CN1968249A - Tds-ofdm transmission system and method for processing signal thereof - Google Patents
Tds-ofdm transmission system and method for processing signal thereof Download PDFInfo
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- CN1968249A CN1968249A CNA2006101633295A CN200610163329A CN1968249A CN 1968249 A CN1968249 A CN 1968249A CN A2006101633295 A CNA2006101633295 A CN A2006101633295A CN 200610163329 A CN200610163329 A CN 200610163329A CN 1968249 A CN1968249 A CN 1968249A
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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
- H04L27/2628—Inverse Fourier transform modulators, e.g. inverse fast Fourier transform [IFFT] or inverse discrete Fourier transform [IDFT] modulators
- H04L27/263—Inverse Fourier transform modulators, e.g. inverse fast Fourier transform [IFFT] or inverse discrete Fourier transform [IDFT] modulators modification of IFFT/IDFT modulator for performance improvement
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L1/00—Arrangements for detecting or preventing errors in the information received
- H04L1/004—Arrangements for detecting or preventing errors in the information received by using forward error control
- H04L1/0041—Arrangements at the transmitter end
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- 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
- H04L25/03012—Arrangements for removing intersymbol interference operating in the time domain
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- Detection And Prevention Of Errors In Transmission (AREA)
Abstract
Provided is a multiple-carrier system and a method thereof. The multiple-carrier emitting system comprises an FEC (Forward Error Correction) unit used for coding data of a frequency region OFDM signal to sense and correct an error of a receiving side; a serial/parallel conversion unit used for collecting the preconcerted amount of frequency region data coded and outputting the coded data of the frequency region as parallel data; a 4k modulator used for generating 4096 parallel data by interpolating 3780 parallel data from the serial/parallel conversion unit, for modulating 4096 data of the frequency region to 4096 sample data according a sample rate of a time region, and performing a data extraction from the 4096 frequency region data; a protective block insertion unit used for inserting protective blocks into the OFDM signals of the time region; and a synchronous information insertion unit used for inserting the synchronous information into the OFDM signals of the time region. The multiple-carrier system is capable of reducing the complexity of the hardware, improving the computation ability and being compatible with 3780 model and 4k model by using a 4K-point IFFT processor into a conventional emitting system which supports a 3780-point-IDFT processor.
Description
The application be that March 17, application number in 2003 are 03107208.9 the applying date, denomination of invention divides an application for the application for a patent for invention of " tds-ofdm transmission system and signal processing method thereof ".
Technical field
The present invention relates to a kind of tds-ofdm transmission system, more particularly, relate to the tds-ofdm transmission system of a kind of compatible 3780 patterns and 4K pattern.
Background technology
OFDM (OFDM) is a kind of multi-carrier modulation method, and this method has good performance under multipath and mobile condition.
The OFDM method adopts a plurality of carrier waves with mutually orthogonal characteristic to improve the utilization rate of frequency.As use the multicarrier approach in wired or wireless channel, the OFDM method is applicable to high data rate launches.On the radio communication channel with multipath fading, when using single carrier wave approach to launch to have at interval high data rate of short code unit, along with the interference of intersymbol degenerates, the complexity of receiving terminal significantly improves.On the other hand, the simple equalizer that has a tap (tap) by use because can extending to the symbol interval of each subcarrier the number of subcarrier, the multicarrier approach keeps data transmission rate simultaneously, so just can easily solve because multipath channel that cause, that have the serious frequency decline.
In the OFDM method, adopt a plurality of carrier waves with mutually orthogonal property, can come these a plurality of carrier waves of modulating/demodulating by using IFFT/FFT (invert fast fourier transformation/fast fourier transform) with two-forty at emission/receiving terminal, this IFFT/FFT has identical result with execution IDFT/DFT (inverse discrete Fourier transformer inverse-discrete/discrete Fourier transform (DFT)).
Fig. 1 illustrates TDS-OFDM (schematic block diagram of (Domain Synchronous-OFDM) emission system, this system is a kind of ofdm system.
The TDS-OFDM emission system comprises FEC (forward error correction) unit 10, be used for data are encoded so that receiving terminal is detected and correct a mistake, map unit 20 is used for by using the encoded data of mapping such as QPSK (quaternary PSK), 16QAM (quadrature amplitude modulation), 64QAM; 3780 IDFT unit 30 are used for the frequency-domain OFDM modulation is become time domain OFDM signal; Protection is inserted unit 40 at interval, and the GI (protection at interval) that is used for the tail (tail) by the ofdm signal after the modulation is constituted inserts before the ofdm signal, so that prevent the ISI (intersymbol interference) under multi-path environment; Synchronizing information is inserted unit 50, is used for synchronizing signal is inserted time domain, and this is the feature of TDS-OFDM method; Shaping filter 60 is used for carrying out shaping filter for shaping pulse for the synchronizing information of inserting, and RF (radio frequency) unit 70, is used for launching ofdm signal on the frequency range of expectation.
Fig. 2 illustrates the figure that carries out the IDFT processing procedure for 3780 frequency domain parallel datas of 3780 IDFT unit 30 of input, and sample frequency is 3780 * 2.0KHz (carrier spacing)=7.56MHz.That is, can be with 3780 sub-carrier allocation on the frequency domain to handle each subcarrier that transforms to time domain through IDFT.
As mentioned above, 3780 IDFT unit 30 are used for ofdm signal from the frequency domain modulation to the time domain.
Table 1 is illustrated in the comparison between 3780 IDFT processors and the 4K point IFFT processor, with reference to Zhi-Xing Yang, Yu-Peng Hu, Chang-Yong Pan and Lin Yang, " Design of a3780-point IFFT Processor for TDS-OFDM ", IEEE TRANSACTION ONBROADCASTING, Vol.48, No.1, March 2002, the 57-61 page or leaf.
| 3780 IDFT | 4096 IDFT | |
| Real add | 140184 | 123792 |
| Real multiply | 50712 | 48248 |
| The stand-by period of buffer generating | 8064 | 4095 sampling clocks |
| Buffer requirements | 14612 | 106470 |
From Yuan 1 as can be seen, when using 3780 processors, the complexity of hardware and amount of calculation increase when using 4K (4096)-IFFT, cause that thus efficient reduces.
Summary of the invention
Therefore, an object of the present invention is: by simple 4K point IFFT processor being used for OFDM emission system traditional, that support 3780 IDFT processors, with provide have can reduce hardware complexity, improve computing capability and also with 3780 patterns and the compatible mutually tds-ofdm transmission system of 4K pattern, solve the problems referred to above.
According to an aspect of the present invention, tds-ofdm transmission system comprises: the FEC unit is used for carrying out coding for frequency domain ofdm signal, so that receiving terminal is detected and error correction; Serial is used to accumulate the encoded frequency domain data of predetermined number, with the output parallel data; The 4K modulator, be used for 3780 parallel datas from serial are carried out interpolation, form 4096 parallel datas, 4096 frequency domain parallel datas are modulated to 4096 time-domain sampling data, and extract from these 4096 sampled datas, so that output has the time domain OFDM signal of the sampled data of predetermined number; Protection is at interval inserted the unit, is used for protection interval is inserted before the time domain OFDM signal; Insert the unit with synchronizing information, be used for synchronizing signal is inserted before this time domain OFDM signal, so that, be inserted with protection in this time domain OFDM signal at interval in receiving terminal channel equalization and synchronization acquistion.
According to this tds-ofdm transmission system, this tentation data number is 3780, and this interpolating unit is carried out linear interpolation and zeroth order interpolation.
According to another aspect of the present invention, the signal processing method of this tds-ofdm transmission system comprises step: carry out coding for frequency domain ofdm signal, so that receiving terminal is detected and error correction; The encoded frequency domain data of accumulation predetermined number is with the output parallel data; The predetermined number destination data is carried out interpolation, export 4096 data; Insert the predetermined number destination data, so that export 4096 data; Carry out IFFT and handle, so that 4096 frequency domain datas are modulated to 4096 time-domain sampling data; These 4096 sampled datas are carried out extraction, so that output has the time domain OFDM signal of a predetermined number sampled data.To protect at interval and insert before the time domain OFDM signal; With synchronizing signal is inserted before this time domain OFDM signal so that, be inserted with protection in this time domain OFDM signal at interval in receiving terminal channel equalization and synchronization acquistion.Best, these 3600 IDFT unit are made of two 60 IDFT modules or 60 IDFT modules.
According to this signal processing method, this tentation data number is 3780, and this interpolation procedure is carried out linear interpolation and zeroth order interpolation.
As mentioned above, because this multicarrier system is used for OFDM emission system traditional, that support 3780 IDFT processors with simple 4K point IFFT processor, so this system can reduce hardware complexity, improve computing capability, and also compatible mutually with 3780 patterns and 4K pattern.
Description of drawings
Describe the present invention with reference to the accompanying drawings in detail, identical in the accompanying drawings label is represented components identical:
Fig. 1 is the schematic block diagram that traditional TDS-OFDM emission system is shown;
Fig. 2 illustrates 3780 IDFT processors among Fig. 1 are carried out signal processing to ofdm signal figure;
Fig. 3 is the schematic block diagram that the TDS-OFDM emission system is shown, and this TDS-OFDM emission system has the 4K modulating unit according to the embodiment of the invention;
Fig. 4 is the detailed block diagram that 4K modulator unit as shown in Figure 3 is shown;
Fig. 5 a illustrates the figure of the processing that is used to explain interpolating unit as shown in Figure 3 to 5c;
Fig. 6 illustrates the figure that 4780 IFFT processors being used for key-drawing 4 are handled ofdm signal;
Fig. 7 explanation is according to the flow chart of the signal processing method of the TDS-OFDM emission system with 4K modulating unit of the present invention.
Embodiment
Followingly will explain the present invention with reference to accompanying drawing.
Fig. 3 shows to have the TDS-OFDM emission system of the 4K modulating unit according to the present invention.
This TDS-OFDM emission system comprises FEC (forward error correction) unit 100 and OFDM modulator 200.OFDM modulator 200 comprises map unit 210, serial 220,4K modulator 230, parallel/serial converting unit 250, synchronizing information insertion unit 260, shaping filter 270 and RF (radio frequency) unit 280.
Coding is carried out so that receiving terminal is detected and error correction in FEC (forward error correction) unit 100.
As shown in Figure 4,4K modulator 230 comprises interpolating unit 231,4K point IFFT processor 233 and extracting unit 235.
Interpolating unit 231 is used the predetermined number destination data, inserts 3780 parallel datas from serial 220, forms 4096 parallel datas corresponding to 4096.The interpolation of interpolating unit 231 can realize by using different interpolation algorithms, for example: zeroth order interpolation (Nearest NeighborInterpolation), be attended by the linear interpolation of zeroth order interpolation, perhaps the interpolation that adopts part to hold filtering wave by prolonging time device (fractional delay filter).
Fig. 5 a is that the figure that is used to explain the linear interpolation method that is attended by the zeroth order interpolation is shown to 5c.
Arrange 3780 parallel datas as shown in Figure 5, and carry out 2m linear interpolation (m equal 1,2,3 etc.), here for these 3780 parallel datas.One after the other, as shown in Figure 5, the most adjacent data are carried out the zeroth order interpolation, to form 4096 parallel datas.
4096 IFFT processors 233 are modulated to 4096 sampled datas of time domain with 4096 frequency domain parallel datas, and these 4096 frequency domain parallel datas are generated by carrying out predetermined interpolation algorithm by interpolating unit 231.That is, will be modulated to time domain OFDM signal through 4096 parallel datas of interpolation gained, this time domain OFDM signal has 4096 sampled datas and 8.192MHz (4096X2KHz) sampling rate.
Extracting unit 235 is carried out for the ofdm signal after modulating according to the 4K pattern and is extracted, so that obtain sampled data and sampling rate about 3780 patterns.
In detail, extracting unit 235 will be reduced to 3780 sampled datas by 4096 handled 4096 sampled datas of IFFT processor, and also the sampling rate with 8.192MHz is reduced to 7.56MHz, reduce the number and the sampling rate of sampled data thus, so that obtain the identical value with 3780 traditional IDFT processor processing gained.
Protection is inserted unit 240 at interval GI is inserted the OFDM code element before to prevent the ISI under the multipath conditions again, and this GI copy is since the sampled data that afterbody intercepted of this OFDM code element.The length of GI can be 1/6,1/9,1/12,1/20 or 1/30 of 3780 sampled datas.
Parallel/serial converting unit 250 is converted to serial data with parallel data.
Synchronizing information is inserted unit 260 with before the PN sequence insertion GI, obtains the information of time synchronized and channel equalization in order to make receiving terminal.
Hereinafter with reference to the signal processing method of Fig. 7 explanation according to TDS-OFDM emission system of the present invention.
Coding is carried out so that receiving terminal is detected and error correction (S10) in FEC unit 100.
Interpolating unit 231 is used predetermined method, carries out interpolation for 3780 parallel datas from serial 220, to export 4096 parallel datas (S30).
233 pairs of 4096 parallel datas through the interpolation gained of 4096 IFFT processors are carried out IFFT and are handled.The time domain OFDM signal of gained has 4096 sampled datas and 8.192MHz sampling rate (S40) as a result.
Extracting unit 235 is carried out and is extracted, so that the sample frequency of 4096 sampled datas and 8.192MHz is reduced to 3780 sampled datas and 7.56MHz sampling rate (S50).
Protection is inserted unit 240 at interval with before 3780 sampled datas of GI insertion (S60).Synchronizing information is inserted unit 260 with before PN sequence or the synchronizing information insertion GI (S70).
As mentioned above, according to the present invention, by 4K point IFFT processor being used to support the OFDM emission system of 3780 IDFT processors, this will make hardware realize simplifying and receptivity is improved.In addition, can be compatible mutually according to OFDM emission system of the present invention with the OFDM emission system of supporting 4K point IFFT processor.
The OFDM emission system is by use 4K point IFFT processor, but not 3780 IDFT processors are treated to an ofdm signal with 3780 frequency domain parallel datas, so that carry out IFFT, this causes hardware to realize simplifying and receptivity is improved.
In addition, design system to traditional OFDM emission system mutually compatibility be possible, this traditional OFDM emission system is supported 4K point IFFT processor.
Although be illustrated for the present invention with reference to its some preferred embodiment, but those skilled in the art is to be understood that, under the situation that does not break away from the spirit and scope of the present invention that are defined by the following claims, can carry out in form and the various modifications on the details.
The foregoing description and advantage only are exemplary, and do not limit the present invention.Inventive concept can be used for the device of other types.Specification of the present invention is illustrative, and the scope of unrestricted claim.For those skilled in the art, many selections, improvement and variation are obvious.In the claims, device adds the function statement and is used to comprise structure described herein, that finish described function, and not only comprises the device of equivalence on the structure, and comprises the device that is equivalent to this structure.
Claims (4)
1, a kind of tds-ofdm transmission system comprises:
The FEC unit is used for carrying out coding for frequency domain ofdm signal, so that receiving terminal is detected and error correction;
Serial is used to accumulate the encoded frequency domain data of predetermined number, with the output parallel data;
The 4K modulator, be used for 3780 parallel datas from serial are carried out interpolation, form 4096 parallel datas, 4096 frequency domain parallel datas are modulated to 4096 time-domain sampling data, and extract from these 4096 sampled datas, so that output has the time domain OFDM signal of the sampled data of predetermined number;
Protection is at interval inserted the unit, is used for protection interval is inserted before the time domain OFDM signal; With
Synchronizing information is inserted the unit, is used for synchronizing signal is inserted before this time domain OFDM signal, so that in receiving terminal channel equalization and synchronization acquistion, be inserted with protection in this time domain OFDM signal at interval.
2, tds-ofdm transmission system as claimed in claim 1, wherein the 4K modulator comprises:
Interpolating unit is used to insert the predetermined number destination data, so that export 4096 data;
4096 IFFT unit are used for 4096 frequency domain parallel datas are modulated to 4096 sampled datas of time domain;
Extracting unit is used for the sampled data of this predetermined number is carried out extraction, so that the output time domain OFDM signal.
3, as claim 1 or 2 described tds-ofdm transmission systems, wherein the sampled data number of this predetermined number is 3780.
4, as claim 1 or 2 described tds-ofdm transmission systems, wherein this interpolating unit is carried out linear interpolation and zeroth order interpolation.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| KR10200261899 | 2002-10-10 | ||
| KR1020020061899A KR20040032676A (en) | 2002-10-10 | 2002-10-10 | TDS-OFDM transmission system and a method proessing OFDM signal thereof |
Related Parent Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CNB031072089A Division CN1298124C (en) | 2002-10-10 | 2003-03-17 | Multiple-carrier emitting system and signal processing method |
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| CN1968249A true CN1968249A (en) | 2007-05-23 |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CNB031072089A Expired - Fee Related CN1298124C (en) | 2002-10-10 | 2003-03-17 | Multiple-carrier emitting system and signal processing method |
| CNA2006101633295A Pending CN1968249A (en) | 2002-10-10 | 2003-03-17 | Tds-ofdm transmission system and method for processing signal thereof |
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| Application Number | Title | Priority Date | Filing Date |
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| CNB031072089A Expired - Fee Related CN1298124C (en) | 2002-10-10 | 2003-03-17 | Multiple-carrier emitting system and signal processing method |
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| KR (1) | KR20040032676A (en) |
| CN (2) | CN1298124C (en) |
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| Publication number | Priority date | Publication date | Assignee | Title |
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| KR101174131B1 (en) | 2004-10-14 | 2012-08-14 | 삼성전자주식회사 | Error detection method and apparatus in a DMB receiver |
| KR100744056B1 (en) * | 2006-08-17 | 2007-07-30 | 삼성전자주식회사 | Apparatus and method for transmitting and receiving digital broadcasting signal |
| CN108234374B (en) * | 2016-12-14 | 2020-09-25 | 联芯科技有限公司 | Uplink multi-carrier transmitting device, system and method |
| CN108462664A (en) * | 2017-02-22 | 2018-08-28 | 联芯科技有限公司 | The launching technique and device of multi-carrier data |
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| Publication number | Priority date | Publication date | Assignee | Title |
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| KR100243649B1 (en) * | 1997-12-23 | 2000-02-01 | 정선종 | Wideband mobile multimedia transmitter and receiver |
| CN1332556A (en) * | 2001-04-27 | 2002-01-23 | 清华大学 | Channel transmission method for ground digital multimeldia television broadcast system |
| KR100449225B1 (en) * | 2002-01-19 | 2004-09-22 | 학교법인 성균관대학 | Transmission Diversity Apparatus In Radio Communication System |
| KR100530771B1 (en) * | 2002-10-07 | 2005-11-23 | 한국전자통신연구원 | Transmitting System and Method of Base Station in Orthogonal Frequency Division Multiplexer-Code Division Multiplexing Access |
| KR100532586B1 (en) * | 2002-10-30 | 2005-12-02 | 한국전자통신연구원 | Appratus and Method for transmitting and receiving using orthogonal code and non binary value in CDMA/OFDM |
-
2002
- 2002-10-10 KR KR1020020061899A patent/KR20040032676A/en not_active Application Discontinuation
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2003
- 2003-03-17 CN CNB031072089A patent/CN1298124C/en not_active Expired - Fee Related
- 2003-03-17 CN CNA2006101633295A patent/CN1968249A/en active Pending
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| Publication number | Publication date |
|---|---|
| CN1489310A (en) | 2004-04-14 |
| CN1298124C (en) | 2007-01-31 |
| KR20040032676A (en) | 2004-04-17 |
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