CN113783818A - Method for reducing peak-to-average ratio based on medium-voltage carrier iterative peak clipping - Google Patents
Method for reducing peak-to-average ratio based on medium-voltage carrier iterative peak clipping Download PDFInfo
- Publication number
- CN113783818A CN113783818A CN202110038981.9A CN202110038981A CN113783818A CN 113783818 A CN113783818 A CN 113783818A CN 202110038981 A CN202110038981 A CN 202110038981A CN 113783818 A CN113783818 A CN 113783818A
- Authority
- CN
- China
- Prior art keywords
- time domain
- peak
- vector
- domain waveform
- waveform 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.)
- Granted
Links
- 238000000034 method Methods 0.000 title claims abstract description 24
- 239000013598 vector Substances 0.000 claims description 49
- 239000000969 carrier Substances 0.000 claims description 2
- 238000004891 communication Methods 0.000 abstract description 4
- 238000001914 filtration Methods 0.000 abstract 3
- 238000010586 diagram Methods 0.000 description 7
- 238000005516 engineering process Methods 0.000 description 6
- 238000001228 spectrum Methods 0.000 description 4
- 238000004364 calculation method Methods 0.000 description 3
- 230000000694 effects Effects 0.000 description 3
- 238000005070 sampling Methods 0.000 description 3
- 208000021907 Central cloudy dystrophy of François Diseases 0.000 description 2
- 230000009286 beneficial effect Effects 0.000 description 2
- 230000005540 biological transmission Effects 0.000 description 2
- 238000004088 simulation Methods 0.000 description 2
- 238000000605 extraction Methods 0.000 description 1
- 230000008054 signal transmission Effects 0.000 description 1
Images
Classifications
-
- 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
- H04L27/2614—Peak power aspects
- H04L27/2623—Reduction thereof by clipping
-
- 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
Landscapes
- Engineering & Computer Science (AREA)
- Computer Networks & Wireless Communication (AREA)
- Signal Processing (AREA)
- Physics & Mathematics (AREA)
- Discrete Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Mathematical Physics (AREA)
- Transmitters (AREA)
Abstract
The invention relates to a method for reducing peak-to-average power ratio based on medium-voltage carrier iterative peak clipping, belonging to the technical field of broadband power line carrier communication. The iterative peak clipping filtering in the invention is to interpolate frequency domain data, then transform the frequency domain data into time domain waveform after IFFT, clip the peak of the time domain data, then take out the frequency domain data through FFT, filter the frequency domain, transform into time domain waveform data, through IFFT/FFT iterative processing for many times, finally the time domain data sends out the last time domain waveform when reaching the peak-to-average ratio threshold. The method has the main characteristics that the peak-to-average ratio can be effectively reduced through multiple times of peak clipping filtering, frequency domain filtering is added in each iteration, and the problem of out-of-band leakage of the transmitted time domain waveform data is solved.
Description
Technical Field
The invention relates to the technical field of broadband power line carrier communication, in particular to a method for reducing peak-to-average power ratio based on medium-voltage carrier iterative peak clipping.
Background
An important drawback of OFDM transmission is the high peak-to-average power ratio of the transmitted signal. Since OFDM modulation superimposes several subcarrier signals in the time domain, if the symbol phases on the subcarriers are the same, a very high time domain power peak-to-average ratio is caused, and therefore a certain peak-to-average ratio reduction technique needs to be adopted.
The existing technology for reducing the peak-to-average power ratio comprises a predistortion technology, a coding technology and the like, the coding technology has high capability of reducing the peak-to-average power ratio, but the calculation amount required by the coding technology is large, redundant information needs to be added, the traditional peak clipping technology carries out peak clipping on transmission time domain waveform data, then the time domain waveform data after the peak clipping is filtered, a part of out-of-band signal transmission still exists, not only can interference be caused on communication equipment of a nearby frequency band, but also a part of sending capability can be wasted.
Disclosure of Invention
In order to solve the above problems, the present invention provides a method for reducing peak-to-average ratio based on iterative peak clipping of medium voltage carrier, which achieves the purpose of reducing the equal-to-average ratio by repeatedly performing peak clipping on a time domain signal, and meanwhile, does not interfere with communication equipment, and has small calculation amount and no need of adding redundant information.
The invention discloses a method for reducing peak-to-average power ratio based on iterative peak clipping of medium-voltage carrier, which comprises the following steps:
step 1: sampling the vector to modulate a signal vector Ai＝[a0,a1,a2...aN-1]Wherein N is the number of subcarriers, M is selected as an oversampling factor, M-1 0 s are added in front of each element in the vector A to generate a new vector Ck＝[c0,c1,c2...cN*M-1]The number of elements in C is N M, the elements in vector A are uniformly distributed in vector C, and the address L of A in C is recorded0,l1,l2...lN-1]；
Step 2: carrying out IFFT operation on the newly generated vector, and selecting a real part of the vector to generate time domain waveform data of the vector;
and step 3: by PAPR 10lg (max (| s)n|2)/(∑|sn|2/N)) formula, calculating PAPR (peak-to-average ratio) of the time-domain waveform data, where SnIs the value in the time domain waveform data, N is the number of elements in the time domain waveform data, and the result is compared with a threshold St if the PAPR at that time is the<Step 5, entering St; if PAPR is>St, indicating that the peak-to-average ratio needs to be reduced, and entering step 4;
and 4, step 4: performing peak clipping processing on the time domain waveform generated by the vector C, wherein the peak clipping parameter is V, namely when the element of the time domain waveform data is larger than V, the time domain waveform data is equal to V, and if the element of the time domain waveform data is smaller than-V, the time domain waveform data is equal to-V, and then FFT is applied to the time domain waveform data after peak clipping to obtain a group of vectors Dk＝[d0,d1,d2...dN*M-1]Extracting element B according to address Li＝[b0,b1,b2...bN-1](when the PAPR is calculated for the first time, the vector B is consistent with the vector A, and the vector C is consistent with the vector B), then the operation is repeated by returning to the step 1, and the vector A in the step 1 is assigned by the vector B in the step 4 until the target PAPR is reached<＝St；
And 5: and performing IFFT on the vector A, and transmitting the generated time domain waveform to a power line channel.
Further, the peak-to-average ratio threshold St in step 3 is set according to the requirement, and is generally set to the maximum value of the linear operating region of the power amplifier.
Further, the peak clipping parameter V in step 3 is set according to actual conditions, and is usually set to 90% of the maximum value of the symbol time domain waveform data.
The invention has the beneficial effects that:
1. the method for reducing the peak-to-average power ratio by the peak clipping method is simple to implement, and has obvious effect of reducing the peak-to-average power ratio by the method of continuous time domain peak clipping, FFT extraction of useful signals and interpolation, and can effectively inhibit the peak value of the signals.
2. Compared with the conventional peak clipping method, the iterative peak clipping method only transmits IFFT of the position of the modulation signal vector, can effectively prevent out-of-band and does not lose extra power.
Drawings
In order to make the object, technical scheme and beneficial effect of the invention more clear, the invention provides the following drawings for explanation:
fig. 1 is a flowchart of a method for reducing peak-to-average ratio based on iterative peak clipping of medium-voltage carriers according to the present invention.
Fig. 2 is a schematic diagram illustrating comparison of the effect of the method for reducing the peak-to-average ratio based on the iterative peak clipping of the medium-voltage carrier in the present invention with that of the conventional peak clipping method.
Fig. 3 is a schematic diagram illustrating comparison between the iterative peak clipping and peak-to-average ratio reduction method based on medium-voltage carrier and a conventional peak clipping method CCDF in the present invention.
Fig. 4 is a schematic diagram of a comparison of the frequency spectrums of the iterative peak clipping and peak-to-average ratio reduction method based on the medium-voltage carrier according to the present invention and the conventional peak clipping method.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is described in further detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and do not limit the invention.
As shown in fig. 1, the present invention provides a method for reducing peak-to-average ratio based on iterative peak clipping of medium voltage carrier, which specifically includes the following steps:
step 1: sampling the vector to modulate a signal vector Ai＝[a0,a1,a2...aN-1]Wherein N is the number of subcarriers, M is selected as an oversampling factor, M-1 0 s are added in front of each element in the vector A to generate a new vector Ck＝[c0,c1,c2...cN*M-1]The number of elements in C is N M, the elements in vector A are uniformly distributed in vector C, and the address L of A in C is recorded0,l1,l2...lN-1]；
Step 2: performing IFFT operation on the newly generated vector, and selecting a real part to generate time domain waveform data of the vector;
and step 3: calculating the PAPR (peak-to-average power ratio) of the time domain waveform data, comparing the result with a threshold St, if the PAPR at the moment is less than St, performing IFFT on the vector A, sending the generated time domain waveform to a power line channel, and if the PAPR is equal to St, entering the next step;
and 4, step 4: performing peak clipping processing on the time domain waveform generated by the vector C, wherein the peak clipping parameter is V, namely when the element of the time domain waveform data is larger than V, the time domain waveform data is equal to V, and if the element of the time domain waveform data is smaller than-V, the time domain waveform data is equal to-V, and then FFT is applied to the time domain waveform data after peak clipping to obtain a group of vectors Dk＝[d0,d1,d2...dN*M-1]Extracting element B according to address Li＝[b0,b1,b2...bN-1](when the first PAPR calculation satisfies the threshold, vector B is consistent with vector A, and vector C is consistent with vector B), at this time, repeating steps 1-3, and assigning the vector A in step 1 by the vector B in step 4 until the target PAPR is reached<＝St；
And 5: the vector a is subjected to IFFT, and the generated time domain waveform is transmitted onto the power line channel.
Taking an example of a specific implementation and performing a simulation experiment on the example, a sampling rate of 40.96MHz and an FFT point number of 8192 are selected, when a frequency band is selected from 0.11MHz to 0.51MHz, 51 subcarriers are totally included in the frequency band, a PAPR threshold is 9.5dB, a peak clipping parameter is 0.7, and the number of iterations is 3. As shown in fig. 2, a comparison graph of the peak-to-average ratio of the original data, the peak-to-average ratio of the conventional peak clipping data, and the peak-to-average ratio of the original data after iterative peak clipping is shown in the graph, and the peak-to-average ratio of the data after 3 iterations is reduced by 0.8-1.2dB compared with the peak-to-average ratio of the conventional peak clipping data and is reduced by 1.8-2.2dB compared with the peak-to-average ratio of the original data under the condition of 20 times of simulation. Fig. 3 is a schematic diagram showing CCDF comparison of original data, conventional peak clipping data, and original data by iterative peak clipping, and it can be seen from the diagram that iterative peak clipping has a better effect of reducing peak-to-average ratio. Fig. 4 shows a comparison diagram of frequency spectrums of conventional peak clipping data and original data after iterative peak clipping, and it can be seen from the diagram that the frequency spectrum of the original data after iterative peak clipping has no out-of-band leakage, while the frequency spectrum of the conventional data after peak clipping has out-of-band leakage.
Claims (3)
1. A method for reducing peak-to-average power ratio based on iterative peak clipping of medium-voltage carriers is characterized by comprising the following steps:
step 1: vector a of modulation signalsi＝[a0,a1,a2...aN-1]Wherein N is the number of subcarriers, M is selected as an oversampling factor, M-1 0 s are added in front of each element in the vector A to generate a new vector Ck＝[c0,c1,c2...cN*M-1]The number of elements in C is N M, the elements in vector A are uniformly distributed in vector C, and the address L of A in C is recorded0,l1,l2...lN-1]；
Step 2: carrying out IFFT on the newly generated vector, and selecting time domain waveform data of which part generates the vector;
and step 3: by PAPR 10lg (max (| s)n|2)/(∑|sn|2/N)) formula, calculating the PAPR of the time domain waveform data, wherein SnIs the value in the domain waveform data, N is the number of elements in the time domain waveform data, and the result is compared with a threshold St if the PAPR at that time is<Step 5, entering St; if PAPR is>If St is determined, the peak-to-average ratio needs to be reduced, and the step 4 is carried out;
and 4, step 4: performing peak clipping processing on the time domain waveform generated by the vector C, wherein the peak clipping parameter is V, namely when the element of the time domain waveform data is larger than V, the time domain waveform data is equal to V, and if the element of the time domain waveform data is smaller than-V, the time domain waveform data is equal to-V, and then FFT is applied to the time domain waveform data after peak clipping to obtain a group of vectors Dk＝[d0,d1,d2...dN*M-1]Extracting element B according to address Li＝[b0,b1,b2...bN-1]And returning to the step 1 to repeat the operation, wherein the vector A in the step 1 is assigned by the vector B in the step 4 until the target PAPR is reached<＝St；
And 5: the vector a is subjected to IFFT, and the generated time domain waveform is transmitted onto the power line channel.
2. The method according to claim 1, wherein the peak-to-average ratio threshold St in step 3 is set according to requirements, and is generally set to a maximum value of a linear operating region of the power amplifier.
3. The method as claimed in claim 1, wherein the peak-clipping parameter V in step 3 is set to 90% of the maximum value of the symbol time domain waveform data.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110038981.9A CN113783818B (en) | 2021-01-12 | 2021-01-12 | Method for reducing peak-to-average ratio based on intermediate-voltage carrier iterative peak clipping |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110038981.9A CN113783818B (en) | 2021-01-12 | 2021-01-12 | Method for reducing peak-to-average ratio based on intermediate-voltage carrier iterative peak clipping |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN113783818A true CN113783818A (en) | 2021-12-10 |
| CN113783818B CN113783818B (en) | 2024-01-05 |
Family
ID=78835434
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202110038981.9A Active CN113783818B (en) | 2021-01-12 | 2021-01-12 | Method for reducing peak-to-average ratio based on intermediate-voltage carrier iterative peak clipping |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN113783818B (en) |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105553909A (en) * | 2015-12-08 | 2016-05-04 | 北京遥测技术研究所 | Iterative clipping and filtering method for reducing peak-to-average ratio of OFDM signals |
-
2021
- 2021-01-12 CN CN202110038981.9A patent/CN113783818B/en active Active
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105553909A (en) * | 2015-12-08 | 2016-05-04 | 北京遥测技术研究所 | Iterative clipping and filtering method for reducing peak-to-average ratio of OFDM signals |
Non-Patent Citations (6)
| Title |
|---|
| 刘晓明;李志;吴皓威;: "降低OFDM***PAPR的RCF算法分析与FPGA实现", 世界科技研究与发展, no. 05 * |
| 张丽丽;叶宇煌;苏凯雄;吴林煌;翁义龙;: "基于深度限幅滤波的DTMB峰均比抑制技术研究", 电视技术, no. 17 * |
| 李铀;张晓林;: "过采样下预留载波OFDM***峰均比抑制方法", 太赫兹科学与电子信息学报, no. 01 * |
| 柴丽敏;王向阳;潘志文;: "应用限幅降低OFDM***的峰均比性能", 电子工程师, no. 02 * |
| 解来历;辜方林;马东堂;张晓瀛;: "一种基于预留子载波降峰均比的改进方法", 通信技术, no. 06 * |
| 陈宁;卢长兵;: "降低OFDM***峰均比方法的研究", 计算机工程与应用, no. 21 * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN113783818B (en) | 2024-01-05 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| KR100948729B1 (en) | Method and system for reducing peak-to-average power ratio in orthogonal frequency division multiplexed signal | |
| Nikookar et al. | Random phase updating algorithm for OFDM transmission with low PAPR | |
| CN101035105B (en) | Method and device for reserving the sub-carrier to reduce the peak average power ratio of the OFDM system based on IFFT/FFT | |
| KR20110087115A (en) | Method and apparatus for reducing peak to average power ratio by using peak windowing | |
| Wang et al. | Compensation of nonlinear distortions with memory effects in OFDM transmitters | |
| Padarti et al. | An improved ASOICF algorithm for PAPR reduction in OFDM systems | |
| Mowla et al. | Performance improvement of PAPR reduction for OFDM signal in LTE system | |
| CN104320371A (en) | System and method for decreasing peak-to-average power ratio of OFDMA uplink | |
| Sravanti et al. | Precoding PTS scheme for PAPR reduction in OFDM | |
| WO2010138032A1 (en) | Papr reduction by tone selection | |
| Mowla et al. | Performance comparison of two clipping based filtering methods for PAPR reduction in OFDM signal | |
| Yadav et al. | Nonlinearity effect of Power Amplifiers in wireless communication systems | |
| CN113783818B (en) | Method for reducing peak-to-average ratio based on intermediate-voltage carrier iterative peak clipping | |
| Arora et al. | Partial transmit sequence (PTS)-PAPR reduction technique in OFDM systems with reduced complexity | |
| Yadav et al. | A novel hybrid technique for PAPR reduction of Rayleigh fading channel based OFDM system | |
| Devlin et al. | Gaussian pulse based tone reservation for reducing PAPR of OFDM signals | |
| CN115996167B (en) | Peak-to-average ratio suppression method, system, device and medium for mixed parameter set system | |
| Dardari et al. | A novel low complexity technique to reduce non-linear distortion effects in OFDM systems | |
| RU2280953C2 (en) | Method for adaptive control of signal peak factor | |
| Mohammady et al. | Comparison of Piece-Wise and full CFR for OFDM (LTE, 5G beyond), WCDMA, and DVB-S2X signals | |
| Islam et al. | PAPR Reduction in an OFDM system using Recursive Clipping and Filtering Technique | |
| Mowla et al. | A Modified Design Of Acf Operation For Reducing Papr Of Ofdm Signal | |
| Al-Rayif et al. | Experimental demonstration for PAPR reduction in OFDM system using partial-OSLM technique | |
| Deng et al. | An improved algorithm to reduce PAPR based clipping-and-filtering | |
| Wang et al. | Papr reduction method based on pilot-assisted fbmc in broadband power line communication |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |