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A single 160 Gbaud Nyquist channel transmission based on coherent matched sampling under 4 km lab-emulated free-space turbulence link is demonstrated. Turbulence induced power fluctuation is found to be main reason of performance deterioration.
Chaotic communication has become research hotspot in recent years. But in high speed data transmission communication, due to the restriction of chaos synchronization, its communicating effect is not superior to the traditional methods (such as Quadrature Phase Shift Keying). In this paper a novel spatiotemporal chaos Hamilton oscillator is discussed in detail, and a new chaos M-ary digital modulation...
The analytical calculation of the bit error rate (BER) of digital optical receivers that employ avalanche photodiodes (APDs) is challenging due to 1) the stochastic nature of the avalanche photodiode's impulse-response function and 2) the presence of intersymbol interference (ISI). At ultrafast transmission rates, ISI becomes a dominant component of the BER, and its effect on the BER should be carefully...
A low-power CMOS-driven VCSEL-based link using a 2-tap feed-forward equalizer in the transmitter is reported at 850-nm wavelengths. Power efficiencies of 1.5, 2.0, and 3.8 pJ/b are achieved at 22.5, 25, and 28.5 Gb/s, respectively.
Cognitive radio (CR) technology provides great flexibility in spectrum utilization with orthogonal frequency-division multiplexing (OFDM) as its candidate transmission technique. In this paper, we propose a simple spectrum shaping scheme for OFDM-based CRs to enhance spectral compactness and ensure bandwidth efficiency. By mapping antipodal symbol pairs onto adjacent subcarriers at the edges of the...
We investigate DQPSK modulation combined with QC-LDPC coding. By applying iterative demodulation and soft-decision decoding, the differential decoding penalty is reduced by 2.05dB offering an attractive solution for coherent optical systems with soft-decision FEC.
In this paper, we evaluate the communication quality, energy consumption and bandwidth of different transmitters with different modulation schemes. The performance in short distance communication, for instance wireless personal area network (WPAN), is evaluated. Simulation results demonstrate that for WPAN communication, the transmitter with high modulation level PSK and a linear class A power amplifier...
In this paper, we evaluate the communication quality, energy consumption and bandwidth of different transmitters with different modulation schemes. The performance in wireless personal area network (WPAN) is evaluated. Simulation results demonstrate that for WPAN communication, the transmitter with high modulation level PSK and a linear class A power amplifier can acquire higher spectral efficiency...
The paper studies the multipath characteristics of the wideband channels at 3.5 GHz in a typical outdoor urban environment. A channel measurement system for this frequency band was developed; Based on the measurement data, the channel modeling parameters including the tapped delay line models, the multipath distribution, the excess delay and the Ricean K-factor were extracted. Then by using the measured...
A novel iterative channel estimation approach is proposed for cyclic prefix-code division multiple access systems. Code-multiplexed pilots are used for channel estimation while maintaining bandwidth efficiency. The proposed method achieves a significant improvement when compared to the conventional correlation approach by reconstructing data signals for channel estimation. Simulation results demonstrate...
We demonstrate tunable dispersion slope compensation for 40-Gb/s WDM systems using two inverse 3rd-order chirped gratings. The inherent errors in a single grating are eliminated. The slope range is -20 to +20 ps/nm2over a 5-nm bandwidth.
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