We experimentally demonstrate wavelength division multiplexing passive optical network system delivering downstream 5-Gbps data and upstream 2.5-Gbps data over 153km single mode fiber on a single wavelength using pulse source that is mode-locked laser generating a single pulse of ‗‗sech'' shape with specified power and width, that is, soliton pulse. The optical source for downstream data and upstream data is soliton pulse generator at central office and reflective semiconductor optical amplifier at each optical network unit. We also investigate analysis of backscattered optical signal for upstream data and downstream data simultaneously. Bit error rate and Quality factor was measured to demonstrate the proposed scheme.
KeywordsWavelength division multiplexing passive optical network, soliton pulse, reflective semiconductor optical amplifier, erbium doped fiber amplifier, single mode fiber, photo detector, arrayed waveguide grating.
Speech enhancement is the process of eliminating noise and increasing the quality of a speech signal, which is contaminated with other kinds of distortions. Conventional Kalman filtering is known as an effective speech enhancement technique, in which speech signal is usually modeled as autoregressive (AR) model and perform a lot of matrix operations. In this paper we proposed a fast adaptive algorithm in presence of environment noise which eliminates the matrix operations and reduces the calculating time by only constantly updating the first value of state vector X(n). To evaluate the system performance we employed the calculation of SNR. Simulation results show that the fast adaptive algorithm using Kalman filtering is effective for speech enhancement.
General TermsKalman filter algorithms, Speech enhancement.
We demonstrate bidirectional wavelength division multiplexing passive optical network (WDM-PON) based on soliton pulse using two channels. The system uses 1550 nm and 1550.04 nm wavelength for each channel, which is capable of delivering 5-Gbps downstream data over 203 km and 2.5-Gbps upstream data over 153 km optical fiber with 0.2dB/km attenuation loss. The optical source for downstream transmission is sech pulse generator at central office and refractive semiconductor optical amplifier at each optical network unit for upstream transmission. The maximum optical to signal noise ratio for upstream and downstream transmission is obtained at input power 7.56dBm. We investigate backscattered optical power, quality factor and bit error rate (BER). The BER performance shows that our proposed scheme is a practical solution to meet the data rate and cost-efficient of the optical links simultaneously in tomorrow's WDM-PON access networks.
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