Multiband OFDM UWB
- an overview or tutorial about the air interface for MBOFDM Multiband OFDM
format for UWB, Ultra Wideband technology
Multi Band OFDM UWB is a form of ultra wideband technology
that differs in approach to the impulse, or direct sequence form of ultra
wideband.
MB-OFDM UWB transmits data simultaneously over multiple
carriers spaced apart at precise frequencies. Fast Fourier Transform algorithms
provide nearly 100 percent efficiency in capturing energy in a multi-path
environment, while only slightly increasing transmitter complexity. Beneficial
attributes of MB-OFDM include high spectral flexibility and resiliency to RF
interference and multi-path effects
Although a wide band of frequencies could be used from a
theoretical viewpoint, certain practical considerations limit the frequencies
that are normally used for MB-OFDM UWB. Based on existing CMOS technology
geometries, use of the spectrum from 3.1GHz to 4.8GHz is considered optimal for
initial deployments. Limiting the upper bound simplifies the design of the radio
and analogue front end circuitry as well as reducing interference with other
services. Additionally the frequency band from 3.1 GHz to 4.8 GHz is sufficient
for three sub-bands of 500 MHz when using MB OFDM UWB.
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