32.65-Gbps OFDM RoF signal generation at 60GHz employing an adaptive I/Q imbalance correction

Design and demonstration of ultra-fast W-band photonic transmitter-mixer and detectors for 25 Gbits/sec error-free wireless linking

“…0.3-3.5 GHz, the electromagnetic waves at MMW frequencies suffer from substantial path loss and have poorer penetration through buildings due to their inherent straight-line path of propagation [1]. A promising solution to resolving this problem is the radio-over-fiber (RoF) technique [3,[9][10][11][12][13]. With the RoF technique, the MMW carrier and the intermediate frequency (IF) signal are simultaneously distributed through a low-loss optical fiber, and the signal-modulated MMW is delivered to end-users through free-space radiation at the last-mile.…”

“…The key to the hardware realization of this system is the development of a high-speed integrated photonic transmitter (-mixer) (PTM) [15,16] together with an ultra-fast and highly sensitive receiver (envelope detector) [17]. With regards to MMW signal modulation, the schemes, such as on-off-keying (OOK) [3,10,18], ultra-wideband (UWB) [19,20], and optical orthogonal frequency-division multiplexing (OFDM) [11,21], have been adopted for the ultrafast photonic communication. Compared to the OFDM, the OOK suffers from the multipath fading and is vulnerable to undesired signals.…”

2 <formula formulatype="inline"><tex Notation="TeX">$\times$</tex></formula> 2 MIMO OFDM-RoF System Employing LMS-Based Equalizer With I/Q Imbalance Compensation at 60 GHz

“…Recently, 60-GHz technology has been recognized as a potential candidate to realize multi-gigabitper-second wireless applications because of the wideband license-free spectrum (e.g., 7 GHz in USA, and 9 GHz in Europe) [1]- [4]. However, compared with the conventional wireless systems (e.g., WiFi, cellular), 60-GHz wireless communication system has limited signal coverage because of the significantly high propagation loss and attenuation through walls.…”

“…In recent years, we have investigated the key system performance bottlenecks and demonstrated practical solutions for realizing high data-rate mm-wave-over-fiber systems: We successfully used Orthogonal Frequency Division-Multiplexing (OFDM) with the bit-loading algorithm to minimize the impact of the un-even frequency response on the overall system performance [6]. We have also demonstrated the use of recursive least squares (RLS) and least mean squares (LMS) algorithms to compensate for the I/Q imbalance (which is mainly induced by the electrical I/Q mixer) in Single Input Single Output (SISO) antenna systems [7].…”