CN102365832A - Mixed format media transmission systems and methods - Google Patents

Mixed format media transmission systems and methods Download PDF

Info

Publication number
CN102365832A
CN102365832A CN2010800157008A CN201080015700A CN102365832A CN 102365832 A CN102365832 A CN 102365832A CN 2010800157008 A CN2010800157008 A CN 2010800157008A CN 201080015700 A CN201080015700 A CN 201080015700A CN 102365832 A CN102365832 A CN 102365832A
Authority
CN
China
Prior art keywords
signal
constellation
frame
video
qam
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
CN2010800157008A
Other languages
Chinese (zh)
Other versions
CN102365832B (en
Inventor
K·兰姆
M·菲莫弗
G·托梅扎克
D·穆扎鲍夫
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Intersil Americas LLC
Original Assignee
Techwell LLC
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority claimed from US12/363,669 external-priority patent/US8300114B2/en
Application filed by Techwell LLC filed Critical Techwell LLC
Priority to CN201511015730.XA priority Critical patent/CN105704366B/en
Publication of CN102365832A publication Critical patent/CN102365832A/en
Application granted granted Critical
Publication of CN102365832B publication Critical patent/CN102365832B/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Images

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N7/00—Television systems
    • H04N7/10—Adaptations for transmission by electrical cable
    • H04N7/106—Adaptations for transmission by electrical cable for domestic distribution
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L27/00—Modulated-carrier systems
    • H04L27/26—Systems using multi-frequency codes
    • H04L27/2601—Multicarrier modulation systems
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L27/00—Modulated-carrier systems
    • H04L27/32—Carrier systems characterised by combinations of two or more of the types covered by groups H04L27/02, H04L27/10, H04L27/18 or H04L27/26
    • H04L27/34—Amplitude- and phase-modulated carrier systems, e.g. quadrature-amplitude modulated carrier systems
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L27/00—Modulated-carrier systems
    • H04L27/32—Carrier systems characterised by combinations of two or more of the types covered by groups H04L27/02, H04L27/10, H04L27/18 or H04L27/26
    • H04L27/34—Amplitude- and phase-modulated carrier systems, e.g. quadrature-amplitude modulated carrier systems
    • H04L27/38—Demodulator circuits; Receiver circuits
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N23/00—Cameras or camera modules comprising electronic image sensors; Control thereof
    • H04N23/60—Control of cameras or camera modules
    • H04N23/63—Control of cameras or camera modules by using electronic viewfinders
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N23/00—Cameras or camera modules comprising electronic image sensors; Control thereof
    • H04N23/60—Control of cameras or camera modules
    • H04N23/66—Remote control of cameras or camera parts, e.g. by remote control devices
    • H04N23/661—Transmitting camera control signals through networks, e.g. control via the Internet
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N7/00—Television systems
    • H04N7/08—Systems for the simultaneous or sequential transmission of more than one television signal, e.g. additional information signals, the signals occupying wholly or partially the same frequency band, e.g. by time division
    • H04N7/0806—Systems for the simultaneous or sequential transmission of more than one television signal, e.g. additional information signals, the signals occupying wholly or partially the same frequency band, e.g. by time division the signals being two or more video signals
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L25/00—Baseband systems
    • H04L25/02—Details ; arrangements for supplying electrical power along data transmission lines
    • H04L25/03—Shaping networks in transmitter or receiver, e.g. adaptive shaping networks
    • H04L25/03006—Arrangements for removing intersymbol interference
    • H04L2025/0335—Arrangements for removing intersymbol interference characterised by the type of transmission
    • H04L2025/03375—Passband transmission
    • H04L2025/0342—QAM
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L25/00—Baseband systems
    • H04L25/02—Details ; arrangements for supplying electrical power along data transmission lines
    • H04L25/03—Shaping networks in transmitter or receiver, e.g. adaptive shaping networks
    • H04L25/03006—Arrangements for removing intersymbol interference
    • H04L2025/03592—Adaptation methods
    • H04L2025/03598—Algorithms
    • H04L2025/03611—Iterative algorithms
    • H04L2025/03617—Time recursive algorithms
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L27/00—Modulated-carrier systems
    • H04L27/0014—Carrier regulation
    • H04L2027/0044—Control loops for carrier regulation
    • H04L2027/0053—Closed loops
    • H04L2027/0057—Closed loops quadrature phase
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L27/00—Modulated-carrier systems
    • H04L27/0014—Carrier regulation
    • H04L2027/0044—Control loops for carrier regulation
    • H04L2027/0063—Elements of loops
    • H04L2027/0067—Phase error detectors

Abstract

Systems and methods for operating cameras are described. An image signal received from an image sensor can be processed as a plurality of video signals representative of the image signal. An encoder may combine baseband and digital video signals in an output signal for transmission over a cable. The video signals may include substantially isochronous baseband and digital video signals. A decoder demodulates an upstream signal to obtain a control signal for controlling the position and orientation of the camera and content of the baseband and digital video signals. Systems and methods are described that receive the various signals, provide synchronization information associated with the signal, correct phase shift offsets in the signals and employ or detect encoding schemes used in signaling. Systems and methods for detecting presence of the signals are described.

Description

Mixed format medium transmission system and method
Background of invention
Background technology
Along with the appearance of digital broadcast television with the stream video technique, many digital camera, monitor and video record devices with enhancing definition and advanced have become available.Nowadays the Close Circuit Television (CCTV) system provides the digital video signal of HD video output and compression to be used for for example building management, the access control of facility and the occasion of telemonitoring.Yet old system rests on original place and SD analog video signal and is in and is widely used and in carrying out the transition to the process of digital, high definition system, still can continues to use.Specifically, coaxial cable (" coaxial ") has been deployed the signal of carrying from CCTV video camera to monitoring station.The CCTV video camera of some deployment on local area network (LAN) or wide area network, transmit through the compression vision signal, but and these video camera internet usage agreements (IP) as means of communication transmit through the compression vision signal.
Fig. 1 illustrates the legacy system that uses coaxial cable carrier SD analog video.Basic analog video camera 10 general generations can use coaxial cable 11 transmission to reach 300 meters composite video baseband signal (CVBS).The CVBS signal is provided for a kind of video recording system usually, and this video recording system often comprises the digital video recordings device (DVR) 12 of recording CVBS with number format.Conventional monitors 14 can be connected in DVR 12 to show this SD analog video simultaneously, and this SD analog video generally has the resolution of 720*480 pixel.
Digital camera 16 is instead analog video camera 10 in some applications.Digital camera 16 can be supported serial digital interface (SDI), this serial digital interface approximately the speed of 270Mbps on coaxial cable 17 with the SD digital video transmission of uncompressed to DVR.
Fig. 2 is illustrated in the conventional method of transmitting HD video (1920 * 1080 pixel) in the current deployment system.At first, digital camera 20 can be supported high definition serial digital interface (HD-SDI), and the speed that HD-SDI can 1.5Gbps transfers to DVR 22 with the high-definition digital video of uncompressed on coaxial cable 21.The cable distance of under such high transmission rates, supporting can reach 100 meters.Secondly, IP-based high definition (HD) video camera 24 can use standard class 5 (CAT 5) twisted-pair cables 25 on the 100Mbps Ethernet, to produce the digital HD vision signal through compression, and its transmission range is 100 meters.This signal DVR 22 receives and is recorded to do the non real-time playback.Existing coaxial cable 26 can be used to use type 5-coaxial cable bridge joint modulator- demodulator 27,29 or other conversion equipment that video is transferred to DVR 22 from video camera 24.Make the use of networking network of video camera transmission digital video allow these systems to add some upstream communications, be generally control and audio signal 28.
Invention field
The present invention relates generally to multi-media transmission system and relate more specifically on single cable the system and method for transmission high-definition digital video and SD analog video.
Summary of the invention
Some embodiment of the present invention provides the system and method for video camera and operation video camera.Processor can receive picture signal and produce a plurality of vision signals of token image signal from imageing sensor.Encoder is used for baseband video signal and digital video signal are combined as the output signal that on cable, transmits.Baseband video signal and digital video signal when vision signal can comprise basic the grade.Video camera can be used as closed circuit HDTV video camera.
According to some aspect of the present invention, baseband video signal can comprise the SD analog video signal and digital video signal can with baseband video signal combination before modulated.Digital video signal can comprise the high-definition digital video signal through compression.The frame rate of digital video signal can be lower than the frame rate of picture signal, especially modulated digital signal is being offered under the situation of video record device.
In certain embodiments, the configuration decoder is with to carrying out demodulation from transmission cable or from the stream signal that cordless communication network receives, and this transmission cable is used for carrying the downstream video.Stream signal through demodulation can comprise control signal, and said control signal comprises that a part that signal, the control of the position of controlling video camera and direction produces the signal of baseband video signal and digital video signal through processor and select picture signal is to carry out encoded signals as baseband video signal.Control signal also can comprise selects a part of picture signal to carry out encoded signals and be used to drive the for example audio signal of the camera audio output of loud speaker as digital video signal.
Some embodiment of the present invention provides the method for transmitting video image.These methods can comprise: the vision signal to receiving from the high definition imaging device is carried out frequency division multiplexing to obtain modulated digital signal; Through being made up to produce the output signal and will export signal simultaneously, modulated digital signal and the base-band analog signal that characterizes vision signal be sent to monitor and digital video storage device.In some of these embodiment, the baseband analog of monitor display video signal characterizes and/or the digital video memory uses the digital video recordings device to record a series of high definition frames that extract from modulated digital signal.Digital video signal can be compressed.
In certain embodiments, transmission output signal comprises the output signal is offered coaxial cable and/or offers transmitting set.But the input signal that demodulation receives from coaxial cable or wireless network is to obtain control signal.Base-band analog signal can be through producing a part of video signal coding in composite video signal, and intend that part of vision signal that is coded in the composite video signal and can use control signal to control.The position of control signal may command video camera.The demodulation input signal can produce an audio signal from input signal extraly.
Some embodiment of the present invention is provided for operating the system and method for video camera.Processor can receive picture signal and produce a plurality of vision signals from imageing sensor, the configurable control signal that receives in pairs of control logic by video camera respond and the configurable one-tenth modulation digital of modulator vision signal to obtain modulated signal.A plurality of vision signals can comprise baseband video signal and digital video signal.In a plurality of vision signals each is represented at least a portion of the video camera ken, and the content of control signal may command base band and digital video signal.Modulated signal and baseband video signal are transmitted by video camera usually simultaneously.
Base band and digital video signal can be when waiting basically.Encoder can be combined as the output signal that is used on cable, transmitting with baseband video signal with through modulation signal.For example, can receive control signal from wireless network by wireless mode.Can transmit with wireless mode at least in part through modulation signal.Digital video signal can be the high-definition digital video signal, and can be the digital video signal through compression.Control signal moves the part by the ken of a sign in the vision signal.
The accompanying drawing summary
Fig. 1 explains orally the prior art systems of using coaxial cable carrier SD analog video.
Fig. 2 explains orally the art methods of transmission high-definition digital video.
Fig. 3 describes the system that is used for transportation simulator and digital video of some aspect according to the present invention.
Fig. 4 describes the networked systems that is used for transportation simulator and digital video of some aspect according to the present invention.
Fig. 5 illustrates the allocated bandwidth at the transmission over coaxial cable analog and digital video that is used for of according to the present invention some aspect.
Fig. 6 explains orally the example of the CCTV camera equipment of some aspect structure according to the present invention.
Fig. 7 explains orally the example of the modulator-demodulator that in the DVR equipment, uses of some aspect structure according to the present invention.
Fig. 8 explains orally the example of the modulator-demodulator that in the network exchange equipment, uses of some aspect structure according to the present invention.
Fig. 9 is the example of the frame structure that in the ATSC DTV, uses.
Figure 10 is the example of conventional frame synchronized packets.
Figure 11 is the example of the data sementation in the conventional data frame.
Figure 12 provides the simplification diagrammatic sketch of frame configuration.
Figure 13 is the block diagram of the modulator of some aspect according to the present invention.
Figure 14 is the block representation of the frame structure that in certain embodiments of the invention, adopts.
The operation of the convolutional byte interleaver of Figure 15 explanation in certain embodiments of the invention.
Figure 16 is the block diagram of the selectable code check perforation trellis coding modulation adopted in the certain embodiments of the invention.
Figure 17 explains orally the example of QAM mapping.
Figure 18 illustrates frame synchronization/mould and divides into groups.
Figure 19 is the simplification frame structure that in certain embodiments of the invention, adopts.
Figure 20 is the block diagram of the demodulator of some aspect according to the present invention.
Figure 21 is the block diagram of the camera side modulator-demodulator of some aspect according to the present invention.
Figure 22 is the block diagram of the monitor side modulator-demodulator of some aspect according to the present invention.
Figure 23 explains orally the camera side base band-passband QAM modulator of some aspect according to the present invention.
Figure 24 A and 24B explain orally the monitor side passband-base band qam demodulator of some aspect according to the present invention.
Figure 25 explains orally the monitor side digital equalizer and the carrier phase/frequency loop of some aspect according to the present invention.
Figure 26 illustrates the decay of describing because of the frequency that becomes in coaxial cable.
Figure 27 A describes the power spectral density (PSD) of equalizer input.
Figure 27 B illustrates the amplitude response of the equalizer tap of convergence.
Figure 28 A, 28B, 29A and 29B illustrate under the different frequency loss in the passband digital video signal with respect to crooked.
Figure 30 illustrates the monitor modulator-demodulator that in qam demodulator, has digital equalizer of some aspect according to the present invention.
Figure 31 describes the Active Analog Filter that is suitable for equalization base band CVBS of some aspect according to the present invention.
Figure 32 illustrates the example of the filter response in the certain embodiments of the invention.
Figure 33 A and 33B are the QPSK planispheres of explaining orally the rotation in the complex plane.
Figure 34 is a block diagram of explaining orally the phase correction process of some aspect according to the present invention.
Figure 35 describes integration ratio (IP) filter of some aspect according to the present invention.
Figure 36 explains orally the code element of a transmission.
Figure 37 A, 37B, 37C and 37D explain orally the possible recovery code element based on the transmission code element of Figure 36.
Figure 38 illustrates the example of the phase shift in the receiving symbol.
Figure 39 illustrates the example based on the transmission planisphere of the typical real part of frame synchronization code element and imaginary part.
Figure 40 is the block diagram of the expression phase deviation adjuster that in certain embodiments of the invention, adopts.
Figure 41 explanation is used for confirming the process of the reliability relevant with frame synchronization.
Figure 42 is depicted in the equalizer that adopts in the certain embodiments of the invention and some aspect of carrier phase/frequency loop.
Figure 43 is illustrated in sheer and the phase error detector module that adopts in the certain embodiments of the invention.
The complex exponential LUT module that Figure 44 explanation is adopted in certain embodiments of the invention.
Figure 45 A, 45B illustrate the real part of the equilibrium output in QPSK signal (Figure 45 A) and 16-QAM signal (Figure 45 B).
Figure 46 A, 46B and 46C are when constellation is QPSK (Figure 46 A), 16-QAM (Figure 46 B) and 64-QAM (Figure 46 C), use the distribution map of the power of the equilibrium output that equalizer convergence produces at the embodiment of R=58.
Figure 47 explains orally the example at the constellation of equalizer output and input place of carrier phase/frequency recovery loop module.
Figure 48 illustrates the example of the QAM mapping with threshold value of depicting.
Figure 49 illustrates the right upper quadrant of all three constellations that cover on the same area.
Figure 50 explains orally the operation of a kind of way of confirming constellation.
Figure 51 A and 51B describe the system that is used for transmitting simultaneously SD and HD video of some aspect according to the present invention, and this system has tap or signal interruption.
Figure 52 A and 52B explain orally according to the present invention some aspect produces frame-synchronizing impulse from noise signal process.
Figure 53 is the block diagram of the camera side modulator-demodulator of the indicating device with coaxial cable connection of some aspect according to the present invention.
Figure 54 explains orally some aspect of automatic gain control loop.
Embodiment
Referring now to accompanying drawing embodiments of the invention are described in detail, these accompanying drawings provide so that those skilled in that art can realize the present invention as the illustrative example.Obviously, following accompanying drawing and example are not intended to scope of the present invention is limited in the scope of single embodiment, but can through exchange said or shown in key element some or all make other embodiment possibility that becomes.No matter where, as long as convenient, promptly run through institute's drawings attached and use identical Reference numeral to represent same or analogous parts.Can use under the part or all of situation that realizes of known elements in some key element of these embodiment; Only to describing understanding necessary those parts of the present invention in these known elements, and save detailed description to other part of these known elements with the unlikely the present invention of obscuring.In this manual, the embodiment that single part is shown should not be regarded as restriction; On the contrary, the present invention is intended to contain other embodiment that comprises a plurality of same parts, and vice versa, only if explicit state is really not so in this article.In addition, the applicant is not intended to make any term in specification or claims to ascribe common or not special implication to, and the way it goes only if clearly illustrate.In addition, the present invention is contained among this paper through explaining orally present with the following known equivalent of the parts of quoting from.
Some embodiment of the present invention provides the system and method that allows video camera on coaxial cable, to send high-definition digital video and SD analog video simultaneously.High-definition camera is suitable for producing digital video signal and the analog baseband signal through compression.Digital signal with frequency range that the upper frequency of baseband video signal separates on modulation and sending.Can encode to analog signal according to any standard that needs of closing, comprise PAL, SECAM and NTSC standard and distortion thereof.
For the purpose of description, the example that adopts the system of safety chain (SLOC) on the coaxial cable will be described.In addition, SLOC is generally described as with respect to video camera and has the upstream and downstream signal: the position for video camera is in the upper reaches.In this manual, the example of SLOC system is provided at downstream high definition (HD) vision signal, the upper reaches audio frequency in second passband and control signal and the downstream composite video baseband signal (CVBS) in first passband.To understand, can use other passband signal and allocated bandwidth.For example, system can adopt the two-way digital video signal of SD or high definition resolution.
Fig. 3 describes to explain orally the embodiments of the invention of some operation principle of the present invention.This example depiction hope and be about to the video record of high definition version and in DVR 32, watch the deployment of the HD video camera 30 in the system of the live video that produces by video camera 30.The example of this kind system is safety or surveillance.Can remotely control the function of HD video camera 30 like hereinafter in greater detail.HD video camera 30 is suitable for producing simultaneously high-definition signal 332 and simulation CVBS signal 330.In certain embodiments, high-definition signal 332 and simulation CVBS signal 330 are when waiting, if but for example unequal in the time-delay of handling unlike signal, then they possibly be when roughly waiting.In one example, because number-Mo conversion expense, CVBS signal 330 can be delayed time.In another example, compressible high-definition signal 332 and make its experience different time delay based on compression ratio etc.In certain embodiments, CVBS 330 can keep constant time relationship with the common audio signal that is produced by video camera 30 synchronously or with it with high-definition signal 332.
Can be through adding external component or hardware and software being integrated into video camera 30 and adaptive video camera 30.In this example, safety chain modulator-demodulator (SLOC-T) on the coaxial cable is provided in video camera 30.SLOC-T 31 can be configured to integrate or use as the additives of video camera 30 modulator-demodulator of the parts realization that has been integrated into video camera 30.SLOC-T 30 allows multimedia to present transmission downstream on communication channel: as shown in the figure; SLOC-T 31 is a kind of equipment; This equipment allows on coaxial cable 33, to transmit a plurality of signals, and said a plurality of signaling bearers characterize the different resolution signal by video camera 30 video that produces.In order to clearly demonstrate, the SLOC that will be deployed among this paper in the transmitting apparatus (such as video camera 30) is called SLOC-T, and the SLOC that will be arranged in the receiving equipment (such as DVR, the network switch etc.) is called SLOC-R.Description to SLOC-T and SLOC-R equipment will provide hereinafter in more detail.
SLOC-T 31 can cooperate and/or can increase and make video camera 30 be operated in the enhancement function under the various patterns with other parts of video camera 30.In one example, video camera 30 can produce the output of unpressed HD digital video and SLOC-T 31 can provide compression HD the ability of digital video signal.Therefore, SLOC-T 31 can provide modulation and demodulation ability in addition to strengthen the function of main frame video camera 30 as required.Therefore, several SLOC-T equipment can be operated under the various patterns, and the some of them pattern provides through example.In a kind of pattern, SLOC-T 31 receives through the SD analog version of the HD vision signal of compression and signal and at coaxial cable 33 these two kinds of signals of transmission from video camera 30.In another kind of pattern, SLOC-T 31 receive from video camera 30 uncompressed HD vision signal and signal the SD analog version and on coaxial cable 33, transmit HD digital signal version through compressing together with the SD analog signal.The SD analog signal that SLOC-T 31 can send the HD digital signal and the HD signal that receives from video camera 30 derives.
In certain embodiments, SLOC-T 31 uses frequency division multiplexing to be created in the output signal of transmission on the coaxial cable 33.In the example that Fig. 5 explained orally, with frequency f CdCarrier wave 53 in the single frequency range 52 at center the downstream digital signal is provided.Frequency range 52 is from surpassing the highest frequency f of base-band analog signal 50 0The position begin.This different frequency range 52 can be called as channel.Channel 52 can be selected based on ability, available bandwidth, signal bandwidth and other reason of SLOC-T 31.In certain embodiments, can basis come selective channel 52 with the compatibility that receives equipment.In one example, but can signal directly be offered Standard Definition Television and selective channel 52 to guarantee the suitable isolation with baseband signal.When using the standard definition coding of signal, also can come a plurality of frequency ranges in the selective channel 52 based on the standard of digital video transmission.Can conceive through using all parts that two or more different channels carry digital signal to transmit the individual digit signal.
Can use any suitable modulation scheme to produce the transmitted version of digital signal.For example, dissimilar wired and wireless connections can with multiple modulation scheme coupling, for example phase shift keying (PSK), frequency shift keying (FSK), quadrature amplitude modulation (qam), OFDM (OFDM) etc.Modulation scheme is normally selected based on some factors, and these factors comprise frame rate and the other factors that influences the available bandwidth of channel 52 of vision signal of characteristic, the requirement of the medium that is used for transmitting.
SLOC-R modulator-demodulator 35 can be arranged in the video capture device such as DVR 32.SLOC-R modulator-demodulator 35 can receive and fast acquisition of digital video and CBS signal.Typically, the CVBS signal is extracted and is directly passed to display system 33 to watch in real time by video camera 30 video captured images.Display system 33 can be the SD monitor, although display system also can receive Analog signals'digital version.In one example, SLOC-R modulator-demodulator 35 can produce the Analog signals'digital version with data monitor or the computer coupling that suitably is equipped with.The extraction of baseband signal typically uses the low pass filter realization, and this low pass filter can use analog component or realize through Digital Signal Processing.Can extract digital HD signal separately and it is offered the portion that records of DVR 32.In certain embodiments, can be before recording in DVR compressed digital HD vision signal.In many examples, digital HD vision signal is as being received through compressed digital signal.
In certain embodiments, SLOC-T 31 and SLOC-R 35 are configured to the transmitted in both directions of supporting signal.In the example of safety device, and as following describe in detail with reference to Fig. 6, video camera 30 can comprise microphone 614, loud speaker 612, transducer 616, the control interface 618 that is used for the controller electric brake and further feature (see figure 6).In this example, SLOC-T 31 is configured to control, audio frequency and other data 36 are conveyed to video camera 30 with SLOC-R 35 usually.
Refer again to Fig. 5, in one embodiment, can upstream data be conveyed to video camera at one or more channels that are arranged in available bandwidth upper end 54.The channel that is used for digital multimedia signal 52, control and audio signal 54 and other data communication is selected and can be selected based on signal to noise ratio, signaling standard and/or specialized requirement that available bandwidth, channel 52 and 54 record.In certain embodiments, in case use training sequence to set up being connected of SLOC-T 31 and SLOC-R 35, channel configuration, bandwidth and signal to noise ratio have promptly been confirmed.Typically, use training sequence to confirm the signalling capability of predetermined or negotiated channel, with the available bandwidth of selecting to be used for the channel 52 of transmission digital video and confirming selected channel 52.The characteristic of selected channel 52 can be used for setting the compression level of digital video signal.
In certain embodiments, stream signal 54 comprises the signal of the content that can control downstream 52 and base band 50 signals.For example, camera optics device 600 the flake visual field and may command camera processes device that the position of being kept watch on by video camera 60 can be provided with a part of image of selecting to be used to transmit as baseband signal 50.Typically, downstream digital signal 52 can provide and be recorded in the complete image that DVR went up or supplied further processing.But baseband signal 50 receiving baseband signals 50 are in the zone under the supervision with real time monitoring.Baseband signal 50 can comprise through the adjustment image, the visual effect that this is formed by fish eye lens through the adjustment image rectification.The observer of baseband signal 50 can observe the visual field is moved in the fish-eye ken through catching image through selecting a new part.For example, the observer can ask " to right translation " so that the ken moves right.The data of transmission then make the part that requires of the extraction of camera processes device and the processing ken in stream signal 54.In certain embodiments, make and be included in the request that the ken in the baseband signal 50 moves and cause the physics of video camera 60 to move.Therefore, the control data in the stream signal 54 possibly influence the content of base band 50 and downstream numeral 52 signals.
In certain embodiments, the downstream audio frequency can be used as the part of HD digital video signal and/or transmits as the part of CVBS signal.Some downstream signalings can be carried in the independent dedicated channel (not shown).In certain embodiments, can use the out-of-band communication method to realize, comprise and for example use wired or wireless network with the upstream communication of video camera 30.In certain embodiments, can conceive and wirelessly send downstream digital signal 52 as substituting or additional the selection.Therefore, in some combinations of wirelessly transmitting the upper reaches 54 and downstream 52, can pass through coaxial cable transmission base band 50.Typically, upstream data 54 comprises the control signal of downstream 52 and base band 50, no matter transmission method why.
In certain embodiments, can cable 33 directly be offered display system 33 with display simulation SD video.SD monitor or display 33 generally include the filter circuit that permission is selected at the TV interchannel of baseband signal and standard modulation.As a result, the carrier signal of monitor 33 discardable high-frequency digital codings.If in the channel of standard definition and use the digital coding mode transmission digital video signal of standard definition, then DVR 32 also can the receiving digital video signal and need not extra process.SLOC-R 35 decodings also will offer DVR 32 with other signal through the HD digital video of decoding by the signal that SLOC-T 31 produces.But SLOC-R 35 also paired domination number encodes according to, voice data and other data and is used for to video camera 30 transmission.
Referring now to Fig. 4,, provide embodiments of the invention, this embodiment explains orally some operation principle of the present invention.Fig. 4 describes an example, and this example provides the system of HD video version when requiring to watch the live video that is produced by video camera 40 on network through the network switch 44.In one example, the HD video feed is hunted down and uses inside or external IP video server to flow and send.HD video camera 40 is suitable for producing simultaneously high-definition signal and ABB vision signal usually.Can be through adding external component or hardware and software being integrated into video camera 40 adaptive video cameras 40, such as SLOC-T 400.SLOC-T 400 can operate with the SLOC-T 31 identical modes of showing among Fig. 3.Yet the mode that SLOC-T 400 configurable one-tenth are beneficial on network, transmit digital video signal is to digital encoding video signal.For example, SLOC-T 400 can send form programming according to the stream that the IP video server is supported or to be configured to provide digital video signal separately.
The multiplex video signal that is sent by digital camera 40 can be received by the network switch 44, and the said network switch 44 is furnished with SLOC-R 440 alternatively.Can extract base band SD analog signal and it is offered display 43.In certain embodiments, SLOC-R 440 can extract digital high-definition video signal and use the suitable networks with enough bandwidth of carrying digital HD vision signal to forward it to video server or other network equipment.Numeral HD vision signal can comprise the HD vision signal through compression.In certain embodiments, the digital high-definition signal that is extracted by SLOC-R 440 is compressed or further compresses to be forwarded to video server or other network equipment.SLOC-R 440 can comprise be used to record and/or again the modulation digital high-definition signal with hardware and software in transmission over networks; For example SLOC-R 440 can produce coding the H-264 signal on Ethernet, to transmit.
Referring now to Fig. 6,, some embodiment of the present invention provides the enhancing that is applicable to safety system ability.In the example of being described, video camera 60 comprises modulator-demodulator SLOC-T 606 and processor, and processor is configured and is adapted to some aspect according to the present invention and provides through digitally coded multi-media signal.Can use the combination of optics 600 and imageing sensor 602 to catch image sequence, this combination can comprise the lens combination that those skilled in that art are known and the combination of ccd sensor.Processor 604 receives sweep signal 603, the image sequence that said imageing sensor 602 provides as requested or the predefine frame rate is caught from imageing sensor 602 usually.
In certain embodiments, imageing sensor 602 can comprise hardware and the logic of the warp scanning analog signal that characterizes the image of being caught by one or more transducers being changed and produced digital video signal.For example, imageing sensor 602 can comprise RGB (red, green, blue) but the output of transducer and imageing sensor 602 inter-process RGB transducers to produce through digitally coded colour-video signal as its output 603.In other embodiments, but processor 604 preliminary treatment from the signal 603 of imageing sensor 602 to obtain the raw digital video signal.No matter be to obtain internally or receive from imageing sensor 602, raw digital video all can be for further processing to obtain initial HD digital video signal by processor 604.Simulation SD signal can obtain through output 603 or the initial HD digital video signal of handling raw digital video signal, transducer 602.Processor 604 can format to obtain to meet one or more HD digital video signals of broadcasting and other standard initial HD digital video signal then.For example, processor 604 can produce the signal that meets such as the broadcast video standard of ATSC and DVB standard.Processor 604 is compressed digital video signals additionally.
Camera processes device 604 can comprise the combination of commercially available parts and custom hardware and software.In one example, processor can comprise microprocessor, digital signal processor, microcontroller, sequencer and other and memory combination and support to carry out one or more in the programming device of logic of series of steps, instruction and/or program.Storage 610 can be used to storage computation machine instructions, when execution should be instructed, and some that describe among execution the application or repertoire.Camera processes device 604 can comprise some processes built-in or " hard coded ", and these processes can be used to make up some embodiment of the present invention.Storage 610 also can be used to the buffer programming and/or keeps configuration information.In certain embodiments, storage 610 can be used for storage by video camera 60 video captured records.Therefore, storage 610 can use be prone to become estranged nonvolatile storage, CD and disk, removable electricity erasable memorizer, USB memory driver and other semiconductor, electromagnetism and light storage device to realize.
Signal 605 comprises upper reaches control, audio frequency and other upstream information that is offered the vision signal of SLOC-T 606 and received and be transmitted to by SLOC-T 606 processor 604 from circuit 62 by processor 604.Can before with voice frequency relay to loud speaker, transducer or other audio output system 612, decode, handle and/or format through 604 pairs of upper reaches audio-frequency informations of processor.The scalable audio signal of processor or can in audio output part 612, adopt independent amplifier.Upper reaches control can comprise optics control 601 and control the signal of external equipment that this signal provides through control interface 618 usually.External equipment can comprise and is used to make video camera 60 translations, rotation or with the motor or the actuator of orientation separately.Optics control signal 601 can produce in response to being ordered by remote control system predefine with external control signal 618.For example; Remote subscriber can be handled a rocking bar; This rocking bar produces a series of coded commands of being explained by camera processes device 604; Thereby expression " deasil rotary camera 90 is spent in horizontal plane ", and processor 604 can be through responding a series of pulsings to the stepping motors of axially installing with respect to video camera 60, this series of pulses makes the rotation that video camera 60 is expected around its vertical axis thus.Similarly order focus, convergent-divergent and the aperture of adjustable optical device 600.
In another example, can in the control information of the upper reaches, instruction and data be provided, this upper reaches control information can be used for the function of processor controls 604 and/or transducer 602.This instruction and data can be used for selecting the interior a certain zone of video camera 60 kens in the vision signal of one or more downstream, to encode.In certain embodiments; Processor and transducer cooperation are to provide one or more virtual video cameras; These virtual video cameras can be selected these parts through empty translation, convergent-divergent and the tilt function that can in the practicality visual of being confirmed by the optics of video camera 60, operate thus by remote control to specify the part that will be encoded in the ken.In certain embodiments, processor 604 can make video camera physics move extraly, expands the scope of translation, inclination and zoom function thus.
In at least some embodiment, conception makes CVBS and digital signal carry the part of the image of being caught by imageing sensor 602 separately.These image sections can be overlapping or be come the zones of different that forms in the comfortable ken that is provided by camera lens 600.In addition, in certain embodiments, can use additional cameras 60 and/or appended drawings image-position sensor 602 to expand the available ken.For example, a plurality of video cameras of desired configuration are to obtain panorama (360 °) view in zone.One or more processors 604 can provide the analog and digital signal of representing view or a part of view.In one embodiment, complete panoramic view can be provided in recording the digital signal of DVR, the CVBS signal can provide selectable view in panorama simultaneously.Selectable view can use convergent-divergent, translation and other control to control.In another example, the public or different piece of panoramic view and these parts can be provided is independently to be controlled by the remote reviewing person for CVBS and digital signal.
Fig. 7 be illustrated in the secure digital video recording system 70 use with Fig. 3 in the example of the SLOC-R 35 similar SLOC-R 700 that describe.System 70 comprises SLOC-R 700, is connected in the DVR processor 702 of ancillary equipment 710,712 and 714, analog video decoder device 704, digital video decoder 708 and HD numeral video-stream processor 706.As stated, SLOC-R 700 receives the decode the signal from coaxial cable 72, and this signal generally includes simulation SD vision signal and HD digital video signal.SLOC-R 700 is also through coaxial cable 72 transmission upper reaches audio frequency and control signals.SLOC-R will simulate the CVBS signal usually and separate with the HD digital video signal in input signal 72, digital video signal 703 is offered processor 702 and CVBS signal 701 is offered SD monitor 74 as presenting in real time from video camera shown in Figure 6 60.SLOC-R 700 offers analog video decoder device 704 with ABB vision signal 701 alternatively, and these analog video decoder device 704 processing signals are to produce digital SD vision signal 705.Video-stream processor 706 multiplexed digital SD signals 705 and the signal 707 of from storage HD digital video playback, deriving also make one's options between these two kinds of signals.Video-stream processor can provide can be through the selected signal of HD TV or monitor 76 displayable forms.
DVR processor 702 receive digital HD vision signal 703 and alternatively at least a portion of storage signal as recording by video camera 60 video captured.Record and to be stored in the local hard drive 714, be stored on the networking memory (not shown) or be stored in other light, electromagnetism or the semiconductor storage that connects through network interface 710 and/or USB/ live wire or other local bus 712.The video of being recorded can further compress to save memory space.The DVR processor can use the video of digital video decoder 708 retrieval of recorded and playback signal 707 is provided.
Fig. 8 is illustrated in the example of using in the networking safety means 80 with SLOC-R 440 similar SLOC-R 800 shown in Figure 4.Equipment 80 comprises SLOC-R 800 and the network exchange processor 802 that is connected in IP video server 86 usually through network.As stated, SLOC-R 800 receives the decode the signal from coaxial cable 82, and this signal generally includes simulation SD vision signal and HD digital video signal.SLOC-R 800 is alternatively through coaxial cable 82 transmission upper reaches audio frequency and control signals.SLOC-R will simulate the CVBS signal usually and separate with the HD digital video signal in input signal 82, digital video signal 803 is offered processor 802 and CVBS signal 801 is offered SD monitor 84 as presenting in real time from video camera 60 shown in Figure 6.In certain embodiments, SLOC-R 80 can comprise parts 804,806 etc., with digitlization CVBS signal 801 with digital display coupling such as high-clear display 85, same as presenting in real time from video camera shown in Figure 6 60.Yet will understand, display device that suitably disposes or computing equipment can receive CVBS signal 801 and carry out the digitlization of signal.Network exchange processor 802 receives digital HD vision signal 803 and transmits signals to network video server 86 alternatively, and this network video server 86 can be kept recording by video camera 60 video captured then.Numeral HD vision signal 803 can be by further compression before transferring to video server 86.
Refer again to Fig. 5 and Fig. 6, some embodiment of the present invention allows to select as required the content of base-band analog signal 50 and downstream signal 52.In one example, both all comprise same image baseband signal 50 and downstream signal 52, and the former is an analog form and the latter is through digitally coded.Digital picture can choose wantonly with selectively with compression and uncompressed form, with SD and high definition and with the frame rate transmission of full motion or reduction.In another example, baseband signal 50 provides the part of the complete image of being caught by imageing sensor 602, and downstream signal 52 carries complete image simultaneously.In another example, baseband signal 50 provides the complete image that is provided by imageing sensor, and downstream comprise the part of complete image simultaneously.As a result, visualize a kind of fine system configured, the user that its allows digital camera makes one's options from the option that is used for showing, record and transmit the wide region of video image.
The analog balanced of baseband signal
Some embodiment of the present invention comprises the system and method for the high frequency shuffle effect that is used for improving cable, and aforementioned high frequency shuffle effect is along with the increase of cable length can cause higher frequency decay.By this crooked baseband analog video and the passband digital video signal deterioration of making that cable is introduced, this deterioration is serious further along with the cable length increase.Yet some embodiment of the present invention provides equalizer usually in digital receiver, and this equalizer is removed crooked on the digital passband signal, allows to send the reliable decoding of code element.
Some embodiment of the present invention has improved the system that comprises aforementioned those systems and the performance of device; Wherein baseband video signal can make up with the digital representation and the control signal of baseband video signal, allows thus on the unit cable such as coaxial cable (" coaxial "), to transmit.Fig. 3 and Fig. 4 illustrate provides SLOC system implementation example, and Fig. 5 illustrates a kind of feasible modulation scheme of SLOC system.With Fig. 3 is example, and HD video camera 30 provides and comprises through the output 332 of the digital HD video of compression and the auxiliary camera output 330 that comprises simulation SD (SD) CVBS.HD vision signal 332 through compression utilizes SLOC camera side modulator-demodulator 31 to be modulated to passband 52; This SLOC camera side modulator-demodulator 31 comprises the QAM modulator; This QAM modulator provides modulated signal, this signal and 330 combinations of baseband analog CVBS signal.Signal through combination transmits on coaxial cable 33 downstream, reaches 300 meters or longer distance usually.In the monitor side, on behalf of the signal of base band CVBS signal 330, SLOC monitor side modulator-demodulator 35 will from the signal of representing passband downstream vision signal 332, isolate.The signal that characterizes CVBS is fed to SD display 34 and is used for not having time-delay and watches in real time.The upper passband downstream signal is used the qam demodulator demodulation, and the output of qam demodulator is fed to host-processor and DVR32, DVR32 support real-time (although the possibly slightly delay time) HD on the monitor 34 watch with non real-time HD playback for watching future.
In this example, according to the for example needs through the IP agreement upstream communication is provided.Can use upstream communication so that audio frequency and video camera control signal 334 are sent to video camera 30 from the monitor side extraly.As a rule, the bit rate of stream signal---and so desired bandwidth---is bit rate and the bandwidth required far below the downstream passband signal usually.Monitor side SLOC modulator-demodulator 35 comprises the QAM modulator, and this QAM modulator is modulated to upper reaches passband 54 with the IP signal.Describe like Fig. 5, upper reaches passband 54 is positioned at the different spectral position with downstream passband 52.In camera side, SLOC modulator-demodulator 31 comprises the qam demodulator that is used to receive stream signal.This method provides the some advantages that are superior to existing system and method, comprising:
(1) increases working range-increase distance.
(2) can use existing infrastructure and re-use coaxial cable and come deployment system.
(3) low delay availability, (live telecast) video in real time.
(4) live CVBS video and HD video can watched dividually.
Figure 21 is the rough schematic view of additional detail that the SLOC camera side modulator-demodulator 49 of Fig. 4 is shown.IP connection to HD video camera 2100 is interfaced to QAM modulator 212 and qam demodulator 214 through GMII (MII) module 210.In one example, MII 210 follows IEEE 802.3 standards.QAM modulator 212 uses principles well-known work to convert baseband I P data flow 2100 to passband QAM code element 2120.216 these code elements and 2160 summations of base band CVBS signal also are fed to duplexer 218 with it subsequently.Duplexer 218 can be a bidirectional analog equipment, and it is passed to the base band and the lower passband downstream signal 2162 of combination coaxial cable and is fed to qam demodulator 214 from coaxial cable reception upper passband stream signal 2140 and with it.Qam demodulator 214 uses principles well-known work to export MII interface 210 with demodulation to from the upper passband stream signal 2140 of monitor side joint receipts and with base band data usually.
Figure 22 is the rough schematic view of additional detail that the SLOC monitor side modulator-demodulator 45 of Fig. 4 is shown.Duplexer 220 receives the base band CVBS that makes up in downstream, and also filtering becomes component elements 2201-2203 with signal segmentation with high pass (HP) through low pass (LP) with lower passband IP signal 2200 from coaxial cable.CVBS signal 2201 can directly be sent to SD monitor or other display device.Lower passband signal 220 can be fed to qam demodulator 222, and this qam demodulator 222 is presented to MII interface module 226.Duplexer also can receive upper passband signal 2203 and can this stream signal be passed to coaxial cable from QAM modulator 224.QAM modulator 222 obtains its input from MII interface 226 usually, and MII interface 226 can be connected in the main frame/DVR that supports the IP agreement.
Coaxial cable shows significant high frequency slip characteristics usually, the frequency decay that this high frequency slip characteristics is higher along with the cable length increase can cause.This " crooked " is significant in the frequency range of passband signal and possibly causes significant intersymbol interference (ISI).Possibly need digital equalising correctly to recover the data that transmitted to allow qam demodulator 222.
Base band to passband is modulated
Figure 23 more specifically illustrates the camera side base band to passband QAM modulator 212 (Figure 21).Data from MII 210 are received by FEC encoder/mapper 2300, and this FEC encoder/mapper 2300 uses Reed-Solomon coding, byte-interleaved and/or the trellis coding of for example cascade the error protection data to be added into the data flow that receives from MII 210.Mapper/encoder 2300 resolves into stream 2300 and 2302 with data multiplex, and wherein the bit group of giving sizing of each stream is represented QAM symbol amplitude level respectively at real axis and imaginary axis direction.Transmission QAM pulse through isolating provides through following formula:
s m ( t ) = d R , m q ( t ) cos ( 2 π f c t ) - d I , m q ( t ) sin ( 2 π f c t ) = Re { d m q ( t ) e j 2 π f c t } ,
D wherein R, mAnd d I, mBe confirm by two independent message stream and the real part and the imaginary parts of the multiple QAM code element of expression respectively, wherein m=1...M is as the index of two-dimentional QAM radix constellation, wherein M is a modulated carrier frequencies and q (t) is a root raised cosine pulse function.
The transmission QAM pulse s (t) of one continuous series is with speed F S=1/T SMultipath channel through the band noise.Therefore, provided by r (t)=s (t) * c (t)+v (t) at the reception signal to the input side of QAM receiver, wherein * representes convolution, and c (t) is a channel impulse response, and v (t) is an additive white Gaussian noise.Therefore:
r ( t ) = Re { e j 2 π ( f LO + f o ) t + θ o Σ n = - ∞ + ∞ [ d [ n ] * q ( t ) ] c ( t - n T s ) } + v ( t ) ,
Wherein d [n] is multiple transmission code element, f 0And θ 0Be respectively frequency shift (FS) and the phase deviation of receiver pass-band to base band demodulator local oscillator with respect to transmitter, f thus LO=f c-f 0
Passband is to base band demodulator
Figure 24 A illustrates in greater detail monitor side passband to base band qam demodulator 222 (Figure 22).Signal r (t) can receive from coaxial cable, for example to be higher than the speed sampling (seeing 240) of chip rate, obtains the signal r (nT through sampling thus Samp).After sampling:
r ( n T samp ) = Re { e j 2 π ( f LO + f o ) n T samp + θ o Σ m = - ∞ + ∞ [ d [ m ] * q ( n T samp ) ] c ( nT samp - m T s ) } + v ( n T samp ) .
Then, after down-conversion, with chip rate 1/T SSampling and matched filtering obtain once more:
x ( kT s ) = x [ k ] = e j 2 π f o k T s + θ o Σ m = - ∞ + ∞ d [ m ] c [ k - m ] + v ′ [ k ] ,
Wherein v ' [k] is through the multiple filter noise of sampling, supposes that any ISI is attributable simply to channel impulse response c, because pulse shaping and matched filtering q and the combination of perfect chip rate sampling timing.
Equalizer and carrier phase/frequency ring
Discuss digital equalizer and the carrier phase/frequency loop of Figure 24 A below in more detail with reference to Figure 25.Signal x [k] gets into adaptive digital equalizer 250, and this adaptive digital equalizer 250 can comprise and is used for compensating the crooked linear digital filter that is caused by channel impulse response c.Can use one or more known methods that comprise the LMS algorithm to realize the tap-weights adjustment.Equalizer is exported y [k] with it and is used for the error signal of the renewal collection of calculating filter tap-weights with establishment with making comparisons through phase place rotation version of two dimension (2D) sheer judgement
Figure BPA00001445843900173
.The LMS algorithm can be operated as follows:
Order: the equalizer input vector of x [k] expression N length, and
Y [k] expression equalizer output vector g H[k] x [k],
G wherein H[k] is that equalizer tap weight vector and the subscript H of N length representes that conjugation exchanges (close conjugation in distress).
e [ k ] = d ^ [ k ] - y [ k ]
g[k+1]＝g[k]-2μx[k]e *[k]，
Wherein μ is a little step parameter and subscript * representes complex conjugate.
In order to eliminate the crooked influence of passband cable, after convergence, the LMS equalizer tap can be similar to the inverse of channel impulse response c.
2-D slicer 252 independently split z [k] of the real and imaginary parts and outputs
Figure BPA00001445843900175
Figure BPA00001445843900176
is the original transmission d [k] estimate.Phase error detection module 258 receives z [k] with
Figure BPA00001445843900177
and to form phase error signal
Figure BPA00001445843900181
low pass (LP) filter 256 can be the integration scale filter, and this integration scale filter allows loop phase calibration to squint and frequency shift (FS).The output of low pass filter 256 is fed to multiple discrete voltage controlled oscillator (VCO) 254, this voltage controlled oscillator 254 output calibration θ oAnd f oBoth complex phase positions/frequency correction factor e -j θ [k]VCO 254 also provides output (e + j θ [k]), section output " is not proofreaied and correct " in this output
Figure BPA00001445843900182
So that it can be used for deriving the error signal that is used for the equalizer tap renewal.Because equalizer is operated in x [k], so this normally needs.Referring to Figure 24 A, equalizer output z [k] is fed to the symbol de-maps device equally, and this symbol de-maps device changes into the bit group with detected real number and imaginary number level.The fec decoder device is carried out Veterbi decoding then, and byte deinterleaves and/or the Reed-Solomon decoding receives the error of bit and the gained data are delivered to the MII interface with correction.
The influence of cable length
The vision signal that is received can experience decay because of becoming in the frequency of some characteristic that is attributable to cable.From purpose is discussed, the example of coaxial cable has been described.The order of severity of decay---often is known as crooked---to depend on type of cable and cable length usually.Figure 26 A and 26B illustrate because of becoming in the decay of the frequency of type of cable RG6 that is directed against all lengths and RG59.Can find out, the crooked multipath distortion that is equivalent to, wherein additional path and main path have minimum delay expansion.Along with crooked increase, the number of important multipath component and gain separately thereof also increase.Multipath distortion causes the ISI that receives in the signal and the transmission reliability of therefore possibly seriously demoting.In digital signal, can in receiver, use equalizer to remove these infringements.Figure 27 A and 27B illustrate the amplitude response of equalizer tap of power spectral density (PSD) and the convergence of equalizer input respectively.Specifically; Figure 27 A is illustrated in the PSD (band connection frequency and relative base band frequency are shown) that imports through 2000 feet the equalizer of RG6 cable after transmission under the 15.98MHz carrier frequency, and Figure 27 B illustrates the amplitude response of the digital equalizer tap of convergence.
Some embodiment of the present invention comprises digital equalizer, this digital equalizer can eliminate by cable introduce crooked, remove the ISI in the passband signal and realize transmitting the reliable decoding of data.Along with cable length increases, can use digital equalizer and the guard method of known numerical data forward error (such as the Reed-Solomon coding and the trellis coding of cascade) to come to be received in reliably the digital passband signal of monitor side.Yet, the crooked high-frequency that also can have influence on baseband analog CVBS signal unfriendly of cable, this can be reduced in the acutance of the picture that the monitor side watches and the intensity of color.Therefore, some embodiment provides sef-adapting filter, and such as analog equalizer, it is crooked with the cable at compensation base band place that this sef-adapting filter can be applied to the CVBS signal in the monitor side.Some embodiment utilizes the crooked amount of passband digital equalizer with estimation base band place, and selects suitable in one a group of baseband analog filter CVBS signal that is received to be applied to subsequently.
The efficient estimation that passband is crooked
During crooked in the estimating signal frequency range, can select crooked among the PSD of input signal when quantizing will be near linear frequency range with dB.Therefore, in the base-band digital equalizer input-2.67MHz will be therefore corresponding to the frequency of 13.31MHz and 18.65MHz in the passband input signal to the frequency of 2.67MHz, the scope that suits is provided.Shown in Figure 26 A, be about 3.7dB to 2000 feet the crooked of RG-6 from 13.31MHz to 18.65MHz.In order to estimate crooked in dB, can carry out down column count from the digital equalizer filter tap of convergence:
Δ ^ DB = G DB [ k 1 ] - G DB [ k 2 ] = 10 Log 10 ( | G [ k 1 ] | 2 | G [ k 2 ] | 2 ) , (equality 1)
Wherein G [k] is the DFT of the equalization filter tap of time domain convergence, and k 1And k 2Certain tones crack corresponding to DFT.Because the digital equalising of Figure 25 can be realized through the time domain convolution, therefore in order to estimate given k 1And k 2Crooked, need FFT (maybe possibly do N time to two points takes advantage of again and be added with) usually.That is,
G [ k 1 ] = G R [ k 1 ] + i G I [ k 1 ] = Σ n = 0 N - 1 g [ n ] e - i 2 πn k 1 / N ,
(equality 2)
G (n)=g wherein R(n)+ig I(n), n=0,1...N-1 are N time-domain equalizer tap (being left in the basket with the interdependence of time index).Notice that the 1/N scalar is unwanted in this calculating.Can be directed against G (k 2) carry out similarly and calculate.Yet, can calculate through select the next significantly minimizing in crack frequently scrupulously.Through making k 1=N/4, this is corresponding to the frequency of 2.67MHz, and the complex exponential in the equality (2) is significantly simplified:
Figure BPA00001445843900193
(equality 3)
The real part of filter freguency response and imaginary part can use anded to go out:
G R [ k 1 ] = Σ n = 0 N / 4 - 1 g R [ 4 n ] + Σ n = 0 N / 4 - 1 g I [ 4 n + 1 ] - Σ n = 0 N / 4 - 1 g R [ 4 n + 2 ] - Σ n = 0 N / 4 - 1 g I [ 4 n + 3 ] .
(equality 4)
G I [ k 1 ] = Σ n = 0 N / 4 - 1 g I [ 4 n ] - Σ n = 0 N / 4 - 1 g R [ 4 n + 1 ] - Σ n = 0 N / 4 - 1 g I [ 4 n + 2 ] + Σ n = 0 N / 4 - 1 g R [ 4 n + 3 ] .
(equality 5)
At last, the power under this frequency crack is:
| G [ k 1 ] | 2 = G R 2 [ k 1 ] + G I 2 [ k 1 ] . (equality 6)
Through making k 1=N/4, power calculation is significantly simplified.Similarly, if k 1=3N/4, it is corresponding to the frequency of-2.67MHz, and then complex exponential is once more by remarkable simplification.
Figure BPA00001445843900202
(equality 7)
Real part and imaginary part are calculated as:
G R [ k 2 ] = Σ n = 0 N / 4 - 1 g R [ 4 n ] - Σ n = 0 N / 4 - 1 g I [ 4 n + 1 ] - Σ n = 0 N / 4 - 1 g R [ 4 n + 2 ] + Σ n = 0 N / 4 - 1 g I [ 4 n + 3 ] , (equality 8)
G I [ k 2 ] = Σ n = 0 N / 4 - 1 g I [ 4 n ] + Σ n = 0 N / 4 - 1 g R [ 4 n + 1 ] - Σ n = 0 N / 4 - 1 g I [ 4 n + 2 ] - Σ n = 0 N / 4 - 1 g R [ 4 n + 3 ] , (equality 9)
And rated output as described above | G [k 1] | 2In Fig. 2 b, the optimum SNR of upwards crooked (is unit with dB) in the amplitude response of the filter tap of convergence and 64QAM signal and tap noise is approximately linear evenly.In addition; When calculating with this kind mode,
Figure BPA00001445843900205
this very approaching actual crooked 3.7dB on this frequency range.
The crooked estimation of passband to base band CVBS skew corrected
After crooked, can select suitable baseband analog filter in one from M different filters to this digital video signal estimation passband.Can find out that the passband that estimates of digital video signal frequency range is crooked will indicate the crooked order of severity in the base band CVBS signal, available then analog filter proofreaies and correct roughly that this is crooked.In Figure 28 A, illustrate to crooked in the digital video signal frequency range of 13.31MHz to 18.65MHz of those electricity of RG-6, RG-11, RG-59 and RG-174 and similar length.Figure 28 A illustrates to RG-6, RG-11, RG-59 and RG-174 type of cable with respect to the loss under the crooked 3.58MHz in the passband digital video signal.Figure 28 B is illustrated in the loss under the 6MHz.Can observe, the loss under 3.58MHz and 6MHz is roughly the same for given all crooked four kinds of type of cables.Figure 29 A illustrates to RG-6, RG-11, RG-59 and RG-174 type of cable with respect to the loss under the crooked 3.58MHz in the passband digital video signal.Figure 29 B is illustrated in the loss under the 6MHz.Can observe, the loss under 3.58MHz and 6MHz is roughly the same for given all crooked four kinds of type of cables.
Because the passband that estimates is crooked is the unique available information about the cable frequency response; Therefore regardless of type of cable or length how desirable scene is the frequency response of cable under base band (CVBS signal frequency range) crooked relevant with the passband digital signal in a known way.Confirmed this situation in Figure 28 B, 29A and the 29B frequency response under DC, 3.58MHz and 6MHz.For example, the crooked place of the 1.5dB in the passband digital video signal is approximately 0.68dB, 4.1dB and 5.3dB to all four kinds of cables respectively in the loss under the DC, loss and the loss under 6MHz under color carrier wave (3.58MHz).Therefore, no matter be that the RG-174 from 275 feet, 750 feet RG-59,825 feet RG-6 or 1825 feet RG-11 cause the passband of 1.5dB crooked, it is crooked that same analog filter will be eliminated the base band of CVBS signal.
Be used for selecting the example of algorithm of suitable analog filter as follows from one group of M filter:
Figure BPA00001445843900211
Note α 0=1; α nOther value＜1 and select them so that the displacement addition be enough to calculate R nTherefore, change the monitor side qam demodulator of Figure 24 A usually so that the digital equalizer of passband qam demodulator provides a signal, this signal is selected in the M simulation CVBS filter response.Figure 24 B illustrates the change part of monitor side qam demodulator, and wherein analog filter is selected output from the digital equalizer according to aforementioned algorithm work.Figure 30 illustrates complete monitor side modulator-demodulator, and the digital equalizer in qam demodulator 304 selects signal 305 to offer CVBS analog equalizer 302 in filter.
An example that is suitable for the Active Analog Filter of equalization base band CVBS signal is illustrated in Figure 31.In this example, M=3 exists 4 kinds of possible filtering to select thus.Through one in the switch of the M+1 in the close switch module 310 and make each RC of being attached thereto that ground connection selection is successively closed the filter response that needs thus.Possible filter response shown in Figure 32.
Those skilled in that art will understand, and the present invention can be applicable to adopt the digital communication system of other passband modulation and forward error correction.Those skilled in that art also will recognize; Can use among the FFT of passband digital equalizer tap-weights vector g [n] plural point is that the CVBS signal is selected analog filter; And can comprise frequency-domain equalizer, wherein G to the digital equalizer design of other type that passband signal adopts 1[k] and G 2The value of [k] calculates as the part of equalization process.In addition, can adopt the known equalizer tap weighing computation method except that LMS, such as RLS.
In certain embodiments, have the CVBS analog filter that to select to respond and can adopt above-mentioned form in addition.Equally, the equalizer of CVBS signal can adopt the form of digital filter, before equilibrium, CVBS is done sampling and digitlization in this case.In this case, be used for selecting predetermined the concentrate tap-weights of selecting digital filter of one identical algorithms of M analog filter response according to describing from M tap-weights vector.
Framing in the digital communication system
Digital data stream has the frame structure of some types usually, so that these data are organized into the bit group or the byte group of homogeneous size.Use any system of block-based forward error correction (FEC) will have the frame that is organized in about the error correcting code word length.Equally, resist impulsive noise if system uses to interweave, then frame structure will consider that the interleaver parameter is configured.If system uses the data randomization to obtain smooth frequency spectrum, the pseudo random sequence of then being utilized can be synchronous with frame structure, when every frame begins, restarts.
For the RF digital communication system, receiver must at first be obtained carrier wave and code element clock synchronization and equilibrium usually.Just can recover the data transmitted then.But in order to understand this data flow of importing into, receiver must be also synchronous with this frame structure.In other words, receiver must know where the error correction code word is from beginning and finish wherein.Also must be able to make such as the receiver module of deinterleaver and operate with the interleaver of coupling transmitter synchronously; The bit that deinterleaves or the byte that obtain are correctly sorted; And remove randomizer, the starting point of pseudo random sequence that is used for transmitter with coupling is so that frequency spectrum becomes smooth.
Legacy system often provides receiver frame synchronous through head or the afterbody that the known pattern with the code element of regular length is attached to frame.The every frame of this identical patterns ground repeatedly, and it often is made up of 2 grades of (being binary system) pseudo random sequences with favourable auto correlation characteristic.Produce a higher value although this means sequence and itself auto-correlation under zero offset, if skew is non-zero then this autocorrelation value (secondary lobe) is very little.In addition, this frame synchronization sequence will produce a smaller value with the relevant of code element at random.Therefore, if receiver then should be expected only to produce a higher value in the accurate starting position of each frame with the association of the storage version execution input symbols of frame synchronization pattern.Receiver can easily be confirmed the initial point of each frame then.
The example of frame structure
Referring to Fig. 9, ATSC DTV (DTV) ground transmission standard that adopted in 1996 provides data with the frame system for transmitting.Each frame 90 comprises 313 sections, and each section comprises 832 code elements, so each frame has 260416 code elements altogether.Four code elements of beginning in each section are segment sync code elements 92, and these code elements constitute sequence [+5 ,-5 ,-5 ,+5].First section in each frame is the frame synchronization section 94 with 312 data sections 96,98.Referring now to Figure 10,, frame synchronization section 94 has segment sync 100,511 code element pseudo noise (PN511) sequences 101,63 code element pseudo noise (PN63) sequences 102, the 2nd PN63 sequence 203 and the 3rd PN63 sequence 104.Be that the indication pattern is the 24 pattern code elements 105 of 8VSB afterwards.Precoding code element 107 and reservation code element 106 configuration frame sync segment 94.Segment sync 100 and PN511101 code element are known and can be used to obtain frame synchronization by correlation technique to receiver priori.All aforementioned code elements be derived from collection+5 ,-5}.Last 12 code elements of this section are from collection { 7-5-3-1+1+3+5+7}, and be the copy of last 12 code elements of last data field.They are called as precoding code element (will not discuss) here.
In addition referring to Figure 11; Form from 207 independent bytes (1657 bit) Reed-Solomon (RS) code word for each follow-up 312 section---they are known as data segments---of field 828 code elements 32 after four segment sync code elements 30, this is through get 2 bits, their trellis codings are become 3 bits and subsequently per unit 3 bits mapped to that { 8 grades of code elements of 7-5-3-1+1+3+5+7} are accomplished from collection at every turn.
Another example of framing is found in the ISDB-T system in digital communication system.Different with single carrier ATSC system, ISDB-T is a multicarrier system of utilizing COFDM (COFDM).For example, the pattern 1 of ISDB-T is used 1404 carrier waves.Frame comprises that 204 COFDM code elements constitute, and each COFDM code element can think the combination of 1404 independent QAM code elements, all has one for each carrier wave.Therefore, this frame is by 204x1404=286, the constituting of 416QAM code element.Wherein, 254,592 code elements are data, and 31,824 code elements comprise pilot frequency information (can be used for frame synchronization) and are dispersed in the pattern information in the frame with known pattern.
The simplicity of illustration of this frame configuration is from Figure 12.Can find out, pilot tone and pattern information with known pattern be dispersed in frame around.This system has three kinds of different qam constellations---the pattern of QPSK, 16QAM and 64QAM of utilizing.It also supports five kinds of different trellis coding speed (1/2,2/3,3/4,5/6,7/8) based on female sign indicating number of single column.This technique known makes that in receiver, making up single Viterbi decoder becomes very economical, and said Viterbi decoder is easy to adjust so that all the five kinds of sign indicating numbers in the designated code are decoded.
Before transmitter side was carried out trellis coding, data formed the long RS piece of 204 bytes (1632 bit).Although the COFDM number of symbols in every frame is always constant, however the number of the RS piece in every frame change with institute's lectotype, always most important ground is this number integer.In case set up frame synchronization and known trellis coding speed, it is synchronous that this just allows to be easy to the RS piece in the receiver.For realizing this, to all patterns, the number of the data bit of every frame must be able to be divided equally by 1632 before trellis coding.
Table 1 illustrates the number to the data bit of every frame of all patterns (combination of qam constellation and trellis coding speed).Under every kind of situation, the number of every frame data bit can be divided equally (data bit means the bit before trellis coding) by 1632.
Figure BPA00001445843900241
Table 1: for every frame data bit of ISDB-T
Some embodiment of the present invention provides a kind of framing structure to the modulating system that is used for digital communication system.Specifically, provide and to be applied to comprise above-mentioned those the signaling system and the method for safety system.Convolutional byte interleaver interleaving data frame, wherein interleaver and randomizer synchronous with frame structure is configurable becomes from the Frame that interweaves, to produce through randomized Frame.In one example, the trellis coded modulation device of perforation is operated under the optional code rate, and this modulator is from producing the Frame of trellis coding through randomized Frame.The QAM mapper maps to modulated symbol with the bit group in the Frame of trellis coding, provides frame and synchronizer through mapping that synchronized packets is added to the frame through mapping thus.The trellis coded modulation device of perforated can be as required by bypass with at the optimization net bit rate that obtains under the various white noise conditions, allow the performance optimization of system thus.
In certain embodiments, novel frame structure is provided in carrier wave communication system.The auto-correlation of known pattern that is in top or the terminal regular length code element of frame in zero offset produces a higher value, is non-zero if this squints, and then correlation (secondary lobe) is very little.Yet this frame synchronization sequence will form a smaller value with the relevant of code element at random.Therefore, the storage version of receiver available frame synchronization pattern is carried out and is imported the relevant of code element into, and to obtain the higher value in the accurate starting position of each frame, this makes receiver confirm the starting point of each frame.Communication system can be operated under the arbitrary pattern in the various modes, and can use the various combinations of symbol constellations, trellis code and interlacing pattern.Receiver must be discerned and the data of understanding pattern successfully to recover to be transmitted.For this reason, can additional pattern code element be added into the frame synchronization pattern.These pattern code elements can use correlation technique to receive reliably, repeat to send because they are every frames.Can make them more strong to these mode code primitive encodings through using block code.
A kind of frame structure utilization of some aspect is similar to those perforation trellis codings and the qam constellation combination of using among the ISDB-T according to the present invention.The code element number of each frame can be to depend on why the variable integer of pattern and the RS grouping number of each frame all are constant integers regardless of pattern.The design such as the receiver processing module of removing randomizer and deinterleaver has been simplified in this configuration, because the RS grouping number of each frame is always fixing.In the legacy system such as ISDB-T, the code element number of every frame is constant, and the RS grouping number of every frame is the variable integer that depends on pattern.The example descriptor frame of the transmitter architecture that will describe with reference to Figure 13, said transmitter architecture some aspect according to the present invention makes up.
RS encoder 1300 is accepted byte data 1301 and the outside frame synchronizing signal that produces, and this frame synchronizing signal is indicated the beginning of every group of 315 Reed-Solomon grouping 1322.Shown in figure 14, each grouping 140 comprises 207 bytes, and wherein 20 bytes are parity bytes 142.These 315 Reed-Solomon divide into groups to form forward error correction (FEC) Frame 1322 that comprises 62205 bytes.
Be convolutional byte interleaver 1302 afterwards.Figure 15 explains orally the mode of operation of the interleaver 1302 of tackling the impulsive noise that influences transmission signals.B parameter in the path 156,158 is set as 207, and the parameter M in path 152,154,156 and 158 is set as 1.Frame synchronizing signal 1303 is pushed into tip position 1500 with input and output change over switch 150,151, make thus interweave synchronous with frame structure.Along with byte entering interleaver and different bytes withdraw from interleaver, input and output change over switch 150,151 moves down a position 1502.When change over switch 150,151 arrived bottom 1508, their switched and back on top 1500.In the B parallel route 1506,1508 each comprises shift register 156,158, and said shift register 156,158 has length shown in Figure 15 (path 1506 has length (B-2) M and path 1508 has length (B-1) M).
Randomizer 1306 is through being operated in 65 of FEC Frame 1324; 205x8=521; Produce randomized FEC Frame 328 on 640 bits and through those bits of PN (pseudo noise) sequence with length 219-1 are carried out XORs, through shorten the length of this PN sequence at each frame synchronization time replacement PN sequencer.
Illustrate in greater detail the example of trellis coding modulation (PTCM) module 1308 that can select the bit rate perforation among Figure 16.PTCM 1308 uses the known method of those skilled in that art.This method starts from the encoder of 64 attitudes, 1/2 speed, and carries out perforation to obtain any in 5 kinds of different bit rates.In certain embodiments, PTCM 1308 also can be by complete bypass (bit rate=1).This allows selectable balance between the net bit rate of system and white noise performance.Similarly the trellis coding technology is used to ISDB-T and DVB-T system.PTCM produces two bits 1332 in output place of each bit that offers input 1328.Yet some that will export in the bit 1332 according to selected bit rate and respective perforations pattern abandon.QAM mapper 1313 is fetched the bit in 2,4 or 6 groups of own coding device output 1332 and they is mapped to respectively in QPSK, 16QAM or the 64QAM code element.Provided the example of these mappings among Figure 17.
Module 1312 adds to frame synchronization/pattern code element packet (all code elements are QPSK) beginning of each FEC Frame 1334.Referring to Figure 18, the first 180 of this grouping comprises 127 code elements and comprises to the real part of code element and the identical binary system PN sequence of imaginary part.Other PN sequence length also is possible, and real part and imaginary part can have opposite symbol.The second portion 182 of this grouping comprises the data of indicating transmission mode, promptly selected qam constellation and selected trellis code speed.This mode data can use the piece error correcting code to encode, and is used to increase the reliability at receiver place.Adoptable method comprises Bose-Chaudhuri-Hocquenghem Code and other block code.In one example, 6 kinds of possible trellis code speed that comprise bypass are possible.In addition, three constellations possibly draw 18 kinds of patterns.Therefore, need 5 bits to characterize each in the possible model selection.These 5 bits can use the BCH code of expansion to be encoded into 16 bit codewords.Because each QPSK code element comprises 2 bits, therefore need 8 pattern code elements.
Figure 19 explanation offers the frame structure 1336 (seeing Figure 13) of passband modulation (PB modulation) 1314.Pay(useful) load 190 comprises 315 RS groupings (521640 bits).The number of 315 RS packet map QAM code element extremely can change along with model selection.PB modulation module 1314 uses the known any proper method of those skilled in that art that base band QAM code element is modulated to passband subsequently.
The frame structure of some aspect usefully overcomes some defective and the shortcoming of conventional frame according to the present invention.Specifically, this frame structure provides all patterns:
The RS grouping constant integer of every frame, no matter pattern is how, and
For all patterns, the QAM code element number of every frame is a variable integer
For all patterns, the perforation pattern cycle of every frame is an integer.
The individual QAM code element of integer of noting the every frame of hypothesis is important realization, because the FEC Frame must accurately comprise I * 207 data bytes, wherein I is that selected integer is so that every frame has a fixed integer RS grouping.Therefore, the data bit number of every frame must be not only integer before trellis coding, and this data bit number must be able to be divided equally by 207 * 8=1656 to all patterns.In addition, the grid encoder of every QAM code element output bit number is respectively 2,4 and 6 bits (see table 2, table 2 illustrates for the bit rate of trellis code bypass=1) to QPSK, 16QAM and 64QAM.In addition, trellis coding has increased bit.The data bit number of each code element is illustrated in table 2 before trellis coding, and wherein each clauses and subclauses is calculated as:
Figure BPA00001445843900271
Figure BPA00001445843900272
The data bit (the QAM code element input bit of each mapping is to grid encoder) of each code element of table 2-
The data bit number of each code element can be RS grouping size and the RS grouping number that the fact of mark requires accurately to select each frame.RS grouping size for every frame 207 and 315 groupings obtains every frame integer code element.As shown in table 3, each clauses and subclauses can be calculated as:
Figure BPA00001445843900273
The code element of each frame of table 3-
This frame provides extra advantage, and just the perforation pattern cycle (pp/ frame) for all each frames of pattern is an integer.For the trellis coding data of the perforated of correctly decoding, the decoder in the receiver must know perforation pattern as how about with data alignment.Be applied to being illustrated in the secondary series of the form among Figure 16 of female sign indicating number grid encoder output place by the bit perforation pattern.In each perforation pattern several 1 is perforation pattern length.In the system of proposing, perforation pattern is aimed at the starting point of FEC Frame always.This allows to use in the receiver frame synchronization to aim at bit stream suitably to make the perforator (de-puncturer) that goes in the receiver Viterbi decoder.The aligning that indication requires in the table 4, it illustrates the integer number to the pp/ frame of all patterns.The perforation pattern of each code element (pp/ code element) clauses and subclauses can be calculated as:
Figure BPA00001445843900282
Pp/ frame entry can be calculated as:
Figure BPA00001445843900284
Figure BPA00001445843900291
The perforation pattern of the every frame of table 4-
To understand, and can use other combination of RS grouping size and every frame packet count to need the result to obtain identical closing.Here the number that provides is merely the explanation purpose and describes.
Shown in figure 20, some embodiment of the present invention provides a receiver, and this receiving mechanism builds up the frame of disposal some aspect structure according to the present invention.The data of transmitting in the module 2000 received passband signals also convert thereof into base band QAM code element.The operation of being carried out by module 2000 can comprise that code element clock synchronization, equilibrium (to remove intersymbol interference) and carrier wave recover, and use submodule usually.Therefore, module 2000 can comprise the equalizer of output through the base band QAM code element 2001 of recovery.Base band QAM signal 2001 is provided for secondary sheer 2018 so that real axis and imaginary axis both direction are done cutting, forms the sequence a that offers frame synchronization module 2020 thus R[k] ∈ [1 ,+1] and a I[k] ∈ [1 ,+1] 2019.The stored copies that 2020 pairs of frame synchronization module are imported the QAM code element 2019 usefulness binary system frame synchronization PN sequences of cutting into is carried out continuous crosscorrelation to real part and imaginary part separately and is operated.Each member of stored copies have value-1 or+1.This operation table is shown:
b R [ k ] = Σ n = 0 126 s [ n ] a R [ n - k ] And b I [ k ] = Σ n = 0 126 s [ n ] a I [ n - k ] , (equality 10)
Wherein s is the copy of storing in 127 long frame synchronization PN sequences.b ROr b IMaximum amplitude represent the beginning of FEC Frame.
In case the position of the code word that comprises mode bit (constellation and trellis code rate) just can be known in the synchronous starting position of locating frame.Can be through for example BCH decoder or through the code word that is received is relevant with all possible code word and select to produce the code word of high end value and come code word is decoded reliably.Because this information is repeated to send, therefore can be through requiring before acceptance, to make identical result repeatedly obtain extra reliability.
This frame synchronizing signal that derives out 2021 is used to refer to be shown in code element is fed to soft mapper 2006 plan which code element of removal in " removing frame-synchronous/pattern code element " module 2004 before of going.In one example, 127 frame synchronization code elements and 8 pattern code elements are removed from stream, to guarantee only to be delivered to the soft mapper 2006 that goes with the corresponding code element of RS grouping.The soft mapper 2006 that goes uses known in the industry algorithm (algorithm of for example being described by Akay and Tosato) to calculate soft bit metric.For correct work, softly go mapper 2006 must know in the transmitter to use which kind of perforation pattern (which kind of trellis code speed) and will know aiming at of this pattern and reception bit.This information 2021 is provided by frame synchronization module 2020, and these frame synchronization module 2020 decoding schema information and the repeating frame synchronizing signal that provides perforation pattern to aim at it simultaneously are no matter present mode why.These soft bit metric are fed to Viterbi decoder 2008, and this Viterbi decoder 2008 is estimated with the bit that draws the PTCM encoder that inputs in the transmitter with known in the industry mode work.
All go randomization respectively, deinterleave and data that the decoded word joint number obtains to get at first the RS encoder in the transmitter according to this by frame synchronizing signal 2021 synchronous go randomizer 2013, byte deinterleaver 2014 and RS decoder 2016.
Carrier phase offset is proofreaied and correct
Some embodiment of the present invention adopts carrier phase offset corrective system and method.In certain embodiments, receiver comprises: phase deviation adjuster, this phase deviation adjuster receive as the equalizing signal of the sign of quadrature amplitude modulated (QAM) signal and from equalizing signal and obtain the signal through phasing; The secondary sheer, this secondary sheer cutting equalizing signal is to obtain real number and imaginary number sequence; Frame synchronizer, this frame synchronizer are carried out real number and imaginary number sequence offer the phase correction signal of phase deviation adjuster with the frame synchronization pseudo random sequence of being stored with by frame synchronizer corresponding real part and imaginary part relevant.Phase correction signal is based on relevant maximum real number and imaginary value.Frame synchronizer is carried out continuous crosscorrelation to the cutting quadrature amplitude modulation code element of importing into.Crosscorrelation is to carry out to real number and imaginary number sequence separately with the stored copies of binary system frame synchronization PN sequence continuously.
Base band to passband is modulated
Some radio digital communication system that comprises broadcasting, WLAN and wide area mobile system adopts QAM with certain form.QAM also is used to use the North America and the European digital cable tv standard of quadrature-carrier multiplexing, and the carrier modulation ripple that quadrature-carrier multiplexing allows two double sidebands to suppress occupies identical channel width, and each ripple is modulated by independent message.As stated, Figure 23 describes to serve as the simple QAM modulator of the PB modulation 1314 in Figure 13 example.The QAM pulse of isolated transmission is represented as follows:
s m ( t ) = d R , m q ( t ) cos ( 2 π f c t ) - d I , m q ( t ) sin ( 2 π f c t ) = Re { d m q ( t ) e j 2 π f c t } ,
D wherein R, mAnd d I, mBe to flow real part and the imaginary parts of confirming and represent multiple QAM code element respectively (seeing for example Figure 17) by two independent message, wherein 2 of m=1...M index radix tie up qam constellations, wherein M is a modulated carrier frequencies, and q (t) is a root raised cosine pulse function.
The transmission QAM pulse s (t) of one continuous series is with speed F s=1/T sMulti-path channel through the band noise transmits.Therefore, be r (t)=s (t) * c (t)+v (t) at the reception signal indication of input place of QAM receiver, wherein * representes convolution, c (t) is a channel impulse response, and v (t) is an additive white Gaussian noise.Therefore:
r ( t ) = Re { e j 2 π ( f LO + f o ) t + θ o Σ n = - ∞ + ∞ [ d [ n ] * q ( t ) ] c ( t - n T s ) } + v ( t ) ,
Wherein d [n] is multiple transmitted symbol, f oAnd θ oBe respectively frequency shift (FS) and phase deviation, thus f with respect to receiver pass-band to the base band demodulator local oscillator of transmitter LO=f c-f o
Passband is to base band demodulator
Figure 35 illustrates in greater detail an example of PB to BB among Figure 20, code element clock synchronization, equalizer/carrier recovery block 2000.The signal r (t) that is received is sampled 350 with the speed that is higher than chip rate, produces the signal r (nT through sampling Samp).After sampling:
r ( n T samp ) = Re { e j 2 π ( f LO + f o ) n T samp + θ o Σ m = - ∞ + ∞ [ d [ m ] * q ( n T samp ) ] c ( nT samp - m T s ) } + v ( n T samp ) .
Then, after demodulation, with chip rate 1/T sSampling and matched filtering obtain once more:
x ( kT s ) = x [ k ] = e j 2 π f o k T s + θ o Σ m = - ∞ + ∞ d [ m ] c [ k - m ] + v ′ [ k ] ,
Wherein v ' [k] is the multiple filter noise through sampling.This hypothesis is because pulse shaping and matched filtering q and perfect chip rate sampling timing make up, and any ISI is attributable simply to channel impulse response c.After demodulation, suppose perfect equilibrium, then the nearly base band complex sequences z [k] of equalizer output place is expressed as:
z [ k ] = d ^ [ k ] e j 2 π f o k T S + θ o + v ′ [ k ]
Therefore, through the constellation that the nearly base band sequence representative that recovers is sent, it has with frequency f oThe phase deviation θ of rotation oFor the d that recovers reliably to be sent RAnd d I, use for example two-dimentional sheer, equalizer and phase place and frequency shift (FS) to recover the loop combination and must eliminate the frequency shift (FS) f that causes constellation rotation o, this and receiver must be eliminated θ oRemaining static phase offset, otherwise will make constellation start from the position of static rotation.
Recover in order to understand phase, it must be understood that qam constellation at the base band place.In the simple examples of Figure 33 A, for the 4QAM modulation that is also referred to as QPSK, constellation is made up of four code elements.In the example of being described, the real part of d [k] and imaginary part 2 the different values (for example ± 3) of can respectively asking for.Phase deviation θ oEffect to the d [k] that recovers is illustrated in Figure 33 B, and Figure 33 B is illustrated in the rotation in the complex plane.Note rotating and in a circle, carry out in time, according to f oSymbol counterclockwise or turn clockwise, so just can understand f oEffect.
Equalizer and carrier phase/frequency ring
In Figure 34, signal x [k] the 340th is received by digital equalizer and carrier phase/frequency ring 248 (for example referring to Figure 24 A).The parts of equalizer 341 generally include linear digital filter; And use privately owned or known method such as lowest mean square (LMS) algorithm; Equalizer 341 with its output y [k] and sheer judgement
Figure BPA00001445843900321
through the version of phase place rotation relatively forming error signal, this error signal is used for the renewal collection of calculating filter tap-weights.This filter is removed the ISI that is caused by channel impulse response c.
2-D slice of cut of 342 independently z [k] of the real part and the imaginary part to output
Figure BPA00001445843900322
Figure BPA00001445843900323
is the original transmission of d [k] estimates.Both get into z [k] and phase error detector module 346 and form phase error signal, and this phase error signal is expressed as
Figure BPA00001445843900325
integration ratio (IP) filter 345 can comprise the filter of Figure 35 or any equivalent that those skilled in that art know.IP filter 345 allows skew of loop phase calibration and frequency shift (FS).The output of IP filter 345 is fed to multiple voltage controlled oscillator (VCO) 344, and these voltage controlled oscillator 344 outputs are used to proofread and correct θ oAnd f oBoth complex phase positions/frequency correction factor e -j θ [k]VCO 344 also exports (e + j θ [k]) export with " not proofreading and correct " cutting
Figure BPA00001445843900326
So that it can be used to obtain being used for the error signal that equalizer tap upgrades.This method is shown, comprises θ because equalizer is operated in oAnd f oOn both x [k].
In certain embodiments, can be through VCO 344 be obtained effect with the delay that absolute version is embodied as an integrator presenting a complex exponential look-up table (LUT).Yet, to θ oCorrection of a final proof can have the ambiguity of pi/2, it possibly be that correct (skew=0) maybe can have the skew of pi/2, the skew of π or the skew of 3 π/4 that this ambiguity means through the phase place of recovering.These results are illustrated in the code element that Figure 36 and Figure 37: Figure 36 illustrates actual transmission, and Figure 37 A-37D illustrates the possible recovery code element with each skew.Typically, receiver can't be known actual transmission of any quilt in these the four kinds possibility code elements, operates because 2D sheer 342 is carried out nearest adjacency.Figure 38 illustrates wherein the code element α that sends and is received as the instance of α ' in equalizer input place, and is as shown in the figure, has angle theta between α and the α ' oTherefore, phase bit recovery loop can make signal rotation with compensation θ o, so that a ' aims at a.Yet the judgement of 2D sheer 162 will be that the correction code element is b, because it is more near α '.This possibly cause phase bit recovery loop with the rotation constellation so that a ' restrain in alignment with the mode of b.In this case, final phase place from its should offset-pi/2.
Some embodiment of the present invention provides the method that minimizes and/or eliminate these problems in the trellis coding system, is included in the analog of the perforation trellis code that uses among the embodiment of some current description.As stated, the output of equalizer through 2D level sheer 342 along real axis and imaginary axis direction by cutting with formation sequence a R[k] ∈ [1 ,+1] and a I[k] ∈ [1 ,+1], this sequence is fed to frame synchronization module 2020 (seeing Figure 20).Frame synchronization module 2020 uses the stored copies of binary system frame synchronization PN sequence on cutting QAM code element, respectively real part and imaginary part to be carried out continuous crosscorrelation operation what import into.Each member of stored copies have value-1 or+1.This computing is characterized as:
b R [ k ] = Σ n = 0 126 s [ n ] a R [ n - k ] and b I [ k ] = Σ n = 0 126 s [ n ] a I [ n - k ] ,
Wherein s is 127 stored copies in the long frame synchronization PN sequence.b ROr b IMaximum amplitude represent the beginning of FEC Frame.
Maximum b RSymbol Maximum b ISymbol Required phasing
+ + 0
- + +π/2
- - +π
+ - -π/2
Table 5
For the frame synchronization code element, real part has identical symbol with imaginary part and its constellation is illustrated in Figure 39.Therefore, can understand maximum amplitude b ROr b ISymbol zero rotation just is.The rotation of-pi/2 produces negative maximum amplitude b RWith positive maximum amplitude b IFor the rotation of π, b RAnd b IBe negative, for the rotation of pi/2, maximum amplitude b RBe maximum amplitude b just IFor negative.This summarizes in above table 5.Therefore, maximum amplitude b RAnd b IEach symbol indicate final phase deviation to converge to which quadrant in the complex plane together.This allows such as illustrated in fig. 20 additive phase is proofreaied and correct to put on signal.Maximum b RAnd b ISymbol from being sent to the phase deviation adjuster based on relevant frame synchronization module.The operation of a phase deviation corrector module is illustrated in Figure 40, and LUT operation 404 wherein has been shown in an example.Suppose z [k]=z R[k]+jz I[k], this operation can be implemented as simply:
φ=+ situation of θ under: z ' [k]=-z R[k]-jz I[k]
φ=+ situation of pi/2 under: z ' [k]=-z I[k]+jz R[k]
φ=-situation of pi/2 under: z ' [k]=+ z I[k]-jz R[k]
Figure 40 is that the look-up table that index has the symbol of maximum real number and imaginary number correlation that passes through of some aspect according to the present invention obtains the block diagram through the phase deviation adjuster of phase correction signal.
The multimode qam constellation detects
Some embodiment is provided for from one group of possible reception qam constellation, confirming the system and method for a unknown qam constellation.A kind of method minimizes intersymbol interference (ISI) afterwards but before carrier frequency and phase place are recovered fully, utilize the distribution map of signal power at the constant modulus algorithm that uses correction (CMA) equalizer.Confirm unknown constellation from this distribution map then.Begin balancing procedure once more so that ISI minimizes based on nowadays known constellation with standard C MA then.Convergent-divergent equalizer output correctly can be carried out the constellation carrier wave of simplifying after this and recover (RCCR) and recover the stage with decision-directed carrier wave, causes thus through the carrier frequency of equalizer carrier frequency/phase loop of making up and the recovery of phase place.In another method that is used for confirming unknown qam constellation, equalizer uses the CMA through revising to work to minimize ISI at the beginning.Although equalizer output this time point of this process maybe be not by convergent-divergent correctly, yet equalizer carrier frequency/phase loop can use RCCR to come reinsertion of carrier frequency and phase place and need not why to know constellation.The phase place of recovering possibly be the band noise.Receiver can read the information that is embedded in the signal frame, and which qam constellation this information indication is transmitting.Restarting equalizer operation based on known constellation with standard C MA then, is that RCCR and decision-directed carrier wave recover afterwards.
Some embodiment of the present invention adopts and is similar to making up with aforesaid those perforation trellis codings and qam constellation of using among the ISDB-T.Use like this paper, constellation is understood that to be illustrated in the mapping that is in the modulation scheme in maybe the complex plane of code element.The code element number of each frame is the variable integer that depends on pattern, and the RS packet count of each frame is constant integer, no matter pattern why.Thisly be configured in the design that the front had illustrated in greater detail and simplified receiver.
Refer again to Figure 20, frame synchronization module 2020 uses the stored copies of binary system frame synchronization PN sequence on the cutting QAM code element of importing into 1219, respectively real part and imaginary part to be carried out continuous crosscorrelation operation.Each member of stored copies have value-1 or+1.This computing that provides through equality 10 (top) here repeats:
b R [ k ] = Σ n = 0 126 s [ n ] a R [ n - k ] And b I [ k ] = Σ n = 0 126 s [ n ] a I [ n - k ] , (equality 10)
Wherein s is 127 stored copies in the long frame synchronization PN sequence.b ROr b IMaximum amplitude represent the beginning of FEC Frame.
As described in greater detail below, the ambiguity that in the exalted carrier phase place, has pi/2.This causes 0, ± the additional arbitrarily recovery phase deviation of pi/2 or π.For the frame synchronization code element, real part has identical symbol with imaginary part, and the constellation that therefore they is sent is shown in figure 39.Therefore, will understand maximum amplitude b ROr b ISymbol zero phase skew just is.As the form 404 of Figure 40 is summarized, the skew of-pi/2 will produce negative maximum amplitude b RWith positive maximum amplitude b IFor the skew of π, b RAnd b IBoth are negative, and for the skew of pi/2, maximum amplitude b RTo be maximum amplitude b just IWill be for negative.Therefore, maximum amplitude b RAnd b IEach symbol indicate final phase deviation to converge to which quadrant in the complex plane together.This allows additional phasing is put on the signal of phase deviation corrector module 2002.Maximum b RAnd b ISymbol can be from being sent to phase deviation adjuster 2002 based on relevant frame synchronization module 2020.
Equally referring to Figure 40, the operation aspect some of the phase deviation adjuster 2002 in Figure 20 example can be better understood.LUT 400 produces based on maximum amplitude b RAnd b IThe output (seeing the element 404 among Figure 40) of symbol.Suppose z [k]=z R[k]+jz I[k], operation 402 is carried out as follows:
1) for φ=+ situation of π: z ' [k]=-z R[k]-jz I[k]
2) for Situation: z ' [k]=-z I[k]+jz R[k]
3) for
Figure BPA00001445843900352
Situation: z ' [k]=+ z I[k]-jz R[k]
In case synchronous starting position of locating frame and the phase deviation of having proofreaied and correct the m pi/2 just can be known the position of the code word that comprises mode bit (constellation and trellis code rate).Can be through for example Bose-Chaudhuri-Hocquenghem Code device or through the code word that is received is relevant with all possible code word and select to produce the code word of high end value and come code word is carried out reliable decoding.Because this information is repeated to send, therefore can be through requiring before acceptance, to make identical result repeatedly obtain extra reliability.
Figure 41 illustrates this process can be by an example of frame synchronization module 2020 execution.In response to frame synchronizing signal 2021, in step 4100, the constellation code word that is received and all effective code word crosscorrelations.Crosscorrelation produces the value that can be used to select the most probable coupling.In one example, select to produce effective code word of maximum related value in step 4102.The code word of this selection then can be used to discern current constellation.In step 4104, the identity of current constellation and the identity of discerning constellation before of record or otherwise storage are made comparisons.If in step 4104, the constellation of current constellation and identification before is same constellation, and then confidence counter increases progressively.If the constellation of identification is different with current constellation before step 4104 is confirmed, the constellation of identification and confidence counter is successively decreased before step 4107 is recorded as current constellation then in step 4017, and at another synchronization frame of step 4109 wait.After step 4106 increases progressively confidence counter, at step 4108 inspection confidence counter, if confirm that in step 4108 confidence counter has exceeded threshold value predetermined or configuration, then makes the judgement of signal constellation (in digital modulation) in step 4110.The iteration that can carry out this process exceeds till the threshold value of predetermined or configuration up to confidence counter.
Equalizer and carrier phase/frequency ring
Referring to Figure 42, with the equalizer of describing Figure 24 A and some aspect of carrier phase/frequency loop 248.Signal x [k] gets into digital equalizer and carrier phase/frequency loop 248, and this digital equalizer and carrier phase/frequency loop 248 can comprise the equalizer 420 with linear digital filter.Error Calculator module 422 error signal e [k], this error signal e [k] can use any proper method well known by persons skilled in the art to come the renewal collection of calculating filter tap-weights.In one example, can use the LMS algorithm.Filter is removed the ISI that is caused by channel impulse response c.The output y [k] of equalizer 420 does the phase place rotation to reduce any remaining carrier phase and frequency shift (FS) 421 subsequently.Output z [k] through the phase place rotation is then handled by sheer and phase error detector module 427, and said phase error detector module 427 is calculated and presented the phase error e to integration ratio (IP) filter 426 θ[k].The output of IP filter 426 is presented to integrator and complex exponential look-up table (LUT) 424, and this complex exponential look-up table (LUT) 424 calculates the complex exponential value of using in the loop and proofreaies and correct carrier phase and frequency shift (FS).Sheer and phase error detector module 427 are also exported the two-dimentional cutting bit decision of nearest neighbor, its phase place 425 through with e + j θ [k]Multiply each other and " not being corrected " and will be used to Error Calculator module 422 subsequently.Error Calculator module 422 utilizes this input and x [k] to come error signal e [k].Like what described, the current generation of operation (1,2 or 3) is depended in the built-in function of Error Calculator module 422 and sheer and phase error detector module 427, and these stages are confirmed by stage controller 423.
In certain embodiments, use the following operation of lowest mean square (LMS) algorithm computation equalization filter tap-weights and do:
Make the equalizer input vector of x [k] expression L length, y [k] expression equalizer output vector, wherein y [k]=g H[k] x [k], wherein g H[k] is that linear equalizer tap-weights vector and the H subscript of L length representes that conjugation exchanges (close conjugation in distress).Then, use the method that for example describes below to come the e [k] through upgrading in the error of calculation calculator modules 422:
G [k+1]=g [k]-2 μ x [k] e *[k], (equality 11)
Wherein μ is a little step parameter and subscript * representes complex conjugate.
In this example, stage controller 423 obtains equalizer and carrier phase/frequency loop 428 through three stages operatings, takes this to carry out from the switching in stage 1 to stage 2 to stage 3 based on the simple count threshold value of input data sampling x [k].Notice that it also is possible switching based on the more complicated stage of the error estimation of equalizer outlet side.This three phases is summarized in table 6.
Figure BPA00001445843900371
Table 6: equalizer and carrier phase/frequency loop stage
Sheer and phase error detector module 427 illustrate in greater detail in Figure 43.According to a configuration switch 430 in the three phases 434 of operation.During the stage 1, switch 430 is in the extreme higher position, so e θ[k]=0.This has broken off carrier loop effectively, during this stage, has no carrier phase to proofread and correct thus.During the stage 2, switch 430 mediates and loop uses constellation carrier wave recovery (RCCR) algorithm work of simplifying.If with | z [k] | 2The power of code element z [k] of expression exceeds threshold xi, supposes that then z [k] is that in the corner code element of constellation one and RCCR launch through the second switch of describing 432 is set in a high position, obtains
Figure BPA00001445843900372
Otherwise, if | z [k] | 2≤ξ, then second switch 432 is in the low level of the forbidding carrier loop of describing.Therefore, have only a sub-set during the stage 2, recovering to have benifit in the code element to carrier wave.Can reduce threshold xi so that comprise more multiple-symbol of height near the zone the constellation corner, but the phase correction terms e of gained θ[k] will have more noises.During the stage 3; Switch 430 is in the extreme lower position of describing, and obtains wherein
Figure BPA00001445843900374
be nearest neighbor 2 the dimension cutting bit decisions
Figure BPA00001445843900375
complex conjugate.During the stage 3, suppose through time enough so that equalizer tap has been restrained and carrier phase basic correction, thereby be reliable through the bit decision of cutting.Especially, relational expression and
Figure BPA00001445843900377
are operated in the single quadrant of complex plane effectively.This causes the ambiguity of m pi/2 in the exalted carrier phase place as described above.
The example of IP filter 426 (seeing Figure 42) illustrates in greater detail in Figure 35.IP filter 426 allows loop phase calibration and frequency shift (FS).The output of IP filter 426 is fed to integrator and complex exponential LUT module 424, and Figure 45 more is shown specifically.The input of integrator/LUT 424 is added step time-delay 442 versions of 440 (Figure 44) to input by 2 π moulds; Thereby form phase error signal θ [k]; This phase error signal θ [k] is fed to look-up table (LUT) 444, this look-up table 444 output phase correction factor 445e -j θ [k], it is used for proofreading and correct θ oAnd f oBoth.LUT 444 also provides output 446 (e + j θ [k]), sheer output " is not proofreaied and correct " in this output
Figure BPA00001445843900381
So that it can be used for deriving the error signal that is used for the equalizer tap renewal.This method is necessary, comprises θ because equalizer is operated in oAnd f oOn both x [k].
Error Calculator module and stage computing are summarized
Error Calculator 422 can adopt distinct methods to calculate e [k] according to the stage.For stage 1 and stage 2, e [k] typically uses that process based on constant modulus algorithm (CMA) calculates:
e[k]＝y[k](|y[k]| 2-R)，
Wherein R is the constant of being scheduled to, and it is expressed as:
R = E { | d [ k ] | 4 } E { | d [ k ] | 2 } , (equality 12)
Wherein E is an expectation operator and d [k] is code element (seeing Figure 17).Note to trigger this e [k] that the tap of above equality 11 upgrades and be the phase place that is independent of bit decision and x [k], and only depend on equalizer output, equalizer is imported and the statistics of constellation.Can find out, during stage 1 and stage 2, use the CDMA error to trigger equality 11 and be equivalent to ISI is minimized, even constellation rotates owing to carrier frequency and phase deviation.
Therefore, during the stage 1, phase recovery loop is forbidden, and equalizer uses the CMA error function that ISI is minimized.After ISI was minimized, stages 2 beginning and loop were for the RCCR conducting; Carrier phase/frequency is recovered only to use the corner code element of constellation and is begun, as the front combines Figure 43 explanation.When the stage 2 finished, carrier phase and frequency were fully recovered so that the 2 dimension sheer 436 of Figure 43 begin to export reliable bit decision
Figure BPA00001445843900383
Decision-directed (DD) error can be used in the stage 3.The DD error can be calculated as
Figure BPA00001445843900384
for purpose of explanation; In three constellations of Figure 17 which what suppose here that receiver confirmed just to send is; Because in these constellations each, R is different.In addition, RCCR requires to know constellation, especially knows the power of the corner code element of constellation.
CMA with unknown constellation
In example described herein, can send in three different Q AM constellations, and above-mentioned equilibrium and phase recovery need be known the constellation that is sent.Although constellation is chosen in the pattern code element and encodes, yet equilibrium and phase recover to lead over frame synchronization (seeing Figure 20), and this moment, this information was as described above by direct decoding (for example referring to Figure 18, Figure 20 and Figure 41).As a result, in certain embodiments, in equalizer and carrier recovery algorithm itself, confirm constellation.
Notice that R (like what provide in the equality 12) is that constellation is interdependent.Also continue in certain embodiments referring to Figure 17, the real part of the code element of 64-QAM and imaginary part are from collection ± { 1,3; 5, to select among the 7}, the real part of the code element of 16-QAM and imaginary part are from collection ± { 2; Select among the 6}, and the real part of QPSK code element and imaginary part are selected from collection ± 4.According to equality 12, the value of R will be:
For in three constellations of Figure 17 any one; Can find out; That uses the CMA Error Calculation makes the equalization filter tap converge to the same class value by
Figure BPA00001445843900392
convergent-divergent through scale value α R, and wherein equalizer output is equally by convergent-divergent.Can find out that ISI still is minimized.In the unknown example of constellation, R can be set at 58 and no matter the constellation that is sent why, ISI was minimized during the stage 1.For said example, but any value R among the scope of application 32-58.Yet the selection of maximum (promptly 58) prevents that the most intensive constellation (being 64-QAM) in equalizer output place from compressing and having alleviated the burden of equalizer performance here.
Use through the CMA of convergent-divergent parameters R causes the upwards convergent-divergent by the equilibrium output of the filter tap of restraining, so the statistical value of equalizer output will be:
E{|y[k]| 4}/E{|y[k]| 2}＝58，
Suppose perfection removed ISI and no matter constellation why.Therefore, for QPSK, during the stage 1, equalizer output will be done as follows convergent-divergent after ISI minimizes:
y [ k ] = e j 2 π f 0 k T S + θ 0 58 32 ( ± 4 ± j 4 ) = e j 2 π f 0 k T S + θ 0 ( ± 5.385 ± j 5.385 ) .
Figure 45 A explains orally at θ 0=f 0The real part of the equilibrium output of the system of use QPSK under=0 the situation.Can see; Because value R=58; When equalizer convergence when eliminating the separating of ISI, output is by
Figure BPA00001445843900394
convergent-divergent.Figure 45 B explains orally at θ 0=f 0The real part of the equilibrium output of the system of use 16-QAM under=0 the situation.Because
Figure BPA00001445843900395
is relatively more near 1, so the real part of equalizer output looks only slightly by convergent-divergent.Therefore, during equalizer convergence, actual convergent-divergent is tangible.
The constellation detection method
In certain embodiments, can before the entering stage 2, use the distribution map method to confirm constellation.Even carrier phase and frequency are not resumed as yet, also can confirm constellation.Consider equalizer power output η [k]=y [k] y *The distribution map of [k], Figure 46 A, 46B and 46C illustrate QPSK constellation, 16-QAM constellation and 64-QAM constellation respectively.These distribution graphs are shown in the power after equalizer has been restrained, wherein R=58.Because it is different basically that the power of equalizer output is independent of the distribution map of phase place and each constellation, therefore can be from the definite constellation that sends of equalizer power output distribution map in receiver.
Do not have additivity or tap noise, for the QPSK constellation, the power of each equalizer output sampling is η [k]=58.For the 16-QAM constellation, the probability mass function of the power of equalizer output is:
Figure BPA00001445843900401
Equally, for the 64-QAM constellation, the probability mass function of equalizer power output is:
Figure BPA00001445843900402
Because noise and additive noise v ' are upgraded in the tap on the input signal,, in the distribution map of these values, certain expansion is arranged also even concerning the substantive SNR of for example 30dB.Noise modeling in the equalizer output is additivity and is independent of code element, and suppose that output does not have ISI, so
| y [k] | 2=| d [k]+n [k] | 2=| d [k]+n [k] | 2=| d [k] | 2+ | n [k] | 2+ 2Re{d [k] n *[k] } (equality 16)
The variance of on given code element, adjusting---itself and 2Re{d [k] n *[k] } association---along with symbol power increases and increases.In distribution map, this phenomenon is expressed as the expansion around the given constellation power, i.e. variance, and it increases and increases along with symbol power.Under the 16-QAM situation, around the expansion of the constellation power of code element ± 2.1 ± j2.1 less than expansion around the constellation power of code element ± 6.3 ± j6.3.
Some other relation can be observed from the distribution map of equalizer power output:
Regional T in the QPSK distribution map 1Roughly drop on the second and the 3rd region R of 16-QAM distribution map respectively 2And R 3Between.Therefore, the zone of which kind of symbol power of declaration transmission is nonoverlapping for QPSK and 16-QAM constellation.
The QPSK distribution map has relatively disclosed for 64-QAM's to the 64-QAM distribution map
Figure BPA00001445843900403
Therefore, for η [k] and regional T 1Comparison, more possible is that η [k] drops on outside this zone.
In 64-QAM, do not exist in the example of noise, η [k] from the collection 2,18,26,34,58, and among the 98} with probability 9/16 value.Therefore, when potential constellation is 64-QAM, ignore noise:
Pr{ (η [k] ∈ R 1) ∪ (η [k] ∈ R 2) ∪ (η [k] ∈ R 3)＜1/2, (equality 17)
Wherein ∪ represent OR (or).Therefore, if the constellation that is sent is 64-QAM and with η [k] and region R 1, R 2And R 3Relatively, then η [k] possibly drop on outside these zones very much.
Some embodiment adopts the algorithm based on these observations:
This algorithm can start after equalizer is restrained, and if the equalizer power output be in regional T 1In, then in N equalizer output sampling, make QPSK counter λ in first 4[k] increases progressively.If the equalizer power output is not in regional T 1In, then counter is successively decreased.Equally, if η [k] drops on region R 1, R 2And R 3In, make 16-QAM counter λ 16[k] increases progressively, otherwise it is successively decreased.
After N equalizer output sampling, can suppose that distribution map is special by the correct face of land.If potential constellation is 64-QAM, because more power capability estimates that η [k] will drop on outside QPSK and the 16-QAM zone, so QPSK and 16-QAM counter will be quite little.If the constellation that is sent is QPSK or 16-QAM, the counter that then sends constellation will be significantly bigger.Therefore,
Threshold value M can confirm by rule of thumb, but it should be less with respect to N.This algorithm is very strong, as transmission QPSK, when 16-QAM or 64-QAM, selects to proofread and correct constellation reliably to low signal-to-noise ratio (SNR).After confirming constellation reliably, can R be set at correct equality 13 values and the stage 1 can tend to finish.Equalizer output will be by suitably convergent-divergent and stage 2 can begin from knowing the desired threshold xi of RCCR.
Be described in the another kind of method that equalizer gets into stage 3 before definite constellations now.In the method, execution phase 1 and allow to finish at R=58.Therefore, as said, all three constellations in equalizer output place by convergent-divergent, this obtains the y [k] shown in three constellations of Figure 47, although these constellations possibly rotate.As combine as described in Figure 43, the key in stage 2 is that RCCR is using | z [k] | 2The unique of code element that the power of code element z [k] of expression exceeds under the situation of threshold xi considers.Can suppose that then z [k] is in the corner code element of constellation.Equivalently,
Figure BPA00001445843900422
can indicate the corner code element.As Figure 48 (A) explained orally to the 64-QAM constellation, it was relatively easy when constellation is known, selecting the value of ξ.Figure 48 is illustrated in equalizer output and carrier phase/frequency is recovered all three constellations of loop module input place.Can find out, for these corner points | z [k] |=9.90.For example, guarantee only to select the corner point by the threshold value
Figure BPA00001445843900423
of broken circle 484 expressions.Equally, circle 480 can use with the abundant allowance of 16-QAM and QPSK respectively
Figure BPA00001445843900424
circle 482 with
Figure BPA00001445843900425
.
Figure 49 illustrates the coverage diagram of the right upper quadrant of all three constellations.Can find out, if
Figure BPA00001445843900426
then the QPSK and the corner point of 16-QAM that only drop on outside the broken circle can be utilized by RCCR.Yet if receive 64-QAM, five constellation point (four non-corners) drop on outside the circle and will be utilized by RCCR.Because the phase place of recovering has less noise, RCCR generally behaves oneself best under the situation of using the corner constellation point.Yet even use some annex points, although can cause the increase of phase noise, RCCR also will successfully recover phase place.Therefore, the stage 2 can be operated in
Figure BPA00001445843900431
at the beginning, and this allows to recover at the fully initial carrier wave of constellation to all three constellations when receiving organizational security to hold the unknown.
As described in front combination Figure 20, equalizer 2000 is presented to 2 grades of sheer 2018, and 2 grades of sheer 2018 are then presented to frame synchronization 2020 successively.The storage version that frame synchronization 2020 can be used binary system frame synchronization PN sequence is carried out continuous crosscorrelation operation to the symbol through the QAM of cutting code element that imports into, as equality 10 is described.The crosscorrelation operation can be carried out real part and imaginary part independently continuously.Each member of storage version have-1 or+1 value.b RAnd b IThe beginning of maximum amplitude indication FEC Frame.Nowadays unique difference is that for the 64-QAM constellation, 2 grades of sheer 2018 are operated on the signal with a certain additive phase noise.Yet this additional phase noise is to 2 grades of cuttings and next have very little negative effect based on the frame synchronization of crosscorrelation, even if it also is very strong existing under the situation of phase noise.As previously mentioned, the decoding of constellation code word also is very strong for phase noise.
Figure 50 explanation is used for the operation of this possible alternative of definite constellation, and this way can be summarized as follows:
(1) equalizer and phase loop finish at R=58 the stage 1, get into the stage 2 then.
(2) different with loitering phase 3, but be to accept the input data during the stage 2 based on relevant frame synchronization 2020, seek frame synchronization, and the constellation code word is decoded.
(3) constellation information of confirming 2021 is sent back to equalizer 2000 and phase loop, this phase loop uses the R value to turn back to the stage 1, and this R value is suitably corresponding to fixed constellation.
(4) ending phase 1,2 and 3 as preceding then.
To understand, the initial differences between the system that Figure 50 and Figure 20 describe is the additional connection 5000 from frame synchronization 2020 to the equalizer that carries constellation information/carrier wave recovery 2000.
SPOT in the coaxial cable safety chain keeps watch on
Some embodiment of the present invention has improved the system that comprises aforementioned those systems and the performance of device; Wherein baseband video signal can make up with the digital representation of baseband video signal and with control signal, allows thus on the unit cable such as coaxial cable (" coaxial "), to transmit.Refer again to Fig. 4, one embodiment of the present of invention provide safety chain on the coaxial cable (SLOC) system.Fig. 5 illustrates a kind of possible modulation scheme of SLOC system.In this example, HD video camera 30 provides and comprises through the IP of compressed digital HD video image output 41 and the auxiliary camera signal that comprises simulation SD CVBS 330.HD video IP signal 332 through compression utilizes SLOC camera side modulator-demodulator 49 to be modulated to passband 52, and SLOC camera side modulator-demodulator 49 comprises QAM modulator (seeing the modulator 212 in the modulator-demodulator 32 of Figure 21).Modulator 212 provide can with baseband analog CVBS signal 330 combination through modulation signal.Signal " downstream " transmission on coaxial cable 41 through combination may extend to 300 meters or longer distance usually.In the monitor side, SLOC monitor side modulator-demodulator 45 separates base band CVBS signal 330 with passband downstream IP signal 332.The CVBS signal 330 that separates be fed to SD display 43 in real time, do not have watching of time-delay.Passband downstream IP signal 332 usefulness qam demodulators (seeing the demodulator 222 among Figure 22) are by demodulation, and this demodulator 222 exports signal to mainframe network switch 44 or processor/DVR (not shown among Fig. 4).
In this example, upstream communication is provided according to the IP protocol requirement.Can use upstream communication 334 so that audio frequency and video camera control signal are delivered to video camera 40 from the monitor side extraly.As a rule, the bit rate of stream signal---and so desired bandwidth---is far below desired bit rate of downstream passband signal and bandwidth.Monitor side SLOC modulator-demodulator 45 comprises QAM modulator (seeing the modulator 224 among Figure 22), and this QAM modulator is modulated to upper reaches passband 44 with the IP signal.Describe like Fig. 5, upper reaches passband 54 is positioned at different spectrum positions with downstream passband 52.In camera side, SLOC modulator-demodulator 49 comprises the qam demodulator (seeing the demodulator 214 of the modulator-demodulator of Figure 21) that is used for receiving stream signal.This way provides the some advantages that are superior to existing system and method, comprise increase working range, be easy to use existing coaxial cable infrastructure deployment and obtain low delay, real-time video.The simplified schematic of Figure 21 and Figure 22 illustrates the further details of SLOC monitor side modulator-demodulator 45 of SLOC camera side modulator-demodulator 49 and Fig. 4 of Fig. 4, and describes in detail in the above.
Figure 51 A illustrates the SLOC system based on Fig. 4 institute interpretation system, and wherein the tap 519 through filtering is set between coaxial cable segmentation 512 and 514 so that tap 513 is connected in the monitor side component with cable segmentation 512,514 works in order to camera side is equipped.Tap 513 through filtering is generally used at least a portion of base band CVBS signal 5100 is extracted into camera side SD display 5130.Display 5130 is monitored for test, configuration and/or part near can being arranged on video camera 510.Tap 513 through filtering generally includes low pass filter, but this low pass filter stops the undesired signal such as modulated numeral, IP and/or control signal of interfere Presentation Function 5130.Tap 513 also can comprise the filter or the switch of the signal transmission that stops between modulator-demodulator 511 and 515.For example; The test modulator-demodulator can be 5131; It can connect trouble shoot or initial configuration with realization camera side modulator-demodulator 511 through tap 513, and display side modulator-demodulator 515 can be disconnected interference and/or the deterioration of connection to avoid signal.As shown in Figure 5; SLOC camera side modulator-demodulator 511 is also exported the lower passband QAM signal that produces part based on the video camera of signal 5102 usually except base band CVBS signal 5100, and 515 outputs of SLOC monitor side modulator-demodulator are based on the upper passband QAM signal of the control signal in the signal 5170.Visible not conforming to needs to disturb and stop IP and control signal on SD display 5130 and/or 516 to avoid can one or more filters to be provided through tap 513.To understand, some displays and monitor lack and stop the necessary filtering of higher frequency signals (with respect to base band VCBS signal 5100) in the passband signal.
Figure 51 B illustrates the SLOC system based on Fig. 3 institute interpretation system; Wherein the cable 514 between camera side and monitor side is broken off by temporary transient in camera side, and SD display device or display 5130 have been directly connected in SLOC camera side modulator-demodulator 511 in cable segmentation 519.Test modulator-demodulator 5131 connects to be used for test/configuration purpose alternatively.SD display device 5130 shows base band CVBS signal and provides supervision near the video the video camera physical location of video camera 510, and possibly require these connections of reconstruct to be beneficial to configuration and trouble shoot.In Figure 51 B, lower passband QAM signal 5102 possibly cause not conforming to the visual interference that needs on the SD display 5130 that lacks High frequency filter.
In the example shown in Figure 51 A and the 51B, the part or all of disconnection of possibility generation signals between modulator-demodulator 511 and 515.The part of signal is broken off the QAM signal transmission path is kept perfectly.Yet some reconstruct of connection cause the disconnection of QAM signaling between camera side modulator-demodulator 511 and the monitor side SLOC modulator-demodulator 515.Some embodiment of the present invention provides the mechanism that makes camera side modulator-demodulator 511 stop passband QAM transmission, when the connection between modulator- demodulator 511 and 515 is broken off, only exports the CVBS signal.To understand; Generally include a series of with substituting of 5131 pairs of display sides of test modulator-demodulator modulator-demodulator temporarily; Comprise: between modulator- demodulator 511 and 515, break off; Set up the connection between modulator- demodulator 511 and 5131, break off between modulator- demodulator 511 and 5131 and rebulid the connection between modulator-demodulator 511 and 515.Can use the various functional parts of modulator-demodulator 511 to detect the disconnection of QAM signal.Therefore, the operation of SLOC system is described in detail as follows.
The QAM modulator architecture of SLOC system
As stated, Figure 19 explanation offers the frame structure 1336 of passband modulation (PB modulation) module 1314 (seeing Figure 13).The trellis coding of Figure 16 has increased bit; The data bit number of the QAM code element of each mapping at trellis coding (as shown in table 2) before.The number of the QAM code element that the 315RS grouping (521640 bit) of Figure 14 maps to changes along with model selection.RS grouping size for every frame 207 and 315 groupings obtains whole every frame integer code element, and is as shown in table 3.PB modulation module 1314 uses the known any proper method of those skilled in that art that base band QAM code element is modulated to passband (referring to the for example explanation of the above Figure 24 of combination) subsequently.
As stated, in conjunction with Figure 20, the qam demodulator of Figure 21 and Figure 22 is described further.The data of transmitting in the module 2000 received passband signals also convert thereof into base band QAM code element.The operation of being carried out by module 2000 generally includes code element clock synchronization, equilibrium (to remove intersymbol interference) and carrier wave recovery, the logical submodule that is to use.Correspondingly, module 2000 can comprise the equalizer of output through the base band QAM code element 2001 of recovery.Base band QAM signal 2001 is provided for secondary sheer 2018 to do cutting at real axis and imaginary axis direction, forms the sequence a that is provided for frame synchronization module 2020 thus R[k] ∈ [1 ,+1] and a I[k] ∈ [1 ,+1] 2019.
Frame synchronization module 2020 is carried out continuous crosscorrelation operation to real part and imaginary part through the stored copies of binary system frame synchronization PN sequence respectively on stacked cutting QAM code element 2019.Each member of stored copies have value-1 or+1.This computing that provides through equality 1 here repeats:
b R [ k ] = Σ n = 0 126 s [ n ] a R [ n - k ] And b I [ k ] = Σ n = 0 126 s [ n ] a I [ n - k ] Equality 10
Wherein s is 127 stored copies in the long frame synchronization PN sequence.b ROr b IMaximum amplitude represent the beginning of FEC Frame.When in data flow, detecting FEC Frame initial point, the one or more communication in frame-synchronizing impulse or other synchronizing signal and the receiver module.
Figure 52 A and 52B illustrate the Process Elements that when receiving the band noise signal, can produce frame-synchronizing impulse reliably.Figure 52 A illustrates the part of the process of confirming frame length.Frame length can change according to selected transmission mode (table 3).The process that starts from step 5200 receives and is repeated along with code element and carries out, and symbol counter keeps following the tracks of the code element number between each time execution of the value that causes exceeding predetermined threshold.In step 5201, the code element of each arrival is carried out crosscorrelation, and symbol counter increases progressively, till confirming to have exceeded predetermined threshold in step 5202.Symbol counter increases progressively 5203 to each code element, till exceeding this threshold value.When exceeding this threshold value in step 5202, then with symbol counter zero clearing 5204 and carry out crosscorrelation step 5205, symbol counter is increased progressively 5207, new code element 5208 is received in the multiple connection of laying equal stress on, till confirming to have exceeded this threshold value in step 5206.At step 5208 record intermediate symbol counting and in step 5209 replacement symbol counter.Crosscorrelation step 5210, step 5213 repetition that makes symbol counter incremental steps 5212 and receive new code element are till confirming to have exceeded this threshold value in step 5211.If in step 5214, symbol counter with count in the intermediate symbol of step 5208 record when identical, then frame length is returned the value as symbol counter 5215.To understand, in said example, can behind twice consistent continuously counting, confirm frame length.Yet, can select required consecutive identical counts as required.
Figure 52 B illustrates a process, works as the frame-synchronizing impulse that also produces correct timing when the signal that is received has very big noise even take this frame synchronization module 2020.This process also provides the acquisition to new frame synchronization position when the interim interruption of signal takes place or when the change of transmitter sending mode causes the corresponding change of frame_size (frame sign).The symbol counter of free-running operation is used the code element counting of mould frame_size algorithm to receiving, and wherein frame_size confirms through the step that combines Figure 52 A to describe.Estimate that the symbol counter value will always have identical value when the result of equality 10 crosscorrelations exceeds selected threshold value.When this value is consistent, confidence counter upwards is incremented to selected maximum, for example maximum 16; Otherwise confidence counter is successively decreased towards zero minimum value.
Therefore,, just carry out crosscorrelations,, then current maximum is changed to threshold value and maximum point is changed to the currency of symbol counter 5253 if exceed threshold value in 5252 result 5251 in case receive code element 5250.In the example of being described, if being changed to, confidence counter is at least 4 value (5254) and current code element counting indication frame synchronization point (5255), then in 5256 output frame synchronizing signals.Then, symbol counter increases progressively 5257, uses mould 4 to add here.Wait for next code element in step 5277, only if be confirmed as zero in step 5270 symbol counter.If symbol counter is zero, then current maximum is reset 5271.Then, if equal the frame synchronization point, confidence counter is increased progressively and waits for next code element in step 5277 5273 at 5272 current maximum points; Otherwise, at 5274 confidence counters that successively decrease.In the example that illustrates at present, fallen below 2 if confirm to put letter in step 5275, then the frame synchronization point is set to current maximum point in step 5276.Under arbitrary situation, wait for next code element in step 5277.
Generally speaking, according to said process, when confidence counter exceeded predetermined value (this value is 4 in this example), frame synchronization was confirmed as reliably and obtains.Frame synchronization module then can be in the correct time by zero clearing so that frame-synchronizing impulse to be provided.If confidence counter surpasses 4, frame-synchronizing impulse will be exported in orthochronous in---common beginning corresponding to frame---, even noise makes equality 10 produce a low value once in a while.
If sending mode changes, then confidence counter will finally be counted and be back to zero.This can be used to trigger the frame length of confirming new frame length and calculates (process of for example using Figure 52 A) again.As following combination carrier wave recovers to discuss, in the exalted carrier phase place, possibly there is the ambiguity of pi/2, this will cause 0, ± the additional arbitrarily recovery phase deviation of pi/2 or π.For the frame synchronization code element, real part has identical symbol with imaginary part and the transmission constellation is illustrated in Figure 39.
Therefore, will understand, for zero phase skew, maximum amplitude b RAnd b ISymbol just be.As table 5 is summarized, the skew of-pi/2 will produce negative maximum amplitude b RWith positive maximum amplitude b IFor the skew of π, b RAnd b IBoth are negative, and for the skew of pi/2, maximum amplitude b RTo be maximum amplitude b just IWill be for negative.Therefore, maximum amplitude b RAnd b IEach symbol can indicate final phase deviation to converge to which quadrant in the complex plane together.This allows in phase deviation corrector module 2002 (Figure 20), the additive phase correction to be put on signal.Maximum b RAnd b ISymbol will be from being sent to phase deviation connector 2002 based on relevant frame synchronization module 2020.
Equally referring to Figure 40, the operation aspect some of the phase deviation adjuster 2002 in Figure 20 example can be better understood.LUT 400 produces based on maximum amplitude b RAnd b IThe output (seeing table 5) of symbol.Suppose z [k]=z R[k]+jz I[k], operation 142 is carried out as follows:
1) for φ=+ situation of π: z ' [k]=-z R[k]-jz I[k]
2) for
Figure BPA00001445843900481
Situation: z ' [k]=-z I[k]+jz R[k]
3) for
Figure BPA00001445843900482
Situation: z ' [k]=+ z I[k]-jz R[k]
In case the position of the code word that comprises mode bit (constellation and trellis code rate) just can be known in the synchronous starting position of locating frame and proofreaied and correct m pi/2 phase skew.Can be through for example BCH decoder or through the code word that is received is relevant with all possible code word and select to produce the code word of high end value and come code word is decoded reliably.Because this information is repeated to send, and therefore can repeatedly obtain additional reliability through before acceptance, requiring same result.Figure 41 illustrates an example of this kind process that can be carried out by frame synchronization module 2020.
Continue the system of Figure 20, can be used to indication from the frame synchronizing signal 2021 of frame synchronization module 2020 outputs and will module 2004, remove which code element before the mapper code element being fed to soft going.In one example, from stream, remove 127 frame synchronization code elements and 8 pattern code elements, this only guarantees and will be passed to the soft mapper 2006 that goes with the RS corresponding code element of dividing into groups.The soft mapper 2006 that goes uses known in the industry algorithm to calculate soft bit metric, and said algorithm comprises the algorithm of for example being described by Akay and Tosato.For correct computing, softly go mapper 2006 must know in the transmitter to use which kind of perforation pattern (which kind of trellis code speed) and will know aiming at of this pattern and reception bit.Regardless of present mode why, this information 2021 is provided by frame synchronization module 2020, and these frame synchronization module 2020 decoding schema information also provide the repeating frame of aiming at perforation pattern synchronizing signal in addition.These soft bit metric are fed to Viterbi decoder 2008, and this Viterbi decoder 2008 is estimated with the bit that draws the PTCM encoder that inputs in the transmitter with known in the industry mode work.All go randomization respectively, deinterleave and data that the decoded word joint number obtains to get at first the RS encoder in the transmitter according to this through frame synchronizing signal 2010 synchronous go randomizer 2010, byte deinterleaver 2014 and RS decoder 2016.
Stage switches
Some embodiment utilizes the stage switching based on the estimation of the mean square error of equalizer output place.A series of error e [k] that the accurate estimation of the mean square error (MSE) of equalizer output can calculate from the Error Calculator module 422 through Figure 42 obtain.For example, can use following formula to obtain estimation:
MSE [k]=(1-β) e 2[k]+β MSE [k-1], (equality 18)
Wherein factor is forgotten in β＜1st.To ask other average method be known and can use to e [k].Equality 18 produces a result, this result can with predetermined threshold relatively and by the stage controller module 423 of Figure 42 use with drop on as MSE [k] threshold value when following from stage 1 to stages 2 handover operation.Can MSE [k] and second predetermined threshold relatively will be operated when following from the stage 2 and switch to the stage 3 to fall second threshold value as MSE [k].
Detection is broken off and is connected
Some embodiment is provided for detecting the disconnection and the system and method for connection event again on the camera side of communication link.Refer again to Figure 51 A and 51B, the part or all of disconnection of the signal between modulator- demodulator 511 and 515 possibly take place in operate as normal.Some breaks off influences the QAM signaling between camera side modulator-demodulator 511 and the monitor side SLOC modulator-demodulator 515.Specifically, the signal that carries the image of catching by HD video camera 510 by modulator-demodulator 511 codings and/or modulation on cable 514, to transfer to display side modulator-demodulator 515.Detect the disconnection related and the several different methods of connection event can be by 511 execution of camera side SLOC modulator-demodulator again with coaxial cable 514.In response to breaking off or connection event again, downstream passband QAM transmission can be ended, begins or restarted to modulator-demodulator 511.In certain embodiments, " coaxial connection " signal that is sent to the QAM modulator from qam demodulator can be used to the transmission of control connection dependent event.
Referring to Figure 53, for example camera side QAM modulator 530 configurable one-tenth only just send downstream passband signal 533 when the signal 531 of coaxial connection is stated by camera side qam demodulator 532.Camera side qam demodulator 532 can be confirmed the existence of input signal 534, and this input signal 534 uses the several different methods transmission by monitor side QAM modulator (not shown).In a single day usually, when the reception of input signal 534 is confirmed reliably, when confirming the constellation sign and/or having obtained the frame synchronization checking, state the signal 531 of coaxial connection by camera side qam demodulator 532.
A kind of method that detects input signal 534 existence comprises the method based on automatic gain control (AGC) ring.The common AGC that finds is used for different phase and the signal level of point in the receiver control in comprising the communication control processor of qam demodulator.An example of describing among Figure 27, it illustrates the AGC loop 540 of the receiver front end that is added into Figure 24.In this AGC loop 540, it is deducted from predetermined reference level 543 in the amplitude of 541 definite complex signals and 542.Carry out filtering to suppress noise and short term variations through 544 couples of results of low pass filter (LPF).LPF 544 provides output, and this output is fed to the accumulator that comprises adder 545 and delay cell 546.Accumulator output is as gain control signal 547, and this gain control signal 547 is fed the gain block 548 that the system of getting back to imports 549 places.In one example, gain control signal 547 is as gain factor or multiplier, be used for confirming the gain that provides by gain block 548 so that the gain that provides by gain block 548 along with gain controlling 547 increases and in predetermined threshold, increases.When (for example coaxial cable disconnection) broken off in input 549, the output of amplitude piece 541 was often very low.Usually, the signal 531 of coaxial connection is only exported under the situation that is higher than predetermined threshold at the amplitude piece and just is declared.In addition, when input 549 was broken off, gain control signal 547 was very high usually.Therefore, the signal 531 of coaxial connection only just is declared under gain control signal is lower than the situation of predetermined threshold.AGC loop 540 can be used to keep watch on the connection status of input 549, even loops are found in other places in qam demodulator 532.
Another method that detects input signal 534 existence is based on equalizer shown in Figure 43 and carrier phase/frequency loop order section (seeing equality 18 in addition).Specifically, when the QAM of qam demodulator 532 modulator order paragraph controller 434 (at the beginning in the stage 1) switches to stage 2 based on the result of equality 18, can state the signal 531 of coaxial connection.Only when connecting coaxial cable and qam demodulator 532 initiatively from monitor side QAM modulator reception stream signal, the transition in stage 1 to stage 2 takes place.The increase of the MSE that any disconnection afterwards of coaxial cable will cause the loss of signal, calculated by equality 18, and can cause to the stage 1 repeatedly.When qam demodulator 532 is in stage 1, can the signal 531 of coaxial connection be reset or otherwise removed statement.In certain embodiments, possibly before the signal 531 of the coaxial connection of statement, require camera side qam demodulator 532 to arrive the stage 3.
The another kind of method that detects input signal 534 existence is based on the demodulator frame synchronization confidence counter that combines Figure 52 B to discuss.Specifically, only deposit one during greater than the value of predetermined threshold when confidence counter, the signal 531 of coaxial connection just can be by 532 statements of camera side qam demodulator.In one example, threshold value can be 4.Therefore, only when connecting coaxial cable and monitor side modulator-demodulator and the SLOC frame is being sent to video camera, the signal 531 of coaxial connection just is declared.Even without receiving code element, if frame synchronizing process continues freely to carry out, then disconnection can make the confidence counter counting in reverse and finally make it be lower than 4, and removes the statement to coaxial connection signal 531.
Another method that detects input signal 534 existence is based on higher level protocol.Refer again to Figure 51 A, HD video camera 30 will use gateway protocol to communicate with monitor side host computer system 38.From this purpose is discussed, ubiquitous Internet protocol (IP) will be as an example of gateway protocol.Some patterns of IP are intrinsic two-way and cause upstream sending data with downstream.If cable breaks off, network controller in HD video camera 30 and/or the modulator-demodulator 32 or processor find that the IP that does not return divides into groups just to arrive from the monitor side also to notify camera side SLOC modulator-demodulator 32 to stop the passband transmission.In one example, these notices can comprise that the packet that will be scheduled to specially through the for example MII interface 536 shown in Figure 53 transfers to modulator-demodulator 32 from HD video camera 30.
The supplemental instruction of some aspect of the present invention
It is illustrative but not determinate that above-mentioned explanation of the present invention is intended to.For example, those skilled in that art will understand, and the present invention can realize through the various combinations of above-mentioned functions and ability, and can comprise than still less above-mentioned or more parts.Set forth some additional aspect of the present invention and characteristic below, and these additional aspect and characteristic can use more than in greater detail function and parts obtain, as those skilled in that art can understand after receiving disclosure teaching.
Some embodiment of the present invention provides the system and method related with video camera.Among these embodiment some comprise: processor, and this processor receives picture signal and produces a plurality of vision signals of token image signal from imageing sensor; And encoder, this encoder is combined into the output signal that on cable, transmits with baseband video signal and digital video signal.In in these embodiment some, vision signal comprises baseband video signal and digital video signal.In in these embodiment some, be when waiting basically through base band and the digital video signal of combination.In in these embodiment some, video camera is closed circuit HDTV video camera.In in these embodiment some, baseband video signal comprises the SD analog video signal.In in these embodiment some, digital video signal is modulated before making up with baseband video signal.In in these embodiment some, digital video signal comprises the digital video through compression.In in these embodiment some, digital video signal is the high-definition digital video signal.In in these embodiment some, the frame rate of digital video signal is lower than the frame rate of picture signal.In in these embodiment some, modulated digital signal is provided for the video record device.
Among these embodiment some comprise and are configured to decoder that the stream signal that receives from cable is carried out demodulation.In in these embodiment some, comprise control signal through the stream signal of demodulation.In in these embodiment some, control signal comprise the position of controlling video camera and towards signal.In in these embodiment some, control signal comprises the signal that produces through processor control baseband video signal and digital video signal.In in these embodiment some, control signal comprises that a part of selecting picture signal is as the baseband video signal encoded signals.In in these embodiment some, control signal comprises a part of the selecting picture signal signal as encoding digital video signals.In in these embodiment some, comprise the audio signal of the audio frequency output that is used for actuated camera through the stream signal of demodulation.
Some embodiment of the present invention provides the system and method for transmitting video image.Among these embodiment some comprise: the vision signal to receiving from high resolution imaging equipment is made frequency division multiplexing to obtain modulated digital signal; Through being made up with the base-band analog signal that characterizes vision signal, modulated digital signal produces the output signal; And will export signal simultaneously and transfer to display system and digital video capture and/or memory device.In in these embodiment some, display system shows the image that characterizes derivation from the baseband analog of vision signal.In in these embodiment some, the digital video storage uses the digital video recordings device to record a series of high definition frames that extract from through modulated digital signal.
Among these embodiment some comprise compressed video signal.In in these embodiment some, the step of frequency division multiplexing digital video signal is included in the preceding compressed video signal of modulation.In in these embodiment some, send the output signal and comprise the output signal is offered coaxial cable.Among these embodiment some comprise that input signal that demodulation receives from coaxial cable is to obtain control signal.Among these embodiment some comprise through a part of video signal coding is produced base-band analog signal in composite video signal.Among these embodiment some comprise that using control signal to select to intend is coded in that part of vision signal in the composite video signal.Among these embodiment some comprise the position of using control signal control video camera.In in these embodiment some, the demodulation input signal comprises from input signal extraction audio signal.
Some embodiment of the present invention provides the system and method for running video camera.Among these embodiment some comprise: processor, and this processor receives picture signal and produces a plurality of vision signals from imageing sensor; Control logic, this control logic are configured to the control signal that is received by video camera is responded; And modulator, this modulator configuration becomes the modulation digital vision signal as modulated signal.In in these embodiment some, a plurality of vision signals comprise baseband video signal and digital video signal.In in these embodiment some, each in a plurality of vision signals characterizes at least a portion in the video camera ken.In in these embodiment some, the content of control signal control base band and digital video signal.In in these embodiment some, transmit simultaneously through video camera through modulation signal and baseband video signal.
In in these embodiment some, base band and digital video signal are when waiting basically.Among these embodiment some comprise encoder, and this encoder is combined in the output signal that transmits on the cable with baseband video signal with through modulation signal.In in these embodiment some, control signal is received as wireless signal.In in these embodiment some, modulated signal is by transmission wirelessly.In in these embodiment some, digital video signal is the high-definition digital video signal.In in these embodiment some, digital video signal comprises the digital video through compression.In in these embodiment some, control signal moves the ken part by a sign in the vision signal.
Some embodiment of the present invention is provided for the equalizer of digital signal and base-band analog signal, and said digital signal and base-band analog signal carry by frequency separation and by cable.Among these embodiment some comprise the digital equalizer of from the digital signal that receiver side receives, removing distortion.Among these embodiment some comprise the analog equalizer of the analog signal decay that compensation is caused by cable.In in these embodiment some, analog equalizer is used in one group of baseband analog filter one with compensate for attenuation.In in these embodiment some, applied baseband analog filter is based on that the estimation of the decay difference under different frequency that is calculated by digital equalizer selects.
In in these embodiment some, digital signal and analog signal are transmitted being presented as between the transmitter and receiver of video camera, and wherein receiver will offer monitor as the equalizing signal that analog signal characterizes.In in these embodiment some, cable comprises coaxial cable.In in these embodiment some, distortion increases along with cable length.In in these embodiment some, distortion comprises multipath distortion.In in these embodiment some, the estimation of decay is from have the crooked frequency range that roughly is linear power spectral density, to calculate.In in these embodiment some, crooked being to use calculated the FFT of a plurality of filter taps.In in these embodiment some, select the frequency response of frequency crack in the frequency range to allow the use summation to calculate the filter of digital equalizer:
G R [ k 1 ] = Σ n = 0 N / 4 - 1 g R [ 4 n ] + Σ n = 0 N / 4 - 1 g I [ 4 n + 1 ] - Σ n = 0 N / 4 - 1 g R [ 4 n + 2 ] - Σ n = 0 N / 4 - 1 g I [ 4 n + 3 ] G I [ k 1 ] = Σ n = 0 N / 4 - 1 g I [ 4 n ] - Σ n = 0 N / 4 - 1 g R [ 4 n + 1 ] - Σ n = 0 N / 4 - 1 g I [ 4 n + 2 ] + Σ n = 0 N / 4 - 1 g R [ 4 n + 3 ] , Wherein
G [k] is the DFT of the equalization filter tap of time domain convergence, and k 1Certain tones crack corresponding to DFT.In in these embodiment some, digital signal comprises that the high definition by video camera video captured image characterizes, and analog signal comprises that the SD of video image characterizes.
Some embodiment of the present invention provides the balanced method of analog signal in the cable that makes the digital signal that same carrying separates with analog signal through frequency.In in these embodiment some, this method is put letter by modulator-demodulator, and this modulator-demodulator receives analog and digital signal and exports baseband video signal.Among these embodiment some comprise calculates crooked in the digital signal.In in these embodiment some, crooked sign is the decay of function with the frequency owing to cable.Among these embodiment some comprise based on the crooked digital signal that makes that calculates balanced.Among these embodiment some comprise uses the crooked analog equalizer that disposes that calculates to select in one group of baseband analog filter.Among these embodiment some comprise uses selected baseband analog filter to come the equilibrium model analog signal.
In in these embodiment some, analog signal comprises baseband video signal and digital signal comprises the high definition version of baseband video signal.In in these embodiment some, cable comprises coaxial cable, and wherein crookedly changes along with cable length.In in these embodiment some, the crooked multipath distortion that is derived from.In in these embodiment some, calculate the crooked decay of estimation in having the crooked frequency range that roughly is linear power spectral density that comprise.In in these embodiment some, the estimation decay comprises the FFT of using to a plurality of filter taps.In in these embodiment some, the estimation decay comprises several frequencies crack of selecting in the frequency range.In in these embodiment some, selected frequency crack makes the efficiency optimization that calculates crooked step.
Some embodiment of the present invention provides the digital communication system of using novel framing structure.Among these embodiment some comprise the convolutional byte interleaver of interleaving data frame, and wherein this interleaver is synchronous with frame structure.Among these embodiment some comprise and being configured to from produce the randomizer of randomized Frame through the Frame that interweaves.Among these embodiment some comprise the perforation trellis coded modulation device that is operated under the optional bit rate, and said perforation trellis coded modulation device is from producing the Frame through trellis coding through randomized Frame.Among these embodiment some comprise the QAM mapper, and this QAM mapper maps to modulated symbol with the many groups bit in the Frame of trellis coding, and the frame through mapping is provided thus.Among these embodiment some comprise with synchronized packets be added into through the mapping frame synchronizer.
In in these embodiment some, perforation trellis coded modulation device by bypass to obtain optimization net bit rate based on the system's white noise performance that records.In in these embodiment some, identical synchronized packets is added into each in a series of successor map frames.In in these embodiment some, identical synchronized packets is added into each frame through mapping.In in these embodiment some, a part of synchronized packets comprises 127 code elements.In in these embodiment some, a part of synchronized packets comprises to the real part of modulated symbol and the different binary sequences of imaginary part.In in these embodiment some, a part of synchronized packets comprises to the real part of modulated symbol and the identical binary sequence of imaginary part.In in these embodiment some, synchronized packets comprises the data of indication through the transmission mode of mapping frame.In in these embodiment some, the indication of transmission mode comprises selected qam constellation and selected trellis code speed.In in these embodiment some, regardless of transmission mode why system divides into groups for each Frame produces constant integer Reed-Solomon.In in these embodiment some, regardless of transmission mode why system produces variable integer modulated symbol for each Frame.In in these embodiment some, regardless of transmission mode why system produces integer perforation pattern cycle to each Frame and.
Some embodiment of the present invention provides the framing method of variable net bit rate digital communication system.Among these embodiment some comprise provides a different set of quadrature amplitude modulation (qam) constellation.Among these embodiment some comprise uses the trellis code of perforation to make up the frame that produces packet, and every kind of combination is corresponding to the pattern that is associated.Among these embodiment some comprise provides the frame with variable integer QAM code element.In in these embodiment some, the QAM code element number is corresponding to selected pattern.In in these embodiment some, byte that every frame is associated and Reed-Solomon grouping number are constant.In in these embodiment some, use the frame of perforation trellis code combination results packet to comprise each Frame is produced an integer perforation pattern cycle, why regardless of the pattern that is associated.In in these embodiment some, the data bit number of each QAM code element is marks for one or more patterns.In in these embodiment some, for all patterns, the number in the grid encoder perforation pattern cycle of every frame is an integer.
Some embodiment of the present invention provides the system of phase calibration skew.Among these embodiment some comprise the phase deviation adjuster, this phase deviation adjuster receive characterize through the signal of quadrature amplitude modulation through equalizing signal and from derive the signal of phasing through equalizing signal.Among these embodiment some comprise with through the equalizing signal cutting to obtain the secondary sheer of real number and imaginary number sequence.Among these embodiment some comprise frame synchronizer, and this frame synchronizer is carried out relevant with the appropriate section of real number and imaginary number sequence and the frame synchronization pseudo random sequence of being stored.Among these embodiment some comprise the phase correction signal that is offered the phase deviation adjuster by frame synchronizer.In in these embodiment some, phase correction signal is based on relevant maximum real number and imaginary value.In in these embodiment some, frame synchronizer is carried out continuous crosscorrelation to the quadrature amplitude modulation code element of importing into through cutting.
In in these embodiment some, continuously the crosscorrelation stored copies that is to use binary system frame synchronization PN sequence is carried out to real number and imaginary number sequence respectively.In in these embodiment some, be to use the perforation trellis coded modulation through the signal of quadrature amplitude modulation.In in these embodiment some, be to use QPSK to modulate through the signal of quadrature amplitude modulation.In in these embodiment some, be to use the 16-QAM modulation through the signal of quadrature amplitude modulation (qam).In in these embodiment some, be to use the 64-QAM modulation through the signal of quadrature amplitude modulation (qam).In in these embodiment some, have identical symbol through the frame synchronization code element of the signal of quadrature amplitude modulation, and the symbol indication of relevant maximum real number and imaginary value is rotated through the phase place of equalizing signal.In in these embodiment some, the phase correction signal that is provided by frame synchronizer comprises the relevant maximum real number and the symbol of imaginary value.In in these embodiment some, the phase deviation adjuster is derived through phase correction signal through the look-up table that index has the symbol of relevant maximum real number and imaginary value, thereby confirms phase correcting value.
Some embodiment of the present invention provides the method for proofreading and correct the carrier phase offset in the signal of quadrature amplitude modulation in the receiver.Among these embodiment some comprise carries out equilibrium to signal.Among these embodiment some comprise the signal of cutting through equilibrium, thus from obtaining real number and imaginary number sequence through balanced signal.Among these embodiment some comprise the frame synchronization sequence in identification real number and the imaginary number sequence.In in these embodiment some, the identification frame synchronization sequence comprises the pseudo random sequence of being stored relevant with the imaginary number sequence with real number.In in these embodiment some, the identification frame synchronization sequence comprises the beginning of confirming frame from the maximum related value that is associated with real number and imaginary number sequence.Among these embodiment some comprise based on maximum correction proofreaies and correct the phase error in equalizing signal.
In in these embodiment some, correlation step comprises uses the storage version of binary system frame synchronization PN sequence that a succession of quadrature amplitude modulation code element through cutting is carried out continuous crosscorrelation.In in these embodiment some, correlation step comprises respectively carries out continuous crosscorrelation with real number and imaginary number sequence to the storage version of frame synchronization sequence.In in these embodiment some, the frame synchronization code element of frame synchronization sequence has identical symbol.In in these embodiment some, the phase calibration error comprises based on the symbol of maximum related value confirms the phase place rotation in equalizing signal.In in these embodiment some, the phase error of proofreading and correct in equalizing signal comprises that the symbol with real number and imaginary number maximum related value comes the index search table.
Some embodiment of the present invention is provided for the method for the carrier phase offset in the correction of orthogonal amplitude-modulated signal.In in these embodiment some, these methods can be implemented in the system that comprises one or more processors that are configured to execute instruction.Among these embodiment some are included in and carry out the instruction that is configured to make signal equalization on one or more processors.Among these embodiment some be included on one or more processors carry out be configured to cutting through equalizing signal thus from obtain the instruction of real number and imaginary number sequence through equalizing signal.Among these embodiment some are included in and carry out the instruction that is configured to discern the frame synchronization sequence in real number and the imaginary number sequence on one or more processors.In in these embodiment some, the identification frame synchronization sequence comprises respectively carries out continuous crosscorrelation with real number and imaginary number sequence to the storage version of frame synchronization sequence.In in these embodiment some, the identification frame synchronization sequence comprises the beginning of confirming frame from the maximum related value that is associated with real number and imaginary number sequence.Among these embodiment some are included in and carry out the instruction that is configured to proofread and correct based on maximum related value the phase error in equalizing signal on one or more processors.In in these embodiment some, the frame synchronization code element of frame synchronization sequence has identical symbol.In in these embodiment some, the phase calibration error comprises based on the symbol of maximum related value confirms the phase place rotation in equalizing signal.
Some embodiment of the present invention provides the method for the constellation of identification code element.In in these embodiment some, this method is to carry out through one or more processors of the communication system of multimode quadrature amplitude modulation.Among these embodiment some comprise carries out the instruction that makes the distribute power in one or more processor characterization signals.In in these embodiment some, the generation of detected power level in the distribute power statistics ground tracking signal.Among these embodiment some comprise carries out the instruction that makes one or more processors confirm one or more peak values appearance of the power level in the distribute power.Among these embodiment some comprise carries out the instruction that constellation is confirmed in the distribution that one or more processors are occurred based on peak value.
In in these embodiment some, one or more processors are also confirmed constellation based on the expansion that one or more peak values occur.In in these embodiment some, signal is to confirm constellation through equalizing signal and said one or more processor through a plurality of sections in the distribution map of inspection distribute power.In in these embodiment some, each section corresponding to a plurality of constellation candidates in one but power level range that non-whole constellation candidate is associated.In in these embodiment some, a plurality of constellation candidates comprise quadrature phase keying constellation and quadrature amplitude modulation (qam) constellation.In in these embodiment some, a plurality of constellation candidates comprise 16-QAM and 64-QAM constellation.In in these embodiment some, a plurality of constellation candidates comprise the 256-QAM constellation.
Among these embodiment some comprise carries out the instruction that makes one or more processors set up the reliability of the constellation of discerning through the step of carrying out each judgement in the continuous constellation judgement.In in these embodiment some, these steps comprise when the identity of constellation is confirmed in judgement subsequently increases progressively counter.In in these embodiment some, these steps comprise when various constellations is discerned in judgement subsequently successively decreases counter.In in these embodiment some, these steps comprise that the value based on counter provides the measurement of reliability.In in these embodiment some, when counter exceeded a threshold value, constellation was identified.In in these embodiment some,, and, its corresponding counter discerns this constellation when exceeding a threshold value in a plurality of constellation candidates each provides a counter.In in these embodiment some, the corner code element corresponding to constellation appears in the peak value of power level.In in these embodiment some, before equalizing signal, discern constellation.
Some embodiment of the present invention is provided for discerning the method for the constellation of the code element in the communication system of multimode quadrature amplitude modulation.In in these embodiment some, these methods are to carry out through the processor in the modulator-demodulator of communication system.Among these embodiment some comprise carrying out makes processor instruction from Frame extraction pattern information in response to the beginning that detects the Frame that receives at the modulator-demodulator place.Among these embodiment some comprise carries out the instruction that the sign indicating number that makes processor pass through the corresponding sign indicating number in the most approximate match pattern bit of selection from a plurality of potential constellation sign indicating numbers is confirmed current constellation.Among these embodiment some comprise if current constellation matees with the constellation of confirming before carries out the instruction that makes processor increase the confidence measure that is associated with the constellation of discerning before.If some among these embodiment comprise that to carry out current constellation different with the constellation of identification before then carry out and make processor reduce confidence measure and current constellation is recorded as the instruction of discerning constellation before.Among these embodiment some comprise repeating to be made processor extract pattern information, select current constellation and adjusts the step of confidence measure till confidence measure exceeds predetermined threshold to subsequent data frame.In in these embodiment some, when confidence measure exceeded predetermined threshold value, constellation was identified.
In in these embodiment some, select the constellation sign indicating number to comprise to make processor to carry out each and the cross correlation of corresponding yard bit in a plurality of potential constellation sign indicating numbers.In in these embodiment some, do not discerning constellation in the equalizing signal, this is equalizing signal this Frame of carrying and subsequent data frame not.In in these embodiment some, in the signal reinsertion of carrier, constellation is identified at processor.Among these embodiment some comprise carry out make processor use constant modulo n arithmetic (CMA) thus come error signal so that equalization filter tap convergence allows the instruction of signal equalization.In in these embodiment some, use and come error signal to improve equalization performance through the CMA of convergent-divergent parameter.In in these embodiment some, the equilibrium of carrying out signal comprises the distribution map of analysis through the power of equalizing signal.In in these embodiment some, analysis distribution figure comprises the probability of use mass function.In in these embodiment some, carry out signal equalization and comprise carrying out processor is calculated and the instruction to related power of a plurality of code elements in equalizing signal.In in these embodiment some, carry out signal equalization and comprise that execution makes processor discern the instruction of the corner code element of constellation through using threshold power level.In in these embodiment some, the identity of threshold power level indication constellation.
Some embodiment of the present invention is provided for the system of transmission video signal; This system comprises the camera side modulator-demodulator; This camera side modem configuration becomes from video camera to receive two signals; The image sequence that each characterization is caught by video camera, this camera side modulator-demodulator further be configured to a road in two signals number as the transmission of composite baseband video signal and with another signal as with nonoverlapping passband vision signal modulation of baseband signal and transmission.In in these embodiment some, the camera side modulator-demodulator comprises that combination base band and passband vision signal are to provide the blender of transmission signals.In in these embodiment some, the camera side modulator-demodulator comprises the duplexer that is configured on transmission line to send transmission signals and extracts the passband signal that is received from transmission line.In in these embodiment some, the camera side modulator-demodulator comprises surveillance camera side modulator-demodulator and when the passband signal that receives is identified, produces the detector of launching signal.In in these embodiment some, launch at least one the transmission in signal controlling baseband video signal and the passband vision signal.
In in these embodiment some, the passband vision signal only just is transmitted when signal is launched in generation.In in these embodiment some, the passband signal that is received is by quadrature amplitude modulation.In in these embodiment some, the estimation of the mean square error in the detector monitors quadrature amplitude demodulation device, and signal is launched in generation when this estimation exceeds threshold value.In in these embodiment some, detector monitors constellation detector.In in these embodiment some, launch signal and be based on that the reliability measurement that provided by the constellation detector produces.In in these embodiment some, reliability measurement is based on frame synchronization sequence.In in these embodiment some, the valuation of the mean square error in the detector monitors equalizer.In in these embodiment some, when valuation exceeds threshold value, produce and launch signal.In in these embodiment some, the gain factor in the automatic gain control module of detector monitors camera side modulator-demodulator.In in these embodiment some, when gain factor has the value less than threshold value, produce and launch signal.In in these embodiment some, the amplitude of the passband signal that detector monitors received.In in these embodiment some, when amplitude has the value that exceeds threshold value, produce and launch signal.In in these embodiment some, the passband signal that is received comprises according to the Internet protocol coded data.
Some embodiment of the present invention is provided for controlling the method for the signaling in the safety system.Among these embodiment some are included in the existence that the upstream modem place confirms the composite signal middle and upper reaches QAM signal of transmission over coaxial cable.Among these embodiment some comprise when definite upper reaches QAM signal exists makes upstream modem on coaxial cable, send composite baseband video signal and passband vision signal.In in these embodiment some, composite baseband video signal and passband vision signal are the parallel signs of the sequence image of being caught by video camera.Among these embodiment some comprise makes upstream modem on coaxial cable, send the composite baseband video signal and stop the passband transmission of video signals when definite upper reaches QAM signal does not exist.
In in these embodiment some, when the yield value in the automatic gaining controling signal exceeded threshold value, upper reaches QAM signal was confirmed as existence.In in these embodiment some, when the amplitude measurement of upper reaches QAM signal during less than threshold value, upper reaches QAM signal is confirmed as existence.In in these embodiment some, when the estimation of the mean square error in the equalizer exceeded threshold value, upper reaches QAM signal was confirmed as and does not exist.In in these embodiment some, when the identification internet protocol datagram divided into groups in the QAM signal of the upper reaches, upper reaches QAM signal was confirmed as and does not exist.
Some embodiment of the present invention is provided for the automatic reconfiguration system of transmission video signal.Among these embodiment some comprise the upstream modem that is configured to receive from video camera two signals.In in these embodiment some, the image sequence that each characterization is caught by video camera.In in these embodiment some, upstream modem be configured to a signal in two signals as composite baseband video signal transmission and with another signal as with the nonoverlapping passband vision signal modulation of baseband signal with send.Among these embodiment some comprise the downstream modulator-demodulator, and this downstream modem configuration becomes from upstream modem reception composite baseband video signal and passband vision signal and further is configured to upper reaches passband signal is transferred to upstream modem.In in these embodiment some, when detecting the deterioration of upper reaches passband signal, upstream modem is ended the transmission of at least one signal in two signals.
Although invention has been described with reference to certain exemplary embodiments, yet obviously, as far as those of ordinary skills, can these embodiment are made various modifications and variation and do not break away from the spirit and the scope of broad of the present invention.For example, digital HD video and the system of baseband analog video signal that provides through compression described.Other embodiments of the invention provide simultaneously SD numeral and simulation to present.Other embodiment is providing full motion numeral HD video together with baseband analog video.Therefore, this specification and accompanying drawing are considered to illustrative but not restrictive, sense.

Claims (109)

1. video camera comprises:
Processor, said processor receives picture signal and produces a plurality of vision signals that characterize said picture signal from imageing sensor, and said vision signal comprises baseband video signal and digital video signal; And
Encoder, said encoder is combined into the output signal that on cable, transmits with said baseband video signal and digital video signal.
2. video camera as claimed in claim 1 is characterized in that, is when waiting basically through base band and the digital video signal of combination.
3. video camera as claimed in claim 1 is characterized in that said baseband video signal comprises the SD analog video signal.
4. video camera as claimed in claim 1 is characterized in that, said digital video signal is modulated before making up with said baseband video signal.
5. video camera as claimed in claim 4 is characterized in that, said digital video signal is the high-definition digital video signal.
6. video camera as claimed in claim 4 is characterized in that, the frame rate of said digital video signal is lower than the frame rate of said picture signal.
7. video camera as claimed in claim 4 is characterized in that, said modulated digital signal is provided for video capture device.
8. video camera as claimed in claim 1 is characterized in that, also comprises decoder, the stream signal that said decoder configurations becomes demodulation to receive from said cable, and wherein the stream signal through demodulation comprises control signal.
9. video camera as claimed in claim 8 is characterized in that, said control signal comprise the position that is used to control video camera and towards signal.
10. video camera as claimed in claim 8 is characterized in that, said control signal comprises the signal that is used for through processor control baseband video signal and digital video signal generation.
11. video camera as claimed in claim 10 is characterized in that, said control signal comprises that a part that is used to select said picture signal is as said baseband video signal encoded signals.
12. video camera as claimed in claim 10 is characterized in that, said control signal comprises and is used to select the signal of the part of said picture signal as said encoding digital video signals.
13. video camera as claimed in claim 8 is characterized in that, said stream signal through demodulation comprises the audio signal of the audio frequency output that is used to drive said video camera.
14. a method that is used for transmitting video image comprises:
The vision signal frequency division multiplexing that will receive from video imaging equipment is to obtain modulated digital signal;
Through said modulated digital signal and the base-band analog signal combination that characterizes vision signal are produced the output signal; And
Said output signal is transferred to one or more equipment, and said one or more equipment comprise digital video capture device and show from the equipment of the video image of said base-band analog signal derivation.
15. method as claimed in claim 14 is characterized in that, said digital video capture device is recorded the frame sequence that from said modulated digital signal, extracts.
16. method as claimed in claim 14 is characterized in that, said digital video capture device comprises video server.
17. method as claimed in claim 14 is characterized in that, the step of the said digital video signal of said frequency division multiplexing comprises:
Compress said vision signal; And
Modulation is through the vision signal of compression on carrier wave.
18. method as claimed in claim 14 is characterized in that, transmits said output signal and comprises said output signal is offered coaxial cable, and comprise that further input signal that demodulation receives from said coaxial cable is to obtain control signal.
19. method as claimed in claim 18 is characterized in that, further comprises:
Through a part of video signal coding is produced said base-band analog signal in composite video signal; And
Use said control signal to select to be coded in that part of vision signal in the said composite video signal.
20. method as claimed in claim 18 is characterized in that, also comprises the position of using said control signal to control said video camera.
21. method as claimed in claim 18 is characterized in that, the said input signal of demodulation comprises from said input signal and extracts audio signal.
22. a video camera comprises:
Processor; Said processor receives picture signal and produces a plurality of vision signals from imageing sensor; In said a plurality of vision signal each characterizes at least a portion of the said video camera ken, and said a plurality of vision signal comprises baseband video signal and digital video signal;
Control logic, said control logic are configured in response to the control signal by said video camera reception, and wherein said control signal is controlled the content of said base band and digital video signal; And
Modulator, said modulator configuration become the said digital video signal of modulation, and wherein modulated digital video signal and said baseband video signal are simultaneously by said video camera transmission.
23. video camera as claimed in claim 22 is characterized in that, said control signal moves the ken part by at least one expression in a plurality of vision signals.
24. video camera as claimed in claim 22 is characterized in that, said control signal is received as wireless signal.
25. video camera as claimed in claim 22 is characterized in that, said modulated digital video signal is by transmission wirelessly.
26. video camera as claimed in claim 22 is characterized in that, said base band and digital video signal are when waiting basically.
27. video camera as claimed in claim 22 is characterized in that, also comprises encoder, said encoder is combined as the output signal that on cable, transmits with said baseband video signal and said modulated digital video signal.
28. a use is by frequency separation and by the digital signal of cable carrying and the system of base-band analog signal, said system comprises:
Digital equalizer, said digital equalizer is removed distortion from the digital signal of receiver reception; And
Analog equalizer; Said analog equalizer compensates the decay of the analog signal that is caused by said cable; One of using in one group of baseband analog filter of wherein said analog equalizer compensates said decay, and wherein applied baseband analog filter is based on that the estimation of the decay difference under different frequency that is calculated by said digital equalizer selects.
29. system as claimed in claim 28; It is characterized in that; Transmit between said digital signal and the transmitter and receiver of said analog signal in being embodied in video camera, and wherein said receiver will be characterized by said analog signal offer monitor through equalizing signal.
30. system as claimed in claim 29 is characterized in that, said cable comprises coaxial cable.
31. system as claimed in claim 30 is characterized in that, said distortion increases along with the length of said cable.
32. system as claimed in claim 28 is characterized in that, said distortion comprises multipath distortion.
33. system as claimed in claim 32 is characterized in that, the estimation of decay difference comprises from having the crooked estimation that calculates the frequency range of linear power spectral density that roughly is.
34. system as claimed in claim 33 is characterized in that, saidly crookedly uses FFTs to calculate to a plurality of filter taps.
35. system as claimed in claim 33 is characterized in that, selects the frequency response of frequency crack to allow the use summation to calculate the filter of said digital equalizer in the said frequency range:
G R [ k 1 ] = Σ n = 0 N / 4 - 1 g R [ 4 n ] + Σ n = 0 N / 4 - 1 g I [ 4 n + 1 ] - Σ n = 0 N / 4 - 1 g R [ 4 n + 2 ] - Σ n = 0 N / 4 - 1 g I [ 4 n + 3 ]
G I [ k 1 ] = Σ n = 0 N / 4 - 1 g I [ 4 n ] - Σ n = 0 N / 4 - 1 g R [ 4 n + 1 ] - Σ n = 0 N / 4 - 1 g I [ 4 n + 2 ] + Σ n = 0 N / 4 - 1 g R [ 4 n + 3 ] ,
Wherein G [k] is the DFT of the equalization filter tap of time domain convergence, and k 1Certain tones crack corresponding to DFT.
36. system as claimed in claim 28 is characterized in that, said digital signal comprises that the high definition by video camera video captured image characterizes, and wherein said analog signal comprises that the SD of said video image characterizes.
37. method that is used for the analog signal of compensating cable; Said cable also carries the digital signal of separating with said analog signal through frequency; Said method is carried out by modulator-demodulator; Said modulator-demodulator receives said analog and digital signal and exports baseband video signal, and said method comprises:
Calculate crooked in the said digital signal, wherein saidly crooked decay is characterized by the function owing to the frequency of said cable;
Based on the crooked next balanced said digital signal that calculates;
Use calculates crookedly disposes said analog equalizer to select in one group of baseband analog filter; And
Use selected baseband analog filter to come balanced said analog signal.
Said digital signal comprises the high definition version of baseband video signal 38. method as claimed in claim 37 is characterized in that, said analog signal comprises baseband video signal.
39. method as claimed in claim 38 is characterized in that, said cable comprises coaxial cable, and said crookedly change along with the length of said cable.
40. method as claimed in claim 39 is characterized in that, the said crooked multipath distortion that is derived from.
41. method as claimed in claim 37 is characterized in that, calculates the crooked decay of estimation in having the crooked frequency range that roughly is linear power spectral density that comprise.
42. method as claimed in claim 41 is characterized in that, the estimation decay comprises to a plurality of filter taps uses FFT.
43. method as claimed in claim 42 is characterized in that, estimation decay comprises the frequency crack of selecting in the said frequency range, and wherein institute frequency-selecting crack makes the efficiency optimizationization of calculating said crooked step.
44. a digital communication system comprises:
The convolutional byte interleaver of interleaving data frame, wherein said interleaver is synchronous with frame structure;
Randomizer, said randomizer is configured to produce randomized Frame from the Frame that is interweaved;
Perforation trellis coded modulation device, said perforation trellis coded modulation device are operated under the optional bit rate and from through randomized Frame, producing the Frame through trellis coding;
The QAM mapper, said QAM mapper maps to modulated symbol with the bit group in the Frame of said trellis coding, provides thus through the mapping frame; And
Synchronizer, said synchronizer adds to synchronized packets said through the mapping frame.
45. system as claimed in claim 44 is characterized in that, said perforation trellis coded modulation device by bypass to obtain optimization net bit rate based on the white noise performance of the said system that records.
46. system as claimed in claim 44 is characterized in that, identical synchronized packets is added into each in the mapping frame sequence.
47. system as claimed in claim 46 is characterized in that, the part of said synchronized packets comprises to the real part of said modulated symbol and the different binary sequences of imaginary part.
48. system as claimed in claim 46 is characterized in that, the part of said synchronized packets comprises to the real part of said modulated symbol and the identical binary sequence of imaginary part.
49. system as claimed in claim 48 is characterized in that, said synchronized packets comprises the data of the transmission mode of the said warp mapping of indication frame.
50. system as claimed in claim 49 is characterized in that, the data of indicating transmission mode comprise selected qam constellation and selected trellis code speed.
51. system as claimed in claim 44 is characterized in that, regardless of transmission mode why said system produces to each Frame that constant integer Reed-Solomon divides into groups and.
52. system as claimed in claim 44 is characterized in that, regardless of transmission mode why said system produces integer modulated symbol to each Frame and.
53. system as claimed in claim 44 is characterized in that, said system produce every Frame integer perforation pattern cycle and no matter transmission mode why.
54. a framing method that is used for variable net bit rate digital communication system comprises:
A different set of quadrature amplitude modulation (qam) constellation is provided;
Use the perforation trellis code to make up and produce data packet frame, every kind of combination is corresponding to the pattern that is associated; And
Frame with variable integer QAM code element is provided, and wherein said QAM code element number is corresponding to institute's lectotype, and be associated byte and the Reed-Solomon packet count of every frame are constant.
55. regardless of the pattern that is associated why method as claimed in claim 54 is characterized in that, uses perforation trellis code combination results data packet frame to comprise that every Frame produces an integer perforation pattern cycle.
56. method as claimed in claim 54 is characterized in that, for all patterns, the number of the grid encoder perforation pattern of every frame circulation is an integer.
57. method as claimed in claim 55 is characterized in that, the data bit number of every QAM code element is marks for one or more patterns.
58. the system of the digital video signal that is used to communicate by letter comprises:
Phase deviation adjuster, said phase deviation adjuster reception characterize deriving through phase correction signal through equalizing signal through equalizing signal and from said through the signal of quadrature amplitude modulation;
The secondary sheer, the cutting of said secondary sheer said through equalizing signal to obtain real number and imaginary number sequence;
Frame synchronizer, said frame synchronizer are carried out relevant with the appropriate section of said real number and imaginary number sequence and the frame synchronization pseudo random sequence of being stored; And
Phase correction signal, said phase correction signal offers said phase deviation adjuster by said frame synchronizer, and wherein said phase correction signal is based on said relevant maximum real number value and imaginary value.
59. system as claimed in claim 58 is characterized in that, said frame synchronizer is carried out continuous crosscorrelation to the unit through the cutting quadrature amplitude modulation of importing into.
60. system as claimed in claim 59 is characterized in that, the stored copies that said continuous crosscorrelation is to use binary system frame synchronization PN sequence is carried out to said real number and imaginary number sequence respectively.
61. system as claimed in claim 58 is characterized in that, saidly is to use the perforation trellis coded modulation through quadrature amplitude modulated (QAM) signal.
62. system as claimed in claim 58 is characterized in that, saidly is to use QPSK to modulate through quadrature amplitude modulated (QAM) signal.
63. system as claimed in claim 58 is characterized in that, saidly is to use 16-QAM modulation through the quadrature amplitude modulation (qam) signal.
64. system as claimed in claim 58 is characterized in that, saidly is to use 64-QAM modulation through the quadrature amplitude modulation (qam) signal.
65. system as claimed in claim 58 is characterized in that, said frame synchronization code element through quadrature amplitude modulated (QAM) signal has identical symbol, and the said relevant maximum real number and the phase place rotation of symbol indication in equalizing signal of imaginary value.
66., it is characterized in that the said phase correction signal that is provided by said frame synchronizer comprises the said relevant maximum real number and the symbol of imaginary value like the described system of claim 65.
67., it is characterized in that the look-up table that said phase deviation adjuster has a symbol of said relevant maximum real number and imaginary value through index is derived said through phase correction signal, thereby confirms phase correcting value like the described system of claim 65.
68. the method for the carrier phase offset in the quadrature amplitude modulated (QAM) signal that is used for proofreading and correct receiver, said method comprises:
Balanced said signal;
Cutting obtains real number and imaginary number sequence from said through equalizing signal thus through equalizing signal; And
Discern the frame synchronization sequence in said real number and the imaginary number sequence,
Wherein discerning said frame synchronization sequence comprises:
Make the pseudo random sequence of storage relevant with the imaginary number sequence with said real number; And
Confirm the beginning of frame from the maximum related value that is associated with said real number and imaginary number sequence; And
Proofread and correct said phase error in equalizing signal based on said maximum related value.
69., it is characterized in that said correlation step comprises uses the storage version of binary system frame synchronization PN sequence to carry out continuous crosscorrelation to a series of through cutting quadrature amplitude modulation code element like the described method of claim 68.
70., it is characterized in that said correlation step comprises uses said real number and imaginary number sequence that the storage version of said frame synchronization sequence is carried out continuous crosscorrelation respectively like the described method of claim 68.
71., it is characterized in that the frame synchronization code element of said frame synchronization sequence has identical symbol like the described method of claim 70.
72., it is characterized in that the phase calibration error comprises based on the symbol of said maximum related value confirms said phase place rotation in equalizing signal like the described method of claim 71.
73. like the described method of claim 72, it is characterized in that, proofread and correct said phase error in equalizing signal and comprise that index has the look-up table of the symbol of said real number and imaginary number maximum related value.
74. a method that is used for the carrier phase offset of correction of orthogonal amplitude-modulated signal, wherein said method realize that in the system that comprises the one or more processors that are configured to execute instruction said method comprises:
On said one or more processors, carry out the instruction that is configured to balanced said signal;
On said one or more processors, carry out be configured to cutting through equalizing signal thus from the said instruction that obtains real number and imaginary number sequence through equalizing signal;
On said one or more processors, carry out the instruction that is configured to discern the frame synchronization sequence in said real number and the imaginary number sequence, wherein discern said frame synchronization sequence and comprise:
Use said real number and imaginary number sequence that the storage version of said frame synchronization sequence is carried out continuous crosscorrelation respectively; And
Confirm the beginning of frame from the maximum related value that is associated with said real number and imaginary number sequence; And
On one or more processors, carry out the instruction that is configured to proofread and correct said phase error in equalizing signal based on said maximum related value; The frame synchronization code element of wherein said frame synchronization sequence has same-sign, and wherein the phase calibration error comprises based on the symbol of said maximum related value and confirms said phase place rotation in equalizing signal.
75. a method that is used to discern symbol constellations, said method is carried out by one or more processors of multimode quadrature amplitude modulation communication system, and said method comprises:
Execution makes the instruction of distribute power in said one or more processor characterization signal, and the appearance of detected power level in the said signal is followed the tracks of on wherein said distribute power statistics ground;
Execution makes said one or more processor confirm the instruction that one or more peak values of the power level in the said distribute power occur; And
The instruction of said constellation is confirmed in the distribution that execution makes said one or more processor occur based on said peak value.
76., it is characterized in that said one or more processors are also confirmed constellation based on the expansion that said one or more peak values occur like the described method of claim 75.
77. like the described method of claim 75; It is characterized in that; Said signal is to confirm said constellation through equalizing signal and said one or more processor through a plurality of sections in the distribution map of checking said distribute power, wherein each said section corresponding to a plurality of constellation candidates in one but not power level range that whole candidates is associated.
78., it is characterized in that said a plurality of constellation candidates comprise quadrature phase keying constellation and quadrature amplitude modulation (qam) constellation like the described method of claim 77.
79., it is characterized in that said a plurality of constellation candidates comprise 16-QAM and 64-QAM constellation like the described method of claim 78.
80., it is characterized in that said a plurality of constellation candidates comprise the 256-QAM constellation like the described method of claim 78.
81., it is characterized in that also comprise and carry out the instruction that makes said one or more processor set up the reliability of the constellation of discerning through the step of carrying out each judgement in a succession of constellation judgement, said step comprises like the described method of claim 75:
When the identity of said constellation is confirmed in judgement subsequently, counter is increased progressively;
When various constellations is discerned in judgement subsequently, counter is successively decreased; And
Value based on said counter provides reliability measurement.
82., it is characterized in that when said counter exceeded threshold value, said constellation was by reliable recognition like the described method of claim 81.
83. like the described method of claim 81, it is characterized in that, to each of a plurality of constellation candidates counter be provided, and when its corresponding counter exceeds threshold value, discern this constellation reliably.
84., it is characterized in that the corner code element corresponding to said constellation appears in the peak value of said power level like the described method of claim 75.
85., it is characterized in that the said constellation of identification before to said signal equalization like the described method of claim 75.
86. the method for the constellation of a code element that is used for discerning multimode quadrature amplitude modulation communication system, said method is to be carried out by the processor in the modulator-demodulator in the said communication system, and may further comprise the steps:
In response to the beginning that detects the Frame that receives at said modulator-demodulator place, carry out making said processor from said Frame, extract the instruction of pattern information;
Execution makes said processor confirm the instruction of current constellation through the sign indicating number of from a plurality of potential constellation sign indicating numbers, selecting the corresponding sign indicating number in the said pattern information of the most approximate coupling;
If said current constellation and the constellation coupling of confirming are before then carried out the instruction that makes said processor increase the confidence measure that is associated with the said constellation of identification before;
If said current constellation is different from the said constellation of identification before, then carry out making processor reduce the instruction that said confidence measure also is recorded as said current constellation the said constellation of discerning before; And
The confidence measure that repeats to make said processor to extract pattern information, selects current constellation and adjust the subsequent data frame exceeds the step of predetermined threshold up to said confidence measure, wherein when said confidence measure exceeds said predetermined threshold, discerns said constellation.
87. like the described method of claim 86, it is characterized in that, select the constellation code to comprise and make said processor to the crosscorrelation of each execution in said a plurality of potential constellation sign indicating numbers with corresponding sign indicating number bit.
88., it is characterized in that the said constellation of identification in the not equalized signal, said Frame of said not equalized signaling bearer and subsequent data frame like the described method of claim 86.
89. like the described method of claim 88, it is characterized in that, in the said signal reinsertion of carrier, discern said constellation at said processor.
90. like the described method of claim 88, it is characterized in that, comprise that also execution makes said processor use constant modulo n arithmetic (CMA) thereby error signal allows the instruction of the equilibrium of said signal with the tap of convergence equalization filter.
91. like the described method of claim 88, it is characterized in that, use through the said error signal of the CMA of convergent-divergent calculation of parameter to improve equalization performance.
92., it is characterized in that the equilibrium of carrying out said signal comprises the distribution map of analysis through the power of equalizing signal, wherein analyzes said distribution map and comprises the probability of use mass function like the described method of claim 88.
93., it is characterized in that the equilibrium of carrying out said signal comprises execution command like the described method of claim 88, said instruction makes processor:
Calculate the power that is associated with said a plurality of code elements in equalizing signal; And
Through using threshold power level to discern the corner code element of said constellation, wherein said threshold power level is indicated the identity of said constellation.
94. system that is used for transmission video signal; Comprise the camera side modulator-demodulator; Said camera side modem configuration becomes from video camera to receive two signals; The image sequence that each characterization is caught by said video camera; Said camera side modulator-demodulator further be configured to a signal in said two signals as composite baseband video signal transmission and with another signal as with nonoverlapping passband vision signal modulation of said baseband signal and transmission, wherein said camera side modulator-demodulator comprises:
Blender, said blender makes up said base band and passband vision signal so that transmission signals to be provided;
Duplexer, said duplexer are configured on transmission line to send said transmission signals and extract the passband signal that receives from said transmission line; And
Detector, the said camera side modulator-demodulator of said detector monitors is also worked as to produce when the passband signal that is received is identified and is launched signal, wherein
Said at least one transmission of launching in said baseband video signal of signal controlling and the said passband vision signal.
95., it is characterized in that said passband vision signal only saidly just is transmitted when launching signal when producing like the described system of claim 94.
96., it is characterized in that the passband signal that is received is by quadrature amplitude modulation like the described system of claim 94.
97. like the described system of claim 96, it is characterized in that, the estimation of the mean square error in the said detector monitors quadrature amplitude demodulation device, and signal is launched in generation when said estimation exceeds threshold value.
98., it is characterized in that said detector monitors constellation detector and produce the said signal of launching like the described system of claim 96 based on the reliability measurement that provides by said constellation detector.
99., it is characterized in that said reliability measurement is based on frame synchronization sequence like the described system of claim 96.
100. like the described system of claim 94, it is characterized in that, the estimation of the mean square error in the said detector monitors equalizer, and signal is launched in generation when said estimation exceeds threshold value.
101. like the described system of claim 94, it is characterized in that, the gain factor in the automatic gain control module of the said camera side modulator-demodulator of said detector monitors, and when said gain factor has the value that is lower than threshold value, produce the said signal of launching.
102. like the described system of claim 94, it is characterized in that, the amplitude of the passband signal that said detector monitors received, and when said amplitude has the value that exceeds threshold value, produce the said signal of launching.
103., it is characterized in that the passband signal that is received comprises according to the Internet protocol coded data like the described system of claim 94.
104. a method that is used for controlling the signaling of safety system comprises:
Confirm the existence of the upper reaches QAM signal in the composite signal of transmission over coaxial cable at the upstream modem place;
When said upper reaches QAM signal is confirmed as when existing; Make said upstream modem in said transmission over coaxial cable composite baseband video signal and passband vision signal, wherein said composite baseband video signal and passband vision signal are the parallel signs of the image sequence of being caught by video camera; And
When confirming there is not said upper reaches QAM signal, make said upstream modem on said coaxial cable, send said composite baseband video signal and stop said passband transmission of video signals.
105. like the described method of claim 104, it is characterized in that, when the yield value in the automatic gaining controling signal exceeds threshold value, confirm to exist said upper reaches QAM signal.
106. like the described method of claim 104, it is characterized in that,, confirm to exist said upper reaches QAM signal when the amplitude measurement of said upper reaches QAM signal during less than threshold value.
107. like the described method of claim 104, it is characterized in that, when the valuation of the mean square error in the equalizer exceeds threshold value, confirm not exist said upper reaches QAM signal.
108. like the described method of claim 104, it is characterized in that, when in the QAM signal of the said upper reaches, recognizing the internet protocol datagram grouping, confirm not exist said upper reaches QAM signal.
109. an automatic reconfigurable system that is used for transmission video signal comprises:
Upstream modem; Said upstream modem is configured to receive two signals from video camera; The image sequence that each characterization is caught by said video camera, said upstream modem further be configured to a signal in said two signals as composite baseband video signal transmission and with another signal as with nonoverlapping passband vision signal modulation of said baseband signal and transmission; And
Downstream modulator-demodulator, said downstream modem configuration become from said upstream modem to receive said composite baseband video signal and said passband vision signal and further be configured to upper reaches passband signal is transferred to said upstream modem, wherein
When detecting the deterioration of said upper reaches passband signal, said upstream modem is ended the transmission of at least one signal in said two signals.
CN201080015700.8A 2009-01-30 2010-02-01 Mixed format medium transmission system and method Active CN102365832B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN201511015730.XA CN105704366B (en) 2009-01-30 2010-02-01 Mixed format medium transmission system and method

Applications Claiming Priority (13)

Application Number Priority Date Filing Date Title
US12/363,669 US8300114B2 (en) 2009-01-30 2009-01-30 Mixed format media transmission systems and methods
US12/363,669 2009-01-30
US18797709P 2009-06-17 2009-06-17
US18798009P 2009-06-17 2009-06-17
US18798609P 2009-06-17 2009-06-17
US18797009P 2009-06-17 2009-06-17
US18799609P 2009-06-17 2009-06-17
US61/187,996 2009-06-17
US61/187,977 2009-06-17
US61/187,970 2009-06-17
US61/187,986 2009-06-17
US61/187,980 2009-06-17
PCT/US2010/022772 WO2010088625A1 (en) 2009-01-30 2010-02-01 Mixed format media transmission systems and methods

Related Child Applications (1)

Application Number Title Priority Date Filing Date
CN201511015730.XA Division CN105704366B (en) 2009-01-30 2010-02-01 Mixed format medium transmission system and method

Publications (2)

Publication Number Publication Date
CN102365832A true CN102365832A (en) 2012-02-29
CN102365832B CN102365832B (en) 2016-01-20

Family

ID=42396071

Family Applications (2)

Application Number Title Priority Date Filing Date
CN201511015730.XA Active CN105704366B (en) 2009-01-30 2010-02-01 Mixed format medium transmission system and method
CN201080015700.8A Active CN102365832B (en) 2009-01-30 2010-02-01 Mixed format medium transmission system and method

Family Applications Before (1)

Application Number Title Priority Date Filing Date
CN201511015730.XA Active CN105704366B (en) 2009-01-30 2010-02-01 Mixed format medium transmission system and method

Country Status (4)

Country Link
KR (3) KR20160070170A (en)
CN (2) CN105704366B (en)
TW (2) TWI530190B (en)
WO (1) WO2010088625A1 (en)

Cited By (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102724459A (en) * 2012-05-16 2012-10-10 浙江大华技术股份有限公司 Analog video signal format determination system and method and related devices
CN103312961A (en) * 2012-03-06 2013-09-18 索尼公司 Imaging apparatus and image transmitting method
WO2016078381A1 (en) * 2014-11-19 2016-05-26 无锡中星微电子有限公司 Digital data sending and receiving method and apparatus based on composite video signal
CN103795971B (en) * 2012-10-30 2016-12-28 3R全球有限公司 Possess identifing source and automatically change DVR and the method for reseptance thereof of image received device
CN106464846A (en) * 2014-06-02 2017-02-22 派视尔株式会社 Camera, DVR, and image monitoring system comprising same
CN107580251A (en) * 2017-09-15 2018-01-12 孙凤兰 The adaptively selected system of information input mode
CN108270446A (en) * 2016-12-30 2018-07-10 上海诺基亚贝尔股份有限公司 Signal processing apparatus and method and the electronic equipment including described device
CN109218563A (en) * 2018-08-06 2019-01-15 杭州雄迈集成电路技术有限公司 A kind of non real-time simulation HD video of 1080P coaxially sends system
CN111866417A (en) * 2019-04-30 2020-10-30 亚德诺半导体国际无限责任公司 Video line inversion for reducing the effect of periodic interference signals on analog video transmission

Families Citing this family (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2012105188A (en) * 2010-11-12 2012-05-31 Sony Corp Image output device, image output method, image processing system, image processing method, program, and imaging apparatus
TWI450589B (en) * 2011-08-05 2014-08-21 Acer Inc Method and apparatus for high definition video wireless transmission
US9252842B2 (en) 2012-01-20 2016-02-02 Intersil Americas LLC Power over coaxial cable
CN103873820B (en) * 2012-12-17 2017-12-01 杭州海康威视数字技术股份有限公司 The method and system being controlled to video camera menu
KR101336636B1 (en) * 2013-10-08 2013-12-04 파인트론 주식회사 Network video recorder connected through analog coaxial cable with ip camera and method automatically assigning an ip address
TWI601421B (en) * 2016-07-01 2017-10-01 物聯智慧科技（深圳）有限公司 Cloud recording system, cloud recording server and cloud recording method
US10395165B2 (en) * 2016-12-01 2019-08-27 Via Alliance Semiconductor Co., Ltd Neural network unit with neural memory and array of neural processing units that collectively perform multi-word distance rotates of row of data received from neural memory
CN108536612B (en) * 2017-03-03 2021-12-21 西部数据技术公司 Determining control states for address mapping in non-volatile memory
WO2020164751A1 (en) * 2019-02-13 2020-08-20 Fraunhofer-Gesellschaft zur Förderung der angewandten Forschung e.V. Decoder and decoding method for lc3 concealment including full frame loss concealment and partial frame loss concealment
CN116488978B (en) * 2023-06-21 2023-08-18 江苏联康信息股份有限公司 Frame synchronization method suitable for BR Bluetooth in test environment

Family Cites Families (26)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5701581A (en) * 1993-12-28 1997-12-23 Hitachi Denshi Kabushiki Kaisha Method for bidirectionally transmitting digital video signal and digital video signal bidirectional transmission system
US5651010A (en) * 1995-03-16 1997-07-22 Bell Atlantic Network Services, Inc. Simultaneous overlapping broadcasting of digital programs
US5877821A (en) * 1997-01-30 1999-03-02 Motorola, Inc. Multimedia input and control apparatus and method for multimedia communications
US5986691A (en) * 1997-12-15 1999-11-16 Rockwell Semiconductor Systems, Inc. Cable modem optimized for high-speed data transmission from the home to the cable head
US6377314B1 (en) * 1998-07-31 2002-04-23 Rf Technology, Inc. Methods and apparatus for transmitting analog and digital information signals
US7003030B2 (en) * 1999-03-08 2006-02-21 Lenovo (Singapore) Pte. Ltd. Receivers, methods, and computer program products for an analog modem that receives data signals from a digital modem
US7089577B1 (en) * 2000-01-14 2006-08-08 Terayon Communication Systems, Inc. Process for supplying video-on-demand and other requested programs and services from a headend
US7000031B2 (en) * 2000-04-07 2006-02-14 Broadcom Corporation Method of providing synchronous transport of packets between asynchronous network nodes in a frame-based communications network
US7248841B2 (en) * 2000-06-13 2007-07-24 Agee Brian G Method and apparatus for optimization of wireless multipoint electromagnetic communication networks
JP2004501579A (en) * 2000-06-19 2004-01-15 オン　コマンド　コーポレーション Secure multimedia communication system
KR100774452B1 (en) * 2001-03-08 2007-11-08 엘지전자 주식회사 Digital broadcasting receiving apparatus for multiplex broadcasting
JP2004533161A (en) * 2001-05-03 2004-10-28 エイチアールエル　ラボラトリーズ，エルエルシー Method and apparatus for analog-to-digital conversion
CN1445995A (en) * 2002-03-18 2003-10-01 丁兆明 Voice, data, video frequency transmission system based on cable TV network
KR100519333B1 (en) * 2002-12-30 2005-10-07 엘지전자 주식회사 Apparatus for recovering carrier
CN1759606B (en) * 2003-03-11 2010-05-05 汤姆森许可贸易公司 Apparatus and method for distributing signals by down-converting to vacant channels
CN1479462A (en) * 2003-06-04 2004-03-03 威海克劳斯数码通迅有限公司 Full view remote network safety monitoring system
US20070229707A1 (en) * 2004-05-20 2007-10-04 Thomson Licensing Inc. Apparatus and Method for Canceling Distortion
CN100515036C (en) * 2004-10-10 2009-07-15 倚强科技股份有限公司 Intelligent image process closed circuit TV camera device and its operation method
US7525600B2 (en) * 2005-01-14 2009-04-28 Broadcom Corporation Single integrated high definition television (HDTV) chip for analog and digital reception
US20070103543A1 (en) * 2005-08-08 2007-05-10 Polar Industries, Inc. Network panoramic camera system
KR100745701B1 (en) * 2005-10-25 2007-08-02 주식회사 서화정보통신 A radio transceiver for measuring environments of wireless communication equipments
JP4899534B2 (en) * 2006-02-28 2012-03-21 ソニー株式会社 Surveillance camera
CN101030903A (en) * 2006-03-03 2007-09-05 南京艾迪恩斯数字技术有限公司 System for accessing, monitoring and exchanging network video
KR101299732B1 (en) * 2006-07-14 2013-09-16 삼성전자주식회사 Method and apparatus for wireless communication in high frequency bandwidth
TW200830828A (en) * 2006-11-07 2008-07-16 Sony Corp Communication system, transmitting device, receiving device, communication method, program and communication cable
KR101336636B1 (en) 2013-10-08 2013-12-04 파인트론 주식회사 Network video recorder connected through analog coaxial cable with ip camera and method automatically assigning an ip address

Cited By (13)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN103312961A (en) * 2012-03-06 2013-09-18 索尼公司 Imaging apparatus and image transmitting method
CN103312961B (en) * 2012-03-06 2017-10-17 索尼半导体解决方案公司 Camera device and image transfer method
CN102724459A (en) * 2012-05-16 2012-10-10 浙江大华技术股份有限公司 Analog video signal format determination system and method and related devices
CN103795971B (en) * 2012-10-30 2016-12-28 3R全球有限公司 Possess identifing source and automatically change DVR and the method for reseptance thereof of image received device
CN106464846A (en) * 2014-06-02 2017-02-22 派视尔株式会社 Camera, DVR, and image monitoring system comprising same
WO2016078381A1 (en) * 2014-11-19 2016-05-26 无锡中星微电子有限公司 Digital data sending and receiving method and apparatus based on composite video signal
CN108270446B (en) * 2016-12-30 2021-10-08 上海诺基亚贝尔股份有限公司 Signal processing device and method and electronic equipment comprising device
CN108270446A (en) * 2016-12-30 2018-07-10 上海诺基亚贝尔股份有限公司 Signal processing apparatus and method and the electronic equipment including described device
CN107580251A (en) * 2017-09-15 2018-01-12 孙凤兰 The adaptively selected system of information input mode
CN107580251B (en) * 2017-09-15 2018-09-21 南京陶特思软件科技有限公司 The adaptively selected system of information input mode
CN109218563A (en) * 2018-08-06 2019-01-15 杭州雄迈集成电路技术有限公司 A kind of non real-time simulation HD video of 1080P coaxially sends system
CN111866417A (en) * 2019-04-30 2020-10-30 亚德诺半导体国际无限责任公司 Video line inversion for reducing the effect of periodic interference signals on analog video transmission
CN111866417B (en) * 2019-04-30 2023-03-28 亚德诺半导体国际无限责任公司 Video line inversion to reduce the effect of periodic interference signals on analog video transmission

Also Published As

Publication number Publication date
KR20160070170A (en) 2016-06-17
TW201624997A (en) 2016-07-01
TWI580272B (en) 2017-04-21
CN102365832B (en) 2016-01-20
CN105704366A (en) 2016-06-22
WO2010088625A1 (en) 2010-08-05
TW201116058A (en) 2011-05-01
CN105704366B (en) 2019-01-08
KR101674524B1 (en) 2016-11-09
KR20150018904A (en) 2015-02-24
KR20110118150A (en) 2011-10-28
TWI530190B (en) 2016-04-11
KR101708386B1 (en) 2017-02-20

Similar Documents

Publication Publication Date Title
CN102365832B (en) Mixed format medium transmission system and method
US8576898B2 (en) SLOC spot monitoring
US11088890B1 (en) Video inspection systems and methods using self-synchronizing QAM
US10069667B1 (en) Systems and methods for data transfer using self-synchronizing quadrature amplitude modulation (QAM)
US9602784B2 (en) Mixed format media transmission systems and methods
US6356598B1 (en) Demodulator for an HDTV receiver
KR100497478B1 (en) Method for acquiring data transmitted on a transmission channel
US8576966B2 (en) Systems and methods for detecting tampering with video transmission systems
CN1677877A (en) Assembly structure of time-domain synchronous orthogonal frequency-division multiplex receiver
JPH10117330A (en) System for extracting and processing video data and program guide sent by different coded format
JP2003518834A (en) Truncation distance for NTSC interference rejection in ATSC-HDTV trellis decoder
CN105611228B (en) Numerical data method of sending and receiving and device based on composite video signal
KR100884402B1 (en) Digital Broadcasting system for inserting pilot tone of the diferencial number according to data priority of data
CN100449940C (en) Blind equalizing method of high resolution TV signal
KR101221660B1 (en) Digital multimedia receiver for processing single-carrier modulated signal, demodulating apparatus and multi-carrier modulated signal and receiving method thereof
MXPA97005810A (en) System to receive variable coding formats and number of transmis channels
CN1972392A (en) Digital multimedia receiver and its receiving method
CN1972393A (en) Digital multimedia receiver and its receiving method
KR20060070387A (en) Digital multimedia receiver for processing single-carrier modulated signal and multi-carrier modulated signal and receiving method thereof
CN1972394A (en) Digital multimedia receiver and its receiving method

Legal Events

Date Code Title Description
C06 Publication
PB01 Publication
C10 Entry into substantive examination
SE01 Entry into force of request for substantive examination
ASS Succession or assignment of patent right

Owner name: INTERSIL AMERICA CO., LTD.

Free format text: FORMER OWNER: TECHWELL LLC

Effective date: 20140103

C41 Transfer of patent application or patent right or utility model
TA01 Transfer of patent application right

Effective date of registration: 20140103

Address after: American California

Applicant after: Intersil Americas LLC

Address before: American California

Applicant before: Techwell LLC

C14 Grant of patent or utility model
GR01 Patent grant