Modeling the interference between 5G and satellite services in 3.4 GHz Band
Spectrum for satellite services are likely to overlap with the ITU 5G spectrum. Critical satellite services may be impacted due to interference between various communication links working in the same frequency band. The worst-case interference scenario between Mobile Base Station (BS) and Satellite Earth Station (ES) is evaluated. Recommendation for path loss for 3.4 GHz operations are given based on ITU-R P.1546-5. Simulations are parameterized by ES height, BS height, terrain, time-variability and location-variability.
OFDM Baud Rate Limitations in an Optical Heterodyne Analog Fronthaul Link using Unlocked Fibre Lasers
The phase noise (PN) of a photo-generated mmwave carrier, resulting from frequency and phase fluctuations of uncorrelated laser sources, limits the performance of heterodyne/millimeter-wave analog radio-over-fibre links. This work analyzes the effect of subcarrier baud rate and frequency offset (FO) variations on the performance of a 60 GHz OFDM signal generated using unlocked fiber lasers. Conventional digital techniques for FO and PN compensation, in a 25 km mm-wave A-RoF heterodyne system, are shown to overcome relatively large FOs and to enable the successful transmission of kHz range sub-carrier baud rates-in line with recent 5G recommendations.
Optical Heterodyne Analog Radio-Over-Fiber Link for Millimeter-Wave Wireless Systems
Optical heterodyne analog radio-over-fiber (A-RoF) links provide an efficient solution for future millimeter wave (mm-wave) wireless systems. The phase noise of the photo-generated mm-wave carrier limits the performance of such links, especially, for the transmission of low subcarrier baud rate multi-carrier signals. In this work, we present three different techniques for the compensation of the laser frequency offset (FO) and phase noise (PN) in an optical heterodyne A-RoF system. The first approach advocates the use of an analog mm-wave receiver; the second approach uses standard digital signal processing (DSP) algorithms, while in the third approach, the use of a photonic integrated mode locked laser (MLL) with reduced DSP is advocated. The compensation of the FO and PN with these three approaches is demonstrated by successfully transmitting a 1.95 MHz subcarrier spaced orthogonal frequency division multiplexing (OFDM) signal over a 25 km 61 GHz mm-wave optical heterodyne A-RoF link. The advantages and limitations of these approaches are discussed in detail and with regard to recent 5G recommendations, highlighting their potential for deployment in next generation wireless systems.