CN107800662A - A kind of method for reducing spread spectrum OFDM signal papr - Google Patents
A kind of method for reducing spread spectrum OFDM signal papr Download PDFInfo
- Publication number
- CN107800662A CN107800662A CN201711268609.7A CN201711268609A CN107800662A CN 107800662 A CN107800662 A CN 107800662A CN 201711268609 A CN201711268609 A CN 201711268609A CN 107800662 A CN107800662 A CN 107800662A
- Authority
- CN
- China
- Prior art keywords
- spread spectrum
- cazac sequences
- data
- spectrum ofdm
- sequence
- 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
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
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04J—MULTIPLEX COMMUNICATION
- H04J13/00—Code division multiplex systems
- H04J13/0007—Code type
- H04J13/0055—ZCZ [zero correlation zone]
- H04J13/0059—CAZAC [constant-amplitude and zero auto-correlation]
Abstract
The invention discloses it is a kind of reduce spread spectrum OFDM signal papr method, comprising：The consensus sequence based on CAZAC sequences is respectively provided with transmitting terminal and receiving terminal；On described transmitting terminal, the digit using K positions packet assembling as the cyclic shift of CAZAC sequences respectively by data to be sent, obtain a series of CAZAC sequences of different cyclic shifts, and mapped described CAZAC sequences as OFDM sub-carrier phase data, it is changed into time-domain signal after carrying out IFFT computings, operated by filtering interpolation, exported via DAC again；In receiving terminal, after carrier synchronization module, bit sync module, obtain the cyclically shifted sequences data of CAZAC sequences, computing cross-correlation is carried out by local CAZAC sequences and the sequence received, the circulating shift data of CAZAC sequences is determined according to maximum value position, so as to demodulate corresponding K positions bit data.
Description
Technical field
It is more particularly to a kind of to reduce spread spectrum OFDM signal peak-to-average power the present invention relates to Anti-jam Communication Technology field
The method of ratio.
Background technology
Spread spectrum technic is a kind of technology having compared with strong anti-interference performance, OFDM (OFDM) be it is a kind of compared with
High data rate and the availability of frequency spectrum, and the multi-carrier modulation technology of frequency selective fading is effective against, thus handle
Both technologies combine the anti-interference and Effect of Carrier Frequency Offset that can further improve system.
OFDM technology breaks a channel into several orthogonal sub-channels, and high-speed data signal is converted into parallel low speed subnumber
According to stream, it is modulated to and is transmitted on each of the sub-channels.Orthogonal signalling can by being separated in receiving terminal using correlation technique,
It can so reduce and interfere ICI between subchannel.Signal bandwidth on per sub-channels is less than the correlation bandwidth of channel,
Therefore flatness decline can be regarded as on every sub-channels, so as to eliminate intersymbol interference.And because every height is believed
The bandwidth in road is only the sub-fraction of former channel width, and channel equalization becomes relatively easy.
On the basis of OFDM, spectrum transmissions are extended in multiple subcarriers using spread spectrum, can further be improved
Interference free performance, the advantages of can so taking into account two kinds of technologies of spread spectrum and OFDM.
But spread-OFDM systems, as ofdm system, its signal is and all sons after IFFT computings carry
Ripple is added, so the transmission signal of time domain has very high peak value, therefore, compared with single-carrier system, spread-OFDM systems have
Very high peak-average power ratio (Peak to Average Power Ratio, PAPR).
The PAPR of signal is defined as the Instantaneous peak power of signal and the ratio of mean power：
In spread-OFDM systems, high PAPR had both reduced the efficiency of transmitter power amplifier, also reduces digital-to-analogue and turns
The signal quantization noise ratio of parallel operation (ADC) and analog-digital converter (DAC).So it is worst factor in spread-OFDM systems
One of.The efficiency of power amplifier is very crucial for the military communication of remote anti-interference application.Therefore, spread spectrum OFDM
PAPR problems in system are more important.
At present, the method for reducing spread spectrum OFDM signal PAPR is a lot, is substantially segmented into three major types：Pre-distortion signal skill
Art, coding class technology and probability class technology.These three methods have their own characteristics each and the starting point, but all there is defect per class method.
Pre-distortion signal technology directly carries out nonlinear operation to the peak value of signal, and it is most direct, most simply, but can bring in-band noise
And out-of-band interference, so as to reduce the performance of BER of system and spectrum efficiency.Encode class technology and utilize coding by original letter
Breath code word is mapped in a transmission code collection with preferable PAPR characteristics, so as to avoid the code that signal peak occurs in those
Word.Such technology is linear process, and it will not make signal produce distortion.But the technical sophistication degree of coding class technology is very high,
Encoding and decoding are all cumbersome.Importantly, the information rate of this kind of technology reduces quickly, therefore it is only applicable to sub-carrier number
Fewer situation.Probability class technology avoids the peak value of signal completely unlike coding class technology, but is conceived to effort drop
The probability that low signal peak value occurs.The method that such technology uses is also for linear process, and therefore, it will not produce abnormal to signal
Become.This kind of technology can very effectively reduce the PAPR values of signal, it the shortcomings that be that computation complexity is too big.
The content of the invention
It is an object of the invention to provide a kind of implementation method for reducing peak-to-average force ratio in spread-OFDM systems, using with Heng Bao
The CAZAC sequences of network characteristic realize that multi-system spread spectrum is carried out to K positions bit information to be adjusted with N positions cyclic shift as frequency expansion sequence
System, and inputted using the CAZAC sequences after cyclic shift as OFDM subcarriers, it can be effectively reduced by this design method
PAPR, and amount of calculation is small, and system complexity is low.
In order to realize the above object the present invention is achieved by the following technical solutions：
A kind of method for reducing spread spectrum OFDM signal papr, is characterized in, comprising：
The consensus sequence based on CAZAC sequences is respectively provided with transmitting terminal and receiving terminal；
On described transmitting terminal, the cyclic shift using K positions packet assembling as CAZAC sequences respectively by data to be sent
Digit, obtain a series of CAZAC sequences of different cyclic shifts, and using described CAZAC sequences as OFDM subcarrier phases
Position data are mapped, and are changed into time-domain signal after carrying out IFFT computings, then are operated by filtering interpolation, are exported via DAC；
In receiving terminal, after carrier synchronization module, bit sync module, the cyclically shifted sequences number of CAZAC sequences is obtained
According to carrying out computing cross-correlation by local CAZAC sequences and the sequence that receives, CAZAC sequences determined according to maximum value position
Circulating shift data, so as to K positions bit data corresponding to demodulating.
In transmitting terminal, described data to be sent are corresponded to N number of phase of CAZAC sequences, N number of phase by K positions bit data
Cyclic shift forms N number of quadrature amplitude modulation signal sequence, and the length of sequence is also N, N number of quadrature amplitude modulation signal sequence
Arrange the corresponding frequency expansion sequence as K positions bit data.
This method also includes：
In transmitting terminal, by the corresponding one group of CAZAC frequency expansion sequence of each group of K positions bit data, and by serial to parallel conversion,
Frequency domain is mapped on corresponding subcarrier, then spread spectrum OFDM symbol is become into time-domain signal stream waiting for transmission by IFFT.
This method also includes：
In receiving terminal, the expansion received is found by computing cross-correlation, frequency synchronization module, bit sync module functional module
The frame synchronization head of frequency ofdm signal, a series of spread spectrum OFDM symbol time-domain signals are determined according to frame synchronization head.
This method also includes：
In receiving terminal, spread spectrum OFDM time-domain signal is passed through into FFT, then by channel estimation and Channel Equalization Algorithm at
After reason, it is changed into quadrature amplitude modulation signal sequence, then carries out conjugation computing cross-correlation with local reference CAZAC sequences, obtain
The position of relevant peaks, the CAZAC sequences of cyclic shift according to corresponding to determining correlation peak location, and it is mapped as K positions bit data.
This method also includes：
Mapping orthogonality amplitude-modulated signal after data to be sent are grouped by K positions bit.
This method also includes：
Cyclic prefix module is provided with transmitting terminal, for the increase cyclic prefix to spread spectrum OFDM signal；
It is provided with receiving terminal and goes cyclic prefix module, for removes the cyclic prefix of transmitting terminal addition.
The present invention compared with prior art, has advantages below：
Initial CAZAC sequence is used to pass through consensus sequence cyclic shift shape as consensus sequence in spread-OFDM systems
Map modulation is spread into multi-system, maps and inputs as OFDM sub-carrier frequency domains, be transmitted after IFFT, lead in receiving terminal
After crossing FFT, related operation is carried out in frequency domain and local reference CAZAC sequences, determines cyclically shifted sequences, demodulation recovers
Multi-system data；Relative to conventional spread spectrum technology, transmission rate is improved under same bandwidth, and enhances anti-multipath fading energy
Power；Relative to OFDM technology, due to, as frequency expansion sequence, greatly reducing PAPR, while improve anti-interference using CAZAC
Energy.
Brief description of the drawings
Fig. 1 is a kind of flow chart for reducing spread spectrum OFDM papr implementation method of the present invention；
Fig. 2 is a kind of schematic diagram for reducing spread spectrum OFDM papr implementation method of the present invention；
Fig. 3 is CAZAC sequence C AZAC cyclic shift mapping principle figures in the present invention.
Fig. 4 a, 4b are the spread spectrum OFDM time domain beamformers based on CAZAC sequences in the present invention.
Embodiment
Below in conjunction with accompanying drawing, by describing a preferable specific embodiment in detail, the present invention is further elaborated.
As shown in figure 1, a kind of method for reducing spread spectrum OFDM signal papr, comprising：
The consensus sequence based on CAZAC sequences is respectively provided with transmitting terminal and receiving terminal；
On described transmitting terminal, the cyclic shift using K positions packet assembling as CAZAC sequences respectively by data to be sent
Digit, obtain a series of CAZAC sequences of different cyclic shifts, and using described CAZAC sequences as OFDM subcarrier phases
Position data are mapped, and are changed into time-domain signal after carrying out IFFT computings, then are operated by filtering interpolation, are exported via DAC；
In receiving terminal, after carrier synchronization module, bit sync module, the cyclically shifted sequences number of CAZAC sequences is obtained
According to carrying out computing cross-correlation by local CAZAC sequences and the sequence that receives, CAZAC sequences determined according to maximum value position
Circulating shift data, so as to K positions bit data corresponding to demodulating.
In transmitting terminal, described data to be sent are corresponded to N number of phase of CAZAC sequences, N number of phase by K positions bit data
Cyclic shift forms N number of quadrature amplitude modulation signal sequence, and the length of sequence is also N, N number of quadrature amplitude modulation signal sequence
Arrange the corresponding frequency expansion sequence as K positions bit data.
This method also includes：
In transmitting terminal, by the corresponding one group of CAZAC frequency expansion sequence of each group of K positions bit data, and by serial to parallel conversion,
Frequency domain is mapped on corresponding subcarrier, then spread spectrum OFDM symbol is become into time-domain signal stream waiting for transmission by IFFT.
This method also includes：
In receiving terminal, the expansion received is found by computing cross-correlation, frequency synchronization module, bit sync module functional module
The frame synchronization head of frequency ofdm signal, a series of spread spectrum OFDM symbol time-domain signals are determined according to frame synchronization head.
This method also includes：
In receiving terminal, spread spectrum OFDM time-domain signal is passed through into FFT, then by channel estimation and Channel Equalization Algorithm at
After reason, it is changed into quadrature amplitude modulation signal sequence, then carries out conjugation computing cross-correlation with local reference CAZAC sequences, obtain
The position of relevant peaks, the CAZAC sequences of cyclic shift according to corresponding to determining correlation peak location, and it is mapped as K positions bit data.
The CAZAC sequences are permanent envelope zero auto-correlation sequence (Constant Amplitude Zero Auto
Correlation CAZAC).Behind any CAZAC sequence cyclic shift n positions, when n is not the integral multiple in the cycle of CAZAC sequences,
Sequence after displacement is uncorrelated to former sequence, and its cross-correlation and partial correlation values are close to 0；CAZAC sequences are passing through Fourier just
It is still CAZAC sequences after anti-change；And the signal being made up of CAZAC sequences, its peak value are very low with its average power.
This method also includes：
Mapping orthogonality amplitude-modulated signal after data to be sent are grouped by K positions bit by bit mapping blocks.
Parallel spread spectrum OFDM symbol is become by data to be transmitted stream by parallel serial conversion module；
The OFDM frame heads for receiving data are found by auto-correlation by synchronization module；
Data sequence is transformed into by OFDM frames by serial to parallel conversion module；
Decoded data are transformed to by frequency domain by time domain by FFT module；
Data after FFT module is handled by channel equalization module pass through channel equalization；
Quadrature amplitude modulation signal is mapped back by bit sequences by signal inverse mapping module.
This method also includes：
Cyclic prefix module is provided with transmitting terminal, for the increase cyclic prefix to spread spectrum OFDM signal；
It is provided with receiving terminal and goes cyclic prefix module, for removes the cyclic prefix of transmitting terminal addition.
Below in conjunction with Fig. 2, the present embodiment is further described：
In transmitting terminal, data to be sent are subjected to serial to parallel conversion with k positions bit data packet assembling respectively and form more bits
Decimal data frame, cyclic shift is carried out to CAZAC sequences according to the multi-system data value, after obtaining cyclic shift
CAZAC sequences, the sub-carrier phase modulation mapping data value using the sequence as spread spectrum OFDM, then carry out IFFT fortune to the value
Calculate, be changed into time-domain signal, then operate to form complete spread spectrum OFDM time-domain symbol data by inserting protection interval, then pass through
Add synchronizing sequence and channel estimation sequence completes framing work, digital-to-analogue conversion DAC is given complete spread spectrum OFDM data frame
Output；
CAZAC sequences { the ckBe defined as follows：
Wherein, N is the length of sequence, and M is relatively prime with N, and q is arbitrary integer.
The cyclic shift coding module of the CAZAC sequences, first have to carry out data prediction to K positions frequency expansion sequence, with
Produce N number of cyclic shift code of K positions original spreading code.An it is assumed that N positions frequency expansion sequence { a0, a1, a2..., aN-3, aN-2, aN-1Logical
The sequence for crossing right cyclic shift processing available N kinds difference position ordering is as follows：
{a0, a1, a2..., aN-3, aN-2, aN-1Ring shift right represents data 00 time；
{aN-1, a0, a1, a2..., aN-3, aN-2Ring shift right represents data 11 time；
{aN-2, aN-1, a0, a1, a2..., aN-3Ring shift right represents data 22 times；
……
{a1, a2..., aN-3, aN-2, aN-1, a0Ring shift right represents data N-1 N-1 times；
According to Fig. 2, in receiving terminal, the data for carrying out self-channel are received after ADC is sampled, first pass around timing and frequency
Rate is synchronous, channel estimation computing, the data frame of the spread spectrum OFDM signal containing protection interval is obtained, successively between removed protection
After the computing such as, serial to parallel conversion and FFT, it is changed into frequency domain spread spectrum ofdm signal, then frequency domain spread spectrum ofdm signal is carried out
Cyclic shift coherently despreading, multi-system data are obtained, most demodulate final bit data flow through parallel serial conversion afterwards.
The cyclic shift related operation is as shown in figure 3, be that is to say CAZAC sequences to the spread spectrum OFDM signal received
Cyclically shifted sequences data carry out N point FFT computings, obtain its frequency-region signal form；Carried out successively by local CAZAC sequences
The frequency-region signal sequence of N point FFTs and conjugate operation, the conjugate operation result and the CAZAC cyclically shifted sequences received
Carry out corresponding points multiplication operation and obtain N point sequences, IFFT computings are done to the N point sequences and obtain N dot cycles displacement related operation sequence
Row result, the digit M=Vp-1, the M of position Vp, the then cyclic shift of CAZAC sequences in the N point sequences of maximum place
The multi-system data as demodulated, demodulation example is as shown in Fig. 4 a, 4b.
In summary, a kind of implementation method for reducing peak-to-average force ratio in spread-OFDM systems of the present invention, using with permanent envelope
The CAZAC sequences of characteristic are realized with N positions cyclic shift and carry out multi-system band spectrum modulation to K positions bit information as frequency expansion sequence,
And inputted using the CAZAC sequences after cyclic shift as OFDM subcarriers, it can be effectively reduced by this design method
PAPR, and amount of calculation is small, and system complexity is low.
Although present disclosure is discussed in detail by above preferred embodiment, but it should be appreciated that above-mentioned
Description is not considered as limitation of the present invention.After those skilled in the art have read the above, for the present invention's
A variety of modifications and substitutions all will be apparent.Therefore, protection scope of the present invention should be limited to the appended claims.
Claims (7)
- A kind of 1. method for reducing spread spectrum OFDM signal papr, it is characterised in that include：The consensus sequence based on CAZAC sequences is respectively provided with transmitting terminal and receiving terminal；On described transmitting terminal, data to be sent are regard as the position of the cyclic shift of CAZAC sequences using K positions packet assembling respectively Number, obtains a series of CAZAC sequences of different cyclic shifts, and using described CAZAC sequences as OFDM sub-carrier phase numbers According to being mapped, it is changed into time-domain signal after carrying out IFFT computings, then is operated by filtering interpolation, is exported via DAC；In receiving terminal, after carrier synchronization module, bit sync module, the cyclically shifted sequences data of CAZAC sequences are obtained, are led to The sequence crossed local CAZAC sequences and received carries out computing cross-correlation, and the circulation of CAZAC sequences is determined according to maximum value position Shifted data, so as to demodulate corresponding K positions bit data.
- 2. the method for spread spectrum OFDM signal papr is reduced as claimed in claim 1, it is characterised in that sending End, described data to be sent are corresponded to N number of phase of CAZAC sequences by K positions bit data, N number of phase loop shift to be formed it is N number of Quadrature amplitude modulation signal sequence, the length of sequence is also N, and N number of quadrature amplitude modulation signal sequence is as K positions bit number According to corresponding frequency expansion sequence.
- 3. the method for spread spectrum OFDM signal papr is reduced as claimed in claim 1, it is characterised in that also wrap Contain：In transmitting terminal, one group of CAZAC frequency expansion sequence is corresponded to by each group of K positions bit data, and by serial to parallel conversion, in frequency domain It is mapped on corresponding subcarrier, then spread spectrum OFDM symbol is become by time-domain signal stream waiting for transmission by IFFT.
- 4. the method for spread spectrum OFDM signal papr is reduced as claimed in claim 1, it is characterised in that also wrap Contain：In receiving terminal, the spread spectrum OFDM signal received is found by computing cross-correlation, frequency synchronization module, bit sync module Frame synchronization head, a series of spread spectrum OFDM symbol time-domain signals are determined according to frame synchronization head.
- 5. the method for spread spectrum OFDM signal papr is reduced as claimed in claim 4, it is characterised in that also wrap Contain：In receiving terminal, spread spectrum OFDM time-domain signal is passed through into FFT, then handle by channel estimation and Channel Equalization Algorithm Afterwards, it is changed into quadrature amplitude modulation signal sequence, then carries out conjugation computing cross-correlation with local reference CAZAC sequences, obtain phase Guan Feng position, the CAZAC sequences of cyclic shift according to corresponding to determining correlation peak location, and it is mapped as K positions bit data.
- 6. the method for spread spectrum OFDM signal papr is reduced as claimed in claim 1, it is characterised in that also wrap Contain：Mapping orthogonality amplitude-modulated signal after data to be sent are grouped by K positions bit.
- 7. the method for spread spectrum OFDM signal papr is reduced as claimed in claim 1, it is characterised in that also wrap Contain：Cyclic prefix module is provided with transmitting terminal, for the increase cyclic prefix to spread spectrum OFDM signal；It is provided with receiving terminal and goes cyclic prefix module, for removes the cyclic prefix of transmitting terminal addition.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201711268609.7A CN107800662B (en) | 2017-12-05 | 2017-12-05 | Method for reducing peak-to-average power ratio of spread spectrum OFDM signal |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201711268609.7A CN107800662B (en) | 2017-12-05 | 2017-12-05 | Method for reducing peak-to-average power ratio of spread spectrum OFDM signal |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN107800662A true CN107800662A (en) | 2018-03-13 |
| CN107800662B CN107800662B (en) | 2021-01-19 |
Family
ID=61536814
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201711268609.7A Active CN107800662B (en) | 2017-12-05 | 2017-12-05 | Method for reducing peak-to-average power ratio of spread spectrum OFDM signal |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN107800662B (en) |
Cited By (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109309541A (en) * | 2018-10-10 | 2019-02-05 | 西北工业大学 | One kind being based on the jamproof half physical varification system of Unmanned Aerial Vehicle Data Link and verification method |
| WO2020103687A1 (en) * | 2018-11-19 | 2020-05-28 | 华为技术有限公司 | Signal transmission method and apparatus |
| CN111628953A (en) * | 2020-04-28 | 2020-09-04 | 珠海中慧微电子有限公司 | Method for reducing peak-to-average ratio of OFDM signal |
| CN112737997A (en) * | 2020-12-25 | 2021-04-30 | 上海微波技术研究所（中国电子科技集团公司第五十研究所） | Navigation communication integrated signal waveform construction method and system based on FH-OFDM |
| CN112787610A (en) * | 2020-12-22 | 2021-05-11 | 湖南艾科诺维科技有限公司 | Parallel implementation device and method for constantly establishing time digital AGC loop |
| CN113541914A (en) * | 2021-07-05 | 2021-10-22 | 中国人民解放军国防科技大学 | CNAV-2 text frame synchronization method based on association rule |
| CN113904907A (en) * | 2021-10-18 | 2022-01-07 | 中国人民解放军陆军工程大学 | Orthogonal multi-subset spread spectrum OFDM modulation and demodulation method based on comparison amplitude |
| CN114747185A (en) * | 2019-12-13 | 2022-07-12 | 中兴通讯股份有限公司 | Modulation scheme based on non-zero insertion for low peak-to-average power ratio |
| CN115208725A (en) * | 2022-05-07 | 2022-10-18 | 中国人民解放军国防科技大学 | Method, device and medium for combining OFDM synchronization and information modulation |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1674570A (en) * | 2005-04-30 | 2005-09-28 | 北京航空航天大学 | Short-distance radio network data transmitting method |
| CN1674467A (en) * | 2005-05-13 | 2005-09-28 | 北京航空航天大学 | Data transmitting method in short-distance radio network |
| CN1677885A (en) * | 2005-05-26 | 2005-10-05 | 北京航空航天大学 | Diversity receiving method in spread spectrum communication system based on linear frequency regulation series |
| CN103763061A (en) * | 2014-01-13 | 2014-04-30 | 宁波大学 | Anti-fading mobile signal framing modulation method for multimedia broadcast single frequency network |
-
2017
- 2017-12-05 CN CN201711268609.7A patent/CN107800662B/en active Active
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1674570A (en) * | 2005-04-30 | 2005-09-28 | 北京航空航天大学 | Short-distance radio network data transmitting method |
| CN1674467A (en) * | 2005-05-13 | 2005-09-28 | 北京航空航天大学 | Data transmitting method in short-distance radio network |
| CN1677885A (en) * | 2005-05-26 | 2005-10-05 | 北京航空航天大学 | Diversity receiving method in spread spectrum communication system based on linear frequency regulation series |
| CN103763061A (en) * | 2014-01-13 | 2014-04-30 | 宁波大学 | Anti-fading mobile signal framing modulation method for multimedia broadcast single frequency network |
Cited By (17)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109309541B (en) * | 2018-10-10 | 2021-04-02 | 西北工业大学 | Unmanned aerial vehicle data chain anti-interference-based semi-physical verification system and verification method |
| CN109309541A (en) * | 2018-10-10 | 2019-02-05 | 西北工业大学 | One kind being based on the jamproof half physical varification system of Unmanned Aerial Vehicle Data Link and verification method |
| WO2020103687A1 (en) * | 2018-11-19 | 2020-05-28 | 华为技术有限公司 | Signal transmission method and apparatus |
| US11368348B2 (en) | 2018-11-19 | 2022-06-21 | Huawei Technologies Co., Ltd. | Signal transmission method and apparatus |
| CN114747185B (en) * | 2019-12-13 | 2024-02-06 | 中兴通讯股份有限公司 | Non-zero insertion based modulation scheme for low peak-to-average power ratio |
| CN114747185A (en) * | 2019-12-13 | 2022-07-12 | 中兴通讯股份有限公司 | Modulation scheme based on non-zero insertion for low peak-to-average power ratio |
| CN111628953A (en) * | 2020-04-28 | 2020-09-04 | 珠海中慧微电子有限公司 | Method for reducing peak-to-average ratio of OFDM signal |
| CN111628953B (en) * | 2020-04-28 | 2022-11-11 | 珠海中慧微电子有限公司 | Method for reducing peak-to-average ratio of OFDM signal |
| CN112787610A (en) * | 2020-12-22 | 2021-05-11 | 湖南艾科诺维科技有限公司 | Parallel implementation device and method for constantly establishing time digital AGC loop |
| CN112737997B (en) * | 2020-12-25 | 2022-09-13 | 上海微波技术研究所（中国电子科技集团公司第五十研究所） | Navigation communication integrated signal waveform construction method and system based on FH-OFDM |
| CN112737997A (en) * | 2020-12-25 | 2021-04-30 | 上海微波技术研究所（中国电子科技集团公司第五十研究所） | Navigation communication integrated signal waveform construction method and system based on FH-OFDM |
| CN113541914B (en) * | 2021-07-05 | 2022-05-24 | 中国人民解放军国防科技大学 | CNAV-2 text frame synchronization method based on association rule |
| CN113541914A (en) * | 2021-07-05 | 2021-10-22 | 中国人民解放军国防科技大学 | CNAV-2 text frame synchronization method based on association rule |
| CN113904907A (en) * | 2021-10-18 | 2022-01-07 | 中国人民解放军陆军工程大学 | Orthogonal multi-subset spread spectrum OFDM modulation and demodulation method based on comparison amplitude |
| CN113904907B (en) * | 2021-10-18 | 2023-05-30 | 中国人民解放军陆军工程大学 | Orthogonal multi-subset spread spectrum OFDM modulation demodulation method based on phase discrimination phase contrast |
| CN115208725A (en) * | 2022-05-07 | 2022-10-18 | 中国人民解放军国防科技大学 | Method, device and medium for combining OFDM synchronization and information modulation |
| CN115208725B (en) * | 2022-05-07 | 2024-02-02 | 中国人民解放军国防科技大学 | Method, device and medium for combining OFDM synchronization and information modulation |
Also Published As
| Publication number | Publication date |
|---|---|
| CN107800662B (en) | 2021-01-19 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN107800662A (en) | A kind of method for reducing spread spectrum OFDM signal papr | |
| CN1973467B (en) | Apparatus and method for transmitting/receiving pilot signals in a communication system using an orthogonal frequency division multiplexing scheme | |
| RU2268547C2 (en) | Method and device for transmitting and receiving additional information from series transferred in portions via communication system | |
| TWI405429B (en) | Apparatus for transmitting data using carriers and method thereof | |
| JP2014526201A (en) | Method and apparatus for reducing PAPR in a filter bank multi-carrier system | |
| CN101848184B (en) | Selective mapping scrambling method for reducing peak-to-average power ratio of orthogonal frequency division multiplexing system | |
| CN1885846A (en) | Orthogonal frequency-division multiplexing system and selective mapping transmitting and receiving method | |
| CN101783781A (en) | Information transmission method for lowering peak to average power ratio of OFDM system signal | |
| CN110290087B (en) | Method and device for modulating and demodulating GFDM signal | |
| CN106534034B (en) | The coding method and system of peak-to-average force ratio in a kind of reduction ofdm system | |
| CN113315541B (en) | Pseudo-random phase sequence spread spectrum modulation method | |
| CN101394385B (en) | Method for promoting OFDM system based on time domain processing combined channel estimation | |
| Kumbasar et al. | Better wavelet packet tree structures for PAPR reduction in WOFDM systems | |
| CN109861939B (en) | OQPSK frequency domain equalization wireless data transmission method | |
| CN109067686A (en) | Method for transmitting signals based on binary phase shift keying modulation and orthogonal frequency division multiplexi | |
| CN110071890A (en) | A kind of low peak average ratio FBMC-OQAM signal processing method and system | |
| CN101237251A (en) | Direct frequency spreading-OFDM modulation and demodulation method under high-speed mobile environment | |
| CN103001916B (en) | Time domain reshaping method of orthogonal frequency division multiplexing (OFDM) communication system | |
| Rony et al. | Performance analysis of OFDM signal using BPSK and QPSK modulation techniques | |
| CN1791081A (en) | Training symbol transmitting method based on CAZAC code in wireless communication system | |
| CN107566311B (en) | Transmission method based on resource block filtering RB F-OFDM system | |
| Khare et al. | Effect of Doppler frequency and ber in FFT based OFDM system with Rayleigh fading channel | |
| CN112671686B (en) | Method, device and system for inhibiting peak-to-average power ratio of orthogonal frequency division multiplexing signal | |
| KR20040035288A (en) | Multi-carrier transmission system capable of improving the performance of receiving and a method proessing signal thereof | |
| CN111245755A (en) | Self-adaptive rate transmission method of low-complexity single carrier frequency domain equalization system |
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 |