دانلود کتاب Ultra-Wideband Pulse-based Radio: Reliable Communication over a Wideband Channel

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.