论文部分内容阅读
This paper proposes an ultra narrowband system by combining DS-UWB with conventional amplitude modulation. The basic principle of the combination is modulating single cycle or integer cycles of a sinusoidal carrier with DS-UWB pulse. The benefit of combination is extremely narrow bandwidth occupation and simplified receiver structure. In addition, the combined modulation scheme increases the maximum distance of transmission under the regulation of FCC emission mask, while supporting very high bit-rate transmission. Being capable of transmitting data at bit-rate of 500M bits/s and consuming frequency bandwidth of only 0.75 MHz, the system achieves spectral efficiency as high as 677 bits/s/Hz.