CN101394380A - Method and system for lowering peak-average-ratio of information symbol in OFDM system - Google Patents
Method and system for lowering peak-average-ratio of information symbol in OFDM system Download PDFInfo
- Publication number
- CN101394380A CN101394380A CNA2007100462867A CN200710046286A CN101394380A CN 101394380 A CN101394380 A CN 101394380A CN A2007100462867 A CNA2007100462867 A CN A2007100462867A CN 200710046286 A CN200710046286 A CN 200710046286A CN 101394380 A CN101394380 A CN 101394380A
- Authority
- CN
- China
- Prior art keywords
- sequence
- pilot frequency
- frequency sequence
- pilot
- data
- 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
- Mobile Radio Communication Systems (AREA)
Abstract
The invention discloses a method and a system for reducing peak-to-average ratio of information symbols in an OFDM system. The method comprises the following steps: changing the values of pilot sequences in OFDM symbols to obtain a pilot sequence set; subjecting each pilot sequence in the pilot sequence set to inverse Fourier transformation to obtain a corresponding pilot sequence set in a time domain; subjecting a coded and interlaced data sequence to inverse Fourier transformation to obtain a corresponding data sequence in the time domain; adding the data sequence in the time domain to each pilot sequence of the pilot sequence set in the time domain to obtain a new sequence set; respectively calculating the peak-to-average ratio of each sequence in the new sequence set; and selecting the pilot sequence corresponding to the sequence with the least peak-to-average ratio in the new sequence set as the emission pilot sequence. In the method, the pilot sequence can be used for reducing the peak-to-average ratio of the information symbols, thereby saving the system overhead and improving the system capacity.
Description
Technical field
The present invention relates to OFDM (OFDM, Orthogonal Frequency DivisionMultiplexing) technical field, relate in particular to the method and system that reduces the peak-to-average force ratio of information symbol in the ofdm system.
Background technology
In ofdm system, each information symbol all is independently to be formed by stacking through the sub-carrier signal of ovennodulation by a plurality of, when each sub-carrier phase is identical or close, superposed signal just might produce very big peak power, can bring very high peak-to-average power ratio (PAPR thus, Peak-to-Average PowerRatio), peak-to-average power ratio is called for short peak-to-average force ratio (PAR).Peak-to-average force ratio is than higher, mean when signal during by nonlinear devices such as power amplifiers, require power amplifier to have very big dynamic range, otherwise will produce nonlinear distortion, the harmonic wave that is produced can cause the phase mutual interference between subchannel, thereby have a strong impact on the performance of ofdm system, therefore, the PAR that reduces information symbol in the ofdm system is that the OFDM technology is used a technical problem that must solve.
In prior OFDM system, propose some and reduced the algorithm of PAR, its computation complexity to the reduction effect of PAR and introducing thus also has nothing in common with each other.Wherein a kind of subcarrier that is called is reserved (TR, Tone Reservation) scheme, and in this scheme, transmitter and receiver all keeps a part of subcarrier and is used to reduce peak-to-average force ratio, and concrete principle is as follows:
Suppose to have N effectively subcarrier, wherein K is used to reduce peak-to-average force ratio as preserved sub-carrier, supposes that X is the frequency domain data signal, and x is the time-domain signal of X, and R is the set of carrying sequence on K the subcarrier, C=[C
0, C
1..., C
K-1] being a sequence among the sequence subset R that keeps the subcarrier generation, c is the time-domain signal of C, the target of TR method is to seek the sign indicating number C that makes PAR minimum, that is:
Wherein, Q is the IDFT matrix of NxN,
It is the NxK submatrix of Q.‖ v ‖
∞Be the infinite norm of v, i.e. greatest member in the vector v.
The simplest method is data-signal x and each c addition, calculates the peak-to-average force ratio of sequence after the addition each time, obtain make sequence peak-to-average force ratio minimum C as the value that keeps subcarrier.
In research and practice process to prior art, the inventor finds, is the reasonable method of a kind of reduction PAR on the TR theoretical method, but when using in real system, there are the following problems:
At first, need to keep plurality of subcarriers, just can obtain the performance that reduces PAR preferably, but this will reduce the spectrum efficiency of system, and then reduce power system capacity;
Secondly, because the position of preserved sub-carrier can influence the performance that reduces peak-to-average force ratio, in order to obtain optimum performance, the position of preserved sub-carrier should random distribution, also should uniformly-spaced distribute simultaneously, other sub-carrier distribution manner effect is not fine, as seen, this method is high especially to the status requirement of preserved sub-carrier, and this can have a strong impact on the flexibility of scheduling of resource;
In addition, these preserved sub-carriers can cause the adjacent area to disturb to adjacent cell, and are difficult to eliminate.
To sum up, because the quantity and the position of preserved sub-carrier all had high requirements, and can be unfavorable for practical application.
Summary of the invention
The technical problem that the embodiment of the invention will solve provides the method and system that reduces the peak-to-average force ratio of information symbol in the ofdm system, can improve power system capacity in the effect that guarantees ofdm system reduction PAR.
An aspect of the embodiment of the invention provides a kind of method that reduces the peak-to-average force ratio of information symbol in the ofdm system, and this method comprises:
Change the value of the pilot frequency sequence in the OFDM symbol, obtain the set of one group of pilot frequency sequence;
Each pilot frequency sequence in the set of described pilot frequency sequence is carried out inverse Fourier transform, obtain the set of pilot frequency sequence in the corresponding time domain;
To also pass through inverse Fourier transform through coding and the data sequence that interweaves, obtain data sequence in the corresponding time domain;
Pilot frequency sequence in each time domain in the set of pilot frequency sequence in data sequence in the described time domain and the described time domain is carried out add operation, obtain the set of one group of new sequence;
Calculate the peak-to-average force ratio of each sequence in the set of described new sequence respectively;
Choose pilot frequency sequence in the pairing pilot frequency sequence set of sequence that has minimum peak-to-average force ratio in the set of described new sequence as the pilot transmitted sequence.
The embodiment of the invention a kind of ofdm system is provided on the other hand, this ofdm system comprises: pilot frequency sequence maker, pilot frequency sequence converter, data sequence converter, adder, peak-to-average force ratio calculator, pilot frequency sequence Chooser, wherein:
The pilot frequency sequence maker by changing the value of the pilot frequency sequence in the OFDM symbol, generates the set of one group of pilot frequency sequence;
The pilot frequency sequence converter, each pilot frequency sequence in the set of the pilot frequency sequence that described pilot frequency sequence maker is generated carries out inverse Fourier transform, obtains the set of pilot frequency sequence in the corresponding time domain;
The data sequence converter will carry out inverse Fourier transform through coding and the data sequence that interweaves, and obtain data sequence in the corresponding time domain;
Adder, each pilot frequency sequence in the time domain that data sequence in the time domain that conversion obtains to described data sequence converter and the conversion of described pilot frequency sequence converter obtain in the set of pilot frequency sequence carries out add operation, obtains the set of one group of new sequence;
The peak-to-average force ratio calculator, the peak-to-average force ratio that computing obtains each sequence in the set of described new sequence to adder calculates;
The pilot frequency sequence Chooser is chosen in the described new arrangement set and is had the pairing pilot frequency sequence of sequence of minimum peak-to-average force ratio as the pilot transmitted sequence.
As can be seen from the above technical solutions, the embodiment of the invention adopts pilot frequency sequence to replace preserved sub-carrier, and pilot tone generally takies the expense more than 10%, and on frequency domain, be spacedly distributed, therefore preferable performance can be obtained with pilot frequency sequence as the sequence that reduces PAR in the TR method, the effect of PAR can be guaranteed to reduce.Simultaneously,, pilot frequency sequence is used for the reduction peak-to-average force ratio in system, has saved overhead, improved power system capacity because pilot frequency sequence is indispensable.
Description of drawings
Fig. 1 reduces PAR method preferred embodiment flow chart in the embodiment of the invention;
Fig. 2 is a kind of structural representation of ofdm system in the embodiment of the invention;
Fig. 3 is the another kind of structural representation of ofdm system in the embodiment of the invention.
Embodiment
The embodiment of the invention provides a kind of method that reduces the PAR of information symbol in the ofdm system, for purpose, technical scheme and the advantage that makes the embodiment of the invention is clearer, below with reference to accompanying drawing, the embodiment of the invention is further described.
With reference to Fig. 1, be to reduce in the embodiment of the invention PAR method preferred embodiment flow chart, below be elaborated by concrete steps:
The value of the pilot frequency sequence in step 11, the change OFDM symbol obtains the set of one group of pilot frequency sequence;
The value of pilot frequency sequence can be by keeping the fixed amplitude of pilot sub-carrier data carried by data, the phase place that changes the pilot sub-carrier data carried by data changes, for example the fixed amplitude with the pilot sub-carrier data carried by data is A, the phase of pilot sub-carrier data carried by data is { ± 1, select among ± the j}, can change the value of the pilot frequency sequence in the OFDM symbol.
Also can be by keeping the phase invariant of pilot sub-carrier data carried by data, the amplitude size that changes the pilot sub-carrier data carried by data changes, and for example keeps the phase of pilot sub-carrier data carried by data to fix, and the amplitude of pilot sub-carrier data carried by data is at { A
1, A
2, A
3, A
4The middle selection, the value of the pilot frequency sequence in the OFDM symbol also can be changed.
Perhaps change the amplitude of pilot sub-carrier data carried by data and the phase place of pilot sub-carrier data carried by data simultaneously and change, for example, the amplitude A of pilot sub-carrier data carried by data is at { A
1, A
2, A
3, A
4The middle selection, the value of the phase of pilot sub-carrier data carried by data can be { ± 1, select among ± the j}, change the amplitude A of pilot sub-carrier data carried by data and the phase of pilot sub-carrier data carried by data simultaneously, change the value of the pilot frequency sequence in the OFDM symbol.
By changing the value of the pilot frequency sequence in the OFDM symbol, obtain the set of one group of pilot frequency sequence, for convenience of description, the set of establishing this pilot frequency sequence is R.From statistical significance, the alternative number of pilot frequency sequence is many more, and the PAR of OFDM symbol is just more little.
If each pilot frequency sequence among the set R of described pilot frequency sequence is C=[C
0, C
1..., C
K-1], wherein, k is the number of pilot tone in the OFDM symbol.C is carried out inverse Fourier transform obtain c, c is the time domain pilot sequence of C.
In actual applications, also can adopt the fast algorithm of inverse Fourier transform, promptly obtain the set of pilot frequency sequence in the corresponding time domain by contrary fast fourier transform.
If through the data sequence frequency-region signal of encoding and interweave is X, X is carried out inverse Fourier transform obtain x, x is the time-domain signal of X.
If the set of the described one group of new sequence that obtains is R ', each sequence is w, wherein w=x+c among the set R '.
The peak-to-average force ratio of each sequence w is the maximum power value of this sequence and the ratio of average power content, specifically can calculate by following formula:
Wherein, x
nCorresponding w, the corresponding maximum instantaneous power value of molecular moiety, denominator is partly represented average power content.
Choose and make w have the pilot frequency sequence Cmin of minimum peak-to-average force ratio as the pilot transmitted sequence.
Because pilot tone is indispensable in an ofdm system important component part, pilot tone generally takies the expense more than 10%, and is spacedly distributed on frequency domain, therefore, can reach the effect that reduces PAR preferably.Simultaneously, replace preserved sub-carrier of the prior art, just do not need to keep a large amount of subcarriers by pilot frequency sequence, therefore can system overhead conserved, improve power system capacity, the situation that preserved sub-carrier causes the adjacent area to disturb to adjacent cell can not appear yet.
In the above-described embodiments, what transmitting terminal sent is a pilot frequency sequence, and receiving terminal need know that the value of the concrete pilot frequency sequence that sends of transmitting terminal just can carry out channel estimating, therefore, can do further perfect to the foregoing description, be specially: pilot frequency sequence and corresponding identification thereof in the set of the resulting pilot frequency sequence of value that will be by changing the pilot frequency sequence in the OFDM symbol are preserved in advance, the sign of described pilot transmitted sequence is sent to receiving terminal by signaling, and receiving terminal carries out channel estimating according to the value that the sign of pilot frequency sequence is chosen corresponding pilot frequency sequence.Wherein, the sign of pilot frequency sequence specifically can be call number.
The sign of pilot transmitted sequence can send with resource allocating message, also can send separately, and wherein, the OFDM symbol at signaling place that carries the sign of described pilot transmitted sequence adopts fixedly pilot tone, i.e. fixed position, fixed overhead.Receiving terminal is according to these OFDM symbols, the information of these symbols carry of demodulation, and then can obtain the pilot value of other symbols, to carry out channel estimating.
More than the method preferred embodiment that the embodiment of the invention provided is described in detail, for those skilled in the art being understood better and realize the present invention, below be elaborated by the ofdm system that the embodiment of the invention provided.
With reference to Fig. 2, be a kind of structural representation of ofdm system in the embodiment of the invention, this system is used to reduce the PAR of OFDM symbol, this system specifically comprises: pilot frequency sequence maker 21, pilot frequency sequence converter 22, data sequence converter 23, adder 24, peak-to-average force ratio calculator 25, pilot frequency sequence Chooser 26, wherein:
Pilot frequency sequence maker 21 by changing the value of the pilot frequency sequence in the OFDM symbol, generates the set of one group of pilot frequency sequence;
Pilot frequency sequence converter 22, each pilot frequency sequence in the set of the pilot frequency sequence that described pilot frequency sequence maker 21 is generated carries out inverse Fourier transform, obtains the set of pilot frequency sequence in the corresponding time domain;
Peak-to-average force ratio calculator 25, the peak-to-average force ratio of each sequence in the new arrangement set that 24 computings obtain to adder calculates;
Pilot frequency sequence Chooser 26 is chosen in the described new arrangement set and is had the pairing pilot frequency sequence of sequence of minimum peak-to-average force ratio as the pilot transmitted sequence.
Wherein, in order to improve conversion rate, described inverse Fourier transform can adopt contrary fast fourier transform.
In ofdm system, pilot tone generally takies the expense more than 10%, and is spacedly distributed on frequency domain, and therefore, the foregoing description can reach the effect that reduces PAR preferably.Simultaneously, replace preserved sub-carrier of the prior art, just do not need to keep a large amount of subcarriers by pilot frequency sequence, therefore can system overhead conserved, improve power system capacity, the situation that preserved sub-carrier causes the adjacent area to disturb to adjacent cell can not appear yet.
In said system embodiment, what transmitting terminal sent is the sign of a pilot frequency sequence, and receiving terminal need know that the value of the concrete pilot frequency sequence that sends of transmitting terminal just can carry out channel estimating, therefore, can do further perfect to the foregoing description, with reference to Fig. 3, be the another kind of structural representation of ofdm system in the embodiment of the invention.On said system embodiment basis, increase pilot sequence information memory 31 and pilot sequence information transmitter 32,
Wherein, pilot sequence information memory 31 is used for storing the pilot frequency sequence and the corresponding identification thereof of the set of the pilot frequency sequence that the pilot frequency sequence maker generated;
Pilot sequence information transmitter 32 is used for the sign of described pilot transmitted sequence is sent to receiving terminal by signaling.
Be understandable that pilot frequency sequence and corresponding identification thereof that described pilot frequency sequence maker is generated all have preservation at described ofdm system and receiving terminal, so, at receiving terminal a same pilot sequence information memory is arranged.
Like this, the receiving terminal value of choosing corresponding pilot frequency sequence according to the sign of pilot frequency sequence is carried out channel estimating.Wherein, the sign of pilot frequency sequence specifically can be call number.
The index information of pilot transmitted sequence can send with resource allocating message, also can send separately.When sending with resource allocating message, can be by the notice of the Pilot ModeIndication field in resource allocating message receiving terminal.
The OFDM symbol at signaling place that carries the sign of described pilot transmitted sequence is fixedly pilot tone, i.e. fixed position, fixed overhead.Receiving terminal is according to these OFDM symbols, the information of these symbols carry of demodulation, and then can obtain the pilot value of other symbols, to carry out channel estimating.
One of ordinary skill in the art will appreciate that all or part of step that realizes in the foregoing description method is to instruct relevant hardware to finish by program, described program can be stored in the computer read/write memory medium, this program comprises the steps: when carrying out
Change the value of the pilot frequency sequence in the OFDM symbol, obtain the set of one group of pilot frequency sequence;
Each pilot frequency sequence in the set of described pilot frequency sequence is carried out inverse Fourier transform, obtain pilot frequency sequence set in the corresponding time domain;
To also pass through inverse Fourier transform through coding and the data sequence that interweaves, obtain data sequence in the corresponding time domain;
Pilot frequency sequence in each time domain in the set of pilot frequency sequence in data sequence in the described time domain and the described time domain is carried out add operation, obtain the set of one group of new sequence;
Calculate the peak-to-average force ratio of each sequence in the set of described new sequence respectively;
Choose pilot frequency sequence in the pairing pilot frequency sequence set of sequence that has minimum peak-to-average force ratio in the set of described new sequence as the pilot transmitted sequence.
Described storage medium, as: ROM/RAM, magnetic disc, CD etc.
More than the method and system of the peak-to-average force ratio of information symbol in the reduction ofdm system provided by the present invention is described in detail, for one of ordinary skill in the art, thought according to the embodiment of the invention, part in specific embodiments and applications all can change, in sum, this description should not be construed as limitation of the present invention.
Claims (8)
1. a method that reduces the peak-to-average force ratio of information symbol in the ofdm system is characterized in that, comprising:
Change the value of the pilot frequency sequence in the OFDM symbol, obtain the set of one group of pilot frequency sequence;
Each pilot frequency sequence in the set of described pilot frequency sequence is carried out inverse Fourier transform, obtain the set of pilot frequency sequence in the corresponding time domain;
To also pass through inverse Fourier transform through coding and the data sequence that interweaves, obtain data sequence in the corresponding time domain;
Pilot frequency sequence in each time domain in the set of pilot frequency sequence in data sequence in the described time domain and the described time domain is carried out add operation, obtain the set of one group of new sequence;
Calculate the peak-to-average force ratio of each sequence in the set of described new sequence respectively;
Choose pilot frequency sequence in the pairing pilot frequency sequence set of sequence that has minimum peak-to-average force ratio in the set of described new sequence as the pilot transmitted sequence.
2. the method for the peak-to-average force ratio of information symbol in the reduction ofdm system as claimed in claim 1, it is characterized in that, the value of the pilot frequency sequence in the described change OFDM symbol is the fixed amplitude by maintenance pilot sub-carrier data carried by data, and the phase place of change pilot sub-carrier data carried by data realizes.
3. the method for the peak-to-average force ratio of information symbol in the reduction ofdm system as claimed in claim 1, it is characterized in that, the value of the pilot frequency sequence in the described change OFDM symbol is the phase invariant by maintenance pilot sub-carrier data carried by data, and the amplitude of change pilot sub-carrier data carried by data realizes.
4. the method for the peak-to-average force ratio of information symbol in the reduction ofdm system as claimed in claim 1, it is characterized in that the value of the pilot frequency sequence in the described change OFDM symbol is to realize by the amplitude that changes the pilot sub-carrier data carried by data simultaneously and the phase place of pilot sub-carrier data carried by data.
5. the method for the peak-to-average force ratio of information symbol is characterized in that in the reduction ofdm system as claimed in claim 1, further comprises:
Pilot frequency sequence and corresponding identification thereof in the set of the resulting pilot frequency sequence of value that in advance will be by changing the pilot frequency sequence in the OFDM symbol are preserved;
The sign of described pilot transmitted sequence is sent to receiving terminal by signaling.
6. the method for the peak-to-average force ratio of information symbol is characterized in that in the reduction ofdm system as claimed in claim 5,
The OFDM symbol at signaling place that carries the sign of described pilot transmitted sequence adopts fixedly pilot tone.
7. an ofdm system is characterized in that, comprising: pilot frequency sequence maker, pilot frequency sequence converter, data sequence converter, adder, peak-to-average force ratio calculator, pilot frequency sequence Chooser, wherein:
The pilot frequency sequence maker by changing the value of the pilot frequency sequence in the OFDM symbol, generates the set of one group of pilot frequency sequence;
The pilot frequency sequence converter, each pilot frequency sequence in the set of the pilot frequency sequence that described pilot frequency sequence maker is generated carries out inverse Fourier transform, obtains the set of pilot frequency sequence in the corresponding time domain;
The data sequence converter will carry out inverse Fourier transform through coding and the data sequence that interweaves, and obtain data sequence in the corresponding time domain;
Adder, each pilot frequency sequence in the time domain that data sequence in the time domain that conversion obtains to described data sequence converter and the conversion of described pilot frequency sequence converter obtain in the set of pilot frequency sequence carries out add operation, obtains the set of one group of new sequence;
The peak-to-average force ratio calculator, the peak-to-average force ratio that computing obtains each sequence in the set of described new sequence to adder calculates;
The pilot frequency sequence Chooser is chosen in the described new arrangement set and is had the pairing pilot frequency sequence of sequence of minimum peak-to-average force ratio as the pilot transmitted sequence.
8. ofdm system as claimed in claim 4 is characterized in that, this system also comprises:
The pilot sequence information memory is used for storing the pilot frequency sequence of set of the pilot frequency sequence that the pilot frequency sequence maker generated and the sign of corresponding pilot frequency sequence.
The pilot sequence information transmitter sends to receiving terminal with the sign of described pilot transmitted sequence by signaling.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CNA2007100462867A CN101394380A (en) | 2007-09-18 | 2007-09-18 | Method and system for lowering peak-average-ratio of information symbol in OFDM system |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CNA2007100462867A CN101394380A (en) | 2007-09-18 | 2007-09-18 | Method and system for lowering peak-average-ratio of information symbol in OFDM system |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN101394380A true CN101394380A (en) | 2009-03-25 |
Family
ID=40494459
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CNA2007100462867A Pending CN101394380A (en) | 2007-09-18 | 2007-09-18 | Method and system for lowering peak-average-ratio of information symbol in OFDM system |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN101394380A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104519004A (en) * | 2013-09-26 | 2015-04-15 | 中国科学院上海高等研究院 | Method of forming position patterns of reserved subcarriers of NGB-W (Next Generation Broadcasting-Wireless) system |
| WO2015168939A1 (en) * | 2014-05-09 | 2015-11-12 | 华为技术有限公司 | Method and device for controlling peak-to-average power ratio and base band unit |
-
2007
- 2007-09-18 CN CNA2007100462867A patent/CN101394380A/en active Pending
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104519004A (en) * | 2013-09-26 | 2015-04-15 | 中国科学院上海高等研究院 | Method of forming position patterns of reserved subcarriers of NGB-W (Next Generation Broadcasting-Wireless) system |
| CN104519004B (en) * | 2013-09-26 | 2018-01-16 | 中国科学院上海高等研究院 | The forming method of the preserved sub-carrier position pattern of NGB W systems |
| WO2015168939A1 (en) * | 2014-05-09 | 2015-11-12 | 华为技术有限公司 | Method and device for controlling peak-to-average power ratio and base band unit |
| CN105409180A (en) * | 2014-05-09 | 2016-03-16 | 华为技术有限公司 | Method and device for controlling peak-to-average power ratio and base band unit |
| CN105409180B (en) * | 2014-05-09 | 2018-08-14 | 华为技术有限公司 | A kind of method, apparatus and Base Band Unit of control papr |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| Baig et al. | DCT precoded SLM technique for PAPR reduction in OFDM systems | |
| Baig et al. | PAPR analysis of DHT-precoded OFDM system for M-QAM | |
| CN102111366B (en) | Peak-to-average power ratio (PAR) cut based on active set tone reservation | |
| CN105656830B (en) | Ofdm signal method for inhibiting peak-to-average ratio based on distributed implementation | |
| CN101005474B (en) | New compression extension method for reducing OFDM signal peak to average ratio | |
| CN102077536A (en) | Methods and systems for reducing papr of an OFDM signal | |
| CN102075483B (en) | Method for reducing peak to average power ratio of OFDM signal | |
| CN102025681B (en) | Sideband information transmission method of SLM (selective mapping method) and PTS (partial transmit sequences) in OFDM (orthogonal frequency division multiplexing) system reduce peak average ratio technology | |
| CN101771652B (en) | Amplitude limiting reserved sub carrier wave reduction PAPR method and system based on amplitude proportion factors | |
| Yang et al. | Two-piecewise companding transform for PAPR reduction of OFDM signals | |
| CN104394116A (en) | Alternative optimization PTS (Partial Transmit Sequence) emission system and method for reducing peak power of OFDM (Orthogonal Frequency Division Multiplexing) system | |
| CN103607265B (en) | The control method of carrier uplink transmission based on selected mapping method mode and device | |
| Mohammad et al. | A time domain SLM for PAPR reduction in SC-FDMA systems | |
| Tiwari et al. | PAPR reduction in MIMO-OFDM using combined methodology of selected mapping (SLM) and partial transmit sequence (PTS) | |
| EP1901510A1 (en) | Peak-to-average-power-ratio reduction in a multicarrier system | |
| CN103457896A (en) | OFDM peak-to-average ratio restraining method | |
| Cuteanu et al. | Papr reduction of OFDM signals using partial transmit sequence and clipping hybrid scheme | |
| CN101394380A (en) | Method and system for lowering peak-average-ratio of information symbol in OFDM system | |
| CN108365875B (en) | Method for reducing PAPR (peak to average power ratio) of multiple antennas based on precoding and MIMO (multiple input multiple output) system | |
| CN101304400A (en) | Method and apparatus for acquiring carrier jamming noise ratio | |
| Hou et al. | Bandwidth efficiency of PC-OFDM systems with high compaction multi-carrier modulation | |
| Cuteanu et al. | Hybrid PAPR reduction scheme using Walsh Hadamard precoding and signal companding | |
| CN108737315B (en) | Reduce the additivity scrambling method and its emission system of ofdm system peak-to-average power ratio | |
| Pandey et al. | Computational complexity reduction of OFDM signals by PTS with alternate optimised grouping phase weighting method | |
| CN104735019B (en) | A kind of emission system and method for optimizing ofdm signal peak-to-average power ratio |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C02 | Deemed withdrawal of patent application after publication (patent law 2001) | ||
| WD01 | Invention patent application deemed withdrawn after publication |
Open date: 20090325 |