Enhanced Data Transmission for ATSC 3.0 Using Cross-Polarization Discrimination and Iterative Channel Refinement

The Advanced Television Systems Committee 3.0 (ATSC 3.0) standard enables ultra-high-definition (UHD) broadcasting and incorporates a transmitter identification (TxID) mechanism to ensure reliable performance within singlefrequency networks (SFNs). Conventionally, TxID employs long spreading sequences to suppress mutual interference; however, this design choice constrains the attainable data throughput. To overcome this constraint, this study presents a new transmission framework that integrates cross-polarization discrimination (XPD) with frequency symbol spreading (FSS). The proposed approach effectively mitigates interference between additional and conventional broadcast signals without imposing extra system complexity. In this configuration, the vertically polarized path carries the conventional broadcast content, whereas the horizontally polarized path conveys the supplementary data stream. To improve channel estimation accuracy under XPD-induced imbalance, an iterative reliability-weighted decision-directed least squares (DD-LS) refinement is applied to the horizontal branch. The FSS technique employs orthogonal Hadamard sequences in the frequency domain to improve the resilience of transmitted signals against multipath fading. According to simulation outcomes, the proposed system achieves a lower bit error rate (BER) across various XPD levels ranging from 5 dB to 15 dB. Moreover, additional performance enhancement is observed when iterative DD-LS channel refinement and longer spreading sequences are applied. The proposed method requires only minor hardware modifications and remains fully compatible with existing ATSC 3.0 infrastructure.