4 documents found, page 1 of 1
Bandwidth aspects in second generation current conveyors
Alves, L. N.; Aguiar, R.L.; Santos, D.M.This paper discusses bandwidth problems associated with second-generation current conveyors (CCII). In particular, our work is centered in high-capacitance applications, and has been oriented for wireless optical links and applied physics. We discuss techniques for improving bandwidth in these CCIIs, and develop a new CCII structure with larger bandwidth than traditional circuits. These circuits are then compar...
A test bed for wireless optical LANs
Aguiar, R.L.; Tavares, A.; Alves, L. N.; Valadas, R.; Santos, D.M.This paper presents a test bed for wireless optical LANS. This test bed is flexible, supporting multiple implementation choices. The test bed currently covers all physical layer issues, from FEC coders and LED drivers to front-ends, clock recovery circuits, Viterbi decoders, and sectored receivers. These are implemented with multiple technologies, with DSPs and FPGAs for digital functions, and ASICs and discret...
An eight-sector wireless infrared receiver
Alves, L. N.; Cura, J.L.; Aguiar, R.L.; Santos, D.M.This paper presents a sectored receiver for infrared wireless networks, with eight sectors. The receiver is designed for bit-rates up to 10Mbps, and implements a diversity technique, specifically a best-sector approach. The circuit has been produced in a 0.8 m CMOS technology. © 2000 IEEE.
Considerations on the design of transceivers for wireless optical LANs
Aguiar, R.L.; Tavares, A.; Cura, J.L.; Vasconcelos, E. de; Alves, L. N.; Valadas, R.; Santos, D.M.This paper discusses practical issues and results on the implementation of low-cost transceivers for several wireless optical LANs, covering most physical layer elements. Target optical LANs under consideration have bit-rates varying between 1Mbps and 25Mbps, and input photodiode capacitance may vary between 10pF and 50pF. PPM modulation, either in a 4-PPM or 16-PPM format, is typically used in the physical lay...