Carl Andren

IEEE 802.11 Wireless LAN: can we use it for multimedia?

The IEEE P802.11 committee developed the 802.11 Wireless LAN standard to cover wireless networks for fixed, portable, and moving stations within a local area. This standard addresses the need for wireless connectivity to stations, equipment, or automatic machinery that requires rapid deployment and may be portable, handheld, or mounted on moving vehicles. It can function totally wireless or connected to a wired network. Most people familiar with the standard expect to use it in providing wireless networks for personal computers or stations connected to the global wired infrastructure through access points. Now that the 802.11 standard is finally here, it will energize the wireless LAN market and result in the proliferation of low cost wireless connectivity in the office and home. Study groups are working on higher rates at 2.4 GHz and at 5 GHz for future inclusion into the standard. These higher rates will make it even more practical to employ this standard for multimedia traffic.

Baseband Demodulator for DPSK

A simple baseband demodulator that does not require use of the arc-tangent function is presented for demodulation of Differential Phase Shift Keyed (DPSK) signals. Performance is compared to the conventional non-baseband approach. The technique presented is shown not to have the severe sensitivity to delay variations that renders the conventional approach unusable in many hardware applications. Simulations and analysis show the performance as a function of Eb/No and Doppler.