A Blind Timing Synchronization Algorithm for DCO-OFDM VLC Systems

Kishore, Vejandla; Prasad, Valluri Siva; Vakamulla, Venkata Mani

doi:10.1109/lpt.2020.3013447

Cited by 20 publications

(13 citation statements)

References 6 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…e Golay TS synchronization scheme adopted in this article refers to the method used by He [1]. On this basis, the Golay TS used for synchronization continued to be used for channel estimation.…”

Section: E Technology For Channel Estimation Based On Golay Tsmentioning

confidence: 99%

“…As we all know, symbol timing synchronization is a key step that must be performed before signal demodulation at the receiving end of the signal. erefore, the symbol timing synchronization step is very important [1][2][3]. If the symbol timing synchronization does not accurately find the start and end points of the symbol, it will lead to the possibility of phase noise.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Improved Training Sequence Channel Estimation Scheme in 16QAM MB-OFDM UWBoF System

Xiang

Yang

Zhou

et al. 2020

Advances in Condensed Matter Physics

View full text Add to dashboard Cite

In this paper, an improved channel estimation scheme based on time-domain orthogonal gray complementary training sequence (Golay TS) is proposed to resist subcarrier mutual beat interference in 16-quadrature amplitude modulation multiband orthogonal-frequency-division-multiplexing ultrawide band over fiber (16QAM MB-OFDM UWBoF) systems. The simulation results showed that the performance of system with the improved Golay TS channel estimation scheme was improved by about 1 dB compared with the traditional Golay TS channel estimation scheme, at a bit error rate (BER) of 3.8 × 10−3 after 70 km standard single mode fiber (SSMF) transmission. At the same time, the synchronization and channel estimation performance of Golay TS and the selected frequency-domain orthogonal training sequences (TSs) were compared. The simulation results showed that the performance of system with the TSs channel estimation was improved by about 2.7 dB compared with the improved Golay TS channel estimation.

show abstract

Section: E Technology For Channel Estimation Based On Golay Tsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Improved Training Sequence Channel Estimation Scheme in 16QAM MB-OFDM UWBoF System

Xiang

Yang

Zhou

et al. 2020

Advances in Condensed Matter Physics

View full text Add to dashboard Cite

show abstract

“…As a result, a bipolar and complex signal such as the traditional OFDM signal must be first converted into real and unipolar signal before modulating an LED. To make signal real and unipolar in DC-biased optical OFDM (DCO-OFDM), Hermitian Symmetry (HS) is imposed before inverse fast Fourier transform (IFFT) at a cost of halving the available electrical bandwidth [17] followed by addition of a DC-bias [18]. However, adding a DC-bias to a large peak to average power ratio (PAPR) signal, and passing it through the limited LED linear dynamic range makes this scheme unsuitable in some VLC applications where the power efficiency is a crucial requirement such as in diming control [19].…”

Section: Introductionmentioning

confidence: 99%

DFT Spread-Optical Pulse Amplitude Modulation for Visible Light Communication Systems

Saied¹,

Rabie

2022

IEEE Access

View full text Add to dashboard Cite

DC-biased optical orthogonal frequency division multiplexing (DCO-OFDM) has been proposed in visible light communication (VLC) to overcome the limited modulation bandwidth of light emitting diode (LED). Due to the implementation of the inverse fast Fourier transform at the DCO-OFDM transmitter, DCO-OFDM suffers from its high peak-to-average power ratio (PAPR), which restricts its use in some VLC applications, especially where the optical power efficiency is a crucial requirement. That is because the LEDs used in VLC systems have a limited optical power-current linear range. To this end, a novel discrete Fourier transform spread-optical pulse amplitude modulation (DFTS-OPAM) signal scheme based on the single carrier-interleaved frequency division multiple access (SC-IFDMA) signal is introduced in this paper to address the high PAPR issue of OFDM. DFTS-OPAM is achieved by considering a PAM as an SC-IFDMA data symbol and duplicate the output vector of the fast Fourier transform at the SC-IFDMA transmitter side. Simulation results show that the PAPR of the proposed scheme is 7 dB lower than that of DCO-OFDM. Furthermore, this significant PAPR improvement is experimentally investigated where the practical results show that the proposed scheme can provide more 2.5 dB reduction in the average transmitted power requirement compared to DCO-OFDM and can subsequently increase the maximum achieved distance between the transmitter and the receiver by 44%.INDEX TERMS single carrier frequency division multiple access, DC-biased optical orthogonal frequency division multiplexing; visible light communication, peak-to-average power ratio, light-emitting diode, dynamic range.

show abstract

“…In view of the constraint conditions of non-negative and real-valued symbols in the VLC system, researchers have done a lot of research on timing synchronization for DCO-OFDM [13][14][15][16]. A timing synchronization algorithm based on the Shapiro-Rudin sequence presented by Guerra on the basis of the Park algorithm to improve the accuracy of timing synchronization [13].…”

Section: Introductionmentioning

confidence: 99%

“…In [15], the authors proposed a timing synchronization method by utilizing zero correlation pair code in the OFDM-based VLC system. A blind timing synchronization method that exploits the cyclostationarity of the receiving signal is presented in [16] to reduce the overhead of the training symbol. However, the synchronization performance is far from the method of using training symbols.…”

Section: Introductionmentioning

confidence: 99%

A Novel Timing Synchronization Method for DCO-OFDM-Based VLC Systems

2021

View full text Add to dashboard Cite

Being sensitive to synchronization errors, symbol timing synchronization is a key factor affecting the performance of orthogonal frequency division multiplexing (OFDM) -based visible light communication (VLC) systems. A novel timing synchronization method based on odd-even symmetry for direct current biased optical OFDM (DCO-OFDM) is investigated in this paper. The proposed method produces an excellent pulse-like timing metric, resulting in a sharper peak at the correct place, while the values of other parts are negligible. The performance of the proposed timing synchronization approach is assessed by measuring the root mean squared error (RMSE) and mean absolute error (MAE) of timing offset estimation and bit error rate (BER) performance by computer simulation. The simulation results show that this novel symbol timing synchronization approach is superior to the typical methods for DCO-OFDM, such as the Park method and Guerra method, in various channel environments.

show abstract

A Blind Timing Synchronization Algorithm for DCO-OFDM VLC Systems

Cited by 20 publications

References 6 publications

Improved Training Sequence Channel Estimation Scheme in 16QAM MB-OFDM UWBoF System

Improved Training Sequence Channel Estimation Scheme in 16QAM MB-OFDM UWBoF System

DFT Spread-Optical Pulse Amplitude Modulation for Visible Light Communication Systems

A Novel Timing Synchronization Method for DCO-OFDM-Based VLC Systems

Contact Info

Product

Resources

About