An all-optical multi-wavelength converter using absorption modulation of an injection-locked Fabry-Perot laser diode (FP-LD) is demonstrated at 2.5Gb/s. The multi-wavelength converter can simultaneously provide 1 to 4 channel outputs and support both inverted and non-inverted conversion. By optimizing the wavelength of pump signal and polarization states of pump, probes, and the FP-LD, all converted outputs show high extinction ratio and negligible crosstalk power penalty. The results guarantee to increase the number of output channels. The proposed scheme can be applied to multicasting functions as well as 1xN wavelength conversion in an all-optical wavelength division multiplexed network.
This paper describes a security system capable of identifying the presence of moving object using ultrasonic sensor, without human intervention. A constrained optimization of the Time of Flight (ToF) technique is employed to obtain the reflected pulses that are easily detectable by means of threshold comparator. Converting the ultrasonic sensor's output into predefined value based on ToF and our novel Top Edge Detection (TED) algorithm, the system is able to fix a position from where CMOS image capturing sensor can capture an instance of image of the object.
We propose a cost-efficient symbol detection scheme, which removes complex functional blocks requiring high hardware complexity and computation power, for MIMO-OFDM systems adapting an SDM technique. In order to reduce the complexity, we modify the conventional approach of symbol detection with maintaining the equivalence between the original and modified equations. From the implementation results, the proposed symbol detector reduces the hardware complexity by 18.2% compared to a conventional symbol detector, and can be a good solution for the low hardware complexity design of SDM-OFDM systems.
A new design of a computationally efficient sharp dc-notch FIR filter is proposed, whereby a modified α - scaled sampling kernel and a complementary filter concept are utilized to implement a programmable dc-notch FIR filter. Design examples demonstrate that the proposed approach provides a practical and efficient design procedure for the realization of a sharp dc-notch FIR filter of lower order, satisfying the given filter specification.