CN1463148A - Orthogonal frequency-division multiplying transmitter and orthogonal frequency-division multiplying method of using same - Google Patents
Orthogonal frequency-division multiplying transmitter and orthogonal frequency-division multiplying method of using same Download PDFInfo
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- CN1463148A CN1463148A CN02147960A CN02147960A CN1463148A CN 1463148 A CN1463148 A CN 1463148A CN 02147960 A CN02147960 A CN 02147960A CN 02147960 A CN02147960 A CN 02147960A CN 1463148 A CN1463148 A CN 1463148A
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- 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
- H04L27/2626—Arrangements specific to the transmitter only
- H04L27/2627—Modulators
- H04L27/2634—Inverse fast Fourier transform [IFFT] or inverse discrete Fourier transform [IDFT] modulators in combination with other circuits for modulation
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04J—MULTIPLEX COMMUNICATION
- H04J11/00—Orthogonal multiplex systems, e.g. using WALSH codes
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- 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
- H04L27/2626—Arrangements specific to the transmitter only
- H04L27/2627—Modulators
- H04L27/264—Pulse-shaped multi-carrier, i.e. not using rectangular window
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04J—MULTIPLEX COMMUNICATION
- H04J11/00—Orthogonal multiplex systems, e.g. using WALSH codes
- H04J2011/0003—Combination with other multiplexing techniques
- H04J2011/0006—Combination with other multiplexing techniques with CDM/CDMA
Abstract
An OFDM transmitter capable of variably inserting pseudo noise PN sequence information for each OFDM symbol according to a service mode and an OFDM transmission method using the OFDM transmitter are provided. An OFDM transmitter includes: a forward error correction (FEC) code unit for encoding data to correct error of the reciever; an inverse discrete fourier transform (IDFT) unit for converting the encoding data of frequency domain into OFDM symbol of time domain; a guide interval (GI) inserting unit inserts a GI into an OFDM symbol outputing from the IDFT unit; a PN sequence distributing unit receives service pattern information and distributes numbers of PN sequence inserting with OFDM signal of GI according to the service pattern; a synchronous information insertion unit inserts PN sequence into each OFDM signal of GI distributing with numbers; a pulse shaping filter performs pulse shaping filtering OFDM signal of GI inserting with PN sequence; a RF upconversing unit for upconversing OFDM signal outputing from the shaping filter to form radio frequency signal.
Description
Technical field
The present invention relates to OFDM (OFDM) transmitter and launching technique thereof; more specifically, relate to and a kind ofly wherein inserted OFDM transmitter and the launching technique thereof that Domain Synchronous (TDS) emission is carried out at interval in protection in the OFDM data of (GI) by being inserted into as pseudo noise (PN) sequence of OFDM data synchronization information.
Background technology
Usually, high definition TV (HD TV) broadcast system can roughly be divided into image encoding unit and modulating unit.The digital data compression of about 1Gbps that the image encoding unit will be imported from the high-definition image source becomes the data of 15-18Mbps.The limited frequency band passage of modulating unit by 6-8MHz with the digital data transmission of tens Mbps to receiving terminal.Terrestrial broadcast system is used in numeral HD television broadcasting, and wherein terrestrial broadcast system is used the very high frequency(VHF)/hyperfrequency (VHF/UHF) that distributes as the television broadcasting purpose.
In Europe, can obtain that emission rate on each bandwidth improves and OFDM (OFDM) system of the digital modulation system of two kinds of effects having prevented to disturb is used as HD television terrestrial broadcasting system.
The OFDM technology is that a kind of symbol row with the input of the order in the predetermined block unit converts parallel symbol to, and this parallel symbol is multiplexed to the technology of different sub-carrier frequencies.This OFDM technology is used multicarrier, and significantly different with the prior art of using single carrier.Multicarrier has orthogonality between each carrier wave." orthogonality " is meant that the product of two carrier waves is the attribute of zero (0), and orthogonality is to use the necessary condition of multicarrier.The OFDM technology realizes by fast Fourier transform (FFT) and invert fast fourier transformation (IFFT), and by orthogonality between the subcarrier and the definition of IFFT, can easily realize.
Use the advantage of OFDM technology as follows:
Because TV ground emission system has following channel characteristic, promptly launch mass depends on reflected wave and the interference in same channels and adjacency channel that produces in the signal emission process, so the condition of emission system design is very complicated.But OFDM is very capable for multipath.In other words, owing to use a plurality of carrier waves, symbol can prolong launch time.Therefore, OFDM is to the relative insensitivity that become by the interference that signal caused of OFDM by multipath emission, so OFDM has the less distorted signals that is caused by long echo (echo) signal.In addition, OFDM is that ability is strong to existing signal, and is subjected to the influence from the less interference of same channels thus.
Because these characteristics can be set up single frequency network (SFN).If use SFN, then can effectively utilize limited frequency resource.
Simultaneously, ofdm signal is made of multicarrier, and each carrier wave has very narrow bandwidth.Therefore, because OFDM has different modulator approaches for each carrier wave, so
Classification(hierarchical) emission is possible.
Usually, use the OFDM transmitter of Domain Synchronous (TDS) that the ofdm signal that forms on frequency domain is carried out conversion, a service that distributes along the predetermined frequency band of time domain is provided.Before forming ofdm signal along time domain, the OFDM transmitter will be used to the protection that suppresses to disturb at interval (GI) be inserted between the symbol of signal, synchronizing information is inserted in before the GI, then with its emission.
Fig. 1 is according to the structure of the frame of the ofdm signal of TDS type during ofdm signal emission.
The frame of ofdm signal has GI and the PN sequence that is inserted in the OFDM symbol.The OFDM data are to be used for the information that the essence carried out at receiver is reproduced.Distribute GI to be used to be suppressed at interference between the symbol of the ofdm signal of being launched.The PN sequence is the synchronizing information of setting up for each ofdm signal when fluidisation (stream) ofdm signal.The PN sequence is used for estimated frequency skew and time migration, and is used for the ofdm signal passage of estimating OFDM receiver.
Simultaneously, each frame (F1 by the ofdm signal of traditional OFDM transmitter emission, F2 is to be launched together with each the corresponding GI (GI1, GI2, GI3) and the PN sequence (PN1, PN2, PN3) that are inserted in this OFDM symbol (OFDM1, OFDM2, OFDM3) F3).Therefore, this ofdm signal be only with the ofdm signal frame in the OFDM symbol in valid data launch together.Therefore, insert the PN sequence in the OFDM symbol of GI if inserted at each, parallel series ground emission PN sequence, then problem is to make the emissivity of substantial data descend because each frame all comprises the PN sequence.
If ofdm signal is launched with each PN sequence of wherein having inserted in the OFDM symbol of GI, then in the mobile reception environment and low signal-to-noise ratio (S/N) channel environment of difference, the emission of ofdm signal and reproduce and can carry out smoothly.But problem is that then PN sequence territory broadens, and the emission rate of substantial data is reduced if wherein inserted at each and to insert the PN sequence in the OFDM symbol of GI.
Summary of the invention
In order to overcome the problems referred to above, the invention provides a kind of OFDM transmitter and use the OFDM launching technique of this OFDM transmitter, wherein can according to the relevant desired emission rate and the transmission channel condition of service mode of emission ofdm signal, insertion quantity variable PN sequence in ofdm signal.
According to the present invention, its purpose can realize by the OFDM transmitter of carrying out Domain Synchronous (TDS), and it will be by what will protect interval (GI) and pseudo noise (PN) sequence to be inserted into to realize in the ofdm signal, and wherein, the OFDM transmitter comprises:
The FEC coding unit is used for coded data to proofread and correct the mistake that process of transmitting occurs in receiver;
The IDFT unit is used for coded data converting with frequency domain and becomes OFDM symbol in the time domain;
GI inserts the unit, and the GI that is used for suppressing the interference between the OFDM symbol is inserted into from the OFDM symbol that the IDFT unit is exported;
PN sequence allocation unit is used to receive service mode information, and according to the service mode that is received, distributes the quantity of the ofdm signal that has inserted GI therein of each PN sequence;
Synchronizing information is inserted the unit, is used for the PN sequence is inserted into the OFDM symbol that has wherein inserted GI of each quantity allotted;
Pulse shaping filter, the OFDM symbol that has been used for to the insertion of the ofdm signal that has wherein inserted GI with quantity allotted the PN sequence carries out pulse shaping filtering; And
The radio frequency up-conversion unit is used for the OFDM symbol from pulse shaping filter output is carried out up conversion, forms radiofrequency signal.
Service mode comprises digital television broadcasting pattern, mobile communication mode, mobile messaging service mode.Therefore, the best PN sequence allocation unit quantity of coming each PN sequence allocation has wherein been inserted the OFDM symbol of GI according to digital television broadcasting pattern, mobile communication mode, mobile messaging service mode.
Best, PN sequence allocation unit distributes the quantity of the OFDM symbol that has wherein inserted GI to each PN sequence, and this quantity can be selected in 1 to 6.Therefore, when service mode was the digital broadcasting pattern, PN sequence allocation unit distributed the quantity of the OFDM symbol that has wherein inserted GI to select in 1 to 6 to each PN sequence.In this service mode, the PN sequence insert the unit in the insertion of institute's quantity allotted insert a PN sequence in every group of OFDM symbol of GI.
In addition, when service mode was mobile communication mode, PN sequence allocation unit distributed the quantity of the OFDM symbol that has wherein inserted GI to select in 1 to 4 to each PN sequence.When service mode was the mobile messaging pattern, PN sequence allocation unit distributed the quantity of the OFDM symbol that has wherein inserted GI to select in 1 to 2 to each PN sequence.
Simultaneously according to the present invention, its objective is by the OFDM launching technique of using the OFDM transmitter to carry out the TDS emission of ofdm signal and realize that the method comprising the steps of:
The input data are carried out the FEC coding to proofread and correct the mistake that occurs in the process of transmitting in receiver;
Coded data IDFT in the frequency domain is transformed into OFDM symbol in the time domain;
The GI that suppresses the interference between the OFDM symbol is inserted in the OFDM symbol that the result exported of IDFT shift step;
The quantity of distributing the OFDM symbol that has wherein inserted GI of each PN sequence;
The PN sequence is inserted in the OFDM symbol that has wherein inserted GI of each quantity allotted;
To the insertion of the ofdm signal that has wherein inserted GI with quantity allotted the OFDM symbol of PN sequence carry out pulse shaping filtering; And
Passages through which vital energy circulates is washed into shape filtering OFDM symbol afterwards carries out up conversion, form radiofrequency signal.
Wherein, the step of insertion PN sequence also comprises step:
Receive service mode information corresponding with the OFDM symbol;
According to service mode, be the ofdm signal that has wherein inserted GI of each PN sequence allocation some;
The PN sequence is inserted in the ofdm signal that has wherein inserted GI of each group institute quantity allotted.
Service mode comprises digital television broadcasting pattern, mobile communication mode, mobile messaging service mode.Therefore, in allocation step, in the sequence of digital television broadcasting pattern, mobile communication mode and mobile messaging service mode, the quantity of the ofdm signal that has wherein inserted GI that each PN sequence is distributed is little.Best, in allocation step, to one in the quantity correspondence 1 to 6 of the OFDM symbol that has wherein inserted GI that each PN sequence is distributed.
According to the present invention, with regard to corresponding to the service mode of the ofdm signal that will be launched, desired emission rate and channel condition, constructed the optimum frame form of ofdm signal, and, in ofdm signal, insert the variable PN sequence of quantity the optimum frame form is provided by according to corresponding to the service mode of the ofdm signal that will be launched, desired emission rate and channel condition.
Description of drawings
By the description of with reference to the accompanying drawings the preferred embodiments of the present invention being carried out, above-mentioned purpose of the present invention and characteristics will become apparent, wherein:
Fig. 1 is the figure of the frame structure of the ofdm signal when being illustrated in emission based on the ofdm signal of TDS type;
Fig. 2 is the block diagram of expression according to the preferred embodiment of OFDM transmitter of the present invention;
Fig. 3 is the ofdm signal frame of unit output is inserted in expression from the synchronizing information of Fig. 2 figure;
Fig. 4 is to use the flow chart according to the preferred embodiment of the OFDM launching technique of OFDM transmitter of the present invention: and
Fig. 5 is the detail flowchart of the PN inserting step of presentation graphs 4.
Embodiment
Hereinafter, the preferred embodiments of the present invention are described with reference to the accompanying drawings in more detail.
Fig. 2 is the block diagram of expression according to the preferred embodiment of OFDM transmitter of the present invention.
The OFDM transmitter has error correction forward (FEC) coding unit 100, inverse discrete Fourier transformer inverse-discrete (IDFT) unit 200, protection, and (GI) inserts unit 300 at interval, synchronizing information is inserted unit 400, pulse-forming filter 600 and RF up-conversion unit 700.
The mistake that 100 pairs of inputs of FEC coding unit data are encoded and occurred in emission process to proofread and correct.IDFT unit 200 becomes OFDM symbol in the time domain with the coded data converting in the frequency domain.The GI that GI insertion unit 300 will suppress to disturb is inserted in and is carried out between the OFDM symbol of IDFT in IDFT unit 200.
Synchronizing information is inserted unit 400 the PN sequence is inserted in the ofdm signal with the GI that inserts in GI insertion unit 300.The PN sequence comprises passage and the synchronizing information that is used for estimating the ofdm signal that receives at the OFDM receiver.During the OFDM symbol that receives in being reproduced in the OFDM receiver, the PN sequence also can be used for the estimation and the equilibrium of timing synchronization and transmission channel.
The synchronizing information of present embodiment is inserted unit 400 according to the service mode of wherein having inserted the OFDM symbol of GI, has inserted therein in the OFDM symbol of GI and has inserted the PN sequence of distributing variable number.
PN sequence allocation unit 540 receives the information relevant with the service mode of the ofdm signal that will be sent out, and according to this service mode to each OFDM symbol that has wherein inserted GI with the PN sequence allocation some that is inserted into.The type of ofdm signal service mode comprises digital television broadcasting pattern, mobile communication mode, mobile messaging service mode etc.
Therefore, synchronizing information is inserted the allocation result that unit 400 provides according to PN sequence allocation unit 540, with the PN sequence ofdm signal that has wherein inserted GI of quantity that has been inserted in every set of dispense.
OFDM symbol of exporting from synchronizing information insertion unit 400 that does not insert the PN sequence comprising GI and the OFDM symbol that has inserted the PN sequence comprising GI are all exported with impulse wave.
600 pairs of pulse shaping filters carry out pulse shaping filtering with the corresponding impulse wave of OFDM symbol that inserts the OFDM symbol that does not insert the PN sequence comprising GI of unit 400 outputs from synchronizing information and inserted the PN sequence comprising GI.700 pairs of RF up-conversion unit are carried out the radio frequency up conversion at the OFDM symbol that pulse shaping filter 600 carries out pulse shaping filtering.OFDM symbol through the radio frequency up conversion in RF up-conversion unit 700 is sent from antenna 800, sends to the OFDM transmitter through sendaisle.
Therefore, for with corresponding, desired emission rate of the service mode of the ofdm signal that will be launched and channel condition, constituted the optimum frame form of ofdm signal, and by according to corresponding to the service mode of the ofdm signal that will be launched, desired emission rate and channel condition, the PN sequence of variable number is inserted into provides this optimum frame form in the ofdm signal.
Simultaneously, when service mode according to reception in PN sequence allocation unit 540, when each PN sequence allocation having been inserted the quantity of OFDM symbol of GI, the quantity of the PN sequence that PN sequence allocation unit 540 distributes in the sequence of digital television broadcasting pattern, mobile communication mode and mobile messaging service mode is little.Preferably, PN sequence allocation unit 540 is to each assignable PN sequence, and the quantity of the ofdm signal that has wherein inserted GI that is distributed is in 1 to 6.
According to present embodiment, when service mode was the digital television broadcasting pattern, with the PN sequence that is inserted into, the quantity of the ofdm signal that has wherein inserted GI that is distributed was preferably in 1 to 6 to each in PN sequence allocation unit 540.In addition, when service mode was mobile communication mode, with the PN sequence that is inserted into, the quantity of the ofdm signal that has wherein inserted GI that is distributed preferably became in 1 to 4 to each in PN sequence allocation unit 540.And when service mode was the mobile messaging service mode, with the PN sequence that is inserted into, the quantity of the ofdm signal that has wherein inserted GI that is distributed was preferably in 1 to 2 to each in PN sequence allocation unit 540.
Therefore, synchronizing information is inserted unit 400 and the PN sequence is inserted in its quantity is distributed in PN sequence allocation unit 540, wherein inserted in every group of ofdm signal of GI.
Have synchronizing information is inserted in the unit 400 ofdm signal that the OFDM symbol that has wherein inserted GI concerning quantity allotted inserts the PN sequence for each, 600 pairs of impulse waves corresponding with it of pulse-forming filter carry out pulse-shaping filter.700 pairs of RF up-conversion unit are carried out ofdm signal pulse-shaping filter, that insert the PN sequence for the OFDM symbol that has wherein inserted GI of each quantity allotted and are amplified in pulse-forming filter 600, so that launch by transmission channel.
Therefore, about corresponding to emission rate service mode, desired and channel condition, can construct best OFDM frame, and by service mode according to the ofdm signal that in PN sequence allocation unit 540, receives, for each with the PN sequence that is inserted into, the quantity of distributing the OFDM symbol that has wherein inserted GI, and by providing this best OFDM frame in the OFDM symbol that the PN sequence is inserted in every set of dispense quantity.
Fig. 3 is the figure of the OFDM frame of output in the synchronizing information insertion unit 400 that is illustrated among Fig. 2.The figure shows: according to the service mode that in PN sequence allocation unit 540, receives, PN sequence allocation unit 540 is the OFDM symbol that has wherein inserted GI of " n " to each with the PN sequence allocation quantity that is inserted into, and synchronizing information insert unit 400 with this PN sequence be inserted in the quantity of being distributed be the GI (GI1 of n, GI2, ..., the corresponding quantity of quantity n GIn) is (OFDM1, OFDM2 in the OFDM symbol of n, ..., OFDMn).If promptly service mode is the digital television broadcasting service mode, n can equal 1,2,3,4,5 or 6; If service mode is a mobile communication mode, n can equal 1,2,3 or 4; And if service mode is the mobile messaging service mode, n can equal 1 or 2.
Therefore, by the PN sequence being inserted in the OFDM symbol of institute's quantity allotted according to service mode, can be at the identical more relatively valid data of time emission.And, because this OFDM symbol is to launch together with the PN sequence of inserting in the OFDM symbol of every group of institute's quantity allotted, so the emission rate of the OFDM symbol that is launched has been accelerated.
Fig. 4 is that preferred according to the OFDM launching technique of OFDM transmitter of the present invention used in expression
The flow chart of embodiment.
At first, FEC coding unit 100 coded input datas are to proofread and correct the mistake (S100) that occurs during launching.Coded data in the 200 pairs of frequency domains in IDFT unit is carried out inverse discrete Fourier transformer inverse-discrete, it is transformed into the ofdm signal (S120) in the time domain.The protection interval (GI) that GI insertion unit 300 will be used to suppress to disturb is inserted between the OFDM symbol of having carried out IDFT (S140).
According to the present invention, synchronizing information is inserted unit 400 to each OFDM symbol that has wherein inserted GI that distributes changeably, inserts the PN sequence and produces corresponding impulse wave (S160).Pulse-forming filter pair carries out pulse-shaping filter (S180) with the ofdm signals that insert the corresponding impulse wave of GI of unit 400 outputs from synchronizing information and have an insertion PN sequence wherein, variable.700 pairs of RF up-conversion unit are carried out pulse-shaping filter in pulse-forming filter 600 ofdm signal carries out radio frequency up conversion (S200).
Therefore, for with corresponding, desired emission rate of the service mode of the ofdm signal that will be launched and channel condition, can constitute the optimum frame form of ofdm signal, and by basis and corresponding, desired emission rate of the service mode of the ofdm signal that will be launched and channel condition, the PN sequence that quantity is variable is inserted into the optimum frame form is provided in the ofdm signal.
Fig. 5 is the detail flowchart that is illustrated in the PN inserting step of Fig. 4.
The information (S162) that PN sequence allocation unit 540 receives about the service mode of ofdm signal.The type of ofdm signal service mode comprises digital television broadcasting pattern, mobile communication mode, mobile messaging service mode etc.
According to service mode, PN sequence allocation unit 540 with the PN sequence that is inserted into, distributes the quantity (S164) of the OFDM symbol that has wherein inserted GI to each.Therefore, according to the allocation result that PN sequence allocation unit 540 produces, synchronizing information is inserted the ofdm signal 400 pairs every group institute in unit quantity allotted, that wherein inserted GI and is inserted a PN sequence (S166).
Therefore, for with corresponding, desired emission rate of service mode and channel condition, can constitute the optimum frame form, and by service mode according to the ofdm signal that is received, to each with the PN sequence that is inserted into, the quantity of distributing the OFDM symbol that has wherein inserted GI, and in the OFDM symbol of every group of institute's quantity allotted, insert this PN sequence, the optimum frame form is provided.
Although described the preferred embodiments of the present invention in detail, it will be appreciated by those skilled in the art that the present invention should be not limited to described preferred embodiment.In the spirit and scope of the invention defined by the appended claims, can produce various changes and modification.
Claims (15)
1. OFDM transmitter of carrying out Domain Synchronous (TDS), it will protect interval (GI) and pseudo noise (PN) sequence to be inserted in the ofdm signal, and this OFDM transmitter comprises:
The FEC coding unit is used for coded data to proofread and correct the mistake that process of transmitting occurs in receiver;
The IDFT unit is used for coded data converting with frequency domain and becomes OFDM symbol in the time domain;
GI inserts the unit, and the GI that is used for suppressing the interference between the OFDM symbol is inserted into from the OFDM symbol that the IDFT unit is exported;
PN sequence allocation unit is used to receive service mode information, and according to the service mode that is received, distributes the quantity of the ofdm signal that has wherein inserted GI of each PN sequence;
Synchronizing information is inserted the unit, is used for the PN sequence is inserted into the OFDM symbol that has wherein inserted GI of each quantity allotted;
Pulse shaping filter, the OFDM symbol that has been used for to the insertion of the ofdm signal that has wherein inserted GI with quantity allotted the PN sequence carries out pulse shaping filtering; And
The radio frequency up-conversion unit is used for the OFDM symbol from pulse shaping filter output is carried out up conversion, forms radiofrequency signal.
2. OFDM transmitter as claimed in claim 1, wherein service mode comprises: at least a in digital television broadcasting pattern, mobile communication mode, the mobile messaging service mode etc.
3. OFDM transmitter as claimed in claim 2, wherein according to digital television broadcasting pattern, mobile communication mode and mobile messaging service mode, PN sequence allocation unit distributes the quantity of the OFDM symbol that has wherein inserted GI to each PN sequence.
4. OFDM transmitter as claimed in claim 3 wherein can be selected in 1 to 6 the quantity of the OFDM symbol that has wherein inserted GI of each PN sequence.
5. OFDM transmitter as claimed in claim 4, wherein in the digital television broadcasting service mode, the quantity of the OFDM symbol that has wherein inserted GI of each PN sequence can be selected in 1 to 6.
6. OFDM transmitter as claimed in claim 5, wherein when service mode was mobile communication mode, the quantity of the OFDM symbol that has wherein inserted GI of each PN sequence can be selected in 1 to 4.
7. OFDM transmitter as claimed in claim 6, wherein when service mode was the mobile messaging service mode, the quantity of the OFDM symbol that has wherein inserted GI of each PN sequence can be selected in 1 to 2.
8. the OFDM launching technique of the OFDM transmitter of a TDS emission of using to carry out ofdm signal, the method comprising the steps of:
The input data are carried out the FEC coding to proofread and correct the mistake that occurs in the process of transmitting in receiver;
Coded data IDFT in the frequency domain is transformed into OFDM symbol in the time domain;
The GI that suppresses the interference between the OFDM symbol is inserted in result's the OFDM symbol of output of IDFT shift step;
The quantity of distributing the OFDM symbol that has wherein inserted GI of each PN sequence;
The PN sequence is inserted in the OFDM symbol that has wherein inserted GI of each quantity allotted;
To the insertion of the ofdm signal that has wherein inserted GI with quantity allotted the OFDM symbol of PN sequence carry out pulse shaping filtering; And
Passages through which vital energy circulates is washed into shape filtering OFDM symbol afterwards carries out up conversion, form radiofrequency signal.
9. the OFDM launching technique of use OFDM transmitter as claimed in claim 8, wherein, the step of inserting the PN sequence also comprises step:
Receive service mode information corresponding with the OFDM symbol;
According to service mode, be the ofdm signal that has wherein inserted GI of each PN sequence allocation some;
The PN sequence is inserted in the ofdm signal that has wherein inserted GI of each group institute quantity allotted.
10. the OFDM launching technique of use as claimed in claim 8 OFDM transmitter, wherein service mode comprises at least a in digital television broadcasting pattern, mobile communication mode, the mobile messaging service mode.
11. the OFDM launching technique of use OFDM transmitter as claimed in claim 10, wherein in allocation step, according to digital television broadcasting pattern, mobile communication mode and mobile messaging service mode, each has wherein been inserted the PN sequence allocation quantity of the OFDM symbol of GI.
12. the OFDM launching technique of use OFDM transmitter as claimed in claim 11, wherein in allocation step, the quantity of the OFDM symbol that has wherein inserted GI of each PN sequence can be selected in 1 to 6.
13. the OFDM launching technique of use OFDM transmitter as claimed in claim 12, wherein in the digital television broadcasting service mode, the quantity of the OFDM symbol that has wherein inserted GI of each PN sequence can be selected in 1 to 6.
14. the OFDM launching technique of use OFDM transmitter as claimed in claim 12, wherein when service mode was mobile communication mode, the quantity of the OFDM symbol that has wherein inserted GI of each PN sequence can be selected in 1 to 4.
15. the OFDM launching technique of use OFDM transmitter as claimed in claim 12, wherein when service mode was the mobile messaging service mode, the quantity of the OFDM symbol that has wherein inserted GI of each PN sequence can be selected in 1 to 2.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| KR30393/2002 | 2002-05-30 | ||
| KR1020020030393A KR100859878B1 (en) | 2002-05-30 | 2002-05-30 | OFDM transmitter capable of inserting the PN in every the number the OFDM symbols variably according to service-mode of OFDM signal |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CNA2009100075420A Division CN101483631A (en) | 2002-05-30 | 2002-10-31 | OFDM transmitter and OFDM receiver |
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| CN1463148A true CN1463148A (en) | 2003-12-24 |
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| CNA2009100075420A Pending CN101483631A (en) | 2002-05-30 | 2002-10-31 | OFDM transmitter and OFDM receiver |
| CN02147960A Pending CN1463148A (en) | 2002-05-30 | 2002-10-31 | Orthogonal frequency-division multiplying transmitter and orthogonal frequency-division multiplying method of using same |
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| CNA2009100075420A Pending CN101483631A (en) | 2002-05-30 | 2002-10-31 | OFDM transmitter and OFDM receiver |
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| CN101411108B (en) * | 2005-12-13 | 2012-11-21 | 摩托罗拉移动公司 | Method and system for synchronizing a receiver in an OFDM system |
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| KR20010027280A (en) * | 1999-09-13 | 2001-04-06 | 정선종 | Parallel combinatory processing adaptive communication system and method for supporting multi-transmission rate |
| US7161924B2 (en) * | 2000-10-19 | 2007-01-09 | Samsung Electronics Co., Ltd. | Device and method for transmitting multimedia data in mobile communication system |
| KR20020035310A (en) * | 2000-11-06 | 2002-05-11 | 윤종용 | Apparatus and method for fast controlling of forward link power using variable rate supplemental channel in mobile communication system |
-
2002
- 2002-05-30 KR KR1020020030393A patent/KR100859878B1/en active IP Right Grant
- 2002-10-31 CN CNA2009100075420A patent/CN101483631A/en active Pending
- 2002-10-31 CN CN02147960A patent/CN1463148A/en active Pending
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN100376103C (en) * | 2004-12-03 | 2008-03-19 | 清华大学 | Time-varying channel evaluation and equalizing method and system for TDS-OFDM receiver |
| CN101411108B (en) * | 2005-12-13 | 2012-11-21 | 摩托罗拉移动公司 | Method and system for synchronizing a receiver in an OFDM system |
Also Published As
| Publication number | Publication date |
|---|---|
| KR20030092658A (en) | 2003-12-06 |
| CN101483631A (en) | 2009-07-15 |
| KR100859878B1 (en) | 2008-09-24 |
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