WO2015149553A1 - Low peak average ratio wireless optical transmission method based on dynamic scalar adjustment - Google Patents

Low peak average ratio wireless optical transmission method based on dynamic scalar adjustment Download PDF

Info

Publication number
WO2015149553A1
WO2015149553A1 PCT/CN2014/095249 CN2014095249W WO2015149553A1 WO 2015149553 A1 WO2015149553 A1 WO 2015149553A1 CN 2014095249 W CN2014095249 W CN 2014095249W WO 2015149553 A1 WO2015149553 A1 WO 2015149553A1
Authority
WO
WIPO (PCT)
Prior art keywords
signal
ofdm
symbol
time domain
received
Prior art date
Application number
PCT/CN2014/095249
Other languages
French (fr)
Chinese (zh)
Inventor
张华�
袁颖
许威
Original Assignee
东南大学
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by 东南大学 filed Critical 东南大学
Publication of WO2015149553A1 publication Critical patent/WO2015149553A1/en

Links

Images

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B10/00—Transmission systems employing electromagnetic waves other than radio-waves, e.g. infrared, visible or ultraviolet light, or employing corpuscular radiation, e.g. quantum communication
    • H04B10/11—Arrangements specific to free-space transmission, i.e. transmission through air or vacuum
    • H04B10/114—Indoor or close-range type systems
    • H04B10/116—Visible light communication
    • 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
    • H04L27/2624—Reduction thereof by clipping by soft 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
    • 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
    • H04L27/2647—Arrangements specific to the receiver only

Definitions

  • the invention relates to a low peak-to-average ratio wireless optical transmission method based on dynamic scalar adjustment, belonging to a wireless optical communication technology.
  • wireless optical communication Due to its rich spectrum resources, good communication security, large transmission power, and low electromagnetic radiation, wireless optical communication has become a hot research topic in the field of communication in recent years.
  • ISI inter-symbol interference
  • OFDM modulation in wireless optical communication
  • Fight multipath effects In order to realize high-speed data transmission of wireless optical communication, reduce inter-symbol interference (ISI), introduce OFDM modulation in wireless optical communication, and provide high-speed data transmission by transmitting modulated symbols in parallel on orthogonal subcarriers. Fight multipath effects.
  • Intensity modulation/direct detection is often used in wireless optical communication, so the time domain transmission signal after OFDM modulation needs to be a positive signal that is guaranteed to be a real value.
  • OFDM DC biased optical OFDM
  • ACO-OFDM asymmetric peaked optical OFDM
  • ACO-OFDM only transmits modulation symbols on odd subcarriers, and even subcarriers do not transmit symbols, discarding the negative part of the time domain signal obtained by IFFT, leaving only the positive part. This can ensure that the transmitted time domain signal is a positive real signal, and can reduce the transmission power and save resources, but the frequency utilization is low, and N subcarriers can only transmit N/4 symbols.
  • DCO-OFDM adds a DC offset to the OFDM-modulated signal, making the signal positive. This method is simple to implement and has high frequency utilization, but increases DC power consumption.
  • the OFDM system in wireless optical communication Similar to the OFDM system in radio frequency communication, the OFDM system in wireless optical communication also has a problem that the signal peak-to-average power ratio is too high.
  • the high PAPR puts high demands on the linearity of the power amplifier at the transmitter end.
  • the PAPR is too high, in addition to the power amplifier, it also puts higher requirements on the linearity of the LED lamp, due to the power amplifier and the LED lamp.
  • Nonlinear characteristics can cause nonlinear distortion, which can seriously degrade the overall performance of the system.
  • high PAPR can also result in an increase in the required DC offset, thereby increasing system power consumption.
  • a variety of methods for reducing PAPR in OFDM systems have been proposed in radio frequency communication, such as limiting, dynamic constellation extension (ACE), coding, partial transmission sequence (PTS), selective mapping (SLM), reserved subcarriers ( TR) and so on.
  • ACE dynamic constellation extension
  • PTS partial transmission sequence
  • SLM selective mapping
  • TR reserved subcarriers
  • the present invention provides a low-peak-to-average ratio wireless optical transmission method based on dynamic scalar adjustment, which is a very simple method for reducing PAPR of wireless optical communication, according to each method.
  • the time domain peak of one OFDM symbol is used to select different scalar adjustment coefficients, so that the symbols with particularly large peaks are compressed to a certain extent, thereby reducing the PAPR of the entire frame signal, thereby improving the transmission performance; only receiving and receiving by measurement at the receiving end
  • the average power of the symbol is used to estimate the scalar coefficient multiplied at the transmitting end, which is simple to implement.
  • the improvement of PAPR reduces the linearity requirements of the system for the power amplifier and the LED lamp, and reduces the nonlinear distortion of the signal in the electric and optical domains.
  • the system receives performance; the PAPR drop also reduces the DC offset required at the transmitter, reducing system power consumption.
  • the system At the transmitting end, first, the system generates a frequency domain symbol through which the bit information stream is modulated by constellation point mapping modulation; secondly, the frequency domain signal is conjugate symmetrically mapped on the system subcarrier and passed an inverse fast Fourier transform (IFFT) Generating a real-valued baseband time-domain orthogonal frequency division multiplexing (OFDM) transmission signal; then, multiplying each symbol by a corresponding scalar adjustment coefficient according to the time domain peak of each OFDM symbol; finally, the time domain transmission signal is added
  • IFFT inverse fast Fourier transform
  • OFDM orthogonal frequency division multiplexing
  • the photodiode converts the received optical signal into an electrical signal
  • the receiver estimates the scalar adjustment coefficient at which the signal is multiplied at the transmitting end according to the received average power of each OFDM symbol; then, it will receive
  • the time domain OFDM symbol is divided by the estimated adjustment coefficient and then subjected to Fast Fourier Transform (FFT) conversion to the frequency domain symbol, and the conjugate symmetric portion is removed; finally, the received symbol is obtained by demodulation.
  • FFT Fast Fourier Transform
  • the invention is simple to implement, can effectively reduce the peak-to-average power ratio of the wireless optical communication OFDM system, reduce the system power consumption, and reduces the nonlinearity of the signal in the electric and optical domains by reducing the linearity requirements of the power amplifier and the LED lamp. Distortion, which improves system reception performance.
  • the above method specifically includes the following steps:
  • the transmitting end :
  • the number of subcarriers in the OFDM system of the wireless optical communication is set to N, and the signal transmitted in each frame has M OFDM symbols; the binary data source generated by the source is subjected to multi-ary quadrature amplitude modulation (M-QAM) ), forming a frequency domain signal to be transmitted
  • M-QAM multi-ary quadrature amplitude modulation
  • the subcarrier mapping in OFDM is performed according to the following formula, which satisfies the conjugate symmetry: (in the case of no confusion, the superscript (m) is omitted for simplicity of explanation)
  • the frequency domain signal is converted to a real value time domain OFDM signal after N point IFFT as follows:
  • the photodiode converts the optical signal into a time domain electrical signal by calculating each received OFDM symbol Average power using the maximum a posteriori (MAP) criterion to estimate the modulation factor of the symbol Detecting received signals based on estimated adjustment factors which is among them Time domain OFDM transmission symbols estimated for the receiving end;
  • MAP maximum a posteriori
  • the low peak-to-average ratio wireless optical transmission method based on dynamic scalar adjustment provided by the invention has the following advantages: 1. No additional sideband information needs to be transmitted, and the peak-to-average power ratio of the system can be effectively reduced without wasting frequency resources. 2, whether it is the implementation of the transmitter or receiver is very simple; 3, low PAPR can reduce the system's linearity requirements for power amplifiers and LED lights, reduce the implementation of the transmitter, and reduce the nonlinear characteristics of the power amplifier and LED lights The resulting nonlinear distortion improves the reception performance of the system. 4. The low PAPR also reduces the size of the DC component that must be added to the transmission, reducing the system power consumption.
  • FIG. 1 is a system block diagram of a low peak-to-average ratio wireless optical transmission method based on dynamic scalar adjustment according to the present invention
  • 2 is a schematic diagram of time-domain OFDM symbols for wireless optical communication without adjustment of scalar coefficients and adjustment;
  • 3 is a PAPR complementary cumulative probability distribution graph of the present invention and a generally unconditioned optical communication OFDM.
  • a low-peak-to-average ratio wireless optical transmission method based on dynamic scalar adjustment is performed as follows: At the transmitting end, first, the system generates a bit information stream and modulates it into a frequency domain symbol to be transmitted through constellation point mapping. Secondly, the frequency domain signal is symmetrically mapped symmetrically on the system subcarrier, and the real value baseband time domain transmission signal is generated by the inverse fast Fourier transform; then, according to the time domain peak of each OFDM symbol, for each The symbol is multiplied by the corresponding scalar adjustment factor; finally, the time domain transmit signal plus the DC bias drives the LED to transmit.
  • the photodiode converts the received optical signal into an electrical signal, and based on the received average power of each OFDM symbol, the scalar adjustment coefficient multiplied at the transmitting end; and then, the received time domain
  • the OFDM symbol is divided by the estimated adjustment coefficient and then converted into a frequency domain symbol by a fast Fourier transform, and the conjugate symmetric portion is removed.
  • the received symbol is obtained by demodulation.
  • the transmitting end :
  • the number of subcarriers in the OFDM system of the wireless optical communication is set to N, and the signal transmitted in each frame has M OFDM symbols; the binary data source generated by the source is subjected to multi-ary quadrature amplitude modulation (M-QAM) ), forming a frequency domain signal to be transmitted
  • M-QAM multi-ary quadrature amplitude modulation
  • the subcarrier mapping in OFDM is performed according to the following formula, which satisfies the conjugate symmetry: (in the case of no confusion, the superscript (m) is omitted for simplicity of explanation)
  • the frequency domain signal is converted to a real value time domain OFDM signal after N point IFFT as follows:
  • the photodiode converts the optical signal into a time domain electrical signal by calculating each received OFDM symbol Average power using the maximum a posteriori (MAP) criterion to estimate the modulation factor of the symbol Detecting received signals based on estimated adjustment factors which is among them Time domain OFDM transmission symbols estimated for the receiving end;
  • MAP maximum a posteriori
  • each symbol is multiplied by a corresponding scalar adjustment coefficient according to the time domain peak of each OFDM, and the entire OFDM symbol is compressed by multiplying the excessively large symbol by the adjustment coefficient ⁇ ( ⁇ 1). Thereby reducing the PAPR of the entire frame signal.
  • Figure 3 shows the optical communication OFDM system without coefficient adjustment and the PAPR complementary cumulative distribution curve of the system after using the method.
  • the system adopts 16-QAM modulation.
  • the adjustment coefficient is adopted.
  • the adjustment coefficient is According to the frame statistics system PAPR, namely:
  • the method can effectively reduce the PAPR of the system, thereby reducing the linearity requirement of the device at the transmitting end, reducing the nonlinear distortion of the signal in the electric and optical domains, and improving the overall receiving performance of the system.

Abstract

A low peak average ratio wireless optical transmission method based on dynamic scalar adjustment is disclosed in the present invention. Different scalar adjustment coefficients are selected according to the time domain peak value of each OFDM symbol, and the symbols with extra-high peak value are compressed at a certain extent, so as to reduce the PAPR of the signals of a whole frame and improve the transmission performance. The method is easy to be realized because that the receiving end only needs to estimate the scalar coefficient multiplied at the transmission end by measuring average power of the received symbols. The improvement of the PAPR reduces the system request for the amplification and the LED light linearity, reduces the non-linear distortion of the signals in electrical domain and optical domain, and improves the receiving performance of the system. The drop of the PAPR also reduces the direct current bias needed at the transmission end, and reduces the power wastage of the system.

Description

一种基于动态标量调节的低峰均比无线光传输方法Low peak-to-average ratio wireless optical transmission method based on dynamic scalar adjustment 技术领域Technical field
本发明涉及一种基于动态标量调节的低峰均比无线光传输方法，属于无线光通信技术。The invention relates to a low peak-to-average ratio wireless optical transmission method based on dynamic scalar adjustment, belonging to a wireless optical communication technology.
背景技术Background technique
无线光通信由于其频谱资源丰富、通信安全性好、发射功率大、电磁辐射少等优势，近些年来已经成为通信领域研究的热点。为了能够实现无线光通信的高速数据传输，降低符号间干扰(ISI)，在无线光通信中引入OFDM调制，通过将调制好的符号并行在正交的子载波上发送，可以提供高速数据传输，对抗多径效应。Due to its rich spectrum resources, good communication security, large transmission power, and low electromagnetic radiation, wireless optical communication has become a hot research topic in the field of communication in recent years. In order to realize high-speed data transmission of wireless optical communication, reduce inter-symbol interference (ISI), introduce OFDM modulation in wireless optical communication, and provide high-speed data transmission by transmitting modulated symbols in parallel on orthogonal subcarriers. Fight multipath effects.
在无线光通信中常使用强度调制/直接检测(IM/DD)，因此OFDM调制后的时域发射信号需要保证为实值的正信号。目前有两种比较常用的光通信OFDM方法，直流偏置光OFDM(DCO-OFDM)和非对称削峰光OFDM(ACO-OFDM)。ACO-OFDM只在奇数子载波上传输调制符号，偶数子载波不发送符号，将经过IFFT得到的时域信号的负数部分丢弃，只保留正值部分。这样既能保证发送的时域信号是正的实信号，又能降低发射功率，节约资源，但是频率利用率较低，N个子载波只能发送N/4个符号，这种方法以牺牲数据速率为代价避免了加入直流偏置的功率损耗。DCO-OFDM即在经过OFDM调制后的信号上加入直流偏置，使得信号变为正值，这种方法实现简单，频率利用率高，但是增加了直流功耗。Intensity modulation/direct detection (IM/DD) is often used in wireless optical communication, so the time domain transmission signal after OFDM modulation needs to be a positive signal that is guaranteed to be a real value. There are currently two commonly used optical communication OFDM methods, DC biased optical OFDM (DCO-OFDM) and asymmetric peaked optical OFDM (ACO-OFDM). ACO-OFDM only transmits modulation symbols on odd subcarriers, and even subcarriers do not transmit symbols, discarding the negative part of the time domain signal obtained by IFFT, leaving only the positive part. This can ensure that the transmitted time domain signal is a positive real signal, and can reduce the transmission power and save resources, but the frequency utilization is low, and N subcarriers can only transmit N/4 symbols. This method sacrifices the data rate. The cost avoids the power loss of adding a DC offset. DCO-OFDM adds a DC offset to the OFDM-modulated signal, making the signal positive. This method is simple to implement and has high frequency utilization, but increases DC power consumption.
与射频通信中的OFDM系统类似，无线光通信中的OFDM系统也存在着信号峰均功率比过高的问题。PAPR偏高会对发射机端功放的线性度提出很高的要求，在光OFDM系统中，PAPR过高除了对功放以外，还对LED灯的线性度提出更高的要求，由于功放和LED灯非线性特性会导致非线性失真，从而严重降低系统的整体性能。同时，在无线光通信DCO-OFDM系统中，高PAPR还会导致需要的直流偏置增加，从而增大系统功率消耗。Similar to the OFDM system in radio frequency communication, the OFDM system in wireless optical communication also has a problem that the signal peak-to-average power ratio is too high. The high PAPR puts high demands on the linearity of the power amplifier at the transmitter end. In the optical OFDM system, the PAPR is too high, in addition to the power amplifier, it also puts higher requirements on the linearity of the LED lamp, due to the power amplifier and the LED lamp. Nonlinear characteristics can cause nonlinear distortion, which can seriously degrade the overall performance of the system. At the same time, in wireless optical communication DCO-OFDM systems, high PAPR can also result in an increase in the required DC offset, thereby increasing system power consumption.
在无线射频通信中已经提出了很多种降低OFDM系统PAPR的方法，如限幅、动态星座图扩展(ACE)、编码、部分传输序列(PTS)、选择性映射(SLM)、预留子载波(TR)等。A variety of methods for reducing PAPR in OFDM systems have been proposed in radio frequency communication, such as limiting, dynamic constellation extension (ACE), coding, partial transmission sequence (PTS), selective mapping (SLM), reserved subcarriers ( TR) and so on.
发明内容Summary of the invention
发明目的：为了克服现有技术中存在的不足，本发明提供一种基于动态标量调节的低峰均比无线光传输方法，是一种实现非常简单的降低无线光通信PAPR的方法，其根据每一个OFDM符号的时域峰值来选择不同的标量调节系数，从而对峰值特别大的符号进行一定程度的压缩，从而降低整帧信号的PAPR，从而提高传输性能；在接收端也只需要通过测量接收符号的平均功率来估计出在发射端被乘以的标量系数，实现简单；PAPR的改善降低了系统对功放和LED灯线性度的要求，减少了信号在电、光域的非线性失真，提高了系统接收性能；PAPR的下降也减少了发射端需要增加的直流偏置，减少了系统功耗。 OBJECT OF THE INVENTION In order to overcome the deficiencies in the prior art, the present invention provides a low-peak-to-average ratio wireless optical transmission method based on dynamic scalar adjustment, which is a very simple method for reducing PAPR of wireless optical communication, according to each method. The time domain peak of one OFDM symbol is used to select different scalar adjustment coefficients, so that the symbols with particularly large peaks are compressed to a certain extent, thereby reducing the PAPR of the entire frame signal, thereby improving the transmission performance; only receiving and receiving by measurement at the receiving end The average power of the symbol is used to estimate the scalar coefficient multiplied at the transmitting end, which is simple to implement. The improvement of PAPR reduces the linearity requirements of the system for the power amplifier and the LED lamp, and reduces the nonlinear distortion of the signal in the electric and optical domains. The system receives performance; the PAPR drop also reduces the DC offset required at the transmitter, reducing system power consumption.
技术方案：为实现上述目的，本发明采用的技术方案为：Technical Solution: In order to achieve the above object, the technical solution adopted by the present invention is:
一种基于动态标量调节的低峰均比无线光传输方法，A low peak-to-average ratio wireless optical transmission method based on dynamic scalar adjustment,
在发射端，首先，系统产生比特信息流经过星座点映射调制需要发射的频域符号；其次，频域信号共轭对称地映射在系统子载波上，并通过快速傅里叶逆变换(IFFT)产生实值的基带时域正交频分复用(OFDM)发射信号；然后，根据每一个OFDM符号的时域峰值，对每个符号乘以相应的标量调节系数；最后，时域发射信号加上直流偏置后驱动发光二极管(LED)进行发射；At the transmitting end, first, the system generates a frequency domain symbol through which the bit information stream is modulated by constellation point mapping modulation; secondly, the frequency domain signal is conjugate symmetrically mapped on the system subcarrier and passed an inverse fast Fourier transform (IFFT) Generating a real-valued baseband time-domain orthogonal frequency division multiplexing (OFDM) transmission signal; then, multiplying each symbol by a corresponding scalar adjustment coefficient according to the time domain peak of each OFDM symbol; finally, the time domain transmission signal is added Driving a light emitting diode (LED) to emit after DC biasing;
在接收端，首先，光电二极管将接收到的光信号转化为电信号，接收机根据接收到的每一个OFDM符号平均功率估计出信号在发射端被乘以的标量调节系数；然后，将接收到的时域OFDM符号除以估计出的调节系数后做快速傅里叶变换(FFT)转换为频域符号，并移除共轭对称部分；最后，经过解调得到接收符号。本发明实现简单，能够有效降低无线光通信OFDM系统的峰均功率比，减少系统功耗，并且通过降低对功率放大器和LED灯线性度的要求，减小了信号在电、光域的非线性失真，从而提高系统接收性能。At the receiving end, first, the photodiode converts the received optical signal into an electrical signal, and the receiver estimates the scalar adjustment coefficient at which the signal is multiplied at the transmitting end according to the received average power of each OFDM symbol; then, it will receive The time domain OFDM symbol is divided by the estimated adjustment coefficient and then subjected to Fast Fourier Transform (FFT) conversion to the frequency domain symbol, and the conjugate symmetric portion is removed; finally, the received symbol is obtained by demodulation. The invention is simple to implement, can effectively reduce the peak-to-average power ratio of the wireless optical communication OFDM system, reduce the system power consumption, and reduces the nonlinearity of the signal in the electric and optical domains by reducing the linearity requirements of the power amplifier and the LED lamp. Distortion, which improves system reception performance.
上述方法具体包括如下步骤：The above method specifically includes the following steps:
发射端：The transmitting end:
(11)在发射端，设定无线光通信OFDM系统的子载波数为N，每帧发送信号有M个OFDM符号；信源产生的二进制数据源经过多进制正交幅度调制(M-QAM)，形成待发送的频域信号
Figure PCTCN2014095249-appb-000001
 (11) At the transmitting end, the number of subcarriers in the OFDM system of the wireless optical communication is set to N, and the signal transmitted in each frame has M OFDM symbols; the binary data source generated by the source is subjected to multi-ary quadrature amplitude modulation (M-QAM) ), forming a frequency domain signal to be transmitted
Figure PCTCN2014095249-appb-000001
(12)为了满足无线光信号为实值，OFDM中子载波映射按照下面公式进行，满足共轭对称性：(在不引起混淆的情况下，为简化说明，上标(m)省略)(12) In order to satisfy the wireless optical signal as a real value, the subcarrier mapping in OFDM is performed according to the following formula, which satisfies the conjugate symmetry: (in the case of no confusion, the superscript (m) is omitted for simplicity of explanation)
Figure PCTCN2014095249-appb-000002
Figure PCTCN2014095249-appb-000002
其中，(□)*表示取复数共轭；Where (□) * indicates that the complex number is conjugated;
(13)频域信号经N点IFFT后转为实值时域OFDM信号如下：(13) The frequency domain signal is converted to a real value time domain OFDM signal after N point IFFT as follows:
Figure PCTCN2014095249-appb-000003
Figure PCTCN2014095249-appb-000003
其中，n＝0,1,…,N-1，为时域OFDM符号序列；Where n=0,1,...,N-1 is a time domain OFDM symbol sequence;
(14)根据每一个时域OFDM符号的峰值，在{1,α}中选择合适的调节系数，其中0<α<1，是用于压缩峰值过大的OFDM符号的标量调节系数，通常取值范围0.5～0.9，一般可取
Figure PCTCN2014095249-appb-000004
有
Figure PCTCN2014095249-appb-000005
其中调节系数满足
Figure PCTCN2014095249-appb-000006
T为正门限值，可以根据发射信号峰值的分布以及信道特性的不同取值，如对于采用16-QAM调制，子载波数N＝128的光OFDM系统，取门限T＝3.1时，有10％的OFDM符号峰值超过门限将被调节压缩；(14) According to the peak value of each time domain OFDM symbol, select an appropriate adjustment coefficient in {1, α}, where 0 < α < 1, which is a scalar adjustment coefficient for compressing an OFDM symbol whose peak value is too large, usually The value ranges from 0.5 to 0.9, which is generally desirable.
Figure PCTCN2014095249-appb-000004
Have
Figure PCTCN2014095249-appb-000005
 Where the adjustment factor is satisfied
Figure PCTCN2014095249-appb-000006
 T is the positive threshold, which can be based on the distribution of the peak value of the transmitted signal and the channel characteristics. For an optical OFDM system with 16-QAM modulation and subcarrier number N=128, 10% when the threshold is T=3.1. The peak value of the OFDM symbol exceeds the threshold and will be adjusted and compressed;
(15)经过调整后的信号
Figure PCTCN2014095249-appb-000007
送往光通信发射模块，加上直流偏置后驱动LED灯发射；(15) The adjusted signal
Figure PCTCN2014095249-appb-000007
 Sended to the optical communication transmitter module, plus DC bias to drive the LED light to launch;
接收端：Receiving end:
(21)在接收端，光电二极管将光信号转换为时域电信号，通过计算每一个接收到的OFDM符号
Figure PCTCN2014095249-appb-000008
的平均功率采用最大后验(MAP)准则估计出该符号的调制系数
Figure PCTCN2014095249-appb-000009
根据估计的调节系数，检测接收信号
Figure PCTCN2014095249-appb-000010
即
Figure PCTCN2014095249-appb-000011
其中
Figure PCTCN2014095249-appb-000012
为接收端估计的时域OFDM发射符号；(21) At the receiving end, the photodiode converts the optical signal into a time domain electrical signal by calculating each received OFDM symbol
Figure PCTCN2014095249-appb-000008
Average power using the maximum a posteriori (MAP) criterion to estimate the modulation factor of the symbol
Figure PCTCN2014095249-appb-000009
Detecting received signals based on estimated adjustment factors
Figure PCTCN2014095249-appb-000010
which is
Figure PCTCN2014095249-appb-000011
among them
Figure PCTCN2014095249-appb-000012
 Time domain OFDM transmission symbols estimated for the receiving end;
(22)对
Figure PCTCN2014095249-appb-000013
作N点FFT变换后得到频域接收信号
Figure PCTCN2014095249-appb-000014
解调获得最终的接收符号。(22) Right
Figure PCTCN2014095249-appb-000013
Frequency domain received signal after N-point FFT transform
Figure PCTCN2014095249-appb-000014
 Demodulation obtains the final received symbol.
有益效果：本发明提供的基于动态标量调节的低峰均比无线光传输方法，具有如下优点：1、不需要传输额外的边带信息，不浪费频率资源即可有效的降低系统峰均功率比；2、无论是发射机还是接收机的实现都非常简单；3、低PAPR可以降低系统对功放和LED灯线性度的要求，降低发射机的实现难度，并且降低由于功放和LED灯非线性特性而导致的非线性失真，提高系统的接收性能；4、低PAPR也降低了发射所必须加入的直流分量大小，减少了系统功耗。Advantageous Effects: The low peak-to-average ratio wireless optical transmission method based on dynamic scalar adjustment provided by the invention has the following advantages: 1. No additional sideband information needs to be transmitted, and the peak-to-average power ratio of the system can be effectively reduced without wasting frequency resources. 2, whether it is the implementation of the transmitter or receiver is very simple; 3, low PAPR can reduce the system's linearity requirements for power amplifiers and LED lights, reduce the implementation of the transmitter, and reduce the nonlinear characteristics of the power amplifier and LED lights The resulting nonlinear distortion improves the reception performance of the system. 4. The low PAPR also reduces the size of the DC component that must be added to the transmission, reducing the system power consumption.
附图说明DRAWINGS
图1为本发明提出的基于动态标量调节的低峰均比无线光传输方法的系统框图；1 is a system block diagram of a low peak-to-average ratio wireless optical transmission method based on dynamic scalar adjustment according to the present invention;
图2是未经标量系数调节以及经调节后的无线光通信时域OFDM符号示意图；2 is a schematic diagram of time-domain OFDM symbols for wireless optical communication without adjustment of scalar coefficients and adjustment;
图3是本发明与一般未调节的光通信OFDM的PAPR互补累计概率分布曲线图。 3 is a PAPR complementary cumulative probability distribution graph of the present invention and a generally unconditioned optical communication OFDM.
具体实施方式detailed description
下面结合附图对本发明作更进一步的说明。The present invention will be further described below in conjunction with the accompanying drawings.
如图1所示为一种基于动态标量调节的低峰均比无线光传输方法，按如下步骤进行：在发射端，首先，系统产生比特信息流经过星座点映射调制为需要发射的频域符号；其次，频域信号共轭对称地映射在系统子载波上，并通过快速傅里叶逆变换产生实值的基带时域发射信号；然后，根据每一个OFDM符号的时域峰值，对每个符号乘以相应的标量调节系数；最后，时域发射信号加上直流偏置驱动发光二极管进行发射。在接收端，首先，光电二极管将接收到的光信号转化为电信号，根据接收到的每一个OFDM符号平均功率估计信号在发射端被乘以的标量调节系数；然后，将接收到的时域OFDM符号除以估计出的调节系数后做快速傅里叶变换转换为频域符号，并移除共轭对称部分；最后，经过解调得到接收符号。As shown in FIG. 1 , a low-peak-to-average ratio wireless optical transmission method based on dynamic scalar adjustment is performed as follows: At the transmitting end, first, the system generates a bit information stream and modulates it into a frequency domain symbol to be transmitted through constellation point mapping. Secondly, the frequency domain signal is symmetrically mapped symmetrically on the system subcarrier, and the real value baseband time domain transmission signal is generated by the inverse fast Fourier transform; then, according to the time domain peak of each OFDM symbol, for each The symbol is multiplied by the corresponding scalar adjustment factor; finally, the time domain transmit signal plus the DC bias drives the LED to transmit. At the receiving end, first, the photodiode converts the received optical signal into an electrical signal, and based on the received average power of each OFDM symbol, the scalar adjustment coefficient multiplied at the transmitting end; and then, the received time domain The OFDM symbol is divided by the estimated adjustment coefficient and then converted into a frequency domain symbol by a fast Fourier transform, and the conjugate symmetric portion is removed. Finally, the received symbol is obtained by demodulation.
上述方法具体实现过程如下：The specific implementation process of the above method is as follows:
发射端：The transmitting end:
(11)在发射端，设定无线光通信OFDM系统的子载波数为N，每帧发送信号有M个OFDM符号；信源产生的二进制数据源经过多进制正交幅度调制(M-QAM)，形成待发送的频域信号
Figure PCTCN2014095249-appb-000015
 (11) At the transmitting end, the number of subcarriers in the OFDM system of the wireless optical communication is set to N, and the signal transmitted in each frame has M OFDM symbols; the binary data source generated by the source is subjected to multi-ary quadrature amplitude modulation (M-QAM) ), forming a frequency domain signal to be transmitted
Figure PCTCN2014095249-appb-000015
(12)为了满足无线光信号为实值，OFDM中子载波映射按照下面公式进行，满足共轭对称性：(在不引起混淆的情况下，为简化说明，上标(m)省略)(12) In order to satisfy the wireless optical signal as a real value, the subcarrier mapping in OFDM is performed according to the following formula, which satisfies the conjugate symmetry: (in the case of no confusion, the superscript (m) is omitted for simplicity of explanation)
Figure PCTCN2014095249-appb-000016
Figure PCTCN2014095249-appb-000016
其中，(□)*表示取复数共轭；Where (□) * indicates that the complex number is conjugated;
(13)频域信号经N点IFFT后转为实值时域OFDM信号如下：(13) The frequency domain signal is converted to a real value time domain OFDM signal after N point IFFT as follows:
Figure PCTCN2014095249-appb-000017
Figure PCTCN2014095249-appb-000017
其中，n＝0,1,…,N-1，为时域OFDM符号序列；Where n=0,1,...,N-1 is a time domain OFDM symbol sequence;
(14)根据每一个时域OFDM符号的峰值，在{1,α}中选择合适的调节系数，其中0<α<1，是用于压缩峰值过大的OFDM符号的标量调节系数，通常取值范围0.5～0.9，一 般可取
Figure PCTCN2014095249-appb-000018
有
Figure PCTCN2014095249-appb-000019
其中调节系数满足
Figure PCTCN2014095249-appb-000020
T为正门限值，可以根据发射信号峰值的分布以及信道特性的不同取值，如对于采用16-QAM调制，子载波数N＝128的光OFDM系统，取门限T＝3.1时，有10％的OFDM符号峰值超过门限将被调节压缩；(14) According to the peak value of each time domain OFDM symbol, select an appropriate adjustment coefficient in {1, α}, where 0 < α < 1, which is a scalar adjustment coefficient for compressing an OFDM symbol whose peak value is too large, usually The value ranges from 0.5 to 0.9, which is generally desirable.
Figure PCTCN2014095249-appb-000018
Have
Figure PCTCN2014095249-appb-000019
 Where the adjustment factor is satisfied
Figure PCTCN2014095249-appb-000020
 T is the positive threshold, which can be based on the distribution of the peak value of the transmitted signal and the channel characteristics. For an optical OFDM system with 16-QAM modulation and subcarrier number N=128, 10% when the threshold is T=3.1. The peak value of the OFDM symbol exceeds the threshold and will be adjusted and compressed;
(15)经过调整后的信号
Figure PCTCN2014095249-appb-000021
送往光通信发射模块，加上直流偏置后驱动LED灯发射；(15) The adjusted signal
Figure PCTCN2014095249-appb-000021
 Sended to the optical communication transmitter module, plus DC bias to drive the LED light to launch;
接收端：Receiving end:
(21)在接收端，光电二极管将光信号转换为时域电信号，通过计算每一个接收到的OFDM符号
Figure PCTCN2014095249-appb-000022
的平均功率采用最大后验(MAP)准则估计出该符号的调制系数
Figure PCTCN2014095249-appb-000023
根据估计的调节系数，检测接收信号
Figure PCTCN2014095249-appb-000024
即
Figure PCTCN2014095249-appb-000025
其中
Figure PCTCN2014095249-appb-000026
为接收端估计的时域OFDM发射符号；(21) At the receiving end, the photodiode converts the optical signal into a time domain electrical signal by calculating each received OFDM symbol
Figure PCTCN2014095249-appb-000022
Average power using the maximum a posteriori (MAP) criterion to estimate the modulation factor of the symbol
Figure PCTCN2014095249-appb-000023
Detecting received signals based on estimated adjustment factors
Figure PCTCN2014095249-appb-000024
which is
Figure PCTCN2014095249-appb-000025
among them
Figure PCTCN2014095249-appb-000026
 Time domain OFDM transmission symbols estimated for the receiving end;
(22)对
Figure PCTCN2014095249-appb-000027
作N点FFT变换后得到频域接收信号
Figure PCTCN2014095249-appb-000028
解调获得最终的接收符号。(22) Right
Figure PCTCN2014095249-appb-000027
Frequency domain received signal after N-point FFT transform
Figure PCTCN2014095249-appb-000028
 Demodulation obtains the final received symbol.
如图2所示，根据每个OFDM的时域峰值，对每个符号乘以相应的标量调节系数，对于峰值过大的符号乘以调节系数α(α<1)，将整个OFDM符号压缩，从而降低整帧信号的PAPR。As shown in FIG. 2, each symbol is multiplied by a corresponding scalar adjustment coefficient according to the time domain peak of each OFDM, and the entire OFDM symbol is compressed by multiplying the excessively large symbol by the adjustment coefficient α (α<1). Thereby reducing the PAPR of the entire frame signal.
图3给出了未经过系数调节的光通信OFDM系统以及使用本方法后系统的PAPR互补累积分布曲线。系统均采用16-QAM调制，子载波数N＝128时，取门限T＝3.1，调节系数
Figure PCTCN2014095249-appb-000029
当子载波数N＝1024时，取门限T＝3.8，调节系数
Figure PCTCN2014095249-appb-000030
按帧统计系统PAPR，即：Figure 3 shows the optical communication OFDM system without coefficient adjustment and the PAPR complementary cumulative distribution curve of the system after using the method. The system adopts 16-QAM modulation. When the number of subcarriers is N=128, the threshold is T=3.1, and the adjustment coefficient is adopted.
Figure PCTCN2014095249-appb-000029
When the number of subcarriers is N=1024, the threshold is taken as T=3.8, and the adjustment coefficient is
Figure PCTCN2014095249-appb-000030
According to the frame statistics system PAPR, namely:
Figure PCTCN2014095249-appb-000031
Figure PCTCN2014095249-appb-000031
从图中可以观察到采用本方法可以有效降低系统的PAPR，从而降低发射端器件的线性度要求，减少信号在电、光域的非线性失真，提高系统总体接收性能。 It can be observed from the figure that the method can effectively reduce the PAPR of the system, thereby reducing the linearity requirement of the device at the transmitting end, reducing the nonlinear distortion of the signal in the electric and optical domains, and improving the overall receiving performance of the system.
以上所述仅是本发明的优选实施方式，应当指出：对于本技术领域的普通技术人员来说，在不脱离本发明原理的前提下，还可以做出若干改进和润饰，这些改进和润饰也应视为本发明的保护范围。 The above description is only a preferred embodiment of the present invention, and it should be noted that those skilled in the art can also make several improvements and retouchings without departing from the principles of the present invention. It should be considered as the scope of protection of the present invention.

Claims (2)

  1. 一种基于动态标量调节的低峰均比无线光传输方法，其特征在于：A low-peak-to-average ratio wireless optical transmission method based on dynamic scalar adjustment, which is characterized by:
    在发射端，首先，系统产生比特信息流经过星座点映射调制为需要发射的频域符号；其次，频域信号共轭对称地映射在系统子载波上，并通过快速傅里叶逆变换产生实值的基带时域发射信号；然后，根据每一个OFDM符号的时域峰值，对每个符号乘以相应的标量调节系数；最后，时域发射信号加上直流偏置驱动发光二极管进行发射；At the transmitting end, first, the system generates a bit information stream and modulates it into a frequency domain symbol to be transmitted through constellation point mapping; secondly, the frequency domain signal is conjugate symmetrically mapped on the system subcarrier, and is generated by fast inverse Fourier transform. a value of the baseband time domain transmit signal; then, according to the time domain peak of each OFDM symbol, multiply each symbol by a corresponding scalar adjustment coefficient; finally, the time domain transmit signal plus DC bias drives the LED to transmit;
    在接收端，首先，光电二极管将接收到的光信号转化为电信号，根据接收到的每一个OFDM符号平均功率估计信号在发射端被乘以的标量调节系数；然后，将接收到的时域OFDM符号除以估计出的调节系数后做快速傅里叶变换转换为频域符号，并移除共轭对称部分；最后，经过解调得到接收符号。At the receiving end, first, the photodiode converts the received optical signal into an electrical signal, and based on the received average power of each OFDM symbol, the scalar adjustment coefficient multiplied at the transmitting end; and then, the received time domain The OFDM symbol is divided by the estimated adjustment coefficient and then converted into a frequency domain symbol by a fast Fourier transform, and the conjugate symmetric portion is removed. Finally, the received symbol is obtained by demodulation.
  2. 根据权利要求1所述的基于动态标量调节的低峰均比无线光传输方法，其特征在于：包括如下步骤：The method according to claim 1, wherein the low-peak-to-average ratio wireless optical transmission method based on the dynamic scalar adjustment comprises the following steps:
    发射端：The transmitting end:
    (11)在发射端，设定无线光通信OFDM系统的子载波数为N，每帧发送信号有M个OFDM符号；信源产生的二进制数据源经过多进制正交幅度调制，形成待发送的频域信号
    Figure PCTCN2014095249-appb-100001
         (11) At the transmitting end, the number of subcarriers in the OFDM system of the wireless optical communication is set to N, and the signal transmitted in each frame has M OFDM symbols; the binary data source generated by the source is modulated by multi-ary quadrature amplitude to form a to-be-sent Frequency domain signal
    Figure PCTCN2014095249-appb-100001
    (12)OFDM中子载波映射按照下面公式进行，满足共轭对称性：(12) The subcarrier mapping in OFDM is performed according to the following formula to satisfy the conjugate symmetry:
    Figure PCTCN2014095249-appb-100002
    Figure PCTCN2014095249-appb-100002
    其中，(□)*表示取复数共轭；Where (□) * indicates that the complex number is conjugated;
    (13)频域信号经N点IFFT后转为实值时域OFDM信号如下：(13) The frequency domain signal is converted to a real value time domain OFDM signal after N point IFFT as follows:
    Figure PCTCN2014095249-appb-100003
    Figure PCTCN2014095249-appb-100003
    其中，n＝0,1,…,N-1，为时域OFDM符号序列；Where n=0,1,...,N-1 is a time domain OFDM symbol sequence;
    (14)根据每一个时域OFDM符号的峰值，在{1,α}中选择合适的调节系数，其中0<α<1，是用于压缩峰值过大的OFDM符号的标量调节系数；有
    Figure PCTCN2014095249-appb-100004
    其中调节 系数满足
    Figure PCTCN2014095249-appb-100005
    T为正门限值；    (14) selecting a suitable adjustment coefficient in {1, α} according to the peak value of each time domain OFDM symbol, where 0 < α < 1, which is a scalar adjustment coefficient for compressing an OFDM symbol whose peak value is too large;
    Figure PCTCN2014095249-appb-100004
    Where the adjustment factor is satisfied
    Figure PCTCN2014095249-appb-100005
     T is the positive threshold;
    (15)经过调整后的信号
    Figure PCTCN2014095249-appb-100006
    m＝1,...,M送往光通信发射模块，加上直流偏置后驱动LED灯发射；    (15) The adjusted signal
    Figure PCTCN2014095249-appb-100006
     m=1,...,M is sent to the optical communication transmitting module, and after the DC offset is applied, the LED lamp is driven to be launched;
    接收端：Receiving end:
    (21)在接收端，光电二极管将光信号转换为时域电信号，通过计算每一个接收到的OFDM符号
    Figure PCTCN2014095249-appb-100007
    的平均功率采用最大后验准则估计出该符号的调制系数
    Figure PCTCN2014095249-appb-100008
    根据估计的调节系数，检测接收信号
    Figure PCTCN2014095249-appb-100009
    即
    Figure PCTCN2014095249-appb-100010
    其中
    Figure PCTCN2014095249-appb-100011
    为接收端估计的时域OFDM发射符号；    (21) At the receiving end, the photodiode converts the optical signal into a time domain electrical signal by calculating each received OFDM symbol
    Figure PCTCN2014095249-appb-100007
    Average power using the maximum a posteriori criterion to estimate the modulation factor of the symbol
    Figure PCTCN2014095249-appb-100008
    Detecting received signals based on estimated adjustment factors
    Figure PCTCN2014095249-appb-100009
    which is
    Figure PCTCN2014095249-appb-100010
    among them
    Figure PCTCN2014095249-appb-100011
     Time domain OFDM transmission symbols estimated for the receiving end;
    (22)对
    Figure PCTCN2014095249-appb-100012
    作N点FFT变换后得到频域接收信号
    Figure PCTCN2014095249-appb-100013
    解调获得最终的接收符号。     (22) Right
    Figure PCTCN2014095249-appb-100012
    Frequency domain received signal after N-point FFT transform
    Figure PCTCN2014095249-appb-100013
     Demodulation obtains the final received symbol.
PCT/CN2014/095249 2014-04-02 2014-12-29 Low peak average ratio wireless optical transmission method based on dynamic scalar adjustment WO2015149553A1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
CN201410131898.6A CN103916356B (en) 2014-04-02 2014-04-02 Low-peak-to-average-ratio wireless optical transmission method based on dynamic scalar regulation
CN201410131898.6 2014-04-02

Publications (1)

Publication Number Publication Date
WO2015149553A1 true WO2015149553A1 (en) 2015-10-08

Family

ID=51041763

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/CN2014/095249 WO2015149553A1 (en) 2014-04-02 2014-12-29 Low peak average ratio wireless optical transmission method based on dynamic scalar adjustment

Country Status (2)

Country Link
CN (1) CN103916356B (en)
WO (1) WO2015149553A1 (en)

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN108896961A (en) * 2018-06-29 2018-11-27 天津大学 A method of the raising visible light positioning accuracy based on signal power estimation
CN109547381A (en) * 2019-01-17 2019-03-29 山东建筑大学 A kind of DCO-OFDM system PAPR suppressing method and system based on self-encoding encoder
CN114465665A (en) * 2022-01-24 2022-05-10 桂林电子科技大学 Light beam forming method based on maximum ratio combination under strong turbulence channel
CN114513256A (en) * 2022-02-02 2022-05-17 复旦大学 Photon counting communication method based on ACO-FBMC modulation
CN114650083A (en) * 2022-03-25 2022-06-21 深圳市力合微电子股份有限公司 Peak-to-average ratio optimization method of HPLC dual-mode high-speed wireless system
CN114679361A (en) * 2022-03-09 2022-06-28 恒玄科技(上海)股份有限公司 OFDM modulation method and communication device

Families Citing this family (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN103916356B (en) * 2014-04-02 2017-02-15 东南大学 Low-peak-to-average-ratio wireless optical transmission method based on dynamic scalar regulation
CN104184693B (en) * 2014-09-09 2017-07-07 东南大学 A kind of DCO ofdm system direct current biasing methods to set up suitable for visible light communication
CN104796195B (en) * 2015-03-25 2017-05-10 东南大学 Visible light multi-carrier transmission method using multiplicative clipping
CN105610541B (en) * 2015-12-29 2018-04-03 东南大学 A kind of four chromatographic signal multiplex transmission methods based on backward superposition in smooth OFDM
CN107370707B (en) * 2016-05-13 2020-06-16 华为技术有限公司 Signal processing method and device
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
CN108206800B (en) * 2016-12-19 2020-11-03 上海诺基亚贝尔股份有限公司 Method and device for reducing peak-to-average power ratio in optical orthogonal frequency division multiplexing system
EP3591861A1 (en) * 2018-07-06 2020-01-08 Signify Holding B.V. Optical data transmission system and method
CN109787685B (en) * 2019-03-21 2022-02-15 东南大学 Self-adaptive low peak ratio method of visible light OFDM system based on subcarrier reservation
CN110045384B (en) * 2019-04-01 2022-01-11 电子科技大学 Laser communication detection device and method
CN110233813B (en) * 2019-06-11 2022-02-01 东南大学 Improved high-order QAM modulation transmitting method
CN111934766B (en) * 2020-06-15 2022-04-26 中山大学 Visible light communication system

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN1588938A (en) * 2004-09-16 2005-03-02 西安电子科技大学 OFDM communication system and method for reducing peak uniform power tatio
CN102859957A (en) * 2010-03-19 2013-01-02 奥菲迪乌姆有限公司 Method and apparatus for fiber non-linearity mitigation
CN103618687A (en) * 2013-12-03 2014-03-05 东南大学 Wireless optical orthogonal multi-carrier communication method with low peak to average power ratio
CN103916356A (en) * 2014-04-02 2014-07-09 东南大学 Low-peak-to-average-ratio wireless optical transmission method based on dynamic scalar regulation

Family Cites Families (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101888361A (en) * 2009-05-13 2010-11-17 中兴通讯股份有限公司 Method and device for processing peak-to-mean ratio
JP5712957B2 (en) * 2012-03-23 2015-05-07 アイコム株式会社 COMMUNICATION DEVICE AND COMMUNICATION METHOD
CN102624669B (en) * 2012-04-23 2014-04-16 西安电子科技大学 Mixed distribution optimization-based orthogonal frequency division multiplexing (OFDM) signal peak-to-average power ratio suppression method
CN103532900A (en) * 2013-09-27 2014-01-22 中国人民解放军信息工程大学 Dynamic compensation method for reducing LED (Light Emitting Diode) nonlinear distortion of visible light Flip-OFDM (Orthogonal Frequency Division Multiplexing) communication system

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN1588938A (en) * 2004-09-16 2005-03-02 西安电子科技大学 OFDM communication system and method for reducing peak uniform power tatio
CN102859957A (en) * 2010-03-19 2013-01-02 奥菲迪乌姆有限公司 Method and apparatus for fiber non-linearity mitigation
CN103618687A (en) * 2013-12-03 2014-03-05 东南大学 Wireless optical orthogonal multi-carrier communication method with low peak to average power ratio
CN103916356A (en) * 2014-04-02 2014-07-09 东南大学 Low-peak-to-average-ratio wireless optical transmission method based on dynamic scalar regulation

Cited By (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN108896961A (en) * 2018-06-29 2018-11-27 天津大学 A method of the raising visible light positioning accuracy based on signal power estimation
CN108896961B (en) * 2018-06-29 2022-03-01 天津大学 Method for improving visible light positioning accuracy based on signal power estimation
CN109547381A (en) * 2019-01-17 2019-03-29 山东建筑大学 A kind of DCO-OFDM system PAPR suppressing method and system based on self-encoding encoder
CN109547381B (en) * 2019-01-17 2021-06-01 山东建筑大学 Self-encoder-based DCO-OFDM system PAPR suppression method and system
CN114465665A (en) * 2022-01-24 2022-05-10 桂林电子科技大学 Light beam forming method based on maximum ratio combination under strong turbulence channel
CN114465665B (en) * 2022-01-24 2024-04-02 桂林电子科技大学 Beam forming method based on maximum ratio combination under strong turbulence channel
CN114513256A (en) * 2022-02-02 2022-05-17 复旦大学 Photon counting communication method based on ACO-FBMC modulation
CN114513256B (en) * 2022-02-02 2023-06-27 复旦大学 Photon counting communication method based on ACO-FBMC modulation
CN114679361A (en) * 2022-03-09 2022-06-28 恒玄科技(上海)股份有限公司 OFDM modulation method and communication device
CN114679361B (en) * 2022-03-09 2023-11-21 恒玄科技(上海)股份有限公司 OFDM modulation method and communication device
CN114650083A (en) * 2022-03-25 2022-06-21 深圳市力合微电子股份有限公司 Peak-to-average ratio optimization method of HPLC dual-mode high-speed wireless system
CN114650083B (en) * 2022-03-25 2023-11-07 深圳市力合微电子股份有限公司 Peak-to-average ratio optimization method for HPLC dual-mode high-speed wireless system

Also Published As

Publication number Publication date
CN103916356B (en) 2017-02-15
CN103916356A (en) 2014-07-09

Similar Documents

Publication Publication Date Title
WO2015149553A1 (en) Low peak average ratio wireless optical transmission method based on dynamic scalar adjustment
CN103618687B (en) Wireless optical orthogonal multi-carrier communication method with low peak to average power ratio
Wang et al. Optical OFDM for visible light communications
Tsonev et al. Avoiding spectral efficiency loss in unipolar OFDM for optical wireless communication
Popoola et al. Pilot-assisted PAPR reduction technique for optical OFDM communication systems
Abdulkafi et al. Performance analysis of DCO-OFDM in VLC system
Yu et al. Peak-to-average power ratio and illumination-to-communication efficiency considerations in visible light OFDM systems
Dimitrov et al. Optimum signal shaping in OFDM-based optical wireless communication systems
Kashani et al. On the performance of single-and multi-carrie modulation schemes for indoor visible light communication systems
Dimitrov et al. On the clipping noise in an ACO-OFDM optical wireless communication system
Jiang et al. An optimal scaling scheme for DCO-OFDM based visible light communications
Dimitrov et al. Double-sided signal clipping in ACO-OFDM wireless communication systems
CN106453191A (en) LED visible light orthogonal multicarrier communication method with low peak average power ratio
CN105871768B (en) A kind of recoverable multistage linear companding method reducing peak-to-average force ratio in ACO-OFDM system
CN106411403A (en) Ultra-wide brightness adjustment visible light transmission method based on clipping movement
WO2016127653A1 (en) Method and apparatus for realizing visible-light wireless communication
CN107453808B (en) A kind of nonlinear μ rule method and system of reduction visible light communication system light source led
CN104158784A (en) Symbol detection method of DCO-OFDM (Direct Current Offset-Orthogonal frequency Division Multiplexing) system
Barrami et al. An optical power efficient asymmetrically companded DCO-OFDM for IM/DD systems
CN104158783B (en) A kind of wireless optical transmission method based on optimization amplitude modulation
Taherkhani et al. Reed solomon encoding for the mitigation of clipping noise in ofdm-based visible light communications
Ranjha et al. Robust timing synchronization for AC-OFDM based optical wireless communications
CN104796195B (en) Visible light multi-carrier transmission method using multiplicative clipping
CN106992954A (en) A kind of clipping method of multi-carrier visible light communication system
Xie et al. A linear receiver for visible light communication systems with phase modulated OFDM

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 14887834

Country of ref document: EP

Kind code of ref document: A1

WA Withdrawal of international application
NENP Non-entry into the national phase

Ref country code: DE