CN101304398A - Method for reducing PAR of OFDM system - Google Patents
Method for reducing PAR of OFDM system Download PDFInfo
- Publication number
- CN101304398A CN101304398A CNA2008100698696A CN200810069869A CN101304398A CN 101304398 A CN101304398 A CN 101304398A CN A2008100698696 A CNA2008100698696 A CN A2008100698696A CN 200810069869 A CN200810069869 A CN 200810069869A CN 101304398 A CN101304398 A CN 101304398A
- Authority
- CN
- China
- Prior art keywords
- peak
- scrambler
- ofdm system
- force ratio
- average force
- 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.)
- Pending
Links
Images
Landscapes
- Digital Transmission Methods That Use Modulated Carrier Waves (AREA)
Abstract
The invention provides a method for reducing the peak-to-average ratio in an orthogonal frequency division multiplexing system and includes the following steps: the input data of the orthogonal frequency division multiplexing system is converted into parallel data by a series-parallel conversion; scrambling codes are inserted, and the signal sequences with the lengths of K of the orthogonal frequency division multiplexing system are evenly divided into M blocks and the K/M is ensured to be an integer and a scrambling code is inserted into the end of each block and the total bit M of the scrambling codes are inserted; then the inverse fourier transform and series-parallel conversion are carried out rapidly; the peak-to-average ratios of signal sequences, which meet the setting requirements are calculated and output; if not meeting the requirements, scrambling codes are carried out. The method adopts a scrambling code insertion technology and can be simply realized at both sending terminal and the receiving terminal of the system without transmitting any auxiliary information. Compared with the scheme of the existing sequence insertion, the method can better reduce the peak-to-average ratio of the OFDM system on the premise of not increasing the complexity of the system.
Description
Technical field
The present invention relates to reduce in a kind of orthogonal frequency division multiplex OFDM system the method for peak-to-average force ratio, in particular a kind of method of the ofdm signal sequence being carried out inserting after sub-piece is cut apart scrambler.Belong to the broadband wireless communication technique field, can be applicable in the next generation mobile communication system.
Background technology
The OFDM technology can be resisted multipath fading and frequency selective fading effectively, realizes high-speed data transmission, and availability of frequency spectrum height has become the key technology of the 4th third-generation mobile communication.The OFDM technology is a kind of of multi-carrier transmission scheme, because it uses a plurality of subcarriers to carry out transfer of data, when the phase place of a plurality of subcarriers is consistent or approximate, ofdm signal will produce very high peak value, cause peak-to-average force ratio very high.In current communication system, devices such as high power amplifier are not desirable linear unit, the peak value of ofdm signal often exceeds the range of linearity of device, when signal when having the device of nonlinear characteristic, intermodulation effect will be produced, except disturbing self channel signals, also frequency spectrum diffusion can be produced, cause monkey chatter, cause systematic function to be had a strong impact on.
At present, the method that reduces the ofdm system peak-to-average force ratio mainly contains three classes, is respectively amplitude limit class methods, coding class methods and method for optimizing.Amplitude limit method be a kind of very directly and effectively reduce the peak-to-average force ratio technology.This method is very simple, but can cause serious in-band noise and out-of-band noise, and in-band noise can not be eliminated by filtering, can cause the error performance of whole system to reduce, and out-of-band noise can reduce spectrum efficiency.Filtering can reduce out-of-band radiation behind the amplitude limit, but this will cause peak value regeneration.Coding method is a kind of technology of undistorted reduction ofdm system peak-to-average force ratio, and its basic thought is: at transmitting terminal, data stream is carried out before the OFDM modulation, by different coding strategies, to avoid using those may produce the code word of higher peak-to-average force ratio; At receiving terminal, carry out corresponding inverse operation after the OFDM demodulation again, recover the code word that sends.The shortcoming of coding method is, when the sub-carrier number of ofdm system was very big, code efficiency sharply descended and reduces the peak-to-average force ratio effect and becomes not obvious.The preferred class method is to represent the ofdm signal sequence of identical information by producing the N bar someway, selects a bars sequence of peak-to-average force ratio minimum to send in this N bar sequence, can arrive the effect that reduces peak-to-average force ratio.The general more complicated of the realization of preferred class method, and need to transmit certain supplementary, so that receiving end is recovered original signal.When the supplementary that sends is made mistakes, can make receiving end when recovering original signal, produce error code, influence systematic function.
Chinese patent CN1913511A discloses a kind of " multicarrier modulation system reduces the method for peak-to-average force ratio ", this invention is transmission multichannel supplementary on vacant subcarrier, every road supplementary and valid data linear combination, calculate the peak-to-average force ratio after each road IFFT exports, by multichannel relatively, select optimum peak-to-average force ratio, vacant subcarrier data is weighted.This invention need not to increase extra redundant transmission phase factor information, has increased the reliability of system, but has lost systematic function.
Chinese patent CN1917490A discloses a kind of " reducing the method for the peak-to-average force ratio of orthogonal frequency-division multiplex singal ", this invention a plurality of weighting sequences of sequential storage according to the rules, data vector in the orthogonal frequency-division multiplex singal is divided into a plurality of subvectors, in a plurality of weighting sequences, select a weighting sequence, make peak value minimum by the signal that linear combination constituted of this weighting sequence and described a plurality of subvectors, according to the position of weighting sequence in a plurality of weighting sequences of in accordance with regulations sequential storage, the pilot tone in the orthogonal frequency-division multiplex singal is shifted.This invention needs extra memory a plurality of weighting sequences that prestore, and the processing procedure workload of transmitting-receiving two-end is bigger.
Researchers such as Heung-Gyoon Ryu have proposed the method that sequence is inserted, this method is more more effective than coding method, methods such as mapping and partial sequence transmission are more simple than selecting, and do not need to transmit any supplementary, can not influence the error performance of system because supplementary is made mistakes, but this method is still waiting to improve at reduction peak-to-average force ratio aspect of performance.
Summary of the invention
The object of the present invention is to provide the method that reduces peak-to-average force ratio in a kind of orthogonal frequency division multiplex OFDM system, this method adopts new scrambler to insert technology, and this method realizes simple at system's transmitting-receiving two-end, and does not need transmitting any auxiliary information.Compare with the existing sequence interleaved plan, under the prerequisite of the complexity that does not increase system, can better reduce the peak-to-average force ratio of ofdm system.
The object of the present invention is achieved like this: reduce the method for peak-to-average force ratio in a kind of ofdm system, it is characterized in that, carry out following steps in ofdm system:
1) the input data of ofdm system, the process string also is converted to parallel data;
2) parallel data of step 1) being carried out scrambler and insert, is that the burst of the ofdm system of K evenly is divided into the M piece with length, guarantees that K/M is an integer, and a scrambler is inserted at every end, and the scrambler total bit of insertion is M;
3) to step 2) parallel data inserted behind the scrambler carries out inverse fast fourier transform;
4) data after the step 3) modulation are carried out and go here and there conversion;
5) calculation procedure 4) peak-to-average force ratio of output signal sequence;
6) determining step 5) in the peak-to-average force ratio of burst whether satisfy the requirement that ofdm system is provided with, if do not meet the demands, then change the 2nd over to) step; Just carry out back-end processing if satisfy.
Further, reduce the method for peak-to-average force ratio in the ofdm system of the present invention, can also in ofdm system, carry out following steps and realize:
1) the input data of ofdm system, the process string also is converted to parallel data;
2) parallel data of step 1) being carried out scrambler and insert, is that the burst of the ofdm system of K evenly is divided into the M piece with length, guarantees that K/M is an integer, and a scrambler is inserted at every end, and the scrambler total bit of insertion is M; The parallel data of step 1) output is carried out N scrambler insert, obtain the different burst of N bar;
3) to step 2) the N bar parallel data inserted behind the scrambler carries out inverse fast fourier transform respectively;
4) the N bar data after the step 3) modulation are carried out respectively and go here and there conversion;
5) calculation procedure 4) peak-to-average force ratio of N bars sequence of output;
6) in N bars sequence, select one of the peak-to-average force ratio minimum and carry out back-end processing.Wherein, N is a natural number.
Compared with prior art, the present invention has following advantage:
(1) compares with the partial sequence transmission method with selecting mapping, the present invention reduces signal peak-to-average ratio by inserting scrambler, and transmitting-receiving two-end is handled more simple, and does not need to transmit any supplementary, can not have better error performance because of the supplementary generation error code of makeing mistakes.
(2) compare with existing sequence insertion method, the present invention evenly is inserted into scrambler in the burst by introducing the thought that sub-piece is cut apart, and under the situation that does not increase system complexity, obtains better reduction peak-to-average force ratio performance.
Therefore, the present invention is a kind of reduction Peak-to-Average Power Ratio method of novelty, and key is to introduce the thought that sub-piece is cut apart, and scrambler evenly is inserted in the ofdm signal sequence.This method realizes simple at system's transmitting-receiving two-end, can obtain the effect of better reduction ofdm system peak-to-average force ratio keeping existing sequence interleaved plan advantage, not increasing under the condition of system complexity.
Description of drawings
Fig. 1 is the inventive method flow diagram;
Fig. 2 inserts operation chart for scrambler among the present invention; Among the figure, a is a useful data, and b is a scrambler.
Fig. 3 is ofdm system sub-carrier number K=64, scrambler figure place M=8, and the BPSK modulation system, it is N=1 that scrambler inserts number of times, the present invention program and existing sequence insertion method performance comparison diagram.
Fig. 4 is ofdm system sub-carrier number K=64, scrambler figure place M=8, and the BPSK modulation system, it is N=4 that scrambler inserts number of times, the present invention program and existing sequence insertion method performance comparison diagram.
Fig. 5 is ofdm system sub-carrier number K=64, scrambler figure place M=4, and the BPSK modulation system is inserted scrambler sequence and is gone through all situations, the present invention program and existing sequence insertion method performance comparison diagram.
Fig. 6 is ofdm system sub-carrier number K=128, scrambler figure place M=8 and M=32, and the BPSK modulation system, scrambler inserts times N=8, and the present invention program reduces peak-to-average force ratio performance simulation figure.
Fig. 7 is ofdm system sub-carrier number K=128, scrambler figure place M=32, and the BPSK modulation system, scrambler inserts times N=2 and N=8, and the present invention program reduces peak-to-average force ratio emulation and can scheme.
Fig. 8 is the method flow block diagram of another embodiment of the present invention.
Embodiment
The invention will be further described below in conjunction with the drawings and specific embodiments.
As shown in Figure 1, reduce the method for peak-to-average force ratio in a kind of ofdm system, in ofdm system, carry out following steps:
1) the input data of ofdm system are converted to parallel data through going here and there and changing 1;
2) parallel data of step 1) being carried out scrambler and insert 2, is that the burst of the ofdm system of K evenly is divided into the M piece with length, guarantees that K/M is an integer, and a scrambler is inserted at every end, and the scrambler total bit of insertion is M;
3) to step 2) parallel data inserted behind the scrambler carries out inverse fast fourier transform 3;
4) data after the step 3) modulation are carried out and go here and there and change 4;
5) calculation procedure 4) peak-to-average force ratio of output signal sequence;
6) determining step 5) in the peak-to-average force ratio of burst whether satisfy the requirement that ofdm system is provided with, if do not meet the demands, then change the 2nd over to) step; Just carry out back-end processing if satisfy.
Present embodiment is repeatedly to insert according to default peak-to-average force ratio thresholding, inserts different scramblers at every turn, just stops to insert if satisfy threshold requirement, otherwise continues to insert up to meeting the demands.
Among the present invention, the scrambler insertion method that scrambler inserts in the operation 2 is a major technique feature of the present invention, realization principle and specific implementation process that scrambler inserts operation 2 are as follows: according to the number of subcarriers K of ofdm system, system efficiency of transmission and the requirement that reduces peak-to-average force ratio are determined to insert the figure place M of scrambler, the useful data figure place is (K-M).It is many more to insert scrambler figure place M, and it is good more to reduce the peak-to-average force ratio effect, but that efficiency of transmission can be lost is more.Shown in Figure of description 2, number of subcarriers K evenly is divided into the M piece, the K/M bit data is arranged in every, wherein front (K-M)/M position is a useful data, one at end is the scrambler that inserts.
Referring to Fig. 8, realize reducing in the ofdm system of the present invention the another kind of mode of the method for peak-to-average force ratio, it is to preestablish to insert times N (N is a natural number), inserts different scramblers at every turn, obtain many barss sequence, select the burst of peak-to-average force ratio minimum to carry out back-end processing.Its execution mode is as follows, carries out following steps in ofdm system:
1) the input data of ofdm system are converted to parallel data through going here and there and changing 1;
2) parallel data of step 1) being carried out scrambler and insert 2, is that the burst of the ofdm system of K evenly is divided into the M piece with length, guarantees that K/M is an integer, and a scrambler is inserted at every end, and the scrambler total bit of insertion is M; The parallel data of step 1) output is carried out N scrambler insert 2, obtain the different burst of N bar;
3) to step 2) the N bar parallel data inserted behind the scrambler carries out inverse fast fourier transform 3 respectively;
4) the N bar data after the step 3) modulation are carried out respectively and go here and there and change 4;
5) calculation procedure 4) peak-to-average force ratio 5 of N bars sequence of output;
6) in N bars sequence, select one of the peak-to-average force ratio minimum and carry out back-end processing.
According to present embodiment the present invention is carried out performance simulation, Fig. 3, Fig. 4 and Fig. 5 are the present invention program and existing sequence insertion method reduction peak-to-average force ratio performance comparison under the same conditions.As can be seen from the results, in CCDF value 10
-3The place, the inventive method performance is better than existing method 0.5dB～1.0dB.Fig. 6 and Fig. 7 are the inventive method when different scrambling codes inserts number of times and inserts the different scrambling codes figure place, reduce the peak-to-average force ratio design sketch.Under this simulated conditions, the present invention can make signal peak-to-average ratio reduce 3.0dB, and under the condition that the scrambler figure place increases and the insertion number of times increases, it is more that signal peak-to-average ratio is reduced.
Claims (2)
1, reduce the method for peak-to-average force ratio in a kind of ofdm system, it is characterized in that, in ofdm system, carry out following steps:
1) the input data of ofdm system are converted to parallel data through string and conversion (1);
2) parallel data of step 1) being carried out scrambler and insert (2), is that the burst of the ofdm system of K evenly is divided into the M piece with length, guarantees that K/M is an integer, and a scrambler is inserted at every end, and the scrambler total bit of insertion is M;
3) to step 2) parallel data inserted behind the scrambler carries out inverse fast fourier transform (3);
4) data after the step 3) modulation are carried out and go here and there conversion (4);
5) calculation procedure 4) peak-to-average force ratio (5) of output signal sequence;
6) determining step 5) in the peak-to-average force ratio of burst whether satisfy the requirement that ofdm system is provided with, if do not meet the demands, then change the 2nd over to) step; Just carry out back-end processing if satisfy.
2, reduce the method for peak-to-average force ratio in a kind of ofdm system, it is characterized in that, in ofdm system, carry out following steps:
1) the input data of ofdm system are converted to parallel data through string and conversion (1);
2) parallel data of step 1) being carried out scrambler and insert (2), is that the burst of the ofdm system of K evenly is divided into the M piece with length, guarantees that K/M is an integer, and a scrambler is inserted at every end, and the scrambler total bit of insertion is M; The parallel data of step 1) output is carried out N scrambler insert (2), obtain the different burst of N bar;
3) to step 2) the N bar parallel data inserted behind the scrambler carries out inverse fast fourier transform (3) respectively;
4) the N bar data after the step 3) modulation are carried out respectively and go here and there conversion (4);
5) calculation procedure 4) peak-to-average force ratio (5) of N bars sequence of output;
6) in N bars sequence, select one of the peak-to-average force ratio minimum and carry out back-end processing.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CNA2008100698696A CN101304398A (en) | 2008-06-20 | 2008-06-20 | Method for reducing PAR of OFDM system |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CNA2008100698696A CN101304398A (en) | 2008-06-20 | 2008-06-20 | Method for reducing PAR of OFDM system |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN101304398A true CN101304398A (en) | 2008-11-12 |
Family
ID=40114111
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CNA2008100698696A Pending CN101304398A (en) | 2008-06-20 | 2008-06-20 | Method for reducing PAR of OFDM system |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN101304398A (en) |
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101848184A (en) * | 2010-06-03 | 2010-09-29 | 山东大学 | Selective mapping scrambling method for reducing peak-to-average power ratio of orthogonal frequency division multiplexing system |
| CN102571678A (en) * | 2012-02-28 | 2012-07-11 | 中兴通讯股份有限公司 | Selection method and device for time-domain alternative signals |
| CN105634651A (en) * | 2014-10-27 | 2016-06-01 | 中南大学 | Method for reducing PAPR of OFDM system based on pre-coding and exponential companding technologies |
| CN105915291A (en) * | 2016-05-27 | 2016-08-31 | 哈尔滨工程大学 | Method of suppressing peak-to-average ratio of asymmetrically clipped DC biased optical system |
| CN109039380A (en) * | 2018-08-23 | 2018-12-18 | 南方电网科学研究院有限责任公司 | Power line communication system and phase deviation method, device and equipment thereof |
| CN110611632A (en) * | 2019-10-11 | 2019-12-24 | 珠海中慧微电子有限公司 | Method for reducing peak-to-average ratio of OFDM (orthogonal frequency division multiplexing) signals |
-
2008
- 2008-06-20 CN CNA2008100698696A patent/CN101304398A/en active Pending
Cited By (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101848184A (en) * | 2010-06-03 | 2010-09-29 | 山东大学 | Selective mapping scrambling method for reducing peak-to-average power ratio of orthogonal frequency division multiplexing system |
| CN101848184B (en) * | 2010-06-03 | 2013-04-03 | 山东大学 | Selective mapping scrambling method for reducing peak-to-average power ratio of orthogonal frequency division multiplexing system |
| CN102571678A (en) * | 2012-02-28 | 2012-07-11 | 中兴通讯股份有限公司 | Selection method and device for time-domain alternative signals |
| CN105634651A (en) * | 2014-10-27 | 2016-06-01 | 中南大学 | Method for reducing PAPR of OFDM system based on pre-coding and exponential companding technologies |
| CN105915291A (en) * | 2016-05-27 | 2016-08-31 | 哈尔滨工程大学 | Method of suppressing peak-to-average ratio of asymmetrically clipped DC biased optical system |
| CN105915291B (en) * | 2016-05-27 | 2018-04-17 | 哈尔滨工程大学 | Asymmetric amplitude limit direct current biasing optical OFDM system method for suppressing peak to average ratio |
| CN109039380A (en) * | 2018-08-23 | 2018-12-18 | 南方电网科学研究院有限责任公司 | Power line communication system and phase deviation method, device and equipment thereof |
| CN110611632A (en) * | 2019-10-11 | 2019-12-24 | 珠海中慧微电子有限公司 | Method for reducing peak-to-average ratio of OFDM (orthogonal frequency division multiplexing) signals |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN107302512B (en) | System and method for controlling combined wireless signals | |
| US7376074B2 (en) | Apparatus and method for transmitting and receiving side information of a partial transmit sequence in an OFDM communication system | |
| US6125103A (en) | Method and device for reducing the crest factor in digital transmission procedures | |
| CN101682592B (en) | Method and/or OFDM device for SC-FDMA data transmission | |
| CN101848184B (en) | Selective mapping scrambling method for reducing peak-to-average power ratio of orthogonal frequency division multiplexing system | |
| KR20070018504A (en) | Apparatus and method for reducing peak to average power ratio in ofdm communication system | |
| CN101291313B (en) | Wireless signal transmitting method, system and mobile station | |
| CN101304398A (en) | Method for reducing PAR of OFDM system | |
| CN110290087B (en) | Method and device for modulating and demodulating GFDM signal | |
| CN108847917B (en) | Orthogonal frequency division multiplexing transmission method modulated by pilot frequency pattern | |
| CN106992952A (en) | The method of peak-to-average force ratio is reduced in ofdm system based on PTS algorithms | |
| Dewangan et al. | A Survey of PAPR Reduction Techniques in LTE-OFDM System | |
| CN112291174A (en) | Peak-to-average power ratio restraining method applied to medium-voltage carrier communication | |
| CN101771644B (en) | Joint detection and soft decision decoding-based signal receiving method | |
| US20060120268A1 (en) | STBC MIMO-OFDM peak-to-average power ratio reduction by cross-antenna rotation and inversion | |
| CN100536382C (en) | MC-CDMA system transmitting and receiving method | |
| CN101355546A (en) | Method for self-eliminating ICI of OFDM system based on self-adapting modulation | |
| CN102916924B (en) | The offset modulation multi-carrier frequency division multiple access transmission method of BREATHABLE BANDWIDTH | |
| CN101729134A (en) | Generalized multiple carrier frequency division multiple access transmission equipment based on orthogonal transformation processing | |
| KR100666689B1 (en) | Real-time Peak-to-Average Power Reduction Method Using Phase Rotation and Selective Mapping Method and Data Transmission System Using the Same | |
| KR100717972B1 (en) | Papr reduction method for ofdm system, and generating method for sub block division sequence | |
| You et al. | A simple construction of OFDM-CDMA signals with low peak-to-average power ratio | |
| Carson et al. | PAPR reduction of OFDM using selected mapping, modified RA codes and clipping | |
| WO2008152596A2 (en) | System and method of transmitting and receiving an ofdm signal with reduced peak -to -average power ratio using dummy sequence insertation | |
| CN108449304B (en) | Partial transmission sequence method for reducing peak-to-average power ratio of OFDM (orthogonal frequency division multiplexing) signal |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| C12 | Rejection of a patent application after its publication | ||
| RJ01 | Rejection of invention patent application after publication |
Application publication date: 20081112 |