The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
We have proposed a novel hybrid software and hardware equalization scheme based on digital zero-padding pre-equalization and differential reception. We have experimental demonstrated a red LED based visible light communication system over 1-meter free space transmission with the measured BER below 7% FEC threshold. The signal is QAM-DMT modulated and the modulation level is varying from 32QAM to 128QAM...
This paper investigates the performance of underwater visible light communications (UVLC) systems employing multiple transmitters and/or multiple receivers to exploit the advantage of spatial diversity. Experimental results are further provided to evaluate the error performance of single input multiple outputs (SIMO), multiple inputs single output (MISO) and multiple inputs multiple outputs (MIMO)...
In this paper, we propose a block decision-aided (BL-DA) laser phase noise (LPN) estimation algorithm for coherent optical OFDM (CO-OFDM) systems. The OFDM symbols are divided into several blocks and the LPN estimation and compensation procedure is performed based on the decisions between these blocks. The proposed BL-DA algorithm can be applied for higher LPN estimation while at the same time ensuring...
We propose a novel system considering layered Pulse Amplitude Modulation with Discrete Hartley Transform (PAM-DHT), in order to improve Effective Data Transmission Efficiency (EDTE) by modulating both odd and even subcarriers. This system is suitable for the optical communication employing Intensity Modulation with Direct Detection (IM/DD). At the transmitter side of this system, signals are divided...
In this paper, a 60cm free-space optical card-to-card wavelength division multiplexing (WDM) transmission architecture using OFDM modulation and coherent detection is proposed and demonstrated, which can offer flexibility and high speed transmission simultaneously. The experimental results show that the net data rate is up to 106.9Gb/s and the receiver sensitivity is −34dBm at the BER threshold of...
We compared the performance of the asymmetric and direct current bias limiting optical orthogonal frequency division multiplexing (ADO-OFDM), asymmetric limiting optical orthogonal frequency division multiplexing (ACO-OFDM), and the direct current bias limiting optical orthogonal frequency division multiplexing (DCO-OFDM) in visible light communication (VLC) systems. We optimize the power ratio between...
In this paper, we propose a novel sampling frequency offset estimation algorithm to improve the performance of the practical intensity-modulation and direction-detection (IMDD)-based OFDM system. For this scheme, only OFDM symbol is used, which reduce the complexity of implement in practical system. And, by taking the relationship of phase rotating of subcarriers into account, we successfully estimate...
In this paper, a solar panel utilized as a photodetector with simultaneous energy harvesting is proposed in visible light communication (VLC). The solar cell is a self-styled passive device, which can convert optical signals into electrical signals. The generated energy can potentially be used to power user terminals or at least to prolong operation time. This work is an important step towards the...
A joint timing offset (TO) and frequency offset (FO) estimation method based on Radon-Wigner transform (RWT) is first proposed for coherent optical orthogonal frequency-division multiplexing (CO-OFDM) systems. The result shows that the timing and frequency synchronization performance of the proposed method are both better than the Schmidl & Cox method and fractional Fourier transform (FrFT) algorithm...
This paper proposes a two-dimension encryption orthogonal frequency division multiplexing passive optical network (OFDM-PON) based on dynamic chaos-iteration. The correlation monitoring method is adopted to achieve dynamic key distribution between OLT and ONUs. It is shown that key space can be larger than 1086, which would be against exhaustive attack effectively. We experimentally demonstrate a...
We demonstrated a dense sub-carrier uniform division labeling transmission system by using MATLAB software. The simulation results indicated that dense sub-carrier uniform division labeling has a good advantage over that ordinary OFDM system, and the signals at a bit rate 50Gbit/s have a good performance which is more than 10 when OSNR is equal to 25dB over 1000km optical fiber channel which only...
The cognitive radio (CR) have been proposed to improve spectral efficiency and to meet growing demands for higher data rates in mobile communications and satellite communications. In this paper, we propose a blind estimation algorithm for a secondary user to estimate transmission parameters of the primary signal in an OFDM overlay system, using only the available fast Fourier transform (FFT) component...
A constant modulus algorithm-(CMA) based carrier frequency offset estimation method for coherent optical orthogonal frequency division multiplexing (CO-OFDM) system is proposed. Theoretical analysis and simulation results indicate that the frequency offset estimation range of the proposed algorithm can achieve [−5.9, +5.9] GHz, and the mean normalized estimation error can be kept under 0.001 even...
We investigate and analyze the asymmetrically clipped and direct-current-biased optical orthogonal frequency division multiplexing (ADO-OFDM) in visible light communication (VLC) system. Then we propose two modified channel equalization algorithms of ADO-OFDM in VLC systems. It is shown that the algorithm combined with channel estimation for interference cancellation to recover ADO-OFDM signal is...
In this paper, we design a novel training symbol structure to estimate in-phase/quadrature (IQ) mismatch. Based on this structure the estimation method is deduced in frequency domain which can achieve the estimation of IQ mismatch and channel distortion independently and improve the system performance obviously. Numerical simulation shows that the proposed method has better system BER performance...
Directly modulated semiconductor lasers for underwater wireless optical communication (UWOC) have limitations in output power and beam quality. Diode-pumped solid-state lasers (DPSSLs) have the merits of long lifetime, high stability, large power and good beam quality, which are promising to realize long-each UWOC. We compose a DPSSL with discrete components and measure its key parameters. The bandwidth...
A converged communication system with 100 Gbps based on photonic RF wave is proposed. In the system, the mechanism of the photonic RF wave with 40 GHz is demonstrated. With the comprehensive applications of advanced modulation technologies and excellent algorithms, the wireless access rate of the downstream can reach up to 100 Gbps. Due to the photoelectric direct detection, the whole system becomes...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.