Filtered modulation schemes for short distance infrared wireless communications

This paper describes two modem prototypes based on spectrally efficient filtered modulations for infrared wireless links. They are fully compatible with commercial IrDA and IEEE 802.11 standards. These links allow more channels, giving a more accurate use of the infrared spectrum. We compare the performances of the two main alternatives: phase (using FQPSK-2 systems) and frequency modulations (GMSK schemes). We have designed and tested 2 Mb/s IR modems with each modulation scheme. Extensive experimental results and BER measurements of these prototypes are also detailed.