Visible light video communication system based on Digital Signal Processing
Technical field
The present invention relates to a kind of visible light video communication system, belong to wireless communication technology field based on digital signal processing module.
Background technology
Digital signal processor (DSP, Digital Signal Processor) is the special chip that carries out Digital Signal Processing, is to be accompanied by microelectronics, Digital Signal Processing, development of computer and the new unit that produces.DSP is widely used in the Voice & Video aspect, and it is not only programmable, and the speed of service can reach the per second number with ten million bar complicated order program in fact the time, considerably beyond general purpose microprocessor, is the computer chip that becomes more and more important in the digitalized electron world.Its powerful data-handling capacity and the high speed of service are two the most commendable big characteristics.DSP can realize processing such as the collection, valuation, enhancing, compressed encoding, decoding, modulation, filtering, identification to signal fast, so digital signal processor is the good selection that realizes that vision signal is handled.
In recent years, along with the LED technology rapid development, the maturation of DSP technology is utilized available research achievements, further studies short distance visible light communication at a high speed.Because the DSP operational capability is strong, processing speed is fast, can realize processing such as vision signal collection fast, analog-to-digital conversion, compressed encoding, decoding, modulation and demodulation can be good at satisfying the actual needs of visible light video communication.Exploitation can realize short distance, big capacity, wireless video communication at a high speed based on the visible light Video transmission system of Digital Signal Processing.Existing wireless communication spectrum resource scarcity; And the visible light communication frequency range need not licence; And there is not electromagnetic interference; In illumination, can realize ubiquitous communication, the visible light spectrum resource can provide jumbo communication service, on airport, medical monitoring, have a extensive future under water with under the special screne such as mine.
Summary of the invention
Technical problem to be solved by this invention provides a kind of short distance based on digital signal processing module, big capacity, visible light video communication system at a high speed.
The present invention adopts following technical scheme for solving the problems of the technologies described above: the present invention has designed a kind of visible light video communication system based on digital signal processing module, comprises video acquisition system, transmitting terminal, receiving terminal and video display apparatus, wherein:
Said transmitting terminal comprises first digital signal processing module, biasing circuit, LED power supply and LED device, and said receiving terminal comprises integrated photonic device module, photodetector, power amplifier and second digital signal processing module.
Said first digital signal processing module receives the vision signal of external video acquisition system output; First digital signal processing module is handled resample successively processing, encoding process, modulation treatment and digital-to-analogue conversion of vision signal; Produce analog signal, and with said analog signal transmission to biasing circuit;
Said LED power supply provides direct voltage to biasing circuit, and biasing circuit produces the signal of telecommunication with the processing that is coupled of the direct voltage of above-mentioned analog signal and LED power supply, and the signal of telecommunication after will being coupled transfers to the LED device, and the driving LED device is luminous;
Said LED device converts above-said current signal to visible light signal, and utilizes the covering of light field, through Wireless transmission mode with said optical signal transmission to photodetector;
Said photodetector is used to receive above-mentioned light signal, and transfers to power amplifier after this light signal is transformed into the signal of telecommunication;
Said power amplifier carries out power amplification with above-said current signal, and the signal of telecommunication after the power amplification is transferred to second digital signal processing module;
The signal of telecommunication of said second digital signal processing module after to above-mentioned power amplification carries out analog-to-digital conversion process, demodulation process, decoding processing and resampling successively to be handled, and produces digital signal, and with said digital data transmission to video display apparatus.
The present invention adopts above technical scheme compared with prior art, has following technique effect:
1. the visible light video communication system based on Digital Signal Processing that the present invention designed adopts the new LED device; Realize the system of the illumination and the one of communicating by letter; The LED device has the high-speed response frequency; Improve the modulation bandwidth and the message transmission rate of system, thereby can realize short distance, jumbo video transmission;
2. the visible light video communication system based on Digital Signal Processing that the present invention designed adopts digital signal processor to realize signal processing; The validity and the reliability of transmission have been improved through coding; Improved the signal to noise ratio of channel through ovennodulation; Thereby improved transmission of video signals efficient, realized the high-speed video transmission;
3. the visible light video communication system based on Digital Signal Processing that the present invention designed adopts visible light to carry out transfer of data, can realize not having the message transmission of electromagnetic interference, improves the deficient present situation of frequency spectrum resource;
4. the visible light video communication system based on Digital Signal Processing that the present invention designed can provide the video communication services of short distance, big capacity, two-forty, in intelligent transportation, under water, scenes such as hospital, mine, the aircraft advantage that is widely used.
Description of drawings
Fig. 1 is the transmission sketch map based on the visible light video communication system of Digital Signal Processing that the present invention designs;
Fig. 2 is the circuit module block diagram based on the visible light video communication system transmitting terminal of Digital Signal Processing that the present invention designs;
Fig. 3 is the circuit module block diagram based on the DSP of the visible light video communication system of Digital Signal Processing that the present invention designs;
Fig. 4 is the circuit module block diagram based on the visible light video communication system receiving terminal of Digital Signal Processing that the present invention designs.
Embodiment
Below in conjunction with accompanying drawing technical scheme of the present invention is done further detailed description:
As shown in Figure 1, the present invention has designed a kind of visible light video communication system based on Digital Signal Processing, it is characterized in that, comprises video acquisition system, transmitting terminal, receiving terminal and video display apparatus, wherein:
Said transmitting terminal comprises first digital signal processing module, biasing circuit, LED power supply and LED device, and said receiving terminal comprises integrated photonic device module, photodetector, power amplifier and second digital signal processing module;
Said first digital signal processing module receives the vision signal of external video acquisition system output; First digital signal processing module is handled resample successively processing, encoding process, modulation treatment and digital-to-analogue conversion of vision signal; Produce analog signal, and with said analog signal transmission to biasing circuit;
Said LED power supply provides direct voltage to biasing circuit; Biasing circuit produce the signal of telecommunication, and the signal of telecommunication after will being coupled transfers to the LED device with the processing that is coupled of the direct voltage of above-mentioned analog signal and LED power supply; The driving LED device is luminous, thereby realizes illumination and communication integral;
Said LED device converts above-said current signal to visible light signal; And through the integrated photonic device module of Wireless transmission mode with said optical signal transmission to receiving terminal; Its operation principle is by means of the modulation of vision signal to light intensity; Utilize the light field of LED device to cover, realize the wireless transmission of information;
In concrete embodiment; In order can be that photodetector reaches better effect; Can be provided with at the input of photodetector and filter and light collecting device, the light that the LED device is sent is through focusing on the sensitization part of photodetector after the filtering, thereby improves the sensitivity of photodetector;
Said photodetector is used to receive above-mentioned light signal, and transfers to power amplifier after this light signal is transformed into the signal of telecommunication;
Said power amplifier carries out power amplification with above-said current signal, and the signal of telecommunication after the power amplification is transferred to second digital signal processing module;
The signal of telecommunication of said second digital signal processing module after to above-mentioned power amplification carries out analog-to-digital conversion process, demodulation process, decoding processing and resampling successively to be handled, and produces digital signal, and with said digital data transmission to video display apparatus.
As shown in Figures 2 and 3, transmitting terminal adopts digital signal processor that vision signal is handled, and process is following:
The first step: the external video input equipment provides the collected digital signal processing module of a frame video image to carry out buffer memory;
Second step: the video data that obtains is resampled;
The 3rd step: the video data to after resampling carries out compressed encoding, obtains the video data stream through processed compressed, realizes source encoding;
The 4th step: the signal after will encoding is sent into modulating unit and is modulated, and obtains modulated signal;
The 5th step: modulated signal is carried out digital-to-analogue conversion, and be sent to biasing circuit to the mixed video output signal that obtains.
Like Fig. 3 and shown in Figure 4, in concrete embodiment, said receiving terminal DSP processing procedure is following:
The first step: the vision signal of the output of received power amplifier, and become video signal to this analog-signal transitions;
Second step: demodulating unit receiver, video digital signal, after demodulation, deliver to video decoding unit;
The 3rd step: handle through decoding unit, obtain video data stream, realize source coding;
The 4th step: above-mentioned video signal is resampled, export video display apparatus to.