| Περίληψη: | Today's booming expanse of personal wireless radio communications is a rich source of new challenges for the designer of the underlying enabling technologies. Because the wireless channel is a shared transmission medium with only very limited resources, a trade-off must be made between mobility and the number of simultaneous users in a confined geographical area. Ultra-Wideband Pulse-based Radio lays the foundations of a new radio transceiver architecture, based on the Ultra-Wideband pulse-based radio principle. Instead of a continuous-time modulated carrier, the pulse-based radio system uses short electromagnetic pulses with a wide spectral footprint. This has considerable advantages for the reliability of a wireless link in an indoor environment. However, what is not accounted for in most high-level theoretical perspectives, is that a wide transmission bandwidth opens up a Pandora's box of many complications at receiver side. A real-world wireless channel, for example, suffers from multipath reflections: multiple, delayed versions of the same signal arrive at the receive antenna and start to interfere with one another, an effect that is known as intersymbol interference. Also, a wide transmission band is a wide open door for in-band interfering signals, caused by other transmitters in the same frequency band. A specially crafted interferer suppression and signal reconstruction (ISSR) algorithm is presented in this book. Without active intervention from the transmitter, the ISSR algorithm is capable of on-the-fly cleaning of frequency bands which have fallen victim to multipath fading or narrowband interference. The unique blend of pulse-based radio, a simple modulation scheme and a powerful signal reconstruction system make the presented pulse-based radio system a very promising alternative for the high-end (but complex) OFDM-based modulation schemes currently used in many WLAN applications.
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