Research On The Converged Transmission Of M-PAM Wired Signal And UWB Wireless Signal

Simultaneously providing services of ultra-wideband(UWB) and baseband wired signal over single wavelength can greatly decrease the complexity and reduce the costs of a wavelength-division multiplexing passive optical network(WDM-PON). Due to UWB signal occupies the spectrum range from 3.1 to 10.6 GHz, a narrow idle frequency band(0~3.1 GHz) could be employed to transport baseband wired signal with limited bitrate. In this paper, we proposed 2 schemes to simultaneously provide UWB wireless and baseband wired services. In the first one, high-order UWB signal was utilized to expand the width of idle frequency band. Besides, the bitrate of baseband wired signal was enhanced by employing multi-level pulse-amplitude modulation(M-PAM) signal in the idle frequency band formed by UWB signal. In the second one, by using multi-band ultra-wideband(MB-UWB) signal, for its unique advantages such as flexible center frequency and narrower bandwidth, the width of idle frequency ban had been expanded extremely. Then, the bitrate of M-PAM signal can be raised higher. In comparison with other advanced modulation formats used for WDM-PON such as quadrature phase shift keying(QPSK) and quadrature amplitude modulation(QAM), M-PAM signal can be easily received by using intensity modulation direct detection(IM-DD), which will greatly reduce the cost of end-users. Based on these, the main achievements and conclusions are listed as follows:(1) The research background and significance of converged transmission technology are introduced. The definition, advantage, application of M-PAM and UWB technology are illustrated.(2) A novel converged M-PAM baseband signal and UWB wireless signal transmission system was proposed. The principle of the proposed system was illustrated, including the generation, merging, modulating, transmitting, receiving and recovering.(3) Based on the principle, converged 2.5 Gbit/s 4-PAM baseband wired signal and 1.25 Gbit/s quadruplet(4th order UWB signal) signal transmission over 20 km standard single mode fiber(SSMF) without compensation was realized. According to the spectra, eye-diagram and bit error rate(BER), this system showed good quality.(4) The idle frequency band is too narrow to raise the bitrate of baseband wired signal in the previous scheme, so a new scheme was proposed to realize the converged 10 Gbit/s 4-PAM baseband wired signal and 1 Gbit/s MB-UWB wireless signal transmission over 20 km SSMF without compensation. The spectra, eye-diagram and BER proved the quality of this system.