary embodiments may be more fully described below with reference to the accompanying drawings, in which some exemplary embodiments are shown. This 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 ji devices of the method of xun and its xun are described in the following embodiments with reference to the drawings, however, the following embodiments are not intended to limit the invention.
Referring to fig. 2, a schematic diagram of an embodiment of the signal intermediate device according to the present invention is shown. In the signal transmission system 2 shown in fig. 2, there is a signal intermediate device 20, in this embodiment, a KVM switch or a matrix array switch, 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 device 3 through the transmission lines 9a, and the second transmission interfaces 201 are electrically connected to the multimedia information display device 21 through the transmission lines 9 b. The multimedia information source device 3 may be a player, such as a DVD player, a blu-ray DVD player, or a computer, but the invention is not limited thereto. The multimedia information display device 21 is, for example, a television wall, a computer monitor, or the like, but the present invention is not limited thereto.
The first transmission interface 200 and the second transmission interface 201 may be DVI, HDMI, or DisplayPort interfaces, which in this embodiment are DisplayPort interfaces. The transmission lines 9a and 9b may be wires for transmitting multimedia video and audio signals, such as DisplayPort signal lines, HDMI signal lines, DVI signal lines, etc., or twisted pair lines, such as five-category twisted pair (category 5, cat.5), six-category or seven-category twisted pair, etc., but the present invention is not limited thereto. In this embodiment, the transmission lines 9a and 9b are DisplayPort transmission lines for transmitting DisplayPort signals of the DisplayPort transmission protocol. The output signal outputted from the multimedia information source device 3 is transmitted to the signal intermediate apparatus 20 via the transmission line 9a, and the signal intermediate apparatus 20 transmits the output signal to the multimedia information display apparatus 21 via the transmission line 9 b. In one embodiment, the output signal includes a multimedia signal related to the multimedia information, and an auxiliary signal related to the 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 embodiment is described with the av interface of DisplayPort, the DisplayPort output signals mentioned below all follow the specifications of the av transmission protocol of DisplayPort, but the invention is not limited thereto.
Referring back to fig. 2, the channel established by the signal intermediate device 20 and the multimedia information source device 3 or the multimedia information display device 21 on the transmission line 9a or 9b 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-visual differential signals ml_lane_0-ml_lane_3 in the DisplayPort signals, the auxiliary transmission channel 91 is a bidirectional half-duplex channel, and is used for transmitting auxiliary signals (aux_ch_p, aux_ch_n) belonging to differential properties in the DisplayPort signals, and the auxiliary signals of DisplayPort are 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 a hot plug signal (HPD), a ground pin and a power pin, which are well known to those skilled in the art, and are not described herein. The transmission wires constituting the multimedia information transmission channel and the auxiliary transmission channel are, for example, twisted pairs of plural pairs, and have the same wire characteristics such as material, transmission attenuation characteristics, and impedance.
In this embodiment, the signal intermediate device 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 for switching and selecting one of the first transmission interfaces 200 to be electrically connected to one of the second transmission interfaces 201 according to a signal for controlling and selecting, so that the multimedia information source device 3 connected to the selected first transmission interface 200 can output an output signal to the multimedia information display device 21 electrically connected to the selected second transmission interface 201 to display and output audio/video information. In the present embodiment, the switching module 202 further has a plurality of first switches 202a and second switches 202b electrically connected to the signal processor 22 respectively, so as to receive the control signal of the signal processor 22 for selecting switching. Each of the first switches 202a is electrically connected to the multimedia information source devices 3, and the first switches 202a are electrically connected to the second switches 202 b. The signal processor 22 is coupled to the second transmission interface 201 for compensating the multimedia signal outputted to the second transmission interface 201. It should be noted that the switching module 202 is not limited in the above manner, for example, in another embodiment, the switching module 202 may be a crossbar (cross point switch).
In the DisplayPort transmission protocol, the multimedia signal and the auxiliary signal are both high-speed differential signals, when the signal is transmitted by the transmission wire, the quality of the signal depends on the length of the transmission wire, the longer the transmission wire is, the more the attenuation of the audio-video quality is, and once the attenuation is to a certain degree, the multimedia information display device 21 cannot smoothly output the audio-video information. In order to solve the problem of signal attenuation without adding any additional component for generating test signals to the multimedia information source device, in this embodiment, the link training signal (LINK TRAINING SIGNAL) with fixed characteristics in the DisplayPort transmission protocol, such as the bidirectional communication characteristic 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 device 21 are used to detect the signal attenuation, so as to perform signal compensation on the multimedia signal, and maintain the efficacy that the output signal output by the multimedia information source device 3 can be displayed on the multimedia information display device 21.
In one embodiment, please refer to fig. 3A and 3B, which are a flowchart illustrating an embodiment of a signal compensation method according to the present invention. The flow of this embodiment is illustrated by the architecture shown in fig. 2. First, in step 40, channels are respectively established on the transmission lines 9a of the signal intermediate device 20 and the multimedia information display device 21 and the transmission lines 9b between the signal intermediate device 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 the link training signal to make the multimedia information source device 3 and the multimedia information display device 21 handshake, wherein the link training signal includes the training check signal sent by the multimedia information source device 3 and the training result signal sent by the multimedia information display device 21 in response to the training check signal to perform handshake, and the detailed handshake process is not described herein according to the transmission protocol. The signal intermediate device 20 transmits the training verification signal received from the multimedia information source apparatus 3 to the multimedia information display device 21 via the auxiliary transmission channel. In one embodiment of step 41, after the multimedia information source device 3 is started, the multimedia information source device 3 transmits an output signal conforming to the DisplayPort transmission protocol to the signal intermediate apparatus 20 via the transmission line 9 a. After the signal intermediate device 20 receives the signal, the output signal outputted from the selected multimedia information source apparatus 3 is transmitted to the multimedia information display device 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 via the output interface 200 of the audio-video frequency number connected thereto. The multimedia signal in the output signal is transmitted to the signal intermediate device 20 via the channel 90, and the auxiliary signal in the output signal is transmitted to the signal intermediate device 20 via the channel 91. The signal intermediate device 20 outputs a multimedia signal to the multimedia information display device 21 via the multimedia information transmission channel 90 of the transmission line 9 b. As for the auxiliary signal, the auxiliary signal is outputted to the multimedia information display device 21 via the auxiliary transmission channel 91 of the transmission line 9b, and the multimedia information source apparatus 3 performs link training according to the transmission protocol by reading the EDID information of the multimedia information display device 21 through the signal intermediate device 20, reading the DPCD information, and then sending the training check signal to the multimedia information display device 21 (LINK TRAINING).
After that, in step 42, after the multimedia information display device 21 receives the training check signal, a training result signal is generated in response to the training check signal according to the signal transmission protocol, and the training result signal is returned to the signal intermediate device 20 through the auxiliary transmission channel 91. When the signal intermediate device 20 receives the signal training result signal transmitted from the multimedia information display device 21, it proceeds to step 43, determines compensation information according to the electrical characteristics of the training result signal, and compensates the multimedia signal outputted to the multimedia information display device 21 through the multimedia information transmission channel 90 according to the determined compensation information. In the present embodiment, the electrical characteristic is implemented by voltage, but the invention is not limited thereto.
In step 43, the signal intermediate device 20 further includes step 430 of capturing a differential signal transmitted from the multimedia information display device according to the electrical characteristics. Since the auxiliary signal is a differential signal and the signal type of the auxiliary channel is not just a single type of link training (LINK TRAINING), in this embodiment, the signal processor 22 captures the signal by listening to determine. There are various ways to determine, for example, in one embodiment, the signal processor 22 determines whether it is a training result signal according to the protocol specification of DisplayPort and according to the format of the monitored backhaul differential signal, such as header data (header). In one embodiment, the signal processor 22 may wait for a specific time difference after receiving the training check signal, and extract the returned training result signal. In another embodiment, the signal processor 22 can determine whether the signal is a training result signal according to the voltage of the captured 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 according to the transmission protocol specification. In another embodiment, the signal processor 22 can determine whether the 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 capturing unit 220 generates a single-ended signal 912 according to the captured differential signal. Then, step 432 is performed, the signal conversion unit 221 generates the dc voltage level 913 according to the single-ended signal 912. Then, step 433 is performed to determine the compensation information according to the DC voltage level 913 when the returned differential signal is determined to be the training result signal 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 in 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 stores information of voltage attenuation and corresponding compensation value. The look-up table is established by measuring the electric characteristic attenuation of the transmission line with respect to the different length sections, and then establishing the relation between the electric characteristic attenuation and the different length sections. And finally, according to different attenuation amounts, establishing a relation between the attenuation amount and the precompensation 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, if the training result signal is the training result signal, the compensation information is determined according to the corresponding dc voltage level, and then the multimedia signal outputted to the multimedia information transmission channel 90 is compensated according to the compensation information.
Referring to fig. 5, another embodiment of the signal intermediate device of the present invention is shown. The signal intermediate device 20a in the transmission system 2b of the present embodiment is suitable for the multimedia information source device 3 and the multimedia information display device 21a. In the present 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 present invention is not limited thereto.
The input interface 200 of the signal intermediate device 20a is directly electrically connected to the multimedia information source device 3 via the first transmission line 9f, the output interface 201 of the signal intermediate device 20a is directly electrically connected to the multimedia information display device 21a 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 multimedia information from the multimedia information source device 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 second transmission line 9g via the output interface 201.
The signal processor 22 has a signal capturing unit 220, a signal converting unit 221, a signal processing unit 222, and a multimedia signal processing unit 223. The multimedia signal processing unit 223 is configured to receive the multimedia information transmitted from the multimedia information transmission channel 90 in the transmission line 9f and output the multimedia information to the multimedia information display device 21a, and the signal capturing unit 220 captures the training result signal returned from the multimedia information display device 21a in response to the training check 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 information according to the compensation information, and further transmits the adjusted multimedia information to the multimedia information display device 21a via the second transmission line 9g, so that the multimedia information display device 21a normally displays the multimedia information. The compensation and adjustment are the processes shown in fig. 3A and 3B, and are not described herein.
It should be noted that the foregoing embodiment is to compensate by detecting the signal attenuation from the signal intermediate device 20 or the signal intermediate device 20a to the multimedia information display device 21 or 21a, and in another embodiment, the signal attenuation from the signal intermediate device 20 or 20a to the multimedia information display device 21 or 21a is not limited. For example, according to the spirit of the foregoing embodiment, the method may also be applied to detect the signal attenuation from the multimedia information source device 3 to the signal intermediate device 20 or 20a, or to compensate the multimedia information by combining the foregoing detection of the signal attenuation from the signal intermediate device 20 or 20a to the multimedia information display device 21 or 21a and the detection of the signal attenuation from the multimedia information source device 3 to the signal intermediate device 20 or 20 a. Since the spirit of the present invention is to use the fixed signal characteristics, such as frequency and voltage, in the video transmission protocol, the training check signal belonging to the link signal can be used to determine the attenuation between the signal intermediate device 20 or 20a and the multimedia information source device 3.
As shown in fig. 4 and fig. 5, in an embodiment, the signal capturing unit 220 is a buffer (buffer) component, which is configured 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, so as to facilitate interpretation. In addition to the ability to capture the differential signal on the auxiliary transmission channel 91, the buffer element may optionally be further selected to have an impedance isolation effect, such as a differential amplifier with an impedance characteristic of 100 ohms or capable of impedance matching with the transmission line without affecting signal quality, for capturing the training verification signal without affecting signal quality of the auxiliary transmission channel 91. The signal capturing 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 converting unit 221 according to the single-ended signal 900. Finally, the signal processing unit 222 determines whether the training check signal is included according to the dc voltage level 910. In one embodiment, the determination of whether the differential signal belongs to the training check signal can be determined according to whether the differential signal has a specific frequency, for example, 1MHz, but the invention is not limited thereto. In one embodiment, the determination may be based on header data (header) unique to the auxiliary signal. In addition, in another embodiment, whether the training check signal is included can be determined according to the voltage of the extracted 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 description of the foregoing embodiments, according to the spirit of the present invention, it is possible to find out the signal attenuation amount caused by the line length from the multimedia information source device to the signal intermediate device and from the multimedia information display device to the signal intermediate device during long-distance transmission, and further determine the compensation amount for compensating the multimedia signal according to the attenuation amount, so that the compensated multimedia signal can be displayed normally by the multimedia information display device. Although the foregoing embodiments are described in terms of the DisplayPort multimedia transport protocol, the spirit can be extended to other transport protocols. For example, in a high-speed multimedia transmission protocol such as DVI or HDMI, an electric signal having a fixed period can be found and the attenuation amount thereof can be judged in the spirit described above.
Although the present invention has been described with reference to the above embodiments, it should be understood that the present invention is not limited to the details of the shape, construction, features, methods and the number of the embodiments described in the claims can be modified somewhat without departing from the spirit and scope of the present invention.
Claims (13)
1. A signal compensation method is characterized by comprising the following steps:
connecting the multimedia information source device and the signal intermediate equipment by a first transmission line;
Connecting the signal intermediate device with the multimedia information display device through a second transmission line;
According to signal transmission protocol, the signal intermediate device receives the link training signals from the multimedia information source device and the multimedia information display device via the first transmission line and the second transmission line respectively, and
The signal intermediate device adjusts the multimedia signal transmitted to the multimedia information display device through the second transmission line according to the electrical characteristics of the link training signal;
wherein, adjust the said multimedia signal according to the electrical characteristic of the said link training signal, also include the following steps:
capturing a differential signal in the link training signal;
generating a single-ended signal according to the differential signal;
generating a DC voltage level based on the single-ended signal, and
And adjusting the multimedia signal transmitted to the multimedia information display device through the second transmission line according to the DC voltage level.
2. The signal compensation method of claim 1, wherein the link training signal comprises a training verification signal and a training result signal.
3. The signal compensation method according to claim 2, wherein the signal intermediate device determines whether the differential signal is an ac signal of a specific frequency to determine whether the differential signal is the training result signal.
4. The signal compensation method according to claim 2, wherein the method for determining the returned differential signal as the training result signal by the signal intermediate device further comprises the steps of:
The signal intermediate device determines whether the returned differential signal is the training result signal according to the voltage difference between the first voltage information about the training result signal and the second voltage information received by the differential signal, which are specified by the signal transmission protocol.
5. The signal compensation method of claim 4, further comprising the step of creating a look-up table, wherein creating the look-up table further comprises the steps of:
Measuring the attenuation of the electrical characteristics of the transmission line with respect to the different length sections;
establishing the relation between the electric characteristic attenuation and the different length sections, and
And according to different attenuation amounts, establishing a relation between the attenuation amount and the precompensation to form the lookup table.
6. The signal compensation method of claim 5, wherein the signal intermediate device determines compensation information via the lookup table according to the attenuation information of the training result signal to compensate the multimedia signal output to the second transmission line.
7. A signal intermediate device electrically connected to a multimedia information source device via a first transmission line and electrically connected to a multimedia information display device via a second transmission line, the signal intermediate device comprising:
The first transmission interfaces are electrically connected with the multimedia information source device through the first transmission lines;
At least one second transmission interface electrically connected with the multimedia information display device through the second transmission line;
the switching module is electrically connected with the plurality of first transmission interfaces and the 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, and
The signal processor is used for capturing link training signals from the multimedia information source device and the multimedia information display equipment according to a signal transmission protocol, and adjusting the multimedia signals transmitted to the multimedia information display equipment through the second transmission line according to the electrical characteristics of the link training signals;
The signal processor comprises a signal capturing unit, a signal conversion 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 conversion unit generates a direct-current voltage level 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 direct-current voltage level.
8. The signal intermediate device of claim 7, wherein the link training signal comprises a training verification signal and a training result signal.
9. The signal intermediate device of claim 8, wherein the signal processor determines whether the differential signal is an ac signal of a specific frequency to determine whether the differential signal is the training result signal.
10. The signal intermediate device of claim 8, wherein the signal processor determines whether the differential signal returned is the training result signal based on a voltage difference between a first voltage information regarding the training result signal and a second voltage information received from the differential signal as specified by the signal transmission protocol.
11. The signal intermediate device of claim 7, wherein the signal processor has a look-up table stored therein, the look-up table having information of a signal attenuation and compensation relationship, the signal processor determining compensation information for compensating the multimedia signal output to the multimedia information display device via the look-up table according to the electrical characteristic.
12. The utility model provides a signal intermediate device, is applicable to multimedia information source device and multimedia information display device, signal intermediate device is through first transmission line is direct with multimedia information source device electric connection, signal intermediate device is through second transmission line is direct with multimedia information display device electric connection, its characterized in that, signal intermediate device includes: 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 device through the second transmission line so that the multimedia information display device normally displays the multimedia signal, wherein the signal processor comprises a signal acquisition unit, a signal conversion unit and a signal processing unit, the signal acquisition unit acquires a differential signal in the training check signal and converts the differential signal into a single-ended signal, the signal conversion unit generates a direct-current voltage level 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 direct-current voltage level.
13. The signal intermediate device of claim 12, wherein the signal processor further receives a training result signal from the multimedia information display device 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 device via the second transmission line, so that the multimedia information display device normally displays the multimedia signal.
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| TW108148765A TWI749439B (en) | 2019-12-31 | 2019-12-31 | Method for compensating signal and signal relaying device using the same |
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| KR20180131286A (en) * | 2017-05-31 | 2018-12-10 | 주식회사 퀄리타스반도체 | Optical communication connector and link training method thereof thereof |
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| US8094684B2 (en) * | 2008-05-09 | 2012-01-10 | Parade Technologies, Ltd. | Link training scheme for displayport source repeaters |
| CN101667412B (en) * | 2008-09-02 | 2011-12-14 | 宏正自动科技股份有限公司 | Signal compensation device, signal compensation method and multi-computer switching system |
| US9552322B2 (en) * | 2014-06-12 | 2017-01-24 | Pericom Semiconductor Corporation | Hybrid repeater for supporting backward compatibility |
| WO2017151925A1 (en) * | 2016-03-02 | 2017-09-08 | Lattice Semiconductor Corporation | Link training in multimedia interfaces |
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| KR20180131281A (en) * | 2017-05-31 | 2018-12-10 | 주식회사 퀄리타스반도체 | Repeater device for displayport and link training method thereof |
| KR20180131286A (en) * | 2017-05-31 | 2018-12-10 | 주식회사 퀄리타스반도체 | Optical communication connector and link training method thereof thereof |
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