We propose a novel method to reconstruct the optical signal phase information using direct detection. The method is suitable for minimum phase signals and it enables low complexity, low latency, and low tone power operation. Moreover, the proposed method offers low optical complexity solution for the short-reach links compared with the concurrent phase retrieval techniques. We apply the method to M-ary signals with the transmitted power of as low as 3 dBm, and we are able to reach 70 km for 100 Gb/s quadrature phase shift keying (QPSK) system without optical amplification. Our method is based on the single sideband (SSB) and DC-Value property of the minimum phase signal. The SSB and DC-Value properties are iteratively imposed on the amplitude signal in the frequency domain to recover the full complex field from a directly detected optical signal. The normalized mean square error (NMSE) value between the available amplitude information and reconstructed minimum phase signal amplitude decreases after each iteration, providing global minimum convergence. A constant scaling factor is exploited to improve the convergence speed. The scaling factor provides 6 dB, 4.5 dB, and 2.5 dB error vector magnitude (EVM) gains with 4, 5, and 8 iterations, respectively.
There has been a growing interconnection across the world owing to various multimedia applications and services. Fixed wireless access (FWA) is an attractive wireless solution for delivering multimedia services to different homes. With the fifth-generation (5G) and beyond mobile networks, the FWA performance can be enhanced significantly. However, their implementation will present different challenges on the transport network due to the incessant increase in the number of required cell-sites and the subsequent increase in the per-site requirements. This paper presents a comprehensive tutorial on the enabling technologies, design considerations, requirements, and prospects of broadband schemes. Furthermore, the related technical challenges of FWA are reviewed, and we proffer potential solutions to address them. Besides, we review various transport network options that can be employed for FWA deployment. In this regard, we offer an in-depth discussion on their related requirements for different use cases. Moreover, we give an insight into the 3GPP RAN functional split implementations and implications on the 5G FWA transport network solutions. The concepts of virtualized RANs for attending flexibly to the dynamic nature of different use cases are also presented.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.