A programmable transversal equalizer for electronic dispersion compensation(EDC) in optical fiber communication systems is developed.Based on the SiGe technology with a cut-off frequency of 80 GHz,the equalizer consis...A programmable transversal equalizer for electronic dispersion compensation(EDC) in optical fiber communication systems is developed.Based on the SiGe technology with a cut-off frequency of 80 GHz,the equalizer consists of 6 seriesparallel amplifiers as delay units and 7 Gilbert variable gain amplifiers as taps,which ensure that the equalizer can work at the bit rate of 10 Gb/s.With different tap gains,the forward voltage gain of the transversal equalizer varies,which demonstrates that the equalizer has various filtering characteristics such as low pass filtering,band pass filtering,band reject filtering,and notch filtering,so it can effectively simulate the inverse transfer function of dispersive channels in optical communications,and can be used for compensating the inter-symbol interference and other nonlinear problems caused by dispersion.The equalizer(including pads) occupies an area of 0.40 mm × 1.08 mm,and its total power dissipation is 400 mW with 3.3 V power supply.展开更多
The short-pulse TDMA signal is an excellent solution to the near-far problem in the pseudolite augmentation systems,and the pulse duty cycle is an important element in the solution.This paper aims at designing the dut...The short-pulse TDMA signal is an excellent solution to the near-far problem in the pseudolite augmentation systems,and the pulse duty cycle is an important element in the solution.This paper aims at designing the duty cycle of the pseudolite pulse signals with a theoretical method.At first,the scope of the duty cycle is derived theoretically with the object of ensuring the reception of both the pseudolite signals and the satellite signals,and the expression for the theoretical upper limit is given.Then based on the proposed expression,the duty cycles of Galileo pseudolite pulse signals are designed.The theoretical upper limit can guide the design of the short-pulse TDMA pseudolite signals.展开更多
基金supported by the Natural Science Foundation of Hebei Province (No.F2008000116)
文摘A programmable transversal equalizer for electronic dispersion compensation(EDC) in optical fiber communication systems is developed.Based on the SiGe technology with a cut-off frequency of 80 GHz,the equalizer consists of 6 seriesparallel amplifiers as delay units and 7 Gilbert variable gain amplifiers as taps,which ensure that the equalizer can work at the bit rate of 10 Gb/s.With different tap gains,the forward voltage gain of the transversal equalizer varies,which demonstrates that the equalizer has various filtering characteristics such as low pass filtering,band pass filtering,band reject filtering,and notch filtering,so it can effectively simulate the inverse transfer function of dispersive channels in optical communications,and can be used for compensating the inter-symbol interference and other nonlinear problems caused by dispersion.The equalizer(including pads) occupies an area of 0.40 mm × 1.08 mm,and its total power dissipation is 400 mW with 3.3 V power supply.
文摘The short-pulse TDMA signal is an excellent solution to the near-far problem in the pseudolite augmentation systems,and the pulse duty cycle is an important element in the solution.This paper aims at designing the duty cycle of the pseudolite pulse signals with a theoretical method.At first,the scope of the duty cycle is derived theoretically with the object of ensuring the reception of both the pseudolite signals and the satellite signals,and the expression for the theoretical upper limit is given.Then based on the proposed expression,the duty cycles of Galileo pseudolite pulse signals are designed.The theoretical upper limit can guide the design of the short-pulse TDMA pseudolite signals.
