Digitized RF transmission over fiber

Performance Improvement and Cost Reduction Techniques for Radio Over Fiber Communications

“…2006 Yu et al [91] It was shown that Optical Carrier Suppression (OCS) modulation has a high spectral efficiency and receiver sensitivity and small dispersion-induced power penalty. Digitized Radio Over 2009 Nirmalathas et al [92] It was shown that DROF ensured greater link linearity and exhibited the performance Fiber (DROF) 2014 Yang et al [93] advantages of a digital optical link.…”

“…By contrast, in Digitized ROF (DROF), the RF signal is sampled, digitized and then is used for modulating the optical carrier. The main motivation behind the design of the DROF architecture is the desire to have a digital optical link and at the same time rely on centralised signal processing at the BS [92]. In the DROF architecture of Fig.…”

“…In the DROF architecture of Fig. 56, the signal processing required for generating the DL RF signal is carried out at the BS, where the RF signal is digitized before modulating the optical carrier [92]. Conventional sampling of the RF signal at a rate higher than twice the highest frequency present in the signal using the Nyquist Theorem is not practically feasible, because of the high values of the wireless carrier frequency.…”

“…Conventional sampling of the RF signal at a rate higher than twice the highest frequency present in the signal using the Nyquist Theorem is not practically feasible, because of the high values of the wireless carrier frequency. Hence, typically critical bandpass sampling is used [92], which is illustrated in Fig. 55, where the sampling frequency is chosen to satisfy the aliasing-free condition, so that the original analog RF signal can be reconstructed by using a bandpass filter centered at f RF = ω RF 2π Hz and having a bandwidth of B Hz.…”

“…55, where the sampling frequency is chosen to satisfy the aliasing-free condition, so that the original analog RF signal can be reconstructed by using a bandpass filter centered at f RF = ω RF 2π Hz and having a bandwidth of B Hz. The valid bandpass sampling rates for a bandwidth of B are [92]:…”