Signal Isolation in Full-Duplex Inter-Tower Communication Networks: Field Trials

Abstract

Future digital terrestrial television (DTT) systems, such as ATSC 3.0, are evolving to offer users new applications and services. These new applications (e.g., target advertisement, connected cars, 4k/8k video content) require a considerable increase in transmission capacity. In contrast, the current standards and technologies need to improve the offered spectral efficiency rate to adapt to the new use cases. A good alternative is to enable full-duplex communications among the ATSC transmission centers to build a mesh network of transmitters (i.e., Inter-Tower Communication Network or ITCN). The main drawback of this idea is the self-interference (SI) or loopback signal that is generated and added to the received signal. To reduce the impact of the SI, the transmission centers combine different signal isolation and cancellation techniques. This paper focuses on the characterization of the signal power isolation between the transmitted and the received signals under different conditions. In particular, this paper shows the results obtained during a measurement campaign in a real broadcast transmission center. The measurements were carried out following a novel signal isolation measurement methodology, and the results analyze the obtained signal isolation and the time variability of the received signal power. The results show that a minimum isolation value of 69.5 dB can be obtained for the worst evaluated case.