Digital Orthogonal Filtering-Enabled Synchronous Transmissions of I/Q Waveforms and Control Words for Bandwidth-Efficient and Low-Complexity Mobile Fronthaul

Abstract

We experimentally demonstrate digital orthogonal filtering-enabled synchronous transmissions of 24 20MHz LTE signals and CWs, achieving an EVM of 3.1% and a SNR of 31.4dB for I/Q waveforms and CWs, respectively, over a 6km SSMF.

Analyzing Peak-to-Average Power Ratio Characteristics in Multi-Channel Intensity Modulation and Direct Detection Flexible Transceivers Deploying Inverse Fast Fourier Transform/Fast Fourier Transform-Based Processing

“…For existing DSP-based multi-channel aggregation and de-aggregation techniques, multi-channel aggregation/de-aggregation can be realized with a single inverse fast Fourier transform/fast Fourier transform (IFFT/FFT) operation [ 2 , 3 , 4 ], a digital filtering operation [ 5 , 6 , 7 , 8 ], and code-division multiplexing [ 9 , 10 ]. In comparison with these techniques, the cascaded IFFT/FFT-based multi-channel aggregation/de-aggregation technique [ 11 ] can not only potentially operate at an ‘add-as-you-grow’ mode to support adaptive and flexible variations in both channel count and channel line rate but also offer additional physical layer network security and guard band-free and highly spectrally efficient transmissions.…”

Rectangular Orthogonal Digital Filter Banks Based on Extended Gaussian Functions

“…For the fixed networks of the 5 th generation and beyond [7], to effectively accommodate a large diversity of new use cases with diversified requirements on bandwidth, latency, coverage, QoS and security, it is envisaged that digital filtering acts as a promising physical layer technology to provide the fixed networks with sufficient flexibility, elasticity and adaptability. On the other hand, for the rollout of 5G and beyond mobile networks, advanced digital filtering techniques are also highly desirable for not only realizing the adaptive spectral confinement of waveforms transmitted over the radio/fiber links [8], [9], but also enabling the fronthaul mobile networks to provide, in a cost effective manner, dynamically reconfigurable, on-demand 'just-the-right-size' elastic connections each tailored to a specific application and/or service requirement [10], [11]. Such operations are vital for achieving the seamless convergence of separately developed and operated optical networks and mobile networks [12], [13].…”